KSC-04PD-2671B

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. A worker at Astrotech Space Operations in Titusville, Fla., begins fueling the Deep Impact spacecraft. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measuring the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-04PD-2669

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Workers at Astrotech Space Operations in Titusville, Fla., suit up before fueling the Deep Impact spacecraft. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measuring the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-04PD-2668

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Workers at Astrotech Space Operations in Titusville, Fla., suit up before fueling the Deep Impact spacecraft. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measuring the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-04PD-2671A

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. A worker at Astrotech Space Operations in Titusville, Fla., begins fueling the Deep Impact spacecraft. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measuring the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

Educating the Public about Deep-Earth Science

NASA Astrophysics Data System (ADS)

Cronin, V. S.

2010-12-01

The nature of Earth’s interior is an active frontier of scientific research. Much of our current understanding of sub-crustal Earth is based on knowledge acquired in the last 2-3 decades, made possible by public funding and by dense seismic arrays, satellite remote sensing, increases in computer power that enable use of enhanced numerical techniques, improved theoretical and experimental knowledge of high PT mineral physics and chemistry, and a vigorous scientific community that has been trained to take advantage of these opportunities. An essential component of science is effective communication; therefore, providing for public education about science is a responsibility of the research community. Current public understanding of Earth’s interior is meager at best. In pre-college texts and in non-technical mass media, Earth's interior is typically visualized as an onion or baseball of concentric different-colored shells along whose upper surface "crustal" plates move like packages on conveyor belts of convecting mantle. Or the crust is thought to float on a molten mantle, as in the 19th century ideas of William Lowthian Green. Misconceptions about Earth that are brought to the undergraduate classroom must be confronted frankly and replaced by current understanding based on good science. Persistent ignorance has consequences. What do we want the public to know? First, the public should understand that knowledge of Earth's interior is important, not irrelevant. The public should know that deep-Earth processes result in Earth's dynamic magnetic field. Deep-Earth processes affect how radiation from the Sun reaches Earth, consequently affecting the atmosphere, the oceans, and the viability of life on Earth. The composition and differentiated structure of Earth's interior is a result of the early accretionary history of Earth and the Earth-Moon system. The public should also know that lithospheric tectonics, with all of its consequences (dynamic topography, volcanoes, earthquakes, resource concentrations, oceans, atmospheric composition and flow, possibly even life), is made possible by the specific characteristics of Earth's interior. Accepting that knowledge of Earth’s interior is important, the next task is to let the public know what we have learned about the deep Earth, and how we have developed that scientific knowledge. How do we incorporate uncertainty in this work? How do we test hypotheses? What are the current open questions about the deep Earth that we seek to address through ongoing or future scientific research? The cognitive distance between research experts and the public must be bridged -- an interpretive task that requires substantial expertise and collaboration. Reaching the ultimate audience (the general public) requires the education and active involvement of K-12+ teachers, education boards, textbook publishers and mass-media producers. Information must be packaged to suit each intended audience, at the appropriate cognitive level. The effectiveness of the education-and-outreach element of any research enterprise largely determines whether the processes and results of science are transferred successfully to the public consciousness.

Regionalized Lunar South Pole Surface Navigation System Analysis

NASA Technical Reports Server (NTRS)

Welch, Bryan W.

2008-01-01

Apollo missions utilized Earth-based assets for navigation because the landings took place at lunar locations in constant view from the Earth. The new exploration campaign to the lunar south pole region will have limited Earth visibility, but the extent to which a navigation system comprised solely of Earth-based tracking stations will provide adequate navigation solutions in this region is unknown. This report presents a dilution-of-precision (DoP)-based, stationary surface navigation analysis of the performance of multiple lunar satellite constellations, Earth-based deep space network assets, and combinations thereof. Results show that kinematic and integrated solutions cannot be provided by the Earth-based deep space network stations. Also, the stationary surface navigation system needs to be operated either as a two-way navigation system or as a one-way navigation system with local terrain information, while the position solution is integrated over a short duration of time with navigation signals being provided by a lunar satellite constellation.

Research and Teaching About the Deep Earth

NASA Astrophysics Data System (ADS)

Williams, Michael L.; Mogk, David W.; McDaris, John

2010-08-01

Understanding the Deep Earth: Slabs, Drips, Plumes and More; Virtual Workshop, 17-19 February and 24-26 February 2010; Images and models of active faults, subducting plates, mantle drips, and rising plumes are spurring new excitement about deep-Earth processes and connections between Earth's internal systems and plate tectonics. The new results and the steady progress of Earthscope's USArray across the country are also providing a special opportunity to reach students and the general public. The pace of discoveries about the deep Earth is accelerating due to advances in experimental, modeling, and sensing technologies; new data processing capabilities; and installation of new networks, especially the EarthScope facility. EarthScope is an interdisciplinary program that combines geology and geophysics to study the structure and evolution of the North American continent. To explore the current state of deep-Earth science and ways in which it can be brought into the undergraduate classroom, 40 professors attended a virtual workshop given by On the Cutting Edge, a program that strives to improve undergraduate geoscience education through an integrated cooperative series of workshops and Web-based resources. The 6-day two-part workshop consisted of plenary talks, large and small group discussions, and development and review of new classroom and laboratory activities.

Opportunities and challenges in studies of deep life (Invited)

NASA Astrophysics Data System (ADS)

Edwards, K. J.

2010-12-01

Over the past two decades, there has been an increasing awareness within the geological, microbiological, and oceanographic communities of the potentially vast microbial biosphere that is harbored beneath the surface of the Earth. With this awareness has come a mounting effort to study this potential biome - to better quantify biomass abundance, activity, and biogeochemical activity. In the Earth system, the largest deep subsurface biome is also the least accessible - the deep ocean subsurface biosphere. The oceanic deep biosphere also has greatest potential for influencing global scale biogeochemical processes -the carbon and energy cycles for example, and other elemental cycles. To address these topics and mount interdisciplinary efforts to study the deep subsurface marine biosphere, we have recently formed a center in support integrative, collaborative investigations. The national science foundation Center for Dark Biosphere Investigations (C-DEBI), has been initiated for the explicit purpose of resolving the extent, function, dynamics and implications of the subseafloor biosphere. This talk will discuss C-DEBI science, with focus on some of the opportunities and challenges in the study of deep life in the ocean, and the role that C-DEBI will play in meeting them

Sedimentary Markers : a window into deep geodynamic processes Examples from the Western Mediterranean Sea

NASA Astrophysics Data System (ADS)

Rabineau, Marina; Aslanian, Daniel; Leroux, Estelle; Pellen, Romain; Gorini, Christian; Moulin, Maryline; Droz, Laurence; Bache, Francois; Molliex, Stephane; Silenzario, Carmine; Rubino, Jean-Loup

2017-04-01

Deep Earth dynamics impact so strongly on surface geological processes that we can use sediment palaeo-markers as a window into the deeper Earth. Derived from climatic and tectonic erosive actions on the continents, and related to eustasy, subsidence and isostasy, the sediment in a deep basin is the main recorder of these processes. Nevertheless, defining and quantifying the relative roles of parameters that interact to give the final sedimentary architecture is not a simple task. Using a 3D-grid of seismic and wide-angle data, boreholes and numerical stratigraphic modelling, we propose here a quantification of post-rift vertical movements in the Provençal Basin (Western Mediterranean) involving three domains of subsidence: seaward tilting on the platform and the slope and purely vertical subsidence in the deep basin (Rabineau et al., 2014 ; Leroux et al., 2015). These domains fit the deeper crustal domains highlighted by previous geophysical data (Moulin et al., 2015 ; Afilhado et al., 2015). Post-break-up sedimentary markers may therefore be used to identify the initial hinge lines of the rifting phase, to quantify sedimentation rates and isostatic rebound (Rabineau et al., 2014) and redefine the subsidence laws. Similar work and results are obtained in the Valencia Basin (Pellen et al., 2016). This Western Mediterranean Sea is a natural laboratory with very high total subsidence rates that enable high sedimentation rates along the margin with sediments provided by the Rhône and Ebro rivers flowing from the Alps, the Pyrennees and Catalan chains, which in turn archives the detailed record of climate/tectonic evolution during the Neogene. The Western Mediterranean Sea could therefore further probe deep-earth and surface connections using deep drillings of this land-locked ocean basin transformed into a giant saline basin (Rabineau et al., 2015). Leroux, E., Aslanian, D., Rabineau, M., M. Moulin, D. Granjeon, C. Gorini, L. Droz, 2015. Sedimentary markers: a window to deep geodynamic processes. Terra Nova 27, 122-129. Moulin, M., Klingelhoefer, F., Afilhado, A., Feld, A., Aslanian, D., Schnurle, P., Nouzé, H., Rabineau, M. & Beslier, M.O., 2015. Deep crustal structure across an young passive margin from wide- angle and reflection seismic date (The SARDINIA Experiment) - I- Gulf of Lion's Margin BSGF, ILP Special Volume, 186 (4-5), pp. 309-330 Afilhado A., M. Moulin, F. Klingelhoefer, D. Aslanian, P. Schnurle, H. Nouzé, M. Rabineau & M.O. Beslier, 2015. Deep crustal structure across a young passive margin from wide- angle and reflection seismic data (The SARDINIA Experiment) - II. Sardinia's margin, BSGF, ILP Special Volume, 186 (4-5), p. 331-351 Pellen, R., Aslanian, D., Rabineau, M., Leroux, E., Gorini, C., Silenzario, C., Blanpied, C., Rubino, J-L., 2016. The Minorca Basin: a buffer zone between Valencia and Provençal Basins, Terra Nova, 28-4, p. 245-256. Rabineau, M., Leroux, E., Aslanian, D., Bache, F., Gorini, C., Moulin, M., Molliex, S., Droz, L., Dos Reis, T., Rubino, J-L., Olivet, J-L., 2014. Quantifying Subsidence and Isostasy using paleobathymetric markers : example from the Gulf of Lion, EPSL, vol. 288, p. 353- 366. http://dx.doi.org/10.1016/j.epsl.2013.11.059 Rabineau, M., S. Cloetingh, J. Kuroda, D. Aslanian, A Droxler, C. Gorini, D. Garcia-Castellanos, A. Moscariello, Y. Hello, E. Burov, F. Sierro, F. Lirer, F. Roure, P.A. Pezard, L. Matenco, Y. Mart, A. Camerlenghi, A. Tripati and the GOLD and DREAM Working Groups, 2015. Probing connections between deep earth and surface processes in a land-locked ocean basin transformed into a giant saline basin: the Mediterranean GOLD project, Marine and Petroleum Geology, Volume: 66 Pages: 6-17.

Deep drilling; Probing beneath the earth's surface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosen, J.250

1991-06-01

This paper reports on boreholes from 4.5 to greater than 10 kilometers deep that are pushing back the boundaries of earth science as they yield information that is used to refine seismic surveys, chart the evolution of sedimentary basins and shield volcanos, and uncover important clues on the origin and migration of mantle-derived water and gas.

The deep Earth may not be cooling down

NASA Astrophysics Data System (ADS)

Andrault, Denis; Monteux, Julien; Le Bars, Michael; Samuel, Henri

2016-06-01

The Earth is a thermal engine generating the fundamental processes of geomagnetic field, plate tectonics and volcanism. Large amounts of heat are permanently lost at the surface yielding the classic view of the deep Earth continuously cooling down. Contrary to this conventional depiction, we propose that the temperature profile in the deep Earth has remained almost constant for the last ∼4.3 billion years. The core-mantle boundary (CMB) has reached a temperature of ∼4400 K in probably less than 1 million years after the Moon-forming impact, regardless the initial core temperature. This temperature corresponds to an abrupt increase in mantle viscosity atop the CMB, when ∼60% of partial crystallization was achieved, accompanied with a major decrease in heat flow at the CMB. Then, the deep Earth underwent a very slow cooling until it reached ∼4100 K today. This temperature at, or just below, the mantle solidus is suggested by seismological evidence of ultra-low velocity zones in the D;-layer. Such a steady thermal state of the CMB temperature excludes thermal buoyancy from being the predominant mechanism to power the geodynamo over geological time. An alternative mechanism to sustain the geodynamo is mechanical forcing by tidal distortion and planetary precession. Motions in the outer core are generated by the conversion of gravitational and rotational energies of the Earth-Moon-Sun system. Mechanical forcing remains efficient to drive the geodynamo even for a sub-adiabatic temperature gradient in the outer core. Our thermal model of the deep Earth is compatible with an average CMB heat flow of 3.0 to 4.7 TW. Furthermore, the regime of core instabilities and/or secular changes in the astronomical forces could have supplied the lowermost mantle with a heat source of variable intensity through geological time. Episodic release of large amounts of heat could have remelted the lowermost mantle, thereby inducing the dramatic volcanic events that occurred during the Earth's history. In this scenario, because the Moon is a necessary ingredient to sustain the magnetic field, the habitability on Earth appears to require the existence of a large satellite.

KSC-04PD-2670

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Workers at Astrotech Space Operations in Titusville, Fla., get ready to begin fueling the Deep Impact spacecraft, seen wrapped in a protective cover in the background. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measuring the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-04PD-2673

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Workers at Astrotech Space Operations in Titusville, Fla., begin fueling operations of the Deep Impact spacecraft, seen wrapped in a protective cover in the background. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measuring the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-04PD-2674

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Workers at Astrotech Space Operations in Titusville, Fla., begin fueling operations of the Deep Impact spacecraft, seen wrapped in a protective cover in the background. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measuring the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-04PD-2671

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Workers at Astrotech Space Operations in Titusville, Fla., get ready to begin fueling the Deep Impact spacecraft, seen wrapped in a protective cover in the background. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measuring the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

Interpreting the strongest deep earthquake ever observed

NASA Astrophysics Data System (ADS)

Schultz, Colin

2013-12-01

Massive earthquakes that strike deep within the Earth may be more efficient at dissipating pent-up energy than similar quakes near the surface, according to new research by Wei et al. The authors analyzed the rupture of the most powerful deep earthquake ever recorded.

Topography: dusting for the fingerprints of mantle dynamics

NASA Astrophysics Data System (ADS)

Faccenna, C.; Becker, T. W.

2016-12-01

The surface of the Earth is an ever-changing expression of the dynamic processes occurring deep in the mantle and at and above its surface, but our ability to "read" landscapes in terms of their underlying tectonic or climatic forcing is rudimentary. During the last decade, particular attention has been drawn to the deep, convection-related component of topography, induced by the stress produced at the base of the lithosphere by mantle flow, and its relevance compared to the (iso)static component. Despite much progress, several issues, including the magnitude and rate of this dynamic component, remain open. Here, we use key sites from convergent margins (e.g., the Apennines) and from intraplate settings (e.g., Ethiopia) to estimate the amplitude and rate of topography change and to disentangle the dynamic from the static component. On the base of those and other examples, we introduce the concept of a Topographic Fingerprint: any combination of mantle, crustal and surface processes that will result in a distinctive, thus predictable, topographic expression.

KSC-05PD-0019

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. From a vantage point above, a worker observes the Deep Impact spacecraft exposed after removal of the canister and protective cover. Next the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0075

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. The Deep Impact spacecraft waits inside the mobile service tower on Launch Pad 17-B, Cape Canaveral Air force Station, Fla., for fairing installation. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nosecone, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0079

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Inside the mobile service tower on Launch Pad 17-B, Cape Canaveral Air force Station, Fla., the partly enclosed Deep Impact spacecraft (background) waits while the second half of the fairing (foreground left) moves toward it. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nosecone, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0076

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Inside the mobile service tower on Launch Pad 17-B, Cape Canaveral Air force Station, Fla., the first half of the fairing is moved toward the Deep Impact spacecraft for installation. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nosecone, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0078

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Inside the mobile service tower on Launch Pad 17-B, Cape Canaveral Air force Station, Fla., the first half of the fairing is moved into place around the Deep Impact spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nosecone, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0074

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. The Deep Impact spacecraft waits inside the mobile service tower on Launch Pad 17-B, Cape Canaveral Air force Station, Fla., for fairing installation. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nosecone, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0077

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Inside the mobile service tower on Launch Pad 17-B, Cape Canaveral Air force Station, Fla., the first half of the fairing is moved into place around the Deep Impact spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nosecone, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0073

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. The Deep Impact spacecraft waits inside the mobile service tower on Launch Pad 17-B, Cape Canaveral Air force Station, Fla., for fairing installation. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nosecone, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0080

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Inside the mobile service tower on Launch Pad 17-B, Cape Canaveral Air force Station, Fla., workers attach the two halves of the fairing around the Deep Impact spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nosecone, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

A call for international soil experiment networks for studying, predicting, and managing global change impacts

DOE PAGES

Torn, M. S.; Chabbi, A.; Crill, P.; ...

2015-08-24

The soil profile encompasses a remarkably large range of biogeochemical conditions, processes, and fluxes. For example, in most soils the turnover time of soil organic carbon (SOC) varies more between the soil surface and 1m deep than between surface soils in the tropics vs. the Arctic (Torn et al., 2009). Moreover, radiocarbon observations in different soil types show that SOC decomposition rates decrease with depth, with residence times of years to decades at the soil surface to over 10 000 years at 1m deep (e.g., Torn et al., 2002). There are many competing hypotheses for this steep decline in SOCmore » turnover with depth. They can be grouped loosely into physical–chemical accessibility, energetic limits to microbial activity, microclimate and pH, and physical disconnect between decomposers and substrate. While all of these mechanisms control deep SOC cycling, data are lacking for unraveling their relative importance in different soils under different environmental conditions. However, critical knowledge for predicting soil responses to global change, because fairly rapid loss (or gain) of old and/or deep SOC stocks is possible and more than 80% of the world’s SOC is found below 20 cm depth (Jobbágy and Jackson, 2000). Currently, the soil modules within Earth system models are parameterized for surface soil and lack mechanisms important for stabilization and losses of deep SOC. We, therefore, suggest that a critical challenge is to achieve process-level understanding at the global level and the ability to predict whether, and how, the large stores of deep, old SOC are stabilized and lost under global change scenarios.« less

Piezophilic Bacteria Isolated from Sediment of the Shimokita Coalbed, Japan

NASA Astrophysics Data System (ADS)

Fang, J.; Kato, C.; Hori, T.; Morono, Y.; Inagaki, F.

2013-12-01

The Earth is a cold planet as well as pressured planet, hosting both the surface biosphere and the deep biosphere. Pressure ranges over four-orders of magnitude in the surface biosphere and probably more in the deep biosphere. Pressure is an important thermodynamic property of the deep biosphere that affects microbial physiology and biochemistry. Bacteria that require high-pressure conditions for optimal growth are called piezophilic bacteria. Subseafloor marine sediments are one of the most extensive microbial habitats on Earth. Marine sediments cover more than two-thirds of the Earth's surface, and represent a major part of the deep biosphere. Owing to its vast size and intimate connection with the surface biosphere, particularly the oceans, the deep biosphere has enormous potential for influencing global-scale biogeochemical processes, including energy, climate, carbon and nutrient cycles. Therefore, studying piezophilic bacteria of the deep biosphere has important implications in increasing our understanding of global biogeochemical cycles, the interactions between the biosphere and the geosphere, and the evolution of life. Sediment samples were obtained during IODP Expedition 337, from 1498 meters below sea floor (mbsf) (Sample 6R-3), 1951~1999 mbsf (19R-1~25R-3; coalbed mix), and 2406 mbsf (29R-7). The samples were mixed with MB2216 growth medium and cultivated under anaerobic conditions at 35 MPa (megapascal) pressure. Growth temperatures were adjusted to in situ environmental conditions, 35°C for 6R-3, 45°C for 19R-1~25R-3, and 55°C for 29R-7. The cultivation was performed three times, for 30 days each time. Microbial cells were obtained and the total DNA was extracted. At the same time, isolation of microbes was also performed under anaerobic conditions. Microbial communities in the coalbed sediment were analyzed by cloning, sequencing, and terminal restriction fragment length polymorphism (t-RFLP) of 16S ribosomal RNA genes. From the partial 16S rRNA gene sequences, we have identified abundant Alkalibacterium sp. in 6R-3 and 29R-7 at the first HP cultivation. We also identified Haloactibacillus sp. in 6R-3 and Anoxybacillus related sp. in 19R-1~25R-3 at the third HP cultivation. These microorganisms are likely piezophiles and play an important role in degradation of sedimentary organic matter and production of microbial metabolites sustaining the deep microbial ecosystem in the Shimokita Coalbed. The complete 16S sequencing and isolation of piezophiles are now ongoing.

USArray Imaging of North American Continental Crust

NASA Astrophysics Data System (ADS)

Ma, Xiaofei

The layered structure and bulk composition of continental crust contains important clues about its history of mountain-building, about its magmatic evolution, and about dynamical processes that continue to happen now. Geophysical and geological features such as gravity anomalies, surface topography, lithospheric strength and the deformation that drives the earthquake cycle are all directly related to deep crustal chemistry and the movement of materials through the crust that alter that chemistry. The North American continental crust records billions of years of history of tectonic and dynamical changes. The western U.S. is currently experiencing a diverse array of dynamical processes including modification by the Yellowstone hotspot, shortening and extension related to Pacific coast subduction and transform boundary shear, and plate interior seismicity driven by flow of the lower crust and upper mantle. The midcontinent and eastern U.S. is mostly stable but records a history of ancient continental collision and rifting. EarthScope's USArray seismic deployment has collected massive amounts of data across the entire United States that illuminates the deep continental crust, lithosphere and deeper mantle. This study uses EarthScope data to investigate the thickness and composition of the continental crust, including properties of its upper and lower layers. One-layer and two-layer models of crustal properties exhibit interesting relationships to the history of North American continental formation and recent tectonic activities that promise to significantly improve our understanding of the deep processes that shape the Earth's surface. Model results show that seismic velocity ratios are unusually low in the lower crust under the western U.S. Cordillera. Further modeling of how chemistry affects the seismic velocity ratio at temperatures and pressures found in the lower crust suggests that low seismic velocity ratios occur when water is mixed into the mineral matrix, and the combination of high temperature and water may point to small amounts of melt in the lower crust of Cordillera.

Enthalpy restoration in geothermal energy processing system

DOEpatents

Matthews, Hugh B.

1983-01-01

A geothermal deep well energy extraction system is provided of the general type in which solute-bearing hot water is pumped to the earth's surface from a relatively low temperature geothermal source by transferring thermal energy from the hot water to a working fluid for driving a primary turbine-motor and a primary electrical generator at the earth's surface. The superheated expanded exhaust from the primary turbine motor is conducted to a bubble tank where it bubbles through a layer of sub-cooled working fluid that has been condensed. The superheat and latent heat from the expanded exhaust of the turbine transfers thermal energy to the sub-cooled condensate. The desuperheated exhaust is then conducted to the condenser where it is condensed and sub-cooled, whereupon it is conducted back to the bubble tank via a barometric storage tank. The novel condensing process of this invention makes it possible to exploit geothermal sources which might otherwise be non-exploitable.

Planetary protection and the search for life beneath the surface of Mars

NASA Technical Reports Server (NTRS)

Mancinelli, Rocco L.

2003-01-01

The search for traces of extinct and extant life on Mars will be extended to beneath the surface of the planet. Current data from Mars missions suggesting the presence of liquid water early in Mars' history and mathematical modeling of the fate of water on Mars imply that liquid water may exist deep beneath the surface of Mars. This leads to the hypothesis that life may exist deep beneath the Martian surface. One possible scenario to look for life on Mars involves a series of unmanned missions culminating with a manned mission drilling deep into the Martian subsurface (approximately 3Km), collecting samples, and conducting preliminary analyses to select samples for return to earth. This mission must address both forward and back contamination issues, and falls under planetary protection category V. Planetary protection issues to be addressed include provisions stating that the inevitable deposition of earth microbes by humans should be minimized and localized, and that earth microbes and organic material must not contaminate the Martian subsurface. This requires that the drilling equipment be sterilized prior to use. Further, the collection, containment and retrieval of the sample must be conducted such that the crew is protected and that any materials returning to earth are contained (i.e., physically and biologically isolated) and the chain of connection with Mars is broken. c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

Planetary protection and the search for life beneath the surface of Mars.

PubMed

Mancinelli, Rocco L

2003-01-01

The search for traces of extinct and extant life on Mars will be extended to beneath the surface of the planet. Current data from Mars missions suggesting the presence of liquid water early in Mars' history and mathematical modeling of the fate of water on Mars imply that liquid water may exist deep beneath the surface of Mars. This leads to the hypothesis that life may exist deep beneath the Martian surface. One possible scenario to look for life on Mars involves a series of unmanned missions culminating with a manned mission drilling deep into the Martian subsurface (approximately 3Km), collecting samples, and conducting preliminary analyses to select samples for return to earth. This mission must address both forward and back contamination issues, and falls under planetary protection category V. Planetary protection issues to be addressed include provisions stating that the inevitable deposition of earth microbes by humans should be minimized and localized, and that earth microbes and organic material must not contaminate the Martian subsurface. This requires that the drilling equipment be sterilized prior to use. Further, the collection, containment and retrieval of the sample must be conducted such that the crew is protected and that any materials returning to earth are contained (i.e., physically and biologically isolated) and the chain of connection with Mars is broken. c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

Large-scale Labeled Datasets to Fuel Earth Science Deep Learning Applications

NASA Astrophysics Data System (ADS)

Maskey, M.; Ramachandran, R.; Miller, J.

2017-12-01

Deep learning has revolutionized computer vision and natural language processing with various algorithms scaled using high-performance computing. However, generic large-scale labeled datasets such as the ImageNet are the fuel that drives the impressive accuracy of deep learning results. Large-scale labeled datasets already exist in domains such as medical science, but creating them in the Earth science domain is a challenge. While there are ways to apply deep learning using limited labeled datasets, there is a need in the Earth sciences for creating large-scale labeled datasets for benchmarking and scaling deep learning applications. At the NASA Marshall Space Flight Center, we are using deep learning for a variety of Earth science applications where we have encountered the need for large-scale labeled datasets. We will discuss our approaches for creating such datasets and why these datasets are just as valuable as deep learning algorithms. We will also describe successful usage of these large-scale labeled datasets with our deep learning based applications.

InSight Spacecraft Lift to Spin Table & Pre-Spin Processing

NASA Image and Video Library

2018-03-28

In the Astrotech facility at Vandenberg Air Force Base in California, technicians and engineers inspect NASA's Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, or InSight, spacecraft after it was placed on a spin table during preflight processing. InSight will be the first mission to look deep beneath the Martian surface. It will study the planet's interior by measuring its heat output and listen for marsquakes. The spacecraft will use the seismic waves generated by marsquakes to develop a map of the planet’s deep interior. The resulting insight into Mars’ formation will provide a better understanding of how other rocky planets, including Earth, were created. InSight is scheduled for liftoff May 5, 2018.

New Techniques for Deep Learning with Geospatial Data using TensorFlow, Earth Engine, and Google Cloud Platform

NASA Astrophysics Data System (ADS)

Hancher, M.

2017-12-01

Recent years have seen promising results from many research teams applying deep learning techniques to geospatial data processing. In that same timeframe, TensorFlow has emerged as the most popular framework for deep learning in general, and Google has assembled petabytes of Earth observation data from a wide variety of sources and made them available in analysis-ready form in the cloud through Google Earth Engine. Nevertheless, developing and applying deep learning to geospatial data at scale has been somewhat cumbersome to date. We present a new set of tools and techniques that simplify this process. Our approach combines the strengths of several underlying tools: TensorFlow for its expressive deep learning framework; Earth Engine for data management, preprocessing, postprocessing, and visualization; and other tools in Google Cloud Platform to train TensorFlow models at scale, perform additional custom parallel data processing, and drive the entire process from a single familiar Python development environment. These tools can be used to easily apply standard deep neural networks, convolutional neural networks, and other custom model architectures to a variety of geospatial data structures. We discuss our experiences applying these and related tools to a range of machine learning problems, including classic problems like cloud detection, building detection, land cover classification, as well as more novel problems like illegal fishing detection. Our improved tools will make it easier for geospatial data scientists to apply modern deep learning techniques to their own problems, and will also make it easier for machine learning researchers to advance the state of the art of those techniques.

3D Numerical modelling of topography development associated with curved subduction zones

NASA Astrophysics Data System (ADS)

Munch, Jessica; Ueda, Kosuke; Burg, Jean-Pierre; May, Dave; Gerya, Taras

2017-04-01

Curved subduction zones, also called oroclines, are geological features found in various places on Earth. They occur in diverse geodynamic settings: 1) single slab subduction in oceanic domain (e.g. Sandwich trench in the Southern Atlantic); 2) single slab subduction in continental domain, (e.g. Gibraltar-Alboran orocline in the Western Mediterranean) 3); multi-slab subduction (e.g. Caribbean orocline in the South-East of the Gulf of Mexico). These systems present various curvatures, lengths (few hundreds to thousands of km) and ages (less than 35 Ma for Gibraltar Alboran orocline, up to 100 Ma for the Caribbean). Recent studies suggested that the formation of curved subduction systems depends on slab properties (age, length, etc) and may be linked with processes such as retreating subduction and delamination. Plume induced subduction initiation has been proposed for the Caribbean. All of these processes involve deep mechanisms such as mantle and slab dynamics. However, subduction zones always generate topography (trenches, uplifts, etc), which is likely to be influenced by surface processes. Hence, surface processes may also influence the evolution of subduction zones. We focus on different kinds of subduction systems initiated by plume-lithosphere interactions (single slab subduction/multi-slab subduction) and scrutinize their surface expression. We use numerical modeling to examine large-scale subduction initiation and three-dimensional slab retreat. We perform two kinds of simulations: 1) large scale subduction initiation with the 3D-thermomechanical code I3ELVIS (Gerya and Yuen, 2007) in an oceanic domain and 2) large scale subduction initiation in oceanic domain using I3ELVIS coupled with a robust new surface processes model (SPM). One to several retreating slabs form in the absence of surface processes, when the conditions for subduction initiation are reached (c.f. Gerya et al., 2015), and ridges occur in the middle of the extensional domain opened by slab retreat. Topography associated with slab retreat is curved. Coupling I3ELVIS with SPM yields more accurate topography of the curved subduction zone. This allows balancing the relative importance of surface and deep processes in the evolution of curved subduction zones and the development of their related topography. References: Gerya, T. V., & Yuen, D. A. (2007). Robust characteristics method for modelling multiphase visco-elasto-plastic thermo-mechanical problems. Physics of the Earth and Planetary Interiors, 163(1), 83-105. Gerya, T. V., Stern, R. J., Baes, M., Sobolev, S. V., & Whattam, S. A. (2015). Plate tectonics on the Earth triggered by plume-induced subduction initiation. Nature, 527(7577), 221-225.

The Evolution and Disruption of Planetary Systems

NASA Technical Reports Server (NTRS)

Laughlin, Gregory; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

Planetary systems that encounter passing stars can experience severe orbital disruption, and the efficiency of this process is greatly enhanced when the impinging systems are binary pairs rather than single stars. Using a Monte Carlo approach, we have performed nearly half a million numerical experiments to examine the long term ramifications of planetary scattering on planetary systems. We have concluded that systems which form in dense environments such as Orion's Trapezium cluster have roughly a ten percent chance of being seriously disrupted. We have also used our programs to explore the long-term prospects for our own Solar system. Given the current interstellar environment, we have computed the odds that Earth will find its orbit seriously disrupted prior to the emergence of a runaway greenhouse effect driven by the Sun's increasing luminosity. This estimate includes both direct disruption events and scattering processes that seriously alter the orbits of the Jovian planets, which then force severe changes upon the Earth's orbit. We then explore the consequences of the Earth being thrown into deep space. The surface biosphere would rapidly shut down under conditions of zero insolation, but the Earth's radioactive heat is capable of maintaining life deep underground, and perhaps in hydrothermal vent communities, for some time to come. Although unlikely for the Earth, this scenario may be common throughout the universe, since many environments where liquid water could exist (e.g., Europa and Callisto) must derive their energy from internal (rather than external) heating.

KSC-05PD-0013

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. The Deep Impact spacecraft is lifted from its transporter into the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, Fla. the spacecraft will be attached to the second stage of the Boeing Delta II rocket. Next the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0010

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. At Astrotech Space Operations in Titusville, Fla., the Deep Impact spacecraft is secure in the canister for its move to Launch Pad 17-B on Cape Canaveral Air Force Station, Fla. Then, in the mobile service tower, the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0012

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. The Deep Impact spacecraft arrives before dawn at the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, Fla. The spacecraft will be attached to the second stage of the Boeing Delta II rocket. Next the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0017

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. In the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, Fla., workers stand by as the canister is lifted away from the Deep Impact spacecraft. Next the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0018

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. In the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, Fla., workers watch as the protective cover surrounding the Deep Impact spacecraft is lifted away. Next the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0015

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. In the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, Fla., workers begin lowering the Deep Impact spacecraft toward the second stage of the Boeing Delta II launch vehicle below for mating. Next the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0016

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. In the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, Fla., workers attach the third stage motor, connected to the Deep Impact spacecraft, to the spin table on the second stage of the Boeing Delta II launch vehicle below. Next the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0014

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. The Deep Impact spacecraft is lifted into the top of the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, Fla. the spacecraft will be attached to the second stage of the Boeing Delta II rocket. Next the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

Energy 101: Geothermal Energy

ScienceCinema

None

2018-05-30

See how we can generate clean, renewable energy from hot water sources deep beneath the Earth's surface. The video highlights the basic principles at work in geothermal energy production, and illustrates three different ways the Earth's heat can be converted into electricity.

Designing a network of critical zone observatories to explore the living skin of the terrestrial Earth

Treesearch

Susan L. Brantley; William H. McDowell; William E. Dietrich; Timothy S. White; Praveen Kumar; Suzanne P. Anderson; Jon Chorover; Kathleen Ann Lohse; Roger C. Bales; Daniel D. Richter; Gordon Grant; Jérôme Gaillardet

2017-01-01

The critical zone (CZ), the dynamic living skin of the Earth, extends from the top of the vegetative canopy through the soil and down to fresh bedrock and the bottom of the groundwater. All humans live in and depend on the CZ. This zone has three co-evolving surfaces: the top of the vegetative canopy, the ground surface, and a deep subsurface below which Earth’s...

Potential impact of global climate change on benthic deep-sea microbes.

PubMed

Danovaro, Roberto; Corinaldesi, Cinzia; Dell'Anno, Antonio; Rastelli, Eugenio

2017-12-15

Benthic deep-sea environments are the largest ecosystem on Earth, covering ∼65% of the Earth surface. Microbes inhabiting this huge biome at all water depths represent the most abundant biological components and a relevant portion of the biomass of the biosphere, and play a crucial role in global biogeochemical cycles. Increasing evidence suggests that global climate changes are affecting also deep-sea ecosystems, both directly (causing shifts in bottom-water temperature, oxygen concentration and pH) and indirectly (through changes in surface oceans' productivity and in the consequent export of organic matter to the seafloor). However, the responses of the benthic deep-sea biota to such shifts remain largely unknown. This applies particularly to deep-sea microbes, which include bacteria, archaea, microeukaryotes and their viruses. Understanding the potential impacts of global change on the benthic deep-sea microbial assemblages and the consequences on the functioning of the ocean interior is a priority to better forecast the potential consequences at global scale. Here we explore the potential changes in the benthic deep-sea microbiology expected in the coming decades using case studies on specific systems used as test models. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Comparative Analysis of Aerosol Retrievals from MODIS, OMI and MISR Over Sahara Region

NASA Technical Reports Server (NTRS)

Lyapustin, A.; Wang, Y.; Hsu, C.; Terres, O.; Leptoukh, G.; Kalashnikova, O.; Korkin, S.

2011-01-01

MODIS is a wide field-of-view sensor providing daily global observations of the Earth. Currently, global MODIS aerosol retrievals over land are performed with the main Dark Target algorithm complimented with the Deep Blue (DB) Algorithm over bright deserts. The Dark Target algorithm relies on surface parameterization which relates reflectance in MODIS visible bands with the 2.1 micrometer region, whereas the Deep Blue algorithm uses an ancillary angular distribution model of surface reflectance developed from the time series of clear-sky MODIS observations. Recently, a new Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm has been developed for MODIS. MAIAC uses a time series and an image based processing to perform simultaneous retrievals of aerosol properties and surface bidirectional reflectance. It is a generic algorithm which works over both dark vegetative surfaces and bright deserts and performs retrievals at 1 km resolution. In this work, we will provide a comparative analysis of DB, MAIAC, MISR and OMI aerosol products over bright deserts of northern Africa.

The Moon: Keystone to Understanding Planetary Geological Processes and History

NASA Technical Reports Server (NTRS)

2002-01-01

Extensive and intensive exploration of the Earth's Moon by astronauts and an international array of automated spacecraft has provided an unequaled data set that has provided deep insight into geology, geochemistry, mineralogy, petrology, chronology, geophysics and internal structure. This level of insight is unequaled except for Earth. Analysis of these data sets over the last 35 years has proven fundamental to understanding planetary surface processes and evolution, and is essential to linking surface processes with internal and thermal evolution. Much of the understanding that we presently have of other terrestrial planets and outer planet satellites derives from the foundation of these data. On the basis of these data, the Moon is a laboratory for understanding of planetary processes and a keystone for providing evolutionary perspective. Important comparative planetology issues being addressed by lunar studies include impact cratering, magmatic activity and tectonism. Future planetary exploration plans should keep in mind the importance of further lunar exploration in continuing to build solid underpinnings in this keystone to planetary evolution. Examples of these insights and applications to other planets are cited.

Probing Metabolic Activity of Deep Subseafloor Life with NanoSIMS

NASA Astrophysics Data System (ADS)

Morono, Y.; Terada, T.; Itoh, M.; Inagaki, F.

2014-12-01

There are very few natural environments where life is absent in the Earth's surface biosphere. However, uninhabitable region is expected to be exist in the deep subsurface biosphere, of which extent and constraining factor(s) have still remained largly unknown. Scientific ocean drilling have revealed that microbial communities in sediments are generally phylogenetically distinct from known spieces isolated from the Earth's surface biosphere, and hence metabolic functions of the deep subseafloor life remain unknown. In addition, activity of subseafloor microbial cells are thought to be extraordinally slow, as indicated by limited supply of neutrient and energy substrates. To understand the limits of the Earth's subseafloor biosphere and metabolic functions of microbial populations, detection and quantification of the deeply buried microbial cells in geological habitats are fundamentary important. Using newly developed cell separation techniques as well as an discriminative cell detection system, the current quantification limit of sedimentary microbial cells approaches to 102 cells/cm3. These techniques allow not only to assess very small microbial population close to the subsurface biotic fringe, but also to separate and sort the target cells using flow cytometric cell sorter. Once the deep subseafloor microbial cells are detached from mineral grains and sorted, it opens new windows to subsequent molecular ecological and element/isotopic analyses. With a combined use of nano-scale secondary ion masspectrometry (NanoSIMS) and stable isotope-probing techniques, it is possible to detect and measure activity of substrate incorporation into biomass, even for extremely slow metabolic processes such as uncharacteriszed deep subseafloor life. For example, it was evidenced by NanoSIMS that at least over 80% of microbial cells at ~200 meters-deep, 460,000-year-old sedimentary habitat are indeed live, which substrate incooporation was found to be low (10-15 gC/cell/day) even under the lab incubation condition. Also microbial activity in ultraoligotrophic biosphere samples such as the South Pacific Gyre (i.e., IODP Expeditions 329) will be shown. Our results demonstrates metabolic potential of microbes that have been survived for geological timescale in extremely starved condition.

MAVEN-Measured Meteoritic Ions on Mars - Tracers of Lower Ionosphere Processes With and Without Analogues On Earth

NASA Astrophysics Data System (ADS)

Benna, M.; Grebowsky, J. M.; Collinson, G.; Plane, J. M. C.; Mitchell, D.; Srivastava, N.

2017-12-01

MAVEN observations of meteoritic metal ion populations during "deep dip" campaigns at Mars have revealed unique non-Earth like behavior that are not yet understood. These deep dip campaigns (6 so far) consisted each of more than a score of repeated orbits through the Martian molecular-ion-dominated lower ionosphere, whose terrestrial parallel (Earth's E-region) has been rather sparcely surveyed in situ by sounding rockets. In regions of weak Mars magnetic fields, MAVEN found ordered exponentially decreasing metal ion concentrations above the altitude of peak meteor ablation. Such an ordered trend has never been observed on Earth. Isolated anomalous high-altitude layers in the metal ion are also encountered, typically on deep dip campaigns in the southern hemisphere where large localized surface remanent magnetic fields prevail. The source of these anomalous layers is not yet evident, although the occurrences of some high-altitude metal ion enhancements were in regions with measured perturbed magnetic fields, indicative of localized electrical currents. Further investigation shows that those currents are also sometimes associated with superthermal/energetic electron bursts offering evidence that that impact ionization of neutral metal populations persisting at high altitudes are the source of metal ion enhancement - a rather difficult assumption to accept far above the ablation region where the metal neutrals are deposited. The relationship of the anomalous layers to the coincident electron populations as well as to the orientation of the magnetic fields which can play a role in the neutral wind generated ion convergences as on Earth is investigated.

Getting Under Mars' Skin: The InSight Mission to the Deep Interior of Mars

NASA Astrophysics Data System (ADS)

Banerdt, W. B.; Asmar, S.; Banfield, D. J.; Christensen, U. R.; Clinton, J. F.; Dehant, V. M. A.; Folkner, W. M.; Garcia, R.; Giardini, D.; Golombek, M. P.; Grott, M.; Hudson, T.; Johnson, C. L.; Kargl, G.; Knapmeyer-Endrun, B.; Kobayashi, N.; Lognonne, P. H.; Maki, J.; Mimoun, D.; Mocquet, A.; Morgan, P.; Panning, M. P.; Pike, W. T.; Spohn, T.; Tromp, J.; Weber, R. C.; Wieczorek, M. A.; Russell, C. T.

2015-12-01

The InSight mission to Mars will launch in March of 2016, landing six months later in Elysium Planitia. In contrast to the 43 previous missions to Mars, which have thoroughly explored its surface features and chemistry, atmosphere, and searched for past or present life, InSight will focus on the deep interior of the planet. InSight will investigate the fundamental processes of terrestrial planet formation and evolution by performing the first comprehensive surface-based geophysical measurements on Mars. It will provide key information on the composition and structure of an Earth-like planet that has gone through most of the evolutionary stages of the Earth up to plate tectonics. The planet Mars can play a key role in understanding early terrestrial planet formation and evolution. Unlike the Earth, its overall structure appears to be relatively unchanged since the first few hundred million years after formation; unlike the Moon, it is large enough that the P-T conditions within the planet span an appreciable fraction of the terrestrial planet range. Thus the large-scale chemical and structural evidence preserved in Mars' interior should tell us a great deal about the processes of planetary differentiation and heat transport. InSight will undertake this investigation using the "traditional" geophysical techniques of seismology, precision tracking (for rotational dynamics), and heat flow measurement. The predominant challenge, in addition to the technical problems of the remote installation and operation of instruments on a distant and harsh planetary surface, comes from the practical limitation of working with data acquired from a single station. We will discuss how we overcome these limitations through the application of single-station seismic analysis techniques, which take advantage of some of the specific attributes of Mars, and global heat flow modeling, which allows the interpretation of a single measurement of a spatially inhomogeneous surface distribution.

How Phoenix Talks to Earth

NASA Technical Reports Server (NTRS)

2008-01-01

[figure removed for brevity, see original site] Click on the image for the animation

This animation shows how NASA's Phoenix Mars Lander stays in contact with Earth. As NASA's Mars Odyssey orbiter passes overhead approximately every two hours, Phoenix transmits images and scientific data from the surface to the orbiter, which then relays the data to NASA's Deep Space Network of antennas on Earth. Similarly, NASA's Deep Space Network transmits instructions from Earth to Odyssey, which then relays the information to Phoenix.

The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

A High-Resolution Multitechniques Approach to Characterize Bio-Organo-Mineral Associations Within Rock Samples: Tracking Biological vs Abiotic Processes? Towards a Better Understanding of the Deep Carbon Cycle.

NASA Astrophysics Data System (ADS)

Pisapia, C.

2015-12-01

Among all elements, carbon plays one of the major roles for the sustainability of life on Earth. Past considerations of the carbon cycle have mainly focused on surface processes occurring at the atmosphere, oceans and shallow crustal environments. By contrast, little is known about the Deep Carbon cycle whereas both geochemical and biological processes may induce organic carbon production and/or consumption at depth. Indeed, the nowadays-recognized capability of geochemical processes such as serpentinization to generate abiotic organic compounds as well as the existence of a potentially important intraterrestrial life raises questions about the limit of biotic/abiotic carbon on Earth's deep interior and how it impacts global biogeochemical cycles. It is then mandatory to increase our knowledge on the nature and extent of carbon reservoirs along with their sources, sinks and fluxes in the subsurface. This implies to be able to finely characterize organomineral associations within crustal rocks although it might be hampered by the scarceness and heterogeneous micrometric spatial distribution of organic molecules in natural rocks. We then developed an in situ analytical strategy based on the combination of high-resolution techniques to track organic molecules at the pore level in natural rocks and to determine their biological or abiotic origin. We associated classical high-resolution techniques and synchrotron-based imaging techniques in order to characterize their nature and localization (SEM/TEM, coupled CLSM/Raman spectroscopy, Tof-SIMS) along with their 3D-distribution relatively to mineral phases (S-FTIR, S-DeepUV, XANES, Biphoton microscopy). The effectiveness of this approach to shed light on the speciation and nature of carbon in subsurface environments will be illustrated through the study of (i) subsurface ecosystems and abiotic organic carbon within ultramafic rocks of the oceanic lithosphere as putative analogs for the nature and functioning of primitive ecosystems on Earth and of (ii) ecosystems inhabiting Archean craton and potentially playing a role in punk-rock karstification processes and rocks weathering.

KSC-04PD-2404

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. On Launch Pad 17-B, Cape Canaveral Air Force Station, Fla., a second Solid Rocket Booster (SRB) is raised off a transporter to be lifted up the mobile service tower. It will be attached to the Boeing Delta II launch vehicle for launch of the Deep Impact spacecraft. A NASA Discovery mission, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measuring the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact project management is handled by the Jet Propulsion Laboratory in Pasadena, Calif. The spacecraft is scheduled to launch Dec. 30, 2004.

KSC-04PD-2699

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. At Astrotech Space Operations in Titusville, Fla., the Deep Impact spacecraft is mated to the Boeing Delta II third stage. When the spacecraft and third stage are mated, they will be moved to Launch Pad 17-B at Cape Canaveral Air Force Station, Fla. There they will be mated to the Delta II rocket and the fairing installed around them for protection during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-04PD-2693

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Boeing technicians at Astrotech Space Operations in Titusville, Fla., prepare the third stage of a Delta II rocket for mating with the Deep Impact spacecraft. When the spacecraft and third stage are mated, they will be moved to Launch Pad 17-B at Cape Canaveral Air Force Station, Fla. There they will be mated to the Delta II rocket and the fairing installed around them for protection during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-04PD-2664

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. This view from inside the mobile service tower on Launch Pad 17-B, Cape Canaveral Air Force Station, shows the Boeing Delta II second stage as it reaches the top. The component will be reattached to the interstage adapter on the Delta II. The rocket is the launch vehicle for the Deep Impact spacecraft, scheduled for liftoff no earlier than Jan. 12. A NASA Discovery mission, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measuring the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network.

KSC-04PD-2662

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. At Launch Pad 17-B, Cape Canaveral Air Force Station, the Boeing Delta II second stage reaches the top of the mobile service tower. The component will be reattached to the interstage adapter on the Delta II. The rocket is the launch vehicle for the Deep Impact spacecraft, scheduled for liftoff no earlier than Jan. 12. A NASA Discovery mission, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measuring the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network.

KSC-04PD-2663

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. This view from inside the mobile service tower on Launch Pad 17-B, Cape Canaveral Air Force Station, shows the Boeing Delta II second stage as it reaches the top. The component will be reattached to the interstage adapter on the Delta II. The rocket is the launch vehicle for the Deep Impact spacecraft, scheduled for liftoff no earlier than Jan. 12. A NASA Discovery mission, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measuring the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network.

KSC-05PD-0113

NASA Technical Reports Server (NTRS)

2005-01-01

JET PROPULSION LABORATORY, CALIF. At Ball Aerospace in Boulder, Colo., the infrared (IR) spectrometer for the Deep Impact flyby spacecraft is inspected in the instrument assembly area in the Fisher Assembly building clean room. Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measuring the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. The spectrometer is part of the High Resolution Instrument in the spacecraft. This imager will be aimed at the ejected matter as the crater forms, and an infrared 'fingerprint' of the material from inside of the comet's nucleus will be taken. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission. Launch of Deep Impact is scheduled for Jan. 12 from Launch Pad 17-B, Cape Canaveral Air Force Station, Fla.

The Deep Space Gateway Lightning Mapper (DLM) — Monitoring Global Change and Thunderstorm Processes through Observations of Earth's High-Latitude Lightning from Cis-Lunar Orbit

NASA Astrophysics Data System (ADS)

Lang, T. J.; Blakeslee, R. J.; Cecil, D. J.; Christian, H. J.; Gatlin, P. N.; Goodman, S. J.; Koshak, W. J.; Petersen, W. A.; Quick, M.; Schultz, C. J.; Tatum, P. F.

2018-02-01

We propose the Deep Space Gateway Lightning Mapper (DLM) instrument. The primary goal of the DLM is to optically monitor Earth's high-latitude (50° and poleward) total lightning not observed by current and planned spaceborne lightning mappers.

Complex Cloud and Radiative Processes Unfolding at the Earth's Terminator: A Unique Perspective from the Proposed Deep Space Gateway

NASA Astrophysics Data System (ADS)

Davis, A. B.; Marshak, A.

2018-02-01

The Deep Space Gateway offers a unique vantage for Earth observation using reflected sunlight: day/night or night/day terminators slowly marching across the disc. It's an opportunity to improve our understanding of clouds at that key moment in their daily cycle.

KSC-05PD-0001

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. The Deep Impact spacecraft waits at Astrotech Space Operations in Titusville, Fla., for placement of a protective cover before the canister is installed around it. Once the spacecraft is completely covered, it will be transferred to Launch Pad 17-B on Cape Canaveral Air Force Station, Fla. Then, in the mobile service tower, the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0004

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. At Astrotech Space Operations in Titusville, Fla., Boeing technicians place the lower segments of a protective canister around the Deep Impact spacecraft. Once the spacecraft is completely covered, it will be transferred to Launch Pad 17-B on Cape Canaveral Air Force Station, Fla. Then, in the mobile service tower, the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0007

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. At Astrotech Space Operations in Titusville, Fla., technicians lower the upper canister toward the Deep Impact spacecraft. It will be attached to the lower segments already surrounding the spacecraft. Once the spacecraft is completely covered, it will be transferred to Launch Pad 17-B on Cape Canaveral Air Force Station, Fla. Then, in the mobile service tower, the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0005

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. At Astrotech Space Operations in Titusville, Fla., Boeing technicians roll the Deep Impact spacecraft into another area where the upper canister can be lowered around it. Once the spacecraft is completely covered, it will be transferred to Launch Pad 17-B on Cape Canaveral Air Force Station, Fla. Then, in the mobile service tower, the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0002

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. At Astrotech Space Operations in Titusville, Fla., a protective cover is being lowered over the Deep Impact spacecraft to protect it before the canister is installed around it. Once the spacecraft is completely covered, it will be transferred to Launch Pad 17-B on Cape Canaveral Air Force Station, Fla. Then, in the mobile service tower, the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0011

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. The Deep Impact spacecraft leaves Astrotech Space Operations in Titusville, Fla., in the pre-dawn hours on a journey to Launch Pad 17-B at Cape Canaveral Air Force Station, Fla. There the spacecraft will be attached to the second stage of the Boeing Delta II rocket. Next the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0003

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. At Astrotech Space Operations in Titusville, Fla., Boeing technicians lower a protective cover over the Deep Impact spacecraft to protect it before the canister is installed around it. Once the spacecraft is completely covered, it will be transferred to Launch Pad 17-B on Cape Canaveral Air Force Station, Fla. Then, in the mobile service tower, the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3- foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0006

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. At Astrotech Space Operations in Titusville, Fla., technicians install a crane onto the upper canister before lifting it to install around the Deep Impact spacecraft. Once the spacecraft is completely covered, it will be transferred to Launch Pad 17-B on Cape Canaveral Air Force Station, Fla. Then, in the mobile service tower, the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0009

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. At Astrotech Space Operations in Titusville, Fla., Boeing technicians attach the upper canister with the lower segments surrounding the Deep Impact spacecraft. Once the spacecraft is completely covered, it will be transferred to Launch Pad 17-B on Cape Canaveral Air Force Station, Fla. Then, in the mobile service tower, the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0008

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. At Astrotech Space Operations in Titusville, Fla., technicians lower the upper canister toward the Deep Impact spacecraft. It will be attached to the lower segments already surrounding the spacecraft. Once the spacecraft is completely covered, it will be transferred to Launch Pad 17-B on Cape Canaveral Air Force Station, Fla. Then, in the mobile service tower, the fairing will be installed around the spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth joint, protecting the spacecraft during launch. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

Deep-focus earthquakes and recycling of water into the earth's mantle

NASA Technical Reports Server (NTRS)

Meade, Charles; Jeanloz, Raymond

1991-01-01

For more than 50 years, observations of earthquakes to depths of 100 to 650 kilometers inside earth have been enigmatic: at these depths, rocks are expected to deform by ductile flow rather than brittle fracturing or frictional sliding on fault surfaces. Laboratory experiments and detailed calculations of the pressures and temperatures in seismically active subduction zones indicate that this deep-focus seismicity could originate from dehydration and high-pressure structural instabilities occurring in the hydrated part of the lithosphere that sinks into the upper mantle. Thus, seismologists may be mapping the recirculation of water from the oceans back into the deep interior of the planet.

Life and Death on Mars and Earth

NASA Technical Reports Server (NTRS)

Zahnle, K. J.; Sleep, N. H.

1999-01-01

Failure to discover life on Mars has led a great many experts to conclude that it must be hiding. Where? The likeliest hiding places are deep beneath the surface, where geothermal heat could permit liquid water. In this the search for life on Mars parallels the search for water on Mars. Liquid water has been, at least on occasion, a geologically significant presence on the surface. Channels were cut and plains dissected. This water is now hidden, in all likelihood having drained to the base of the porous regolith, where it fills possibly frozen aquifers. Presumably any surviving biota has followed the water from the surface to its hiding places in the deep. Accordingly, we have extended our environmental impact assessment of the environmental hazards posed by large asteroid and comet impacts to Mars, and compare its case to Earth's. In particular, we address the continuous habitability of surface and subsurface environments.

Deep Space Gateway - Enabling Missions to Mars

NASA Technical Reports Server (NTRS)

Rucker, Michelle; Connolly, John

2017-01-01

There are many opportunities for commonality between Lunar vicinity and Mars mission hardware and operations. Best approach: Identify Mars mission risks that can be bought down with testing in the Lunar vicinity, then explore hardware and operational concepts that work for both missions with minimal compromise. Deep Space Transport will validate the systems and capabilities required to send humans to Mars orbit and return to Earth. Deep Space Gateway provides a convenient assembly, checkout, and refurbishment location to enable Mars missions Current deep space transport concept is to fly missions of increasing complexity: Shakedown cruise, Mars orbital mission, Mars surface mission; Mars surface mission would require additional elements.

Water cycling between ocean and mantle: Super-earths need not be waterworlds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cowan, Nicolas B.; Abbot, Dorian S., E-mail: n-cowan@northwestern.edu

2014-01-20

Large terrestrial planets are expected to have muted topography and deep oceans, implying that most super-Earths should be entirely covered in water, so-called waterworlds. This is important because waterworlds lack a silicate weathering thermostat so their climate is predicted to be less stable than that of planets with exposed continents. In other words, the continuously habitable zone for waterworlds is much narrower than for Earth-like planets. A planet's water is partitioned, however, between a surface reservoir, the ocean, and an interior reservoir, the mantle. Plate tectonics transports water between these reservoirs on geological timescales. Degassing of melt at mid-ocean ridgesmore » and serpentinization of oceanic crust depend negatively and positively on seafloor pressure, respectively, providing a stabilizing feedback on long-term ocean volume. Motivated by Earth's approximately steady-state deep water cycle, we develop a two-box model of the hydrosphere and derive steady-state solutions to the water partitioning on terrestrial planets. Critically, hydrostatic seafloor pressure is proportional to surface gravity, so super-Earths with a deep water cycle will tend to store more water in the mantle. We conclude that a tectonically active terrestrial planet of any mass can maintain exposed continents if its water mass fraction is less than ∼0.2%, dramatically increasing the odds that super-Earths are habitable. The greatest source of uncertainty in our study is Earth's current mantle water inventory: the greater its value, the more robust planets are to inundation. Lastly, we discuss how future missions can test our hypothesis by mapping the oceans and continents of massive terrestrial planets.« less

Volatiles in the Earth: All shallow and all recycled

NASA Technical Reports Server (NTRS)

Anderson, Don L.

1994-01-01

A case can be made that accretion of the Earth was a high-temperature process and that the primordial Earth was dry. A radial zone-refining process during accretion may have excluded low-melting point and volatile material, including large-ion lithophile elements toward the surface, leaving a refractory and zoned interior. Water, sediments and altered hydrous oceanic crust are introduced back into the interior by subduction, a process that may be more efficient today than in the past. Seismic tomography strongly suggests that a large part of the uppermantle is above the solidus, and this implies wet melting. The mantle beneath Archean cratons has very fast seismic velocities and appears to be strong to 150 km or greater. This is consistent with very dry mantle. It is argued that recycling of substantial quantities of water occurs in the shallow mantle but only minor amounts recycle to depths greater than 200 km. Recycling also oxidizes that mantle; ocean island ('hotspot') basalts are intermediate in oxidation state to island-arc and midocean ridge basalts (MORB). This suggests a deep uncontaminated reservoir for MORB. Plate tectonics on a dry Earth is discussed in order to focus attention on inconsistencies in current geochemical models of terrestrial evolution and recycling.

Placers of cosmic dust in the blue ice lakes of Greenland

NASA Technical Reports Server (NTRS)

Maurette, M.; Hammer, C.; Reeh, N.; Brownlee, D. E.; Thomsen, H. H.

1986-01-01

A concentration process occurring in the melt zone of the Greenland ice cap has produced the richest known deposit of cosmic dust on the surface of the earth. Extraterrestrial particles collected from this region are well preserved and are collectable in large quantities. The collected particles are generally identical to cosmic spheres found on the ocean floor, but a pure glass type was discovered that has not been seen in deep-sea samples. Iron-rich spheres are conspicuously rare in the collected material.

Surface and atmosphere parameter maps from earth-orbiting radiometers

NASA Technical Reports Server (NTRS)

Gloersen, P.

1976-01-01

Earlier studies have shown that an earth-orbiting electrically scanned microwave radiometer (ESMR) is capable of inferring the extent, concentration, and age of sea ice; the extent, concentration, and thickness of lake ice; rainfall rates over oceans; surface wind speeds over open water; particle size distribution in the deep snow cover of continental ice sheets; and soil moisture content in unvegetated fields. Most other features of the surface of the earth and its atmosphere require multispectral imaging techniques to unscramble the combined contributions of the atmosphere and the surface. Multispectral extraction of surface parameters is analyzed on the basis of a pertinent equation in terms of the observed brightness temperature, the emissivity of the surface which depends on wavelength and various parameters, the sensible temperature of the surface, and the total atmospheric opacity which is also wavelength dependent. Implementation of the multispectral technique is examined. Properties of the surface of the earth and its atmosphere to be determined from a scanning multichannel microwave radiometer are tabulated.

Statistical geochemistry reveals disruption in secular lithospheric evolution about 2.5 Gyr ago.

PubMed

Keller, C Brenhin; Schoene, Blair

2012-05-23

The Earth has cooled over the past 4.5 billion years (Gyr) as a result of surface heat loss and declining radiogenic heat production. Igneous geochemistry has been used to understand how changing heat flux influenced Archaean geodynamics, but records of systematic geochemical evolution are complicated by heterogeneity of the rock record and uncertainties regarding selection and preservation bias. Here we apply statistical sampling techniques to a geochemical database of about 70,000 samples from the continental igneous rock record to produce a comprehensive record of secular geochemical evolution throughout Earth history. Consistent with secular mantle cooling, compatible and incompatible elements in basalts record gradually decreasing mantle melt fraction through time. Superimposed on this gradual evolution is a pervasive geochemical discontinuity occurring about 2.5 Gyr ago, involving substantial decreases in mantle melt fraction in basalts, and in indicators of deep crustal melting and fractionation, such as Na/K, Eu/Eu* (europium anomaly) and La/Yb ratios in felsic rocks. Along with an increase in preserved crustal thickness across the Archaean/Proterozoic boundary, these data are consistent with a model in which high-degree Archaean mantle melting produced a thick, mafic lower crust and consequent deep crustal delamination and melting--leading to abundant tonalite-trondhjemite-granodiorite magmatism and a thin preserved Archaean crust. The coincidence of the observed changes in geochemistry and crustal thickness with stepwise atmospheric oxidation at the end of the Archaean eon provides a significant temporal link between deep Earth geochemical processes and the rise of atmospheric oxygen on the Earth.

KSC-04PD-2697

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. At Astrotech Space Operations in Titusville, Fla., Boeing technicians oversee the final movement of the Deep Impact spacecraft being lowered onto the Delta II third stage for mating. When the spacecraft and third stage are mated, they will be moved to Launch Pad 17-B at Cape Canaveral Air Force Station, Fla. There they will be mated to the Delta II rocket and the fairing installed around them for protection during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-04PD-2698

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. At Astrotech Space Operations in Titusville, Fla., Boeing technicians oversee the final movement of the Deep Impact spacecraft being lowered onto the Delta II third stage for mating. When the spacecraft and third stage are mated, they will be moved to Launch Pad 17-B at Cape Canaveral Air Force Station, Fla. There they will be mated to the Delta II rocket and the fairing installed around them for protection during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-04PD-2696

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. At Astrotech Space Operations in Titusville, Fla., Boeing technicians watch as an overhead crane lowers the Deep Impact spacecraft onto the Delta II third stage for mating. When the spacecraft and third stage are mated, they will be moved to Launch Pad 17-B at Cape Canaveral Air Force Station, Fla. There they will be mated to the Delta II rocket and the fairing installed around them for protection during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3- foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-04PD-2695

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. At Astrotech Space Operations in Titusville, Fla., Boeing technicians watch as an overhead crane lifts the Deep Impact spacecraft, which is being moved for mating to the Delta II third stage. When the spacecraft and third stage are mated, they will be moved to Launch Pad 17-B at Cape Canaveral Air Force Station, Fla. There they will be mated to the Delta II rocket and the fairing installed around them for protection during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-04PD-2694

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. At Astrotech Space Operations in Titusville, Fla., Boeing technicians attach a crane to the Deep Impact spacecraft in order to move it to the Delta II third stage at left for mating. When the spacecraft and third stage are mated, they will be moved to Launch Pad 17-B at Cape Canaveral Air Force Station, Fla. There they will be mated to the Delta II rocket and the fairing installed around them for protection during launch and ascent. Scheduled for liftoff Jan. 12, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will reveal the secrets of its interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

Mass Redistribution in the Core and Time-varying Gravity at the Earth's Surface

NASA Technical Reports Server (NTRS)

Kuang, Wei-Jia; Chao, Benjamin F.; Fang, Ming

2003-01-01

The Earth's liquid outer core is in convection, as suggested by the existence of the geomagnetic field in much of the Earth's history. One consequence of the convection is the redistribution of mass resulting from relative motion among fluid parcels with slightly different densities. This time dependent mass redistribution inside the core produces a small perturbation on the gravity field of the Earth. With our numerical dynamo solutions, we find that the mass redistribution (and the resultant gravity field) symmetric about the equator is much stronger than that anti-symmetric about the equator. In particular, J(sub 2) component is the strongest. In addition, the gravity field variation increases with the Rayleigh number that measures the driving force for the geodynamo in the core. With reasonable scaling from the current dynamo solutions, we could expect that at the surface of the Earth, the J(sub 2) variation from the core is on the order of l0(exp -16)/year relative to the mean (i.e. spherically symmetric) gravity field of the Earth. The possible shielding effect due to core-mantle boundary pressure variation loading is likely much smaller and is therefore negligible. Our results suggest that time-varying gravity field perturbation due to core mass redistribution may be measured with modem space geodetic observations, which will result a new means of detecting dynamical processes in the Earth's deep interior.

Earth Surface Processes, Landforms and Sediment Deposits

NASA Astrophysics Data System (ADS)

Bridge, John; Demicco, Robert

Earth surface processes, landforms and sediment deposits are intimately related - involving erosion of rocks, generation of sediment, and transport and deposition of sediment through various Earth surface environments. These processes, and the landforms and deposits that they generate, have a fundamental bearing on engineering, environmental and public safety issues; on recovery of economic resources; and on our understanding of Earth history. This unique textbook brings together the traditional disciplines of sedimentology and geomorphology to explain Earth surface processes, landforms and sediment deposits in a comprehensive and integrated way. It is the ideal resource for a two-semester course in sedimentology, stratigraphy, geomorphology, and Earth surface processes from the intermediate undergraduate to beginning graduate level. The book is also accompanied by a website hosting illustrations and material on field and laboratory methods for measuring, describing and analyzing Earth surface processes, landforms and sediments.

Electromagnetic studies of global geodynamic processes

NASA Astrophysics Data System (ADS)

Tarits, Pascal

1994-03-01

The deep electromagnetic sounding (DES) technique is one of the few geophysical methods, along with seismology, gravity, heat flow, which may be use to probe the structure of the Earth's mantle directly. The interpretation of the DESs may provide electrical conductivity profiles down to the upper part of the lower mantle. The electrical conductivity is extremely sensitive to most of the thermodynamic processes we believe are acting in the Earth's mantle (temperature increases, partial melting, phase transition and to a lesser extent pressure). Therefore, in principle, results from DES along with laboratory measurements could be used to constrain models of these processes. The DES technique is reviewed in the light of recent results obtained in a variety of domains: data acquisition and analysis, global induction modeling and data inversion and interpretation. The mechanisms and the importance of surface distortions of the DES data are reviewed and techniques to model them are discussed. The recent results in terms of the conductivity distribution in the mantle from local and global DES are presented and a tentative synthesis is proposed. The geodynamic interpretations of the deep conductivity structures are reviewed. The existence of mantle lateral heterogeneities in conductivity at all scales and depths for which electromagnetic data are available is now well documented. A comparison with global results from seismology is presented.

Groundwater mixing at fracture intersections triggers massive iron-rich microbial mats

NASA Astrophysics Data System (ADS)

Bochet, O.; Le Borgne, T.; Bethencourt, L.; Aquilina, L.; Dufresne, A.; Pédrot, M.; Farasin, J.; Abbott, B. W.; Labasque, T.; Chatton, E.; Lavenant, N.; Petton, C.

2017-12-01

While most freshwater on Earth resides and flows in groundwater systems, these deep subsurface environments are often assumed to have little biogeochemical activity compared to surface environments. Here we report a massive microbial mat of iron-oxidizing bacteria, flourishing 60 meters below the surface, far below the mixing zone where most microbial activity is believed to occur. The abundance of microtubular structures in the mat hinted at the prevalence of of Leptothrix ochracea, but metagenomic analysis revealed a diverse consortium of iron-oxidizing bacteria dominated by unknown members of the Gallionellaceae family. This deep biogeochemical hot spot formed at the intersection of bedrock fractures, which maintain redox gradients by mixing water with different residence times and chemical compositions. Using measured fracture properties and hydrological conditions we developed a quantitative model to simulate the reactive zone where such deep hot spots could occur. While seasonal fluctuations are generally thought to decrease with depth, we found that meter-scale changes in water table level moved the depth of the reactive zone hundreds of meters because the microaerophilic threshold for ironoxidizers is highly sensitive to changes in mixing rates at fracture intersections. These results demonstrate that dynamic microbial communities can be sustained deep below the surface in bedrock fractures. Given the ubiquity of fractures at multiple scales in Earth's subsurface, such deep hot spots may strongly influence global biogeochemical cycles.

KSC-05PD-0128

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. On Launch Pad 17-B, Cape Canaveral Air Force Station, Fla., the Boeing Delta II rocket carrying the Deep Impact spacecraft stands out against an early dawn sky. Scheduled for liftoff at 1:47 p.m. EST today, Deep Impact will head for space and a rendezvous with Comet Tempel 1 when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impacts flyby spacecraft will reveal the secrets of the comets interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0124

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. On Launch Pad 17-B, Cape Canaveral Air Force Station, Fla., the Boeing Delta II rocket carrying the Deep Impact spacecraft is bathed in light waiting for tower rollback before launch. Scheduled for liftoff at 1:47 p.m. EST today, Deep Impact will head for space and a rendezvous with Comet Tempel 1 when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impacts flyby spacecraft will reveal the secrets of the comets interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-04PD-2180

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. At Astrotech Space Operations in Titusville, Fla., Joe Galamback mounts a bracket on a solar panel on the Deep Impact spacecraft. Galamback is a lead mechanic technician with Ball Aerospace and Technologies Corp. in Boulder, Colo. The spacecraft is undergoing verification testing after its long road trip from Colorado.A NASA Discovery mission, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing a 3- by 3- foot projectile to crash onto the surface, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measuring the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. The spacecraft is scheduled to launch Dec. 30, 2004, aboard a Boeing Delta II rocket from Launch Complex 17 at Cape Canaveral Air Force Station, Fla.

DigitalCrust – a 4D data system of material properties for transforming research on crustal fluid flow

USGS Publications Warehouse

Fan, Yin; Richard, Steve; Bristol, R. Sky; Peters, Shanan; Ingebritsen, Steven E.; Moosdorf, Nils; Packman, Aaron I.; Gleeson, Tom; Zazlavsky, Ilya; Peckham, Scott; Murdoch, Larry; Cardiff, Michael; Tarboton, David; Jones, Norm; Hooper, Richard; Arrigo, Jennifer; Gochis, David; Olson, John

2015-01-01

Fluid circulation in the Earth's crust plays an essential role in surface, near surface, and deep crustal processes. Flow pathways are driven by hydraulic gradients but controlled by material permeability, which varies over many orders of magnitude and changes over time. Although millions of measurements of crustal properties have been made, including geophysical imaging and borehole tests, this vast amount of data and information has not been integrated into a comprehensive knowledge system. A community data infrastructure is needed to improve data access, enable large-scale synthetic analyses, and support representations of the subsurface in Earth system models. Here, we describe the motivation, vision, challenges, and an action plan for a community-governed, four-dimensional data system of the Earth's crustal structure, composition, and material properties from the surface down to the brittle–ductile transition. Such a system must not only be sufficiently flexible to support inquiries in many different domains of Earth science, but it must also be focused on characterizing the physical crustal properties of permeability and porosity, which have not yet been synthesized at a large scale. The DigitalCrust is envisioned as an interactive virtual exploration laboratory where models can be calibrated with empirical data and alternative hypotheses can be tested at a range of spatial scales. It must also support a community process for compiling and harmonizing models into regional syntheses of crustal properties. Sustained peer review from multiple disciplines will allow constant refinement in the ability of the system to inform science questions and societal challenges and to function as a dynamic library of our knowledge of Earth's crust.

Riding the Hype Wave: Evaluating new AI Techniques for their Applicability in Earth Science

NASA Astrophysics Data System (ADS)

Ramachandran, R.; Zhang, J.; Maskey, M.; Lee, T. J.

2016-12-01

Every few years a new technology rides the hype wave generated by the computer science community. Converts to this new technology who surface from both the science community and the informatics community promulgate that it can radically improve or even change the existing scientific process. Recent examples of new technology following in the footsteps of "big data" now include deep learning algorithms and knowledge graphs. Deep learning algorithms mimic the human brain and process information through multiple stages of transformation and representation. These algorithms are able to learn complex functions that map pixels directly to outputs without relying on human-crafted features and solve some of the complex classification problems that exist in science. Similarly, knowledge graphs aggregate information around defined topics that enable users to resolve their query without having to navigate and assemble information manually. Knowledge graphs could potentially be used in scientific research to assist in hypothesis formulation, testing, and review. The challenge for the Earth science research community is to evaluate these new technologies by asking the right questions and considering what-if scenarios. What is this new technology enabling/providing that is innovative and different? Can one justify the adoption costs with respect to the research returns? Since nothing comes for free, utilizing a new technology entails adoption costs that may outweigh the benefits. Furthermore, these technologies may require significant computing infrastructure in order to be utilized effectively. Results from two different projects will be presented along with lessons learned from testing these technologies. The first project primarily evaluates deep learning techniques for different applications of image retrieval within Earth science while the second project builds a prototype knowledge graph constructed for Hurricane science.

Two radars for AIM mission: A direct observation of the asteroid's structure from deep interior to regolith

NASA Astrophysics Data System (ADS)

Herique, A.; Ciarletti, V.

2015-10-01

Our knowledge of the internal structure of asteroids is, so far, indirect - relying entirely on inferences from remote sensing observations of the surface, and theoretical modeling. What are the bulk properties of the regolith and deep interior? And what are the physical processes that shape their internal structures? Direct measurements are needed to provide answers that will directly improve our ability to understand and model the mechanisms driving Near Earth Asteroids (NEA) for the benefit of science as well as for planetary defense or exploration. Radar tomography is the only technique to characterize internal structure from decimetric scale to global scale. This paper reviews the benefits of direct measurement of the asteroid interior. Then the radar concepts for both deep interior and shallow subsurface are presented and the radar payload proposed for the AIDA/AIM mission is outlined.

Water-rich planets: How habitable is a water layer deeper than on Earth?

NASA Astrophysics Data System (ADS)

Noack, L.; Höning, D.; Rivoldini, A.; Heistracher, C.; Zimov, N.; Journaux, B.; Lammer, H.; Van Hoolst, T.; Bredehöft, J. H.

2016-10-01

Water is necessary for the origin and survival of life as we know it. In the search for life-friendly worlds, water-rich planets therefore are obvious candidates and have attracted increasing attention in recent years. The surface H2O layer on such planets (containing a liquid water ocean and possibly high-pressure ice below a specific depth) could potentially be hundreds of kilometres deep depending on the water content and the evolution of the proto-atmosphere. We study possible constraints for the habitability of deep water layers and introduce a new habitability classification relevant for water-rich planets (from Mars-size to super-Earth-size planets). A new ocean model has been developed that is coupled to a thermal evolution model of the mantle and core. Our interior structure model takes into account depth-dependent thermodynamic properties and the possible formation of high-pressure ice. We find that heat flowing out of the silicate mantle can melt an ice layer from below (in some cases episodically), depending mainly on the thickness of the ocean-ice shell, the mass of the planet, the surface temperature and the interior parameters (e.g. radioactive mantle heat sources). The high pressure at the bottom of deep water-ice layers could also impede volcanism at the water-mantle boundary for both stagnant lid and plate tectonics silicate shells. We conclude that water-rich planets with a deep ocean, a large planet mass, a high average density or a low surface temperature are likely less habitable than planets with an Earth-like ocean.

Evidence for Primordial Water in Earths Deep Mantle: D/h Ratios in Baffin Island and Icelandic Picrites

NASA Astrophysics Data System (ADS)

Hallis, L. J.; Huss, G. R.; Nagashima, K.; Taylor, J.; Hilton, D. R.; Mottl, M. J.; Meech, K. J.; Halldorsson, S. A.

2016-12-01

Experimentally based chemical models suggest Jeans escape could have caused an increase in Earth's atmospheric D/H ratio of between a factor of 2 and 9 since the planets formation1. Plate tectonic mixing ensures this change has been incorporated into the mantle. In addition, collisions with hydrogen bearing planetesimals or cometary material after Earth's accretion could have altered the D/H ratio of the planet's surface and upper mantle2. Therefore, to determine Earth's original D/H ratio, a reservoir that has been completely unaffected by these surface and upper mantle changes is required. Most studies suggest that high 3He/4He ratios in some OIBs indicate the existence of relatively undegassed regions in the deep mantle compared to the upper mantle, which retain a greater proportion of their primordial He3-4. Early Tertiary (60-million-year-old) picrites from Baffin Island and west Greenland, which represent volcanic rocks from the proto/early Iceland mantle plume, contain the highest recorded terrestrial 3He/4He ratios3-4. These picrites also have Pb and Nd isotopic ratios consistent with primordial mantle ages (4.45 to 4.55 Ga)5, indicating the persistence of an ancient, isolated reservoir in the mantle. The undegassed and primitive nature6of this reservoir suggests that it could preserve Earth's initial D/H ratio. We measured the D/H ratios of olivine-hosted glassy melt inclusions in Baffin Island and Icelandic picrites to establish whether their deep mantle source region exhibits a different D/H ratio to known upper mantle and surface reservoirs. Baffin Island D/H ratios were found to extend lower than any previously measured mantle values (δD -97 to -218 ‰), suggesting that areas of the deep mantle do preserve a more primitive hydrogen reservoir, hence are unaffected by plate tectonic mixing. Comparing our measured low D/H ratios to those of known extra-terrestrial materials can help determine where Earths water came from. References: [1] Genda and Ikoma, 2008 Icarus 194, 42-52. [2] Abramov, and Mojzsis, (2009) Nature 459, 419-422. [3] Stuart et al. (2003) Nature 424, 57-59. [4] Starkey et al. (2009) Earth Planet. Sci. Lett. 277, 91-100. [5] Jackson et al. (2010) Nature 466, 853-856. [6] Robillard et al. (1992) Contrib. Mineral. Petrol. 112, 230-241.

EPIC Radiance Simulator for Deep Space Climate ObserVatoRy (DSCOVR)

NASA Technical Reports Server (NTRS)

Lyapustin, Alexei; Marshak, Alexander; Wang, Yujie; Korkin, Sergey; Herman, Jay

2011-01-01

The Deep Space Climate ObserVatoRy (DSCOVR) is a planned space weather mission for the Sun and Earth observations from the Lagrangian L1 point. Onboard of DSCOVR is a multispectral imager EPIC designed for unique observations of the full illuminated disk of the Earth with high temporal and 10 km spatial resolution. Depending on latitude, EPIC will observe the same Earth surface area during the course of the day in a wide range of solar and view zenith angles in the backscattering view geometry with the scattering angle of 164-172 . To understand the information content of EPIC data for analysis of the Earth clouds, aerosols and surface properties, an EPIC radiance Simulator was developed covering the UV -VIS-NIR range including the oxygen A and B-bands (A=340, 388, 443, 555, 680, 779.5, 687.7, 763.3 nm). The Simulator uses ancillary data (surface pressure/height, NCEP wind speed) as well as MODIS-based geophysical fields such as spectral surface bidirectional reflectance, column water vapor, and properties of aerosols and clouds including optical depth, effective radius, phase and cloud top height. The original simulations are conducted at 1 km resolution using the look-up table approach and then are averaged to 10 km EPIC radiances. This talk will give an overview of the EPIC Simulator with analysis of results over the continental USA and northern Atlantic.

Geothermal pump down-hole energy regeneration system

DOEpatents

Matthews, Hugh B.

1982-01-01

Geothermal deep well energy extraction apparatus is provided of the general kind in which solute-bearing hot water is pumped to the earth's surface from a subterranean location by utilizing thermal energy extracted from the hot water for operating a turbine motor for driving an electrical power generator at the earth 3 s surface, the solute bearing water being returned into the earth by a reinjection well. Efficiency of operation of the total system is increased by an arrangement of coaxial conduits for greatly reducing the flow of heat from the rising brine into the rising exhaust of the down-well turbine motor.

KSC-05PD-0133

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. From the nearby Press Site at Cape Canaveral Air Force Station, Fla., photographers capture the exciting launch of the Deep Impact spacecraft at 1:47 p.m. EST. A NASA Discovery mission, Deep Impact is heading for space and a rendezvous 83 million miles from Earth with Comet Tempel 1. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impacts flyby spacecraft will reveal the secrets of the comets interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network.

KSC-05PD-0134

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Erupting from the flames and smoke beneath it, NASAs Deep Impact spacecraft lifts off at 1:47 p.m. EST today from Launch Pad 17-B, Cape Canaveral Air Force Station, Fla. A NASA Discovery mission, Deep Impact is heading for space and a rendezvous 83 million miles from Earth with Comet Tempel 1. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impacts flyby spacecraft will reveal the secrets of the comets interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network.

KSC-05PD-0131

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Erupting from the flames and smoke beneath it, NASAs Deep Impact spacecraft lifts off at 1:47 p.m. EST today from Launch Pad 17-B, Cape Canaveral Air Force Station, Fla. A NASA Discovery mission, Deep Impact is heading for space and a rendezvous 83 million miles from Earth with Comet Tempel 1. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impacts flyby spacecraft will reveal the secrets of the comets interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network.

KSC-05PD-0135

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Erupting from the flames and smoke beneath it, NASAs Deep Impact spacecraft lifts off at 1:47 p.m. EST today from Launch Pad 17-B, Cape Canaveral Air Force Station, Fla. A NASA Discovery mission, Deep Impact is heading for space and a rendezvous 83 million miles from Earth with Comet Tempel 1. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impacts flyby spacecraft will reveal the secrets of the comets interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network.

KSC-05PD-0136

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Engulfed by flames and smoke, NASAs Deep Impact spacecraft lifts off at 1:47 p.m. EST today from Launch Pad 17-B, Cape Canaveral Air Force Station, Fla. A NASA Discovery mission, Deep Impact is heading for space and a rendezvous 83 million miles from Earth with Comet Tempel 1. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impacts flyby spacecraft will reveal the secrets of the comets interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network.

KSC-05PD-0130

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. With a burst of flames, NASAs Deep Impact spacecraft lifts off at 1:47 p.m. EST today from Launch Pad 17-B, Cape Canaveral Air Force Station, Fla. A NASA Discovery mission, Deep Impact is heading for space and a rendezvous 83 million miles from Earth with Comet Tempel 1. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impacts flyby spacecraft will reveal the secrets of the comets interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network.

“Points requiring elucidation” about Hawaiian volcanism: Chapter 24

USGS Publications Warehouse

Poland, Michael P.; Carey, Rebecca; Cayol, Valérie; Poland, Michael P.; Weis, Dominique

2015-01-01

Hawaiian volcanoes, which are easily accessed and observed at close range, are among the most studied on the planet and have spurred great advances in the geosciences, from understanding deep Earth processes to forecasting volcanic eruptions. More than a century of continuous observation and study of Hawai‘i's volcanoes has also sharpened focus on those questions that remain unanswered. Although there is good evidence that volcanism in Hawai‘i is the result of a high-temperature upwelling plume from the mantle, the source composition and dynamics of the plume are controversial. Eruptions at the surface build the volcanoes of Hawai‘i, but important topics, including how the volcanoes grow and collapse and how magma is stored and transported, continue to be subjects of intense research. Forecasting volcanic activity is based mostly on pattern recognition, but determining and predicting the nature of eruptions, especially in serving the critical needs of hazards mitigation, require more realistic models and a greater understanding of what drives eruptive activity. These needs may be addressed by better integration among disciplines as well as by developing dynamic physics- and chemistry-based models that more thoroughly relate the physiochemical behavior of Hawaiian volcanism, from the deep Earth to the surface, to geological, geochemical, and geophysical data.

Spatially Resolved Chemical Imaging for Biosignature Analysis: Terrestrial and Extraterrestrial Examples

NASA Astrophysics Data System (ADS)

Bhartia, R.; Wanger, G.; Orphan, V. J.; Fries, M.; Rowe, A. R.; Nealson, K. H.; Abbey, W. J.; DeFlores, L. P.; Beegle, L. W.

2014-12-01

Detection of in situ biosignatures on terrestrial and planetary missions is becoming increasingly more important. Missions that target the Earth's deep biosphere, Mars, moons of Jupiter (including Europa), moons of Saturn (Titan and Enceladus), and small bodies such as asteroids or comets require methods that enable detection of materials for both in-situ analysis that preserve context and as a means to select high priority sample for return to Earth. In situ instrumentation for biosignature detection spans a wide range of analytical and spectroscopic methods that capitalize on amino acid distribution, chirality, lipid composition, isotopic fractionation, or textures that persist in the environment. Many of the existing analytical instruments are bulk analysis methods and while highly sensitive, these require sample acquisition and sample processing. However, by combining with triaging spectroscopic methods, biosignatures can be targeted on a surface and preserve spatial context (including mineralogy, textures, and organic distribution). To provide spatially correlated chemical analysis at multiple spatial scales (meters to microns) we have employed a dual spectroscopic approach that capitalizes on high sensitivity deep UV native fluorescence detection and high specificity deep UV Raman analysis.. Recently selected as a payload on the Mars 2020 mission, SHERLOC incorporates these optical methods for potential biosignatures detection on Mars. We present data from both Earth analogs that operate as our only examples known biosignatures and meteorite samples that provide an example of abiotic organic formation, and demonstrate how provenance effects the spatial distribution and composition of organics.

Subsurface microbial habitats on Mars

NASA Technical Reports Server (NTRS)

Boston, P. J.; Mckay, C. P.

1991-01-01

We developed scenarios for shallow and deep subsurface cryptic niches for microbial life on Mars. Such habitats could have considerably prolonged the persistence of life on Mars as surface conditions became increasingly inhospitable. The scenarios rely on geothermal hot spots existing below the near or deep subsurface of Mars. Recent advances in the comparatively new field of deep subsurface microbiology have revealed previously unsuspected rich aerobic and anaerobic microbal communities far below the surface of the Earth. Such habitats, protected from the grim surface conditions on Mars, could receive warmth from below and maintain water in its liquid state. In addition, geothermally or volcanically reduced gases percolating from below through a microbiologically active zone could provide the reducing power needed for a closed or semi-closed microbial ecosystem to thrive.

Numerical modelling of volatiles in the deep mantle

NASA Astrophysics Data System (ADS)

Eichheimer, Philipp; Thielmann, Marcel; Golabek, Gregor J.

2017-04-01

The transport and storage of water in the mantle significantly affects several material properties of mantle rocks and thus water plays a key role in a variety of geodynamical processes (tectonics, magmatism etc.). The processes driving transport and circulation of H2O in subduction zones remain a debated topic. Geological and seismological observations suggest different inflow mechanisms of water e.g. slab bending, thermal cracking and serpentinization (Faccenda et al., 2009; Korenaga, 2017), followed by dehydration of the slab. On Earth both shallow and steep subduction can be observed (Li et al., 2011). However most previous models (van Keken et al., 2008; Wilson et al., 2014) did not take different dip angles and subduction velocities of slabs into account. To which extent these parameters and processes influence the inflow of water still remains unclear. We present 2D numerical models simulating the influence of the various water inflow mechanisms on the mantle with changing dip angle and subduction velocity of the slab over time. The results are used to make predictions regarding the rheological behavior of the mantle wedge, dehydration regimes and volcanism at the surface. References: van Keken, P. E., et al. A community benchmark for subduction zone modeling. Phys. Earth Planet. Int. 171, 187-197 (2008). Faccenda, M., T.V. Gerya, and L. Burlini. Deep slab hydration induced by bending-related variations in tectonic pressure. Nat. Geosci. 2, 790-793 (2009). Korenaga, J. On the extent of mantle hydration caused by plate bending. Earth Planet. Sci. Lett. 457, 1-9 (2017). Wilson, C. R., et al. Fluid flow in subduction zones: The role of solid rheology and compaction pressure. Earth Planet. Sci. Lett. 401, 261-274 (2014). Li, Z. H., Z. Q. Xu, and T. V. Gerya. Flat versus steep subduction: Contrasting modes for the formation and exhumation of high- to ultrahigh-pressure rocks in continental collision zones. Earth Planet. Sci. Lett. 301, 65-77 (2011).

The origin, source, and cycling of methane in deep crystalline rock biosphere.

PubMed

Kietäväinen, Riikka; Purkamo, Lotta

2015-01-01

The emerging interest in using stable bedrock formations for industrial purposes, e.g., nuclear waste disposal, has increased the need for understanding microbiological and geochemical processes in deep crystalline rock environments, including the carbon cycle. Considering the origin and evolution of life on Earth, these environments may also serve as windows to the past. Various geological, chemical, and biological processes can influence the deep carbon cycle. Conditions of CH4 formation, available substrates and time scales can be drastically different from surface environments. This paper reviews the origin, source, and cycling of methane in deep terrestrial crystalline bedrock with an emphasis on microbiology. In addition to potential formation pathways of CH4, microbial consumption of CH4 is also discussed. Recent studies on the origin of CH4 in continental bedrock environments have shown that the traditional separation of biotic and abiotic CH4 by the isotopic composition can be misleading in substrate-limited environments, such as the deep crystalline bedrock. Despite of similarities between Precambrian continental sites in Fennoscandia, South Africa and North America, where deep methane cycling has been studied, common physicochemical properties which could explain the variation in the amount of CH4 and presence or absence of CH4 cycling microbes were not found. However, based on their preferred carbon metabolism, methanogenic microbes appeared to have similar spatial distribution among the different sites.

The origin, source, and cycling of methane in deep crystalline rock biosphere

PubMed Central

Kietäväinen, Riikka; Purkamo, Lotta

2015-01-01

The emerging interest in using stable bedrock formations for industrial purposes, e.g., nuclear waste disposal, has increased the need for understanding microbiological and geochemical processes in deep crystalline rock environments, including the carbon cycle. Considering the origin and evolution of life on Earth, these environments may also serve as windows to the past. Various geological, chemical, and biological processes can influence the deep carbon cycle. Conditions of CH4 formation, available substrates and time scales can be drastically different from surface environments. This paper reviews the origin, source, and cycling of methane in deep terrestrial crystalline bedrock with an emphasis on microbiology. In addition to potential formation pathways of CH4, microbial consumption of CH4 is also discussed. Recent studies on the origin of CH4 in continental bedrock environments have shown that the traditional separation of biotic and abiotic CH4 by the isotopic composition can be misleading in substrate-limited environments, such as the deep crystalline bedrock. Despite of similarities between Precambrian continental sites in Fennoscandia, South Africa and North America, where deep methane cycling has been studied, common physicochemical properties which could explain the variation in the amount of CH4 and presence or absence of CH4 cycling microbes were not found. However, based on their preferred carbon metabolism, methanogenic microbes appeared to have similar spatial distribution among the different sites. PMID:26236303

Earth's gravity field to the eighteenth degree and geocentric coordinates for 104 stations from satellite and terrestrial data

NASA Technical Reports Server (NTRS)

Gaposchkin, E. M.

1973-01-01

Geodetic parameters describing the earth's gravity field and the positions of satellite-tracking stations in a geocentric reference frame were computed. These parameters were estimated by means of a combination of five different types of data: routine and simultaneous satellite observations, observations of deep-space probes, measurements of terrestrial gravity, and surface-triangulation data. The combination gives better parameters than does any subset of data types. The dynamic solution used precision-reduced Baker-Nunn observations and laser range data of 25 satellites. Data from the 49-station National Oceanic and Atmospheric Administration BC-4 network, the 19-station Smithsonian Astrophysical Observatory Baker-Nunn network, and independent camera stations were employed in the geometrical solution. Data from the tracking of deep-space probes were converted to relative longitudes and distances to the earth's axis of rotation of the tracking stations. Surface-gravity data in the form of 550-km squares were derived from 19,328 1 deg X 1 deg mean gravity anomalies.

Mo isotope record of shales points to deep ocean oxygenation in the early Paleoproterozoic

NASA Astrophysics Data System (ADS)

Asael, Dan; Scott, Clint; Rouxel, Olivier; Poulton, Simon; Lyons, Timothy; Javaux, Emmanuelle; Bekker, Andrey

2014-05-01

Two steps in Earth's surface oxidation lie at either end of the Proterozoic Eon. The first step, known as the Great Oxidation Event (GOE), occurred at ca. 2.32 Ga (1), when atmospheric oxygen first exceeded 0.001% of present atmospheric levels (2). The second step, occurred at ca. 0.58 Ga, resulting in the pervasive oxygenation of the deep oceans, a feature that persisted through most of the Phanerozoic (3). The conventional model envisions two progressive and unidirectional increases in free oxygen. However, recent studies have challenged this simplistic view of the GOE (4, 5). A dramatic increase and decline in Earth oxidation state between 2.3 and 2.0 Ga is now well supported (6-9) and raises the question of how well-oxygenated the Earth surface was in the immediate aftermath of the GOE. In order to constrain the response of the deep oceans to the GOE, we present a study of Mo isotope composition and Mo concentration from three key early Paleoproterozoic black shale units with ages ranging from 2.32 to 2.06 Ga. Our results suggest high and unstable surface oxygen levels at 2.32 Ga, leading to an abrupt increase in Mo supply to the still globally anoxic ocean, and producing extreme seawater Mo isotopic enrichments in these black shales. We thus infer a period of significant Mo isotopic Rayleigh effects and non-steady state behaviour of the Mo oceanic system at the beginning of the GOE. Between 2.2-2.1 Ga, we observe smaller Mo isotopic variations and estimate the δ98Mo of seawater to be 1.42 ± 0.27 ‰W conclude that oxygen levels must have stabilized at a relatively high level and that the deep oceans were oxygenated for the first time in Earth's history. By ca. 2.06 Ga, immediately after the Lomagundi Event, the Mo isotopic composition decreased dramatically to δ98MoSW = 0.80 ± 0.21 o reflecting the end of deep ocean oxygenation and the return of largely anoxic deep oceans. References: [1] A. Bekker et al., 2004, Nature 427, 117-20. [2] A. Pavlov and J. Kasting, 2002, Astrobiology 2, 27-41. [3] C. Scott et al., 2008, Nature 452, 456-9. [4] C. Goldblatt et al., 2006, Nature 443, 683-6. [5] L. Kump et al., 2011, Science 334, 1694-6. [6] A. Bekker and D. Holland, 2012, Earth Planet. Sci. Lett. 317-318, 295-304. [7] N. Planavsky et al., 2012, Proc. Natl. Acad. Sci. U. S. A. 109, 18300-5. [8] C. Partin et al., 2013, Chem. Geol. 362, 82-90. [9] C. Scott et al., 2014, Earth Planet. Sci. Lett. 389, 95-104.

Archaeology of Archaea: geomicrobiological record of Pleistocene thermal events concealed in a deep-sea subseafloor environment.

PubMed

Inagaki, F; Takai, K; Komatsu, T; Kanamatsu, T; Fujioka, K; Horikoshi, K

2001-12-01

A record of the history of the Earth is hidden in the Earth's crust, like the annual rings of an old tree. From very limited records retrieved from deep underground, one can infer the geographical, geological, and biological events that occurred throughout Earth's history. Here we report the discovery of vertically shifted community structures of Archaea in a typical oceanic subseafloor core sample (1410 cm long) recovered from the West Philippine Basin at a depth of 5719 m. Beneath a surface community of ubiquitous deep-sea archaea (marine crenarchaeotic group I; MGI), an unusual archaeal community consisting of extremophilic archaea, such as extreme halophiles and hyperthermophiles, was present. These organisms could not be cultivated, and may be microbial relicts more than 2 million years old. Our discovery of archaeal rDNA in this core sample, probably associated with the past terrestrial volcanic and submarine hydrothermal activities surrounding the West Philippine Basin, serves as potential geomicrobiological evidence reflecting novel records of geologic thermal events in the Pleistocene period concealed in the deep-sea subseafloor.

MX Siting Investigation. Geotechnical Siting Status Report. Volume 2.

DTIC Science & Technology

1978-06-21

greater tnan a nominal 50 feet deep. Rock is considered any earth material which is not readily rippable by conventional excavation techniques. b. Surface...material which is not readily rippable by conventional excavation techniques. _ b. Surface water absent and occurrences of ground water greater than a

The Deep Space Gateway Lightning Mapper (DLM) - Monitoring Global Change and Thunderstorm Processes Through Observations of Earth's High-Latitude Lightning from Cis-Lunar Orbit

NASA Technical Reports Server (NTRS)

Lang, Timothy; Blakeslee, R. J.; Cecil, D. J.; Christian, H. J.; Gatlin, P. N.; Goodman, S. J.; Koshak, W. J.; Petersen, W. A.; Quick, M.; Schultz, C. J.;

Ka-band (32 GHz) allocations for deep space

NASA Technical Reports Server (NTRS)

Degroot, N. F.

1987-01-01

At the 1979 World Administrative Conference, two new bands were allocated for deep space telecommunications: 31.8 to 32.3 GHz, space-to-Earth, and 34.2 to 34.7 GHz, Earth-to-space. These bands provide opportunity for further development of the Deep Space Network and its support of deep space research. The history of the process by which JPL/NASA developed the rationale, technical background, and statement of requirement for the bands are discussed. Based on this work, United States proposals to the conference included the bands, and subsequent U.S. and NASA participation in the conference led to successful allocations for deep space telecommunications in the 30 GHz region of the spectrum. A detailed description of the allocations is included.

The Greenhouse Effect and Built Environment Education.

ERIC Educational Resources Information Center

Greenall Gough, Annette; Gough, Noel

The greenhouse effect has always existed. Without the greenhouse effect, Earth could well have the oven-like environment of Venus or the deep-freeze environment of Mars. There is some debate about how much the Earth's surface temperature will rise given a certain amount of increase in the amount of greenhouse gases such as carbon dioxide, nitrous…

Rare earth element geochemistry characteristics of seawater and porewater from deep sea in western Pacific.

PubMed

Deng, Yinan; Ren, Jiangbo; Guo, Qingjun; Cao, Jun; Wang, Haifeng; Liu, Chenhui

2017-11-28

Deep-sea sediments contain high concentrations of rare earth element (REE) which have been regarded as a huge potential resource. Understanding the marine REE cycle is important to reveal the mechanism of REE enrichment. In order to determine the geochemistry characteristics and migration processes of REE, seawater, porewater and sediment samples were systematically collected from the western Pacific for REE analysis. The results show a relatively flat REE pattern and the HREE (Heavy REE) enrichment in surface and deep seawater respectively. The HREE enrichment distribution patterns, low concentrations of Mn and Fe and negative Ce anomaly occur in the porewater, and high Mn/Al ratios and low U concentrations were observed in sediment, indicating oxic condition. LREE (Light REE) and MREE (Middle REE) enrichment in upper layer and depletion of MREE in deeper layer were shown in porewater profile. This study suggests that porewater flux in the western Pacific basin is a minor source of REEs to seawater, and abundant REEs are enriched in sediments, which is mainly caused by the extensive oxic condition, low sedimentation rate and strong adsorption capacity of sediments. Hence, the removal of REEs of porewater may result in widespread REE-rich sediments in the western Pacific basin.

Earthquake prediction using extinct monogenetic volcanoes: A possible new research strategy

NASA Astrophysics Data System (ADS)

Szakács, Alexandru

2011-04-01

Volcanoes are extremely effective transmitters of matter, energy and information from the deep Earth towards its surface. Their capacities as information carriers are far to be fully exploited so far. Volcanic conduits can be viewed in general as rod-like or sheet-like vertical features with relatively homogenous composition and structure crosscutting geological structures of far more complexity and compositional heterogeneity. Information-carrying signals such as earthquake precursor signals originating deep below the Earth surface are transmitted with much less loss of information through homogenous vertically extended structures than through the horizontally segmented heterogeneous lithosphere or crust. Volcanic conduits can thus be viewed as upside-down "antennas" or waveguides which can be used as privileged pathways of any possible earthquake precursor signal. In particular, conduits of monogenetic volcanoes are promising transmitters of deep Earth information to be received and decoded at surface monitoring stations because the expected more homogenous nature of their rock-fill as compared to polygenetic volcanoes. Among monogenetic volcanoes those with dominantly effusive activity appear as the best candidates for privileged earthquake monitoring sites. In more details, effusive monogenetic volcanic conduits filled with rocks of primitive parental magma composition indicating direct ascent from sub-lithospheric magma-generating areas are the most suitable. Further selection criteria may include age of the volcanism considered and the presence of mantle xenoliths in surface volcanic products indicating direct and straightforward link between the deep lithospheric mantle and surface through the conduit. Innovative earthquake prediction research strategies can be based and developed on these grounds by considering conduits of selected extinct monogenetic volcanoes and deep trans-crustal fractures as privileged emplacement sites of seismic monitoring stations using an assemblage of physical, chemical and biological sensors devised to detect precursory signals. Earthquake prediction systems can be built up based on the concept of a signal emission-transmission-reception system, in which volcanic conduits and/or deep fractures play the role of the most effective signal transmission paths through the lithosphere. Unique "precursory fingerprints" of individual seismic structures are expected to be pointed out as an outcome of target-oriented strategic prediction research. Intelligent pattern-recognition systems are to be included for evaluation of the signal assemblages recorded by complex sensor arrays. Such strategies are expected however to be limited to intermediate-depth and deep seismic structures. Due to its particular features and geotectonic setting, the Vrancea seismic structure in Romania appears to be an excellent experimental target for prediction research.

Preface to "Insights into the Earth's Deep Lithosphere"

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pasyanos, M E

Dear Readers: I am pleased to present a special issue of Tectonophysics entitled 'Insights into the Earth's Deep Lithosphere.' This compilation sought to capture the flavor of the increasing number of studies that are emerging to investigate the complex lithospheric structure of the earth. This issue evolved out of a Fall 2007 AGU special session entitled 'Understanding the Earth's Deep Lithosphere' that I organized with Irina Artemieva from the University of Copenhagen. For that session, we solicited talks that discussed the increasing number of methods that have surfaced to study various aspects of the earth's deep lithosphere. These methods includemore » seismic, gravity, thermal, geochemical, and various combinations of these methods. The quality of the presentations (2 oral sessions with 16 talks and 23 associated poster presentations) was such that we felt that the emerging topic deserved a dedicated forum to address these questions in greater detail. The availability of new data sets has also improved the number and quality of lithospheric studies. With many new studies and methodologies, a better understanding of both continental and oceanic lithospheres is starting to emerge. Questions remain about the thickness and evolution of the lithosphere, the presence of lithospheric keels, the density and anisotropy of lithospheric roots, mechanisms of lithospheric thinning, and differences between mechanical, thermal and chemical boundary layers. While we did not get contributions on the full gamut of methods and regions, a lot of ground was covered in this issue's manuscripts. Like any collection of papers on the deep lithosphere, the topics are quite varied in methodology, geographic location, and what aspect of the lithosphere being studied. Still, the results highlight the rewarding aspects of earth structure, history, and evolution that can be gleaned. A brief synopsis of the papers contained in this issue is given.« less

The primary solar-type atmosphere surrounding the accreting Earth: H2O-induced high surface temperature.

NASA Astrophysics Data System (ADS)

Sasaki, S.

In the solar nebula, a growing planet attracts ambient gas to form a solar-type atmosphere. The structure of this H2-He atmosphere is calculated assuming the Earth was formed in the nebula. The blanketing effect of the atmosphere renders the planetary surface molten when the planetary mass exceeds 0.2 ME (ME being the present Earth's mass). Reduction of the surface melt by atmospheric H2 should add a large amount of H2O to the atmosphere: under the quartz-iron-fayalite oxygen buffer, partial pressure ratio P(H2O)/P(H2) becomes higher than 0.1. Enhancing opacity and gas mean molecular weight, the excess H2O raises the temperature and renders the atmosphere in convective equilibrium, while the dissociation of H2 suppresses the adiabatic temperature gradient. The surface temperature of the proto-Earth can be as high as 4700K when its mass is 1 ME. Such a high temperature may accelerate the evaporation of surface materials. A deep totally-molten magma ocean should exist in the accretion Earth.

KSC-05PP-0138

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Emerging through the smoke and steam, the Boeing Delta II rocket carrying NASAs Deep Impact spacecraft lifts off at 1:47 p.m. EST from Launch Pad 17-B, Cape Canaveral Air Force Station, Fla. A NASA Discovery mission, Deep Impact is heading for space and a rendezvous 83 million miles from Earth with Comet Tempel 1. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impacts flyby spacecraft will reveal the secrets of the comets interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network.

KSC-05PD-0137

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. After a perfect liftoff at 1:47 p.m. EST today from Launch Pad 17-B, Cape Canaveral Air Force Station, Fla., the Boeing Delta II rocket with Deep Impact spacecraft aboard soars through the clear blue sky. A NASA Discovery mission, Deep Impact is heading for space and a rendezvous 83 million miles from Earth with Comet Tempel 1. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impacts flyby spacecraft will reveal the secrets of the comets interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network.

KSC-05pp0138

NASA Image and Video Library

2005-01-12

KENNEDY SPACE CENTER, FLA. - Emerging through the smoke and steam, the Boeing Delta II rocket carrying NASA’s Deep Impact spacecraft lifts off at 1:47 p.m. EST from Launch Pad 17-B, Cape Canaveral Air Force Station, Fla. A NASA Discovery mission, Deep Impact is heading for space and a rendezvous 83 million miles from Earth with Comet Tempel 1. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impact’s flyby spacecraft will reveal the secrets of the comet’s interior by collecting pictures and data of how the crater forms, measuring the crater’s depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network.

KSC-05PD-0132

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Guests of NASA gather near the launch site at Cape Canaveral Air Force Station, Fla., to watch the Deep Impact spacecraft as it speeds through the air after a perfect launch at 1:47 p.m. EST. A NASA Discovery mission, Deep Impact is heading for space and a rendezvous 83 million miles from Earth with Comet Tempel 1. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impacts flyby spacecraft will reveal the secrets of the comets interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network.

KSC-04PD-2460

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. On Launch Pad 17-B at Cape Canaveral Air Force Station, the second stage of the Boeing Delta II rocket arrives at the top of the mobile service tower. The element will be mated to the Delta II, which will launch NASAs Deep Impact spacecraft. A NASA Discovery mission, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing an impactor on a course to hit the comets sunlit side, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measure the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determine the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network.

Deep Impact: 19 gigajoules can make quite an impression

NASA Technical Reports Server (NTRS)

Kubitschek, D.; Bank, T.; Frazier, W.; Blume, W.; Null, G.; Mastrodemos, N.; Synnott, S.

2001-01-01

Deep Impact will impact the comet Tempel-1 on July 4, 2005. The impact event will be clearly visible from small telescopes on Earth, especially in the IR bands. When combined with observations taken from the Flyby spacecraft, this science data set will provide unique insight into the materials and structure within the comet, and the strength of the surface.

The Mothership Mission Architecture

NASA Astrophysics Data System (ADS)

Ernst, S. M.; DiCorcia, J. D.; Bonin, G.; Gump, D.; Lewis, J. S.; Foulds, C.; Faber, D.

2015-12-01

The Mothership is considered to be a dedicated deep space carrier spacecraft. It is currently being developed by Deep Space Industries (DSI) as a mission concept that enables a broad participation in the scientific exploration of small bodies - the Mothership mission architecture. A Mothership shall deliver third-party nano-sats, experiments and instruments to Near Earth Asteroids (NEOs), comets or moons. The Mothership service includes delivery of nano-sats, communication to Earth and visuals of the asteroid surface and surrounding area. The Mothership is designed to carry about 10 nano-sats, based upon a variation of the Cubesat standard, with some flexibility on the specific geometry. The Deep Space Nano-Sat reference design is a 14.5 cm cube, which accommodates the same volume as a traditional 3U CubeSat. To reduce cost, Mothership is designed as a secondary payload aboard launches to GTO. DSI is offering slots for nano-sats to individual customers. This enables organizations with relatively low operating budgets to closely examine an asteroid with highly specialized sensors of their own choosing and carry out experiments in the proximity of or on the surface of an asteroid, while the nano-sats can be built or commissioned by a variety of smaller institutions, companies, or agencies. While the overall Mothership mission will have a financial volume somewhere between a European Space Agencies' (ESA) S- and M-class mission for instance, it can be funded through a number of small and individual funding sources and programs, hence avoiding the processes associated with traditional space exploration missions. DSI has been able to identify a significant interest in the planetary science and nano-satellite communities.

KSC-05PD-0126

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. On Launch Pad 17-B, Cape Canaveral Air Force Station, Fla., shadows paint the Boeing Delta II rocket carrying the Deep Impact spacecraft as the mobile service tower at left is rolled back before launch.Scheduled for liftoff at 1:47 p.m. EST today, Deep Impact will head for space and a rendezvous with Comet Tempel 1 when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impacts flyby spacecraft will reveal the secrets of the comets interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0125

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. On Launch Pad 17-B, Cape Canaveral Air Force Station, Fla., the Boeing Delta II rocket carrying the Deep Impact spacecraft looms into the night sky as the mobile service tower at right is rolled back before launch. Scheduled for liftoff at 1:47 p.m. EST today, Deep Impact will head for space and a rendezvous with Comet Tempel 1 when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impacts flyby spacecraft will reveal the secrets of the comets interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0127

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. On Launch Pad 17-B, Cape Canaveral Air Force Station, Fla., the Boeing Delta II carrying the Deep Impact spacecraft rocket shines under spotlights in the early dawn hours as it waits for launch. Scheduled for liftoff at 1:47 p.m. EST today, Deep Impact will head for space and a rendezvous with Comet Tempel 1 when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impacts flyby spacecraft will reveal the secrets of the comets interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

KSC-05PD-0129

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. The sun rises behind Launch Pad 17-B, Cape Canaveral Air Force Station, Fla., where the Boeing Delta II rocket carrying the Deep Impact spacecraft waits for launch. Gray clouds above the horizon belie the favorable weather forecast for the afternoon launch. Scheduled for liftoff at 1:47 p.m. EST today, Deep Impact will head for space and a rendezvous with Comet Tempel 1 when the comet is 83 million miles from Earth. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface July 4, 2005, Deep Impacts flyby spacecraft will reveal the secrets of the comets interior by collecting pictures and data of how the crater forms, measuring the craters depth and diameter as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network. Deep Impact is a NASA Discovery mission.

Mitigating Climate Change with Ocean Pipes: Influencing Land Temperature and Hydrology and Termination Overshoot Risk

NASA Astrophysics Data System (ADS)

Kwiatkowski, L.; Caldeira, K.; Ricke, K.

2014-12-01

With increasing risk of dangerous climate change geoengineering solutions to Earth's climate problems have attracted much attention. One proposed geoengineering approach considers the use of ocean pipes as a means to increase ocean carbon uptake and the storage of thermal energy in the deep ocean. We use a latest generation Earth System Model (ESM) to perform simulations of idealised extreme implementations of ocean pipes. In our simulations, downward transport of thermal energy by ocean pipes strongly cools the near surface atmosphere - by up to 11°C on a global mean. The ocean pipes cause net thermal energy to be transported from the terrestrial environment to the deep ocean while increasing the global net transport of water to land. By cooling the ocean surface more than the land, ocean pipes tend to promote a monsoonal-type circulation, resulting in increased water vapour transport to land. Throughout their implementation, ocean pipes prevent energy from escaping to space, increasing the amount of energy stored in Earth's climate system despite reductions in surface temperature. As a consequence, our results indicate that an abrupt termination of ocean pipes could cause dramatic increases in surface temperatures beyond that which would have been obtained had ocean pipes not been implemented.

Volatiles in the Earth and Moon: Constraints on planetary formation and evolution

NASA Astrophysics Data System (ADS)

Parai, Rita

The volatile inventories of the Earth and Moon reflect unique histories of volatile acquisition and loss in the early Solar System. The terrestrial volatile inventory was established after the giant impact phase of accretion, and the planet subsequently settled into a regime of long-term volatile exchange between the mantle and surface reservoirs in association with plate tectonics. Therefore, volatiles in the Earth and Moon shed light on a diverse array of processes that shaped planetary bodies in the Solar System as they evolved to their present-day states. Here we investigate new constraints on volatile depletion in the early Solar System, early outgassing of the terrestrial mantle, and the long-term evolution of the deep Earth volatile budget. We develop a Monte Carlo model of long-term water exchange between the mantle and surface reservoirs. Previous estimates of the deep Earth return flux of water are up to an order of magnitude too large, and incorporation of recycled slabs on average rehydrates the upper mantle but dehydrates the plume source. We find evidence for heterogeneous recycling of atmospheric argon and xenon into the upper mantle from noble gases in Southwest Indian Ridge basalts. Xenon isotope systematics indicate that xenon budgets of mid-ocean ridge and plume-related mantle sources are dominated by recycled atmospheric xenon, though the two sources have experienced different degrees of degassing. Differences between the mid-ocean ridge and plume sources were initiated within the first 100 million years of Earth history, and the two sources have never subsequently been homogenized. New high-precision xenon isotopic data contribute to an emerging portrait of two mantle reservoirs with distinct histories of outgassing and incorporation of recycled material in association with plate tectonics. Xenon isotopes indicate that the Moon likely formed within ˜70 million years of the start of the Solar System. To further investigate early Solar System chronology, we determined strontium isotopic compositions in a suite of planetary materials. If the Moon is derived from proto-Earth material, then rubidium-strontium systematics in the lunar anorthosite 60025 and Moore County plagioclase indicate that Moon formation occurred within ~62 million years of the start of the Solar System.

Where microorganisms meet rocks in the Earth's Critical Zone

NASA Astrophysics Data System (ADS)

Akob, D. M.; Küsel, K.

2011-12-01

The Critical Zone (CZ) is the Earth's outer shell where all the fundamental physical, chemical, and biological processes critical for sustaining life occur and interact. As microbes in the CZ drive many of these biogeochemical cycles, understanding their impact on life-sustaining processes starts with an understanding of their biodiversity. In this review, we summarize the factors controlling where terrestrial CZ microbes (prokaryotes and micro-eukaryotes) live and what is known about their diversity and function. Microbes are found throughout the CZ, down to 5 km below the surface, but their functional roles change with depth due to habitat complexity, e.g. variability in pore spaces, water, oxygen, and nutrients. Abundances of prokaryotes and micro-eukaryotes decrease from 1010 or 107 cells g soil-1 or rock-1, or ml water-1 by up to eight orders of magnitude with depth. Although symbiotic mycorrhizal fungi and free-living decomposers have been studied extensively in soil habitats, where they occur up to 103 cells g soil-1, little is known regarding their identity or impact on weathering in the deep subsurface. The relatively low abundance of micro-eukaryotes in the deep subsurface suggests that they are limited in space, nutrients, are unable to cope with oxygen limitations, or some combination thereof. Since deep regions of the CZ have limited access to recent photosynthesis-derived carbon, microbes there depend on deposited organic material or a chemolithoautotrophic metabolism that allows for a complete food chain, independent from the surface, although limited energy flux means cell growth may take tens to thousands of years. Microbes are found in all regions of the CZ and can mediate important biogeochemical processes, but more work is needed to understand how microbial populations influence the links between different regions of the CZ and weathering processes. With the recent development of "omics" technologies, microbial ecologists have new methods that can be used to link the composition and function of in situ microbial communities. In particular, these methods can be used to search for new metabolic pathways that are relevant to biogeochemical nutrient cycling and determine how the activity of microorganisms can affect transport of carbon, particulates, and reactive gases between and within CZ regions.

Carbon dioxide catastrophes: Past and future menace

NASA Technical Reports Server (NTRS)

Baur, Mario E.

1988-01-01

Carbon dioxide is important in its role as coupler of the terrestrial biosphere to inorganic chemical processes and as the principal greenhouse gas controlling Earth's surface temperature. The hypothesis that atmospheric CO2 levels have diminished with time, with the resulting cooling effect offsetting an increase in the solar constant, seems firmly established, and it is shown that feedback mechanisms exist which can maintain the terrestrial surface in a relatively narrow temperature range over geological time. Of the factors involved in such CO2 variation, the oceanic reservoir appears the most important. Surface waters are probably in approximate equilibrium with regard to CO2 exchange with the ambient atmosphere in most regions, but data from deep-ocean water sampling indicates that such waters are somewhat undersaturated in the sense that they would tend to absorb CO2 from the atmosphere if brought to the surface without change in composition or temperature. If major impacts into the ocean can result in loss of a substantial portion of the atmospheric CO2 reservoir, then any such future event could imperil the continuation of most higher forms of life on Earth. The most likely candidate for an inverse Nyos global event in previous Earth history is the Cretaceous-Tertiary terminal extinction event. The Cretaceous was characterized by warm, equable temperatures presumably indicative of relatively high CO2 levels and an intense greenhouse heating. Cooling of the oceans in absence of massive transfer of CO2 to the oceanic reservoir in itself would promote a condition of CO2 undersaturation in abyssal waters, and this is made even more extreme by the pattern of ocean water circulation. It is possible to envision a situation in which deep ocean waters were at least occasionally profoundly undersaturated with regard to CO2. Turnover of a major fraction of such an ocean would then remove, on a very short time scale, as much as 90 percent of the atmospheric CO2 inventory.

Cultures in orbit: Satellite technologies, global media and local practice

NASA Astrophysics Data System (ADS)

Parks, Lisa Ann

Since the launch of Sputnik in 1957, satellite technologies have had a profound impact upon cultures around the world. "Cultures in Orbit" examines these seemingly disembodied, distant relay machines in relation to situated social and cultural processes on earth. Drawing upon a range of materials including NASA and UNESCO documents, international satellite television broadcasts, satellite 'development' projects, documentary and science fiction films, remote sensing images, broadcast news footage, World Wide Web sites, and popular press articles I delineate and analyze a series of satellite mediascapes. "Cultures in Orbit" analyzes uses of satellites for live television relay, surveillance, archaeology and astronomy. The project examines such satellite media as the first live global satellite television program Our World, Elvis' Aloha from Hawaii concert, Aboriginal Australian satellite programs, and Star TV's Asian music videos. In addition, the project explores reconnaissance images of mass graves in Bosnia, archaeological satellite maps of Cleopatra's underwater palace in Egypt, and Hubble Space Telescope images. These case studies are linked by a theoretical discussion of the satellite's involvement in shifting definitions of time, space, vision, knowledge and history. The satellite fosters an aesthetic of global realism predicated on instantaneous transnational connections. It reorders linear chronologies by revealing traces of the ancient past on the earth's surface and by searching in deep space for the "edge of time." On earth, the satellite is used to modernize and develop "primitive" societies. Satellites have produced new electronic spaces of international exchange, but they also generate strategic maps that advance Western political and cultural hegemony. By technologizing human vision, the satellite also extends the epistemologies of the visible, the historical and the real. It allows us to see artifacts and activities on earth from new vantage points; it allows us to read the surface of the earth as a text; and it enables us to see beyond the limits of human civilization and into the alien domain of deep space.

Views from EPOXI: Colors in Our Solar System as an Analog for Extrasolar Planets

NASA Technical Reports Server (NTRS)

Crow, Carolyn A.; McFadden, L. A.; Robinson, T.; Meadows, V. S.; Livengood, T. A.; Hewagama, T.; Barry, R. K.; Deming, L. D.; Lisse, C. M.; Wellnitz, Dennis

2011-01-01

The first visible-light studies of Earth-sized extrasolar planets will employ photometry or low-resolution spectroscopy. This work uses EPOCh medium-hand filter photometry between 150 and 950 nm obtained with the Deep Impact (DI) High Resolution Instrument (HRI) of Earth, the Moon, and Mars in addition to previous full-disk observations of the other six solar system planets and Titan to analyze the limitations of using photometric colors to characterize extrasolar planets. We determined that the HRI 350, 550, and 850 nm filters are optimal for distinguishing Earth from the other planets and separating planets to first order based on their atmospheric and surface properties. Detailed conclusions that can be drawn about exoplanet atmospheres simply from a color-color plot are limited due to potentially competing physical processes in the atmosphere. The presence of a Rayleigh scattering atmosphere can be detected by an increase in the 350-550 nm brightness ratio, but the absence of Rayleigh scattering cannot be confirmed due to the existence of atmospheric and surface absorbing species in the UV. Methane and ammonia are the only species responsible for strong absorption in the 850 nm filter in our solar system. The combination of physical processes present on extrasolar planets may differ from those we see locally. Nevertheless, a generation of telescopes capable of collecting such photometric observations can serve a critical role in first-order characterization and constraining the population of Earth-like extrasolar planets.

Venus Surface Sample Return: A Weighty High-Pressure Challenge

NASA Technical Reports Server (NTRS)

Sweetser, Ted; Cameron, Jonathon; Chen, Gun-Shing; Cutts, Jim; Gershman, Bob; Gilmore, Martha S.; Hall, Jeffrey L.; Kerzhanovich, Viktor; McRonald, Angus; Nilsen, Erik

1999-01-01

A mission to return a sample to Earth from the surface of Venus faces a multitude of multidisciplinary challenges. In addition to the complications inherent in any sample return mission, Venus presents the additional difficulties of a deep gravity well essentially equivalent to Earth's and a hot-house atmosphere which generates extremes of high temperature, density, and pressure unmatched at any other known surface in the solar system. The Jet Propulsion Laboratory of the California Institute of Technology recently conducted a study to develop an architecture for such a mission; a major goal of this study was to identify technology developments which would need to be pursued in order to make such a mission feasible at a cost much less than estimated in previous. The final design of this mission is years away but the study results presented here show our current mission architecture as it applies to a particular mission opportunity, give a summary of the engineering and science trades which were made in the process of developing it, and identify the main technology development efforts needed.

Geomagnetic South Atlantic Anomaly and global sea level rise: A direct connection?

NASA Astrophysics Data System (ADS)

de Santis, A.; Qamili, E.; Spada, G.; Gasperini, P.

2012-01-01

We highlight the existence of an intriguing and to date unreported relationship between the surface area of the South Atlantic Anomaly (SAA) of the geomagnetic field and the current trend in global sea level rise. These two geophysical variables have been growing coherently during the last three centuries, thus strongly suggesting a causal relationship supported by some statistical tests. The monotonic increase of the SAA surface area since 1600 may have been associated with an increased inflow of radiation energy through the inner Van Allen belt with a consequent warming of the Earth's atmosphere and finally global sea level rise. An alternative suggestive and original explanation is also offered, in which pressure changes at the core-mantle boundary cause surface deformations and relative sea level variations. Although we cannot establish a clear connection between SAA dynamics and global warming, the strong correlation between the former and global sea level supports the idea that global warming may be at least partly controlled by deep Earth processes triggering geomagnetic phenomena, such as the South Atlantic Anomaly, on a century time scale.

New Observationally-Based Metrics for the Analysis of Coupled Climate Model and Earth System Model Simulations of the Southern Ocean

NASA Astrophysics Data System (ADS)

Russell, J. L.

2014-12-01

The exchange of heat and carbon dioxide between the atmosphere and ocean are major controls on Earth's climate under conditions of anthropogenic forcing. The Southern Ocean south of 30°S, occupying just over ¼ of the surface ocean area, accounts for a disproportionate share of the vertical exchange of properties between the deep and surface waters of the ocean and between the surface ocean and the atmosphere; thus this region can be disproportionately influential on the climate system. Despite the crucial role of the Southern Ocean in the climate system, understanding of the particular mechanisms involved remains inadequate, and the model studies underlying many of these results are highly controversial. As part of the overall goal of working toward reducing uncertainties in climate projections, we present an analysis using new data/model metrics based on a unified framework of theory, quantitative datasets, and numerical modeling. These new metrics quantify the mechanisms, processes, and tendencies relevant to the role of the Southern Ocean in climate.

Teleseismic studies indicate existence of deep magma chamber below Yellowstone National Park

USGS Publications Warehouse

Iyer, H.M.

1974-01-01

The secrets of Yellowstone National Park's spectacular geysers and other hot water and steam phenomena are being explored by the U.S Geological Survey with the aid of distant earthquakes (teleseisms). For some time geologists have known that the remarkable array of steam and hot water displays, for which the park is internationally famous, is associated with intense volcanic activity that occurred in the reigon during the last 2 million years. The most recent volcanic eruption took place about 600,000 years ago creating a large caldera, or crater, 75 kilometers long and 50 kilometers wide. This caldera occupies most of the central part of the present-day park. geologists knew from studies of the surface geology that the volcanic activity which creates the present caldera was caused the present caldera was caused by a large body of magma, a mixture composed of molten rock, hot liquids, and gases, that had forced its way from the deep interior of the Earth into the upper mantle and crust below the Yellowstone area. The dimensions and depth below the surface of this magma body were largely unknown, however, because there was no way to "see" deep below the surface. A tool was needed that would enable earth scientists to look into the curst and upper mantle of the Earth. Such a tool became availabe with the installation by the Geological Survey of a network of seismograph stations in the park. 

Rapid broad area search and detection of Chinese surface-to-air missile sites using deep convolutional neural networks

NASA Astrophysics Data System (ADS)

Marcum, Richard A.; Davis, Curt H.; Scott, Grant J.; Nivin, Tyler W.

2017-10-01

We evaluated how deep convolutional neural networks (DCNN) could assist in the labor-intensive process of human visual searches for objects of interest in high-resolution imagery over large areas of the Earth's surface. Various DCNN were trained and tested using fewer than 100 positive training examples (China only) from a worldwide surface-to-air-missile (SAM) site dataset. A ResNet-101 DCNN achieved a 98.2% average accuracy for the China SAM site data. The ResNet-101 DCNN was used to process ˜19.6 M image chips over a large study area in southeastern China. DCNN chip detections (˜9300) were postprocessed with a spatial clustering algorithm to produce a ranked list of ˜2100 candidate SAM site locations. The combination of DCNN processing and spatial clustering effectively reduced the search area by ˜660X (0.15% of the DCNN-processed land area). An efficient web interface was used to facilitate a rapid serial human review of the candidate SAM sites in the China study area. Four novice imagery analysts with no prior imagery analysis experience were able to complete a DCNN-assisted SAM site search in an average time of ˜42 min. This search was ˜81X faster than a traditional visual search over an equivalent land area of ˜88,640 km2 while achieving nearly identical statistical accuracy (˜90% F1).

Making the Venus Concept Watch 1.0

NASA Astrophysics Data System (ADS)

Balint, Tibor S.; Melchiorri, Julian P.

2014-08-01

Over the past year we have celebrated the 50th anniversary of planetary exploration, which started with the Venus flyby of Mariner-2; and the 35th anniversary of the Pioneer-Venus multi-probe mission where one large and three small probes descended to the surface of Venus, encountering extreme environmental conditions. At the surface of Venus the temperature is about 460 °C, and the pressure is 92 bar, with a highly corrosive super-critical CO2 atmosphere. At a Venusian altitude of 50 km the pressure and temperature conditions are near Earth-like, but the clouds carry sulfuric acid droplets. Deep probe missions to Jupiter and Saturn, targeting the 100 bar pressure depth encounter similar pressure and temperature conditions as the Pioneer-Venus probes did. Mitigating these environments is highly challenging and requires special considerations for designs and materials. While assessing such space mission concepts, we have found that there is an overlap between the extreme environments in planetary atmospheres and the environments experienced by deep-sea explorers back on Earth. Consequently, the mitigation approaches could be also similar between planetary probes and diver watches. For example, both need to tolerate about 100 bar of pressure-although high temperatures are not factors on Earth. Mitigating these environments, the potential materials are: titanium for the probe and the watch housing; sapphire for the window and glass; resin impregnated woven carbon fiber for the aeroshell's thermal protection system and for the face of the watch; and nylon ribbon for the parachute and for the watch band. Planetary probes also utilize precision watches; thus there is yet another crosscutting functionality with diver watches. Our team, from the Innovation Design Engineering Program of the Royal College of Art, has designed and built a concept watch to commemorate these historical events, while highlighting advances in manufacturing processes over the past three to five decades, relevant to both future planetary mission designs and can be used to produce deep diver watches. In this paper we describe our design considerations; give a brief overview of the extreme environments these components would experience on both Venus and Earth; the manufacturing techniques and materials we used to build the Venus Watch; and its outreach potential to bring a distant concept of planetary exploration closer to Earth. We will also address lessons learned from this project and new ideas forward, for the next generation of this concept design.

Cosmopolitanism and Biogeography of the Genus Manganonema (Nematoda: Monhysterida) in the Deep Sea

PubMed Central

Zeppilli, Daniela; Vanreusel, Ann; Danovaro, Roberto

2011-01-01

Simple Summary The deep sea comprises more than 60% of the Earth surface, and likely represents the largest reservoir of as yet undiscovered biodiversity. Nematodes are the most abundant taxon on Earth and are particularly abundant and diverse in the deep sea. Nevertheless, knowledge of their biogeography especially in the deep sea is still at its infancy. This article explores the distribution of the genus Manganonema in the deep Atlantic Ocean and Mediterranean Sea providing new insights about this apparently rare deep-sea genus. Abstract Spatial patterns of species diversity provide information about the mechanisms that regulate biodiversity and are important for setting conservation priorities. Present knowledge of the biogeography of meiofauna in the deep sea is scarce. This investigation focuses on the distribution of the deep-sea nematode genus Manganonema, which is typically extremely rare in deep-sea sediment samples. Forty-four specimens of eight different species of this genus were recorded from different Atlantic and Mediterranean regions. Four out of the eight species encountered are new to science. We report here that this genus is widespread both in the Atlantic and in the Mediterranean Sea. These new findings together with literature information indicate that Manganonema is a cosmopolitan genus, inhabiting a variety of deep-sea habitats and oceans. Manganonema shows the highest diversity at water depths >4,000 m. Our data, therefore, indicate that this is preferentially an abyssal genus that is able, at the same time, to colonize specific habitats at depths shallower than 1,000 m. The analysis of the distribution of the genus Manganonema indicates the presence of large differences in dispersal strategies among different species, ranging from locally endemic to cosmopolitan. Lacking meroplanktonic larvae and having limited dispersal ability due to their small size, it has been hypothesized that nematodes have limited dispersal potential. However, the investigated deep-sea nematodes were present across different oceans covering macro-scale distances. Among the possible explanations (hydrological conditions, geographical and geological pathways, long-term processes, specific historical events), their apparent preference of colonizing highly hydrodynamic systems, could suggest that these infaunal organisms are transported by means of deep-sea benthic storms and turbidity currents over long distances. PMID:26486501

Geophysical Exploration Technologies for the Deep Lithosphere Research: An Education Materials for High School Students

NASA Astrophysics Data System (ADS)

Xu, H.; Xu, C.; Luo, S.; Chen, H.; Qin, R.

2012-12-01

The science of Geophysics applies the principles of physics to study of the earth. Geophysical exploration technologies include the earthquake seismology, the seismic reflection and refraction methods, the gravity method, the magnetic method and the magnetotelluric method, which are used to measure the interior material distribution, their structure and the tectonics in the lithosphere of the earth. Part of the research project in SinoProbe-02-06 is to develop suitable education materials for carton movies targeting the high school students and public. The carton movies include five parts. The first part includes the structures of the earth's interior and variation in their physical properties that include density, p-wave, s-wave and so on, which are the fundamentals of the geophysical exploration technologies. The second part includes the seismology that uses the propagation of elastic waves through the earth to study the structure and the material distribution of the earth interior. It can be divided into earthquake seismology and artifice seismics commonly using reflection and refraction. The third part includes the magnetic method. Earth's magnetic field (also known as the geomagnetic field)extends from the Earth's inner core to where it meets the solar wind, a stream of energetic particles emanating from the Sun. The aim of magnetic survey is to investigate subsurface geology on the basis of anomalies in the Earth's magnetic field resulting from the magnetic properties of the underlying rocks. The magnetic method in the lithosphere attempts to use magnetic disturbance to analyse the regional geological structure and the magnetic boundaries of the crust. The fourth part includes the gravity method. A gravity anomaly results from the inhomogeneous distribution of density of the Earth. Usually gravity anomalies contain superposed anomalies from several sources. The long wave length anomalies due to deep density contrasts are called regional anomalies. They are important for understanding the large-scale structure of the earth's crust under major geographic features, such as mountain ranges, oceanic ridges and subduction zones. Short wave length residual anomalies are due to shallow anomalous masses that may be of interest for commercial exploitation. The last part is the magnetotellurics (MT), which is an electromagnetic geophysical method of imaging the earth's subsurface by measuring natural variations of electrical and magnetic fields at the Earth's surface. The long-period MT technique is used to exploration deep crustal. MT has been used to investigate the distribution of silicate melts in the Earth's mantle and crust and to better understand the plate-tectonic processes.

Tropical Storm Ernesto over Cuba

NASA Technical Reports Server (NTRS)

2006-01-01

[figure removed for brevity, see original site] Microwave Image

These infrared, microwave, and visible images were created with data retrieved by the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite.

Infrared Image Because infrared radiation does not penetrate through clouds, AIRS infrared images show either the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the storm. In cloud-free areas the AIRS instrument will receive the infrared radiation from the surface of the Earth, resulting in the warmest temperatures (orange/red).

Microwave Image In the AIRS microwave imagery, deep blue areas in storms show where the most precipitation occurs, or where ice crystals are present in the convective cloud tops. Outside of these storm regions, deep blue areas may also occur over the sea surface due to its low radiation emissivity. On the other hand, land appears much warmer due to its high radiation emissivity.

Microwave radiation from Earth's surface and lower atmosphere penetrates most clouds to a greater or lesser extent depending upon their water vapor, liquid water and ice content. Precipitation, and ice crystals found at the cloud tops where strong convection is taking place, act as barriers to microwave radiation. Because of this barrier effect, the AIRS microwave sensor detects only the radiation arising at or above their location in the atmospheric column. Where these barriers are not present, the microwave sensor detects radiation arising throughout the air column and down to the surface. Liquid surfaces (oceans, lakes and rivers) have 'low emissivity' (the signal isn't as strong) and their radiation brightness temperature is therefore low. Thus the ocean also appears 'low temperature' in the AIRS microwave images and is assigned the color blue. Therefore deep blue areas in storms show where the most precipitation occurs, or where ice crystals are present in the convective cloud tops. Outside of these storm regions, deep blue areas may also occur over the sea surface due to its low radiation emissivity. Land appears much warmer due to its high radiation emissivity.

The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

The geobiological nitrogen cycle: From microbes to the mantle.

PubMed

Zerkle, A L; Mikhail, S

2017-05-01

Nitrogen forms an integral part of the main building blocks of life, including DNA, RNA, and proteins. N 2 is the dominant gas in Earth's atmosphere, and nitrogen is stored in all of Earth's geological reservoirs, including the crust, the mantle, and the core. As such, nitrogen geochemistry is fundamental to the evolution of planet Earth and the life it supports. Despite the importance of nitrogen in the Earth system, large gaps remain in our knowledge of how the surface and deep nitrogen cycles have evolved over geologic time. Here, we discuss the current understanding (or lack thereof) for how the unique interaction of biological innovation, geodynamics, and mantle petrology has acted to regulate Earth's nitrogen cycle over geologic timescales. In particular, we explore how temporal variations in the external (biosphere and atmosphere) and internal (crust and mantle) nitrogen cycles could have regulated atmospheric pN 2 . We consider three potential scenarios for the evolution of the geobiological nitrogen cycle over Earth's history: two in which atmospheric pN 2 has changed unidirectionally (increased or decreased) over geologic time and one in which pN 2 could have taken a dramatic deflection following the Great Oxidation Event. It is impossible to discriminate between these scenarios with the currently available models and datasets. However, we are optimistic that this problem can be solved, following a sustained, open-minded, and multidisciplinary effort between surface and deep Earth communities. © 2017 The Authors Geobiology Published by John Wiley & Sons Ltd.

Geochemical evidence for a magmatic CO2 degassing event at Mammoth Mountain, California, September-December 1997

USGS Publications Warehouse

McGee, K.A.; Gerlach, T.M.; Kessler, R.; Doukas, M.P.

2000-01-01

Recent time series soil CO2 concentration data from monitoring stations in the vicinity of Mammoth Mountain, California, reveal strong evidence for a magmatic degassing event during the fall of 1997 lasting more than 2 months. Two sensors at Horseshoe Lake first recorded the episode on September 23, 1997, followed 10 days later by a sensor on the north flank of Mammoth Mountain. Direct degassing from shallow intruding magma seems an implausible cause of the degassing event, since the gas released at Horseshoe Lake continued to be cold and barren of other magmatic gases, except for He. We suggest that an increase in compressional strain on the area south of Mammoth Mountain driven by movement of major fault blocks in Long Valley caldera may have triggered an episode of increased degassing by squeezing additional accumulated CO2 from a shallow gas reservoir to the surface along faults and other structures where it could be detected by the CO2 monitoring network. Recharge of the gas reservoir by CO2 emanating from the deep intrusions that probably triggered deep long-period earthquakes may also have contributed to the degassing event. The nature of CO2 discharge at the soil-air interface is influenced by the porous character of High Sierra soils and by meteorological processes. Solar insolation is the primary source of energy for the Earth atmosphere and plays a significant role in most diurnal processes at the Earth surface. Data from this study suggest that external forcing due largely to local orographic winds influences the fine structure of the recorded CO2 signals.

The dynamical control of subduction parameters on surface topography

NASA Astrophysics Data System (ADS)

Crameri, F.; Lithgow-Bertelloni, C. R.; Tackley, P. J.

2017-04-01

The long-wavelength surface deflection of Earth's outermost rocky shell is mainly controlled by large-scale dynamic processes like isostasy or mantle flow. The largest topographic amplitudes are therefore observed at plate boundaries due to the presence of large thermal heterogeneities and strong tectonic forces. Distinct vertical surface deflections are particularly apparent at convergent plate boundaries mostly due to the convergence and asymmetric sinking of the plates. Having a mantle convection model with a free surface that is able to reproduce both realistic single-sided subduction and long-wavelength surface topography self-consistently, we are now able to better investigate this interaction. We separate the topographic signal into distinct features and quantify the individual topographic contribution of several controlling subduction parameters. Results are diagnosed by splitting the topographic signal into isostatic and residual components, and by considering various physical aspects like viscous dissipation during plate bending. Performing several systematic suites of experiments, we are then able to quantify the topographic impact of the buoyancy, rheology, and geometry of the subduction-zone system to each and every topographic feature at a subduction zone and to provide corresponding scaling laws. We identify slab dip and, slightly less importantly, slab buoyancy as the major agents controlling surface topography at subduction zones on Earth. Only the island-arc high and the back-arc depression extent are mainly controlled by plate strength. Overall, his modeling study sets the basis to better constrain deep-seated mantle structures and their physical properties via the observed surface topography on present-day Earth and back through time.

The Search for Sustainable Subsurface Habitats on Mars, and the Sampling of Impact Ejecta

NASA Astrophysics Data System (ADS)

Ivarsson, Magnus; Lindgren, Paula

2010-07-01

On Earth, the deep subsurface biosphere of both the oceanic and the continental crust is well known for surviving harsh conditions and environments characterized by high temperatures, high pressures, extreme pHs, and the absence of sunlight. The microorganisms of the terrestrial deep biosphere have an excellent capacity for adapting to changing geochemistry, as the alteration of the crust proceeds and the conditions of their habitats slowly change. Despite an almost complete isolation from surface conditions and the surface biosphere, the deep biosphere of the crustal rocks has endured over geologic time. This indicates that the deep biosphere is a self-sufficient system, independent of the global events that occur at the surface, such as impacts, glaciations, sea level fluctuations, and climate changes. With our sustainable terrestrial subsurface biosphere in mind, the subsurface on Mars has often been suggested as the most plausible place to search for fossil Martian life, or even present Martian life. Since the Martian surface is more or less sterile, subsurface settings are the only place on Mars where life could have been sustained over geologic time. To detect a deep biosphere in the Martian basement, drilling is a requirement. However, near future Mars sample return missions are limited by the mission's payload, which excludes heavy drilling equipment and restrict the missions to only dig the topmost meter of the Martian soil. Therefore, the sampling and analysis of Martian impact ejecta has been suggested as a way of accessing the deeper Martian subsurface without using heavy drilling equipment. Impact cratering is a natural geological process capable of excavating and exposing large amounts of rock material from great depths up to the surface. Several studies of terrestrial impact deposits show the preservation of pre-impact biosignatures, such as fossilized organisms and chemical biological markers. Therefore, if the Martian subsurface contains a record of life, it is reasonable to assume that biosignatures derived from the Martian subsurface could also be preserved in the Martian impact ejecta.

Deformation of phase D and Earth's deep water cycle

NASA Astrophysics Data System (ADS)

Walker, A.; Skelton, R.; Nowacki, A.

2016-12-01

The stability of dense hydrous magnesium silicates such as phase D in subducting slabs provide a potential path for hydrogen transport from the Earth's surface environment into the lower mantle. Recent analysis of source-side shear wave splitting for rays from deep earthquakes around slabs detected a signal of anisotropy that could be attributed to the deformation of phase D [Nowacki et al. 2015; Geochem. Geophys. Geosyst., 16, 764-784]. If this is the case these observations could provide an estimate of the hydrogen flux into the lower mantle at depths beyond shallow recycling through the volcanic arc. However, the processes leading to the deformation of phase D and the generation of seismic anisotropy are not well known and this is a barrier to progress. Here we present initial results of simulations designed to reveal how easily different dislocations move in phase D during deformation and lead to the generation of seismic anisotropy measured by shear wave splitting. In particular, we use atomic scale simulations to calculate the energies of generalised stacking faults in phase D, which are used to parameterise Peierls-Nabarro models of dislocation structures and Peierls stresses at pressures up to 60 GPa. We then use results from these calculations as parameters for models of texture development in polycrystalline aggregates during deformation using the visco-plastic self-consistent approach. In combination with measurement of the distribution of seismic anisotropy around subducting slabs, and an analysis of the strain pattern expected as slabs pass through the transition zone, these results could constrain an important part of Earth's deep water cycle.

Quantifying Atmospheric Moist Processes from Earth Observations. Really?

NASA Astrophysics Data System (ADS)

Shepson, P. B.; Cambaliza, M. O. L.; Salmon, O. E.; Heimburger, A. M. F.; Davis, K. J.; Lauvaux, T.; McGowan, L. E.; Miles, N.; Richardson, S.; Sarmiento, D. P.; Hardesty, M.; Karion, A.; Sweeney, C.; Iraci, L. T.; Hillyard, P. W.; Podolske, J. R.; Gurney, K. R.; Patarasuk, R.; Razlivanov, I. N.; Song, Y.; O'Keeffe, D.; Turnbull, J. C.; Vimont, I.; Whetstone, J. R.; Possolo, A.; Prasad, K.; Lopez-Coto, I.

2014-12-01

The amount of water in the Earth's atmosphere is tiny compared to all other sources of water on our planet, fresh or otherwise. However, this tiny amount of water is fundamental to most aspects of human life. The tiny amount of water that cycles from the Earth's surface, through condensation into clouds in the atmosphere returning as precipitation falling is not only natures way of delivering fresh water to land-locked human societies but it also exerts a fundamental control on our climate system producing the most important feedbacks in the system. The representation of these processes in Earth system models contain many errors that produce well now biases in the hydrological cycle. Surprisingly the parameterizations of these important processes are not well validated with observations. Part of the reason for this situation stems from the fact that process evaluation is difficult to achieve on the global scale since it has commonly been assumed that the static observations available from snap-shots of individual parameters contain little information on processes. One of the successes of the A-Train has been the development of multi-parameter analysis based on the multi-sensor data produced by the satellite constellation. This has led to new insights on how water cycles through the Earth's atmosphere. Examples of these insights will be highlighted. It will be described how the rain formation process has been observed and how this has been used to constrain this process in models, with a huge impact. How these observations are beginning to reveal insights on deep convection and examples of the use these observations applied to models will also be highlighted as will the effects of aerosol on clouds on radiation.

Quantifying Atmospheric Moist Processes from Earth Observations. Really?

NASA Astrophysics Data System (ADS)

Stephens, G. L.

2015-12-01

The amount of water in the Earth's atmosphere is tiny compared to all other sources of water on our planet, fresh or otherwise. However, this tiny amount of water is fundamental to most aspects of human life. The tiny amount of water that cycles from the Earth's surface, through condensation into clouds in the atmosphere returning as precipitation falling is not only natures way of delivering fresh water to land-locked human societies but it also exerts a fundamental control on our climate system producing the most important feedbacks in the system. The representation of these processes in Earth system models contain many errors that produce well now biases in the hydrological cycle. Surprisingly the parameterizations of these important processes are not well validated with observations. Part of the reason for this situation stems from the fact that process evaluation is difficult to achieve on the global scale since it has commonly been assumed that the static observations available from snap-shots of individual parameters contain little information on processes. One of the successes of the A-Train has been the development of multi-parameter analysis based on the multi-sensor data produced by the satellite constellation. This has led to new insights on how water cycles through the Earth's atmosphere. Examples of these insights will be highlighted. It will be described how the rain formation process has been observed and how this has been used to constrain this process in models, with a huge impact. How these observations are beginning to reveal insights on deep convection and examples of the use these observations applied to models will also be highlighted as will the effects of aerosol on clouds on radiation.

Global Warming - Are We on Thin Ice?

NASA Technical Reports Server (NTRS)

Tucker, Compton J.

2007-01-01

The evidence for global warming is very conclusive for the past 400-500 years. Prior to the 16th century, proxy surface temperature data are regionally good but lack a global distribution. The speaker will review surface temperature reconstruction based upon ice cores, coral cores, tree rings, deep sea sediments, and bore holes and discuss the controversy surrounding global warming. This will be contrasted with the excellent data we have from the satellite era of earth observations the past 30+ years that enables the quantitative study of climate across earth science disciplines.

Deep-sea bioluminescence blooms after dense water formation at the ocean surface.

PubMed

Tamburini, Christian; Canals, Miquel; Durrieu de Madron, Xavier; Houpert, Loïc; Lefèvre, Dominique; Martini, Séverine; D'Ortenzio, Fabrizio; Robert, Anne; Testor, Pierre; Aguilar, Juan Antonio; Samarai, Imen Al; Albert, Arnaud; André, Michel; Anghinolfi, Marco; Anton, Gisela; Anvar, Shebli; Ardid, Miguel; Jesus, Ana Carolina Assis; Astraatmadja, Tri L; Aubert, Jean-Jacques; Baret, Bruny; Basa, Stéphane; Bertin, Vincent; Biagi, Simone; Bigi, Armando; Bigongiari, Ciro; Bogazzi, Claudio; Bou-Cabo, Manuel; Bouhou, Boutayeb; Bouwhuis, Mieke C; Brunner, Jurgen; Busto, José; Camarena, Francisco; Capone, Antonio; Cârloganu, Christina; Carminati, Giada; Carr, John; Cecchini, Stefano; Charif, Ziad; Charvis, Philippe; Chiarusi, Tommaso; Circella, Marco; Coniglione, Rosa; Costantini, Heide; Coyle, Paschal; Curtil, Christian; Decowski, Patrick; Dekeyser, Ivan; Deschamps, Anne; Donzaud, Corinne; Dornic, Damien; Dorosti, Hasankiadeh Q; Drouhin, Doriane; Eberl, Thomas; Emanuele, Umberto; Ernenwein, Jean-Pierre; Escoffier, Stéphanie; Fermani, Paolo; Ferri, Marcelino; Flaminio, Vincenzo; Folger, Florian; Fritsch, Ulf; Fuda, Jean-Luc; Galatà, Salvatore; Gay, Pascal; Giacomelli, Giorgio; Giordano, Valentina; Gómez-González, Juan-Pablo; Graf, Kay; Guillard, Goulven; Halladjian, Garadeb; Hallewell, Gregory; van Haren, Hans; Hartman, Joris; Heijboer, Aart J; Hello, Yann; Hernández-Rey, Juan Jose; Herold, Bjoern; Hößl, Jurgen; Hsu, Ching-Cheng; de Jong, Marteen; Kadler, Matthias; Kalekin, Oleg; Kappes, Alexander; Katz, Uli; Kavatsyuk, Oksana; Kooijman, Paul; Kopper, Claudio; Kouchner, Antoine; Kreykenbohm, Ingo; Kulikovskiy, Vladimir; Lahmann, Robert; Lamare, Patrick; Larosa, Giuseppina; Lattuada, Dario; Lim, Gordon; Presti, Domenico Lo; Loehner, Herbert; Loucatos, Sotiris; Mangano, Salvatore; Marcelin, Michel; Margiotta, Annarita; Martinez-Mora, Juan Antonio; Meli, Athina; Montaruli, Teresa; Moscoso, Luciano; Motz, Holger; Neff, Max; Nezri, Emma Nuel; Palioselitis, Dimitris; Păvălaş, Gabriela E; Payet, Kevin; Payre, Patrice; Petrovic, Jelena; Piattelli, Paolo; Picot-Clemente, Nicolas; Popa, Vlad; Pradier, Thierry; Presani, Eleonora; Racca, Chantal; Reed, Corey; Riccobene, Giorgio; Richardt, Carsten; Richter, Roland; Rivière, Colas; Roensch, Kathrin; Rostovtsev, Andrei; Ruiz-Rivas, Joaquin; Rujoiu, Marius; Russo, Valerio G; Salesa, Francisco; Sánchez-Losa, Augustin; Sapienza, Piera; Schöck, Friederike; Schuller, Jean-Pierre; Schussler, Fabian; Shanidze, Rezo; Simeone, Francesco; Spies, Andreas; Spurio, Maurizio; Steijger, Jos J M; Stolarczyk, Thierry; Taiuti, Mauro G F; Toscano, Simona; Vallage, Bertrand; Van Elewyck, Véronique; Vannoni, Giulia; Vecchi, Manuela; Vernin, Pascal; Wijnker, Guus; Wilms, Jorn; de Wolf, Els; Yepes, Harold; Zaborov, Dmitry; De Dios Zornoza, Juan; Zúñiga, Juan

2013-01-01

The deep ocean is the largest and least known ecosystem on Earth. It hosts numerous pelagic organisms, most of which are able to emit light. Here we present a unique data set consisting of a 2.5-year long record of light emission by deep-sea pelagic organisms, measured from December 2007 to June 2010 at the ANTARES underwater neutrino telescope in the deep NW Mediterranean Sea, jointly with synchronous hydrological records. This is the longest continuous time-series of deep-sea bioluminescence ever recorded. Our record reveals several weeks long, seasonal bioluminescence blooms with light intensity up to two orders of magnitude higher than background values, which correlate to changes in the properties of deep waters. Such changes are triggered by the winter cooling and evaporation experienced by the upper ocean layer in the Gulf of Lion that leads to the formation and subsequent sinking of dense water through a process known as "open-sea convection". It episodically renews the deep water of the study area and conveys fresh organic matter that fuels the deep ecosystems. Luminous bacteria most likely are the main contributors to the observed deep-sea bioluminescence blooms. Our observations demonstrate a consistent and rapid connection between deep open-sea convection and bathypelagic biological activity, as expressed by bioluminescence. In a setting where dense water formation events are likely to decline under global warming scenarios enhancing ocean stratification, in situ observatories become essential as environmental sentinels for the monitoring and understanding of deep-sea ecosystem shifts.

Eddy-Pump: Pelagic carbon pump processes along the eddying Antarctic Polar Front in the Atlantic Sector of the Southern Ocean

NASA Astrophysics Data System (ADS)

Strass, Volker H.; Wolf-Gladrow, Dieter; Pakhomov, Evgeny A.; Klaas, Christine

2017-04-01

The Southern Ocean influences earth's climate in many ways. It hosts the largest upwelling region of the world oceans where 80% of deep waters resurface (Morrison et al., 2015). A prominent feature is the broad ring of cold water, the Antarctic Circumpolar Current (ACC), which encircles the Antarctic continent and connects all other oceans. The ACC plays a major role in the global heat and freshwater transports and ocean-wide cycles of chemical and biogenic elements, and harbours a series of unique and distinct ecosystems. Due to the upwelling of deep-water masses in the Antarctic Divergence, there is high supply of natural CO2 as well as macronutrients, leading to the worldwide highest surface nutrient concentrations. Despite the ample macronutrients supply, phytoplankton concentration is generally low, limited either by low micronutrient (iron) availability, insufficient light due to deep wind-mixed layers or grazing by zooplankton, or by the combination of all, varying temporally and regionally.

Acquisition and Early Losses of Rare Gases from the Deep Earth

NASA Technical Reports Server (NTRS)

Porcelli, D.; Cassen, P.; Woolum, D.; Wasserburg, G. J.

1998-01-01

Direct observations show that the deep Earth contains rare gases of solar composition distinct from those in the atmosphere. We examine the implications of mantle rare gas characteristics on acquisition of rare gases from the solar nebula and subsequent losses due to a large impact. Deep mantle rare gas concentrations and isotopic compositions can be obtained from a model of transport and distribution of mantle rare gases. This model assumes the lower mantle closed early, while the upper mantle is open to subduction from the atmosphere and mass transfer from the lower mantle. Constraints are derived that can be incorporated into models for terrestrial volatile acquisition: (1) Calculated lower-mantle Xe-isotopic ratios indicate that the fraction of radiogenic Xe produced by I-129 and Pu-244 during the first about 10(exp 8) yr was lost, a conclusion also drawn for atmospheric Xe. Thus, either the Earth was made from materials that had lost >99% of rare gases about (0.7-2) x 10(exp 8) yr after the solar system formed, or gases were then lost from the fully formed Earth. (2) Concentrations of 3He and 20Ne in the lower mantle were established after these losses. (3) Neon-isotopic data indicates that mantle Ne has solar composition. The model allows for solar Ar/Ne and Xe/Ne in the lower mantle if a dominant fraction of upper mantle Ar and Xe are subduction-derived. If Earth formed in the presence of the solar nebula, it could have been melted by accretional energy and the blanketing effect of a massive, nebula-derived atmosphere. Gases from this atmosphere would have been sequestered within the molten Earth by dissolution at the surface and downward mixing. It was found that too much Ne would be dissolved in the Earth unless the atmosphere began to escape when the Earth was only partially assembled. Here we consider conditions required to initially dissolve sufficient rare gases to account for the present lower mantle concentrations after subsequent losses at 10(exp 8) yr. It is assumed that equilibration of the atmosphere with a thoroughly molten mantle was rapid, so that initial abundances of gases retained in any mantle layer reflected surface conditions when the layer solidified. For subsequent gas loss of 99.5% and typical solubility coefficients, a total pressure of 100 atm was required for an atmosphere of solar composition. Calculations of the pressure at the base of a primordial atmosphere indicate that this value might be exceeded by an order of magnitude or more for an atmosphere supported by accretional energy. Surface temperatures of about 4000 K would have been produced, probably high enough to melt the deep mantle. Initial distributions of retained rare gases would then be determined by the history of surface pressure and temperature during mantle cooling and solidification, i.e., the coupled cooling of Earth and atmosphere. The Earth's thermal state was determined by its surface temperature and the efficiency of convection in the molten mantle, estimated to be sufficient to maintain an adiabatic gradient. Because the melting curve is steeper than the adiabat, solidification of the mantle proceeded outward from the interior. Incorporation of atmospheric gases in the mantle therefore occurred over a range in surface temperature of a few thousand degrees Kelvin. The thermal state of the atmosphere was controlled by total luminosity of the Earth (energy) released by accreting planetesimals and the cooling Earth), nebular temperature and pressure, and atmospheric opacity. The energy released by accretion declined with time as did nebular pressure. Analytical solutions for an idealized (constant opacity radiative atmosphere show that declining energy sources under constant nebular conditions result in slowly diminishing surface temperature but dramatically increasing surface pressure. For such an atmosphere with declining nebular pressure but constant total luminosity, surface pressure decreases gradually with decreasing temperaure. A decline in accretion luminosity might be compensated by energy released as the mantle cools for about 10(exp 5) year, after which luminosity must decline. The total complement of dissolved rare gases will depend on the particular evolutionary path determined by the declining accretional luminosity, the Earth thermal history, removal of the nebula, and opacity variations of the atmosphere. Models for these coupled evolutionary histories for Earth's acquisition of nebular-derived noble gases are in progress. The later losses required at about 10(exp 8) yr (depleting the interior concentrations of the sequestered solar gases by a factor of > 100) were presumably related to the major impact in which the Moon formed.

Specular Reflection of Sunlight from Earth

NASA Astrophysics Data System (ADS)

Varnai, T.; Marshak, A.

2018-02-01

The Deep Space Gateway vantage point offers advantages in observing specular reflection from water surfaces or ice crystals in clouds. Such data can give information on clouds and atmospheric aerosols, and help test algorithms of future exoplanet characterization.

Typhoon Ioke in the Western Pacific

NASA Technical Reports Server (NTRS)

2006-01-01

[figure removed for brevity, see original site] [figure removed for brevity, see original site] Microwave ImageVisible Light Image

These infrared, microwave, and visible images were created with data retrieved by the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite.

Infrared Image Because infrared radiation does not penetrate through clouds, AIRS infrared images show either the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the storm. In cloud-free areas the AIRS instrument will receive the infrared radiation from the surface of the Earth, resulting in the warmest temperatures (orange/red).

Microwave Image In the AIRS microwave imagery, deep blue areas in storms show where the most precipitation occurs, or where ice crystals are present in the convective cloud tops. Outside of these storm regions, deep blue areas may also occur over the sea surface due to its low radiation emissivity. On the other hand, land appears much warmer due to its high radiation emissivity.

In the AIRS microwave imagery, deep blue areas in storms show where the most precipitation occurs, or where ice crystals are present in the convective cloud tops. Outside of these storm regions, deep blue areas may also occur over the sea surface due to its low radiation emissivity. On the other hand, land appears much warmer due to its high radiation emissivity.

Microwave radiation from Earth's surface and lower atmosphere penetrates most clouds to a greater or lesser extent depending upon their water vapor, liquid water and ice content. Precipitation, and ice crystals found at the cloud tops where strong convection is taking place, act as barriers to microwave radiation. Because of this barrier effect, the AIRS microwave sensor detects only the radiation arising at or above their location in the atmospheric column. Where these barriers are not present, the microwave sensor detects radiation arising throughout the air column and down to the surface. Liquid surfaces (oceans, lakes and rivers) have 'low emissivity' (the signal isn't as strong) and their radiation brightness temperature is therefore low. Thus the ocean also appears 'low temperature' in the AIRS microwave images and is assigned the color blue. Therefore deep blue areas in storms show where the most precipitation occurs, or where ice crystals are present in the convective cloud tops. Outside of these storm regions, deep blue areas may also occur over the sea surface due to its low radiation emissivity. Land appears much warmer due to its high radiation emissivity.

Vis/NIR Image The AIRS instrument suite contains a sensor that captures radiation in four bands of the visible/near-infrared portion of the electromagetic spectrum. Data from three of these bands are combined to create 'visible' images similar to a snapshot taken with your camera.

The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

Observation to Theory in Deep Subsurface Microbiology Research: Can We Piece It Together?

NASA Astrophysics Data System (ADS)

Colwell, F. S.; Thurber, A. R.

2016-12-01

Three decades of observations of microbes in deep environments have led to startling discoveries of life in the subsurface. Now, a few theoretical frameworks exist that help to define Stygian life. Temperature, redox gradients, productivity (e.g., in the overlying ocean), and microbial power requirements are thought to determine the distribution of microbes in the subsurface. Still, we struggle to comprehend the spatial and temporal spectra of Earth processes that define how deep microbe communities survive. Stommel diagrams, originally used to guide oceanographic sampling, may be useful in depicting the subsurface where microbial communities are impacted by co-occurring spatial and temporal phenomena that range across exponential scales. Spatially, the geological settings that influence the activity and distribution of microbes range from individual molecules or minerals all the way up to the planetary-scale where geological formations, occupying up to 105 km3, dictate the bio- and functional geography of microbial communities. Temporally, life in the subsurface may respond in time units familiar to humans (e.g., seconds to days) or to events that unfold over hundred millennial time periods. While surface community dynamics are underpinned by solar and lunar cycles, these cycles only fractionally dictate survival underground where phenomena like tectonic activity, isostatic rebound, and radioactive decay are plausible drivers of microbial life. Geological or planetary processes that occur on thousand or million year cycles could be uniquely important to microbial viability in the subsurface. Such an approach aims at a holistic comprehension of the interaction of Earth system dynamics with microbial ecology.

Survival of marine heterotrophic flagellates isolated from the surface and the deep sea at high hydrostatic pressure: Literature review and own experiments

NASA Astrophysics Data System (ADS)

Živaljić, Suzana; Schoenle, Alexandra; Nitsche, Frank; Hohlfeld, Manon; Piechocki, Julia; Reif, Farina; Shumo, Marwa; Weiss, Alexandra; Werner, Jennifer; Witt, Madeleine; Voss, Janine; Arndt, Hartmut

2018-02-01

Although the abyssal seafloor represents the most common benthic environment on Earth, eukaryotic microbial life at abyssal depths is still an uncharted territory. This is in striking contrast to their potential importance regarding the material flux and bacteria consumption in the deep sea. Flagellate genotypes determined from sedimentary DNA deep-sea samples might originate from vital deep-sea populations or from cysts of organisms sedimented down from surface waters. The latter one may have never been active under deep-sea conditions. We wanted to analyze the principal ability of cultivable heterotrophic flagellates of different phylogenetic groups (choanoflagellates, ancyromonads, euglenids, kinetoplastids, bicosoecids, chrysomonads, and cercozoans) to survive exposure to high hydrostatic pressure (up to 670 bar). We summarized our own studies and the few available data from literature on pressure tolerances of flagellates isolated from different marine habitats. Our results demonstrated that many different flagellate species isolated from the surface waters and deep-sea sediments survived drastic changes in hydrostatic pressure. Barophilic behavior was also recorded for several species isolated from the deep sea indicating their possible genetic adaptation to high pressures. This is in accordance with records of heterotrophic flagellates present in environmental DNA surveys based on clone libraries established for deep-sea environments.

Report of the panel on the land surface: Process of change, section 5

NASA Technical Reports Server (NTRS)

Adams, John B.; Barron, Eric E.; Bloom, Arthur A.; Breed, Carol; Dohrenwend, J.; Evans, Diane L.; Farr, Thomas T.; Gillespie, Allan R.; Isaks, B. L.; Williams, Richard S.

1991-01-01

The panel defined three main areas of study that are central to the Solid Earth Science (SES) program: climate interactions with the Earth's surface, tectonism as it affects the Earth's surface and climate, and human activities that modify the Earth's surface. Four foci of research are envisioned: process studies with an emphasis on modern processes in transitional areas; integrated studies with an emphasis on long term continental climate change; climate-tectonic interactions; and studies of human activities that modify the Earth's surface, with an emphasis on soil degradation. The panel concluded that there is a clear requirement for global coverage by high resolution stereoscopic images and a pressing need for global topographic data in support of studies of the land surface.

Water mass circulation and weathering inputs in the Labrador Sea based on coupled Hf-Nd isotope compositions and rare earth element distributions

NASA Astrophysics Data System (ADS)

Filippova, Alexandra; Frank, Martin; Kienast, Markus; Rickli, Jörg; Hathorne, Ed; Yashayaev, Igor M.; Pahnke, Katharina

2017-02-01

The Labrador Sea is one of the key areas for deep water formation driving the Atlantic thermohaline circulation and thus plays an important role in Northern Hemisphere climatic fluctuations. In order to better constrain the overturning processes and the origins of the distinct water masses, combined dissolved Hf-Nd isotopic compositions and rare earth element (REE) distribution patterns were obtained from four water depth profiles along a section across the Labrador Sea. These were complemented by one surface sample off the southern tip of Greenland, three shallow water samples off the coast of Newfoundland, and two deep water samples off Nova Scotia. Although light REEs are markedly enriched in the surface waters off the coast of Newfoundland compared to north Atlantic waters, the REE concentration profiles are essentially invariant throughout the water column across the Labrador Sea. The hafnium concentrations of surface waters exhibit a narrow range between 0.6 and 1 pmol/kg but are not significantly higher than at depth. Neodymium isotope signatures (ɛNd) vary from unradiogenic values between -16.8 and -14.9 at the surface to more radiogenic values near -11.0 at the bottom of the Labrador Sea mainly reflecting the advection of the Denmark Strait Overflow Water and North East Atlantic Deep Water, the signatures of which are influenced by weathering contributions from Icelandic basalts. Unlike Nd, water column radiogenic Hf isotope signatures (ɛHf) are more variable representing diverse weathering inputs from the surrounding landmasses. The least radiogenic seawater ɛHf signatures (up to -11.7) are found in surface waters close to Greenland and near the Canadian margin. This reflects the influence of recirculating Irminger Current Waters, which are affected by highly unradiogenic inputs from Greenland. A three to four ɛHf unit difference is observed between Denmark Strait Overflow Water (ɛHf ∼ -4) and North East Atlantic Deep Water (ɛHf ∼ -0.1), although their source waters have essentially the same ɛNd signature. This most likely reflects different weathering signals of hafnium delivered to Denmark Strait Overflow Water and North East Atlantic Deep Water (incongruent weathering of old rocks from Greenland versus basaltic rocks from Iceland). In addition, the ɛHf data resolve two layers within the main body of Labrador Sea Water not visible in the ɛNd distribution, which are shallow Labrador Sea Water (ɛHf ∼ -2) and deep Labrador Sea Water (ɛHf ∼ -4.5). The latter layer was formed between the late 1980's and mid 1990's during the last cold state of the Labrador Sea and underwent substantial modification since its formation through the admixture of Irminger Water, Iceland Slope Water and North East Atlantic Deep Water, which is reflected in its less radiogenic ɛHf signature. The overall behavior of Hf in the water column suggests its higher sensitivity to local changes in weathering inputs on annual to decadal timescales. Although application of Hf isotopes as a tracer for global water mass mixing is complicated by their susceptibility to incongruent weathering inputs they are a promising tracer of local processes in restricted basins such as the Labrador Sea.

Dissolved Rare Earth Elements in the US GEOTRACES North Atlantic Section

NASA Astrophysics Data System (ADS)

Shiller, A. M.

2016-12-01

The rare earth elements (REEs) are a unique chemical set wherein there are systematic changes in geochemical behavior across the series. Furthermore, while most REEs are in the +III oxidation state, Ce and Eu can be in other oxidation states leading to distinct characteristics of those elements. Thus, the geochemical properties of the REEs make them particularly useful tools for inquiring into various geochemical processes. As part of the US GEOTRACES effort, we determined dissolved REEs and Y at 32 stations across the North Atlantic during US cruises GT10 and GT11 along a meridional transect from Lisbon to the Cape Verde Islands and a zonal transect from Cape Cod to the Mauritanian coast. While profiles are similar to previous reports, the high spatial resolution of the section allows for better elucidation of processes. Light rare earths (LREEs) show removal in the upper water column with a minimum at the chlorophyll maximum. LREE concentrations then increase into the oxygen minimum followed by a slight decrease and fairly constant concentrations in the mid-water column followed by an increase into the deep and bottom waters. Heavy rare earths (HREEs) show a more monotonic increase with depth. We also take advantage of a previously published water mass analysis for the section to estimate that most of the deep water changes can be explained by conservative mixing of waters with different pre-formed REE concentrations. Nonetheless, the pattern of LREE shallow water removal followed by regeneration, possible re-scavenging, and then deep water input is still preserved. Other features of note include an increase in LREEs in the strong oxygen minimum zone off Mauritania, consistent with an association of REE cycling with the redox cycles of Fe and Mn. Also along the eastern margin, but below the oxygen minimum, a small but distinct increase in the cerium and europium anomalies is observed, consistent with terrigenous input. In hydrothermally influenced waters along the mid-Atlantic Ridge, there are increases in Ce/Ce*, Eu/Eu*, and Y/Ho but a decrease in Nd/Yb and in REE concentrations. Surface water distributions are more consistent with elements influenced by margin inputs than with atmospheric input.

A ten-meter optical telescope for deep-space communications

NASA Technical Reports Server (NTRS)

Shaik, Kamran; Kerr, Edwin L.

1990-01-01

Optical communications using laser light in the visible spectral range is being considered for future deep-space missions. Such a system will require a large telescope in earth vicinity to be used as a receiving station for data return from the spacecraft. A preliminary discussion for a ground-based receiving station consisting of a 10-meter hexagonally segmented primary with high surface tolerance and a unique sunshade is presented.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rustad, James

Since they first puzzled over the geometric regularity of faceted crystals, geologists have been striving for a molecular-level understanding of the processes that control the transformation of earth materials. The relative lack of success in this endeavor can be revealed by asking why, if everyone knows what a molecular biologist is, there is no such corresponding occupation as a molecular geologist. That this should be so is even more surprising considering the vast amount of effort devoted over the 20th century to the determination of thousands of crystal structures of minerals of geological importance. Up through the 1970s every geologymore » department in a major research university had at least one specialist in X-ray mineralogy and crystallography. Roughly contemporaneous with the understanding of plate tectonics, geology had completed a remarkably comprehensive database of the crystal structures of thousands of minerals making up the Earth's crust and the more remote mineral assemblages making up the Earth's mantle. Uncovering the fundamental atomic structures of earth materials should have had the same transformational effect on geology that, for example, protein crystallography had on biology. The most basic and most interesting questions, such as the motions of tectonic plates, the rates of dissolution and weathering of rocks at the earth's surface into primary oxides and clay minerals, the process of replacing and preserving biological materials with minerals on deep time-scales, and the fractionation of isotopes during establishment of the earth's rock record have a molecular component that is no less central or less fascinating than those underpinning biological processes.« less

Using DSP technology to simplify deep space ranging

NASA Technical Reports Server (NTRS)

Bryant, S.

2000-01-01

Commercially available Digital Signal Processing (DSP) technology has enabled a new spacecraft ranging design. The new design reduces overall size, parts count, and complexity. The design implementation will also meet the Jet Propulsion Laboratory (JPL) requirements for both near-Earth and deep space ranging.

Deep mantle structure as a reference frame for movements in and on the Earth.

PubMed

Torsvik, Trond H; van der Voo, Rob; Doubrovine, Pavel V; Burke, Kevin; Steinberger, Bernhard; Ashwal, Lewis D; Trønnes, Reidar G; Webb, Susan J; Bull, Abigail L

2014-06-17

Earth's residual geoid is dominated by a degree-2 mode, with elevated regions above large low shear-wave velocity provinces on the core-mantle boundary beneath Africa and the Pacific. The edges of these deep mantle bodies, when projected radially to the Earth's surface, correlate with the reconstructed positions of large igneous provinces and kimberlites since Pangea formed about 320 million years ago. Using this surface-to-core-mantle boundary correlation to locate continents in longitude and a novel iterative approach for defining a paleomagnetic reference frame corrected for true polar wander, we have developed a model for absolute plate motion back to earliest Paleozoic time (540 Ma). For the Paleozoic, we have identified six phases of slow, oscillatory true polar wander during which the Earth's axis of minimum moment of inertia was similar to that of Mesozoic times. The rates of Paleozoic true polar wander (<1°/My) are compatible with those in the Mesozoic, but absolute plate velocities are, on average, twice as high. Our reconstructions generate geologically plausible scenarios, with large igneous provinces and kimberlites sourced from the margins of the large low shear-wave velocity provinces, as in Mesozoic and Cenozoic times. This absolute kinematic model suggests that a degree-2 convection mode within the Earth's mantle may have operated throughout the entire Phanerozoic.

KSC-04PD-2413

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. On Launch Pad 17-B, Cape Canaveral Air Force Station, Fla., a crane begins lifting the third in a set of three Solid Rocket Boosters (SRBs). The SRBs will be hoisted up the mobile service tower and join three others already mated to the Boeing Delta II rocket that will launch the Deep Impact spacecraft. A NASA Discovery mission, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing an impactor on a course to hit the comets sunlit side, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measure the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determine the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network.

Long wavelength gravity and topography anomalies

NASA Technical Reports Server (NTRS)

Watts, A. B.; Daly, S. F.

1981-01-01

It is shown that gravity and topography anomalies on the earth's surface may provide new information about deep processes occurring in the earth, such as those associated with mantle convection. Two main reasons are cited for this. The first is the steady improvement that has occurred in the resolution of the long wavelength gravity field, particularly in the wavelength range of a few hundred to a few thousand km, mainly due to increased coverage of terrestrial gravity measurements and the development of radar altimeters in orbiting satellites. The second reason is the large number of numerical and laboratory experiments of convection in the earth, including some with deformable upper and lower boundaries and temperature-dependent viscosity. The oceans are thought to hold the most promise for determining long wavelength gravity and topography anomalies, since their evolution has been relatively simple in comparison with that of the continents. It is also shown that good correlation between long wavelength gravity and topography anomalies exists over some portions of the ocean floor

KSC-04PD-2533

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Ball Aerospace technicians at Astrotech in Titusville, Fla., begin lifting the high-gain communications antenna to attach it to an overhead crane. The antenna will be installed on the Deep Impact spacecraft. A NASA Discovery mission, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. During the encounter phase, the high-gain antenna transmits near-real- time images of the impact back to Earth. The spacecraft is scheduled to launch Jan. 8 aboard a Boeing Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station, Fla.

A role for subducted super-hydrated kaolinite in Earth's deep water cycle

NASA Astrophysics Data System (ADS)

Hwang, Huijeong; Seoung, Donghoon; Lee, Yongjae; Liu, Zhenxian; Liermann, Hanns-Peter; Cynn, Hyunchae; Vogt, Thomas; Kao, Chi-Chang; Mao, Ho-Kwang

2017-12-01

Water is the most abundant volatile component in the Earth. It continuously enters the mantle through subduction zones, where it reduces the melting temperature of rocks to generate magmas. The dehydration process in subduction zones, which determines whether water is released from the slab or transported into the deeper mantle, is an essential component of the deep water cycle. Here we use in situ and time-resolved high-pressure/high-temperature synchrotron X-ray diffraction and infrared spectra to characterize the structural and chemical changes of the clay mineral kaolinite. At conditions corresponding to a depth of about 75 km in a cold subducting slab (2.7 GPa and 200 °C), and in the presence of water, we observe the pressure-induced insertion of water into kaolinite. This super-hydrated phase has a unit cell volume that is about 31% larger, a density that is about 8.4% lower than the original kaolinite and, with 29 wt% H2O, the highest water content of any known aluminosilicate mineral in the Earth. As pressure and temperature approach 19 GPa and about 800 °C, we observe the sequential breakdown of super-hydrated kaolinite. The formation and subsequent breakdown of super-hydrated kaolinite in cold slabs subducted below 200 km leads to the release of water that may affect seismicity and help fuel arc volcanism at the surface.

Geomorphology: the Shock of the Familiar

NASA Astrophysics Data System (ADS)

Dietrich, W. E.

2008-12-01

Everyone experiences landscapes and has a sense about how they work: water runs down hill, it erodes and carries sediments, and that's about it, right? Introductory earth science text books are uniformly qualitative about the field, and leave one with little sense of wonder, and certainly not "shock". But four shocks occur if one peels away the first impressions. First, landscapes are surprisingly similar: the same forms are repeated in virtually all environments, including under the ocean and on other planets. Second, we lack theory and mechanistic observations to answer many simple first-order questions, e.g. what controls the width of a river, how does rock type control hillslope form and erosion rate, or, is there a topographic signature of life. Third, there are unexpected connections between surface erosion, deep earth processes, and climate. And fourth, the field itself, despite having been a subject of study for well over 100 years, is currently experiencing a revolution of ideas and discoveries through new tools, observatories, centers, journals, books, contributions of researchers from other disciplines, and from a significant hiring of young researchers in geomorphology. Deep messages await discovery in the simple landforms surrounding us.

Using Deep Space Climate Observatory Measurements to Study the Earth as an Exoplanet

NASA Astrophysics Data System (ADS)

Jiang, Jonathan H.; Zhai, Albert J.; Herman, Jay; Zhai, Chengxing; Hu, Renyu; Su, Hui; Natraj, Vijay; Li, Jiazheng; Xu, Feng; Yung, Yuk L.

2018-07-01

Even though it was not designed as an exoplanetary research mission, the Deep Space Climate Observatory ( DSCOVR ) has been opportunistically used for a novel experiment in which Earth serves as a proxy exoplanet. More than 2 yr of DSCOVR Earth images were employed to produce time series of multiwavelength, single-point light sources in order to extract information on planetary rotation, cloud patterns, surface type, and orbit around the Sun. In what follows, we assume that these properties of the Earth are unknown and instead attempt to derive them from first principles. These conclusions are then compared with known data about our planet. We also used the DSCOVR data to simulate phase-angle changes, as well as the minimum data collection rate needed to determine the rotation period of an exoplanet. This innovative method of using the time evolution of a multiwavelength, reflected single-point light source can be deployed for retrieving a range of intrinsic properties of an exoplanet around a distant star.

Response of a comprehensive climate model to a broad range of external forcings: relevance for deep ocean ventilation and the development of late Cenozoic ice ages

NASA Astrophysics Data System (ADS)

Galbraith, Eric; de Lavergne, Casimir

2018-03-01

Over the past few million years, the Earth descended from the relatively warm and stable climate of the Pliocene into the increasingly dramatic ice age cycles of the Pleistocene. The influences of orbital forcing and atmospheric CO2 on land-based ice sheets have long been considered as the key drivers of the ice ages, but less attention has been paid to their direct influences on the circulation of the deep ocean. Here we provide a broad view on the influences of CO2, orbital forcing and ice sheet size according to a comprehensive Earth system model, by integrating the model to equilibrium under 40 different combinations of the three external forcings. We find that the volume contribution of Antarctic (AABW) vs. North Atlantic (NADW) waters to the deep ocean varies widely among the simulations, and can be predicted from the difference between the surface densities at AABW and NADW deep water formation sites. Minima of both the AABW-NADW density difference and the AABW volume occur near interglacial CO2 (270-400 ppm). At low CO2, abundant formation and northward export of sea ice in the Southern Ocean contributes to very salty and dense Antarctic waters that dominate the global deep ocean. Furthermore, when the Earth is cold, low obliquity (i.e. a reduced tilt of Earth's rotational axis) enhances the Antarctic water volume by expanding sea ice further. At high CO2, AABW dominance is favoured due to relatively warm subpolar North Atlantic waters, with more dependence on precession. Meanwhile, a large Laurentide ice sheet steers atmospheric circulation as to strengthen the Atlantic Meridional Overturning Circulation, but cools the Southern Ocean remotely, enhancing Antarctic sea ice export and leading to very salty and expanded AABW. Together, these results suggest that a `sweet spot' of low CO2, low obliquity and relatively small ice sheets would have poised the AMOC for interruption, promoting Dansgaard-Oeschger-type abrupt change. The deep ocean temperature and salinity simulated under the most representative `glacial' state agree very well with reconstructions from the Last Glacial Maximum (LGM), which lends confidence in the ability of the model to estimate large-scale changes in water-mass geometry. The model also simulates a circulation-driven increase of preformed radiocarbon reservoir age, which could explain most of the reconstructed LGM-preindustrial ocean radiocarbon change. However, the radiocarbon content of the simulated glacial ocean is still higher than reconstructed for the LGM, and the model does not reproduce reconstructed LGM deep ocean oxygen depletions. These ventilation-related disagreements probably reflect unresolved physical aspects of ventilation and ecosystem processes, but also raise the possibility that the LGM ocean circulation was not in equilibrium. Finally, the simulations display an increased sensitivity of both surface air temperature and AABW volume to orbital forcing under low CO2. We suggest that this enhanced orbital sensitivity contributed to the development of the ice age cycles by amplifying the responses of climate and the carbon cycle to orbital forcing, following a gradual downward trend of CO2.

Planetary Perspective on Life on Early Mars and the Early Earth

NASA Technical Reports Server (NTRS)

Sleep, Norman H.; Zahnle, Kevin

1996-01-01

Impacts of asteroids and comets posed a major hazard to the continuous existence of early life on Mars as on the Earth. The chief danger was presented by globally distributed ejecta, which for very large impacts takes the form of transient thick rock vapor atmospheres; both planets suffered such impacts repeatedly. The exposed surface on both planets was sterilized when it was quickly heated to the temperature of condensed rock vapor by radiation and rock rain. Shallow water bodies were quickly evaporated and sterilized. Any surviving life must have been either in deep water or well below the surface.

The tremendous potential of deep-sea mud as a source of rare-earth elements.

PubMed

Takaya, Yutaro; Yasukawa, Kazutaka; Kawasaki, Takehiro; Fujinaga, Koichiro; Ohta, Junichiro; Usui, Yoichi; Nakamura, Kentaro; Kimura, Jun-Ichi; Chang, Qing; Hamada, Morihisa; Dodbiba, Gjergj; Nozaki, Tatsuo; Iijima, Koichi; Morisawa, Tomohiro; Kuwahara, Takuma; Ishida, Yasuyuki; Ichimura, Takao; Kitazume, Masaki; Fujita, Toyohisa; Kato, Yasuhiro

2018-04-10

Potential risks of supply shortages for critical metals including rare-earth elements and yttrium (REY) have spurred great interest in commercial mining of deep-sea mineral resources. Deep-sea mud containing over 5,000 ppm total REY content was discovered in the western North Pacific Ocean near Minamitorishima Island, Japan, in 2013. This REY-rich mud has great potential as a rare-earth metal resource because of the enormous amount available and its advantageous mineralogical features. Here, we estimated the resource amount in REY-rich mud with Geographical Information System software and established a mineral processing procedure to greatly enhance its economic value. The resource amount was estimated to be 1.2 Mt of rare-earth oxide for the most promising area (105 km 2  × 0-10 mbsf), which accounts for 62, 47, 32, and 56 years of annual global demand for Y, Eu, Tb, and Dy, respectively. Moreover, using a hydrocyclone separator enabled us to recover selectively biogenic calcium phosphate grains, which have high REY content (up to 22,000 ppm) and constitute the coarser domain in the grain-size distribution. The enormous resource amount and the effectiveness of the mineral processing are strong indicators that this new REY resource could be exploited in the near future.

Snowball Earth prevention by dissolved organic carbon remineralization.

PubMed

Peltier, W Richard; Liu, Yonggang; Crowley, John W

2007-12-06

The 'snowball Earth' hypothesis posits the occurrence of a sequence of glaciations in the Earth's history sufficiently deep that photosynthetic activity was essentially arrested. Because the time interval during which these events are believed to have occurred immediately preceded the Cambrian explosion of life, the issue as to whether such snowball states actually developed has important implications for our understanding of evolutionary biology. Here we couple an explicit model of the Neoproterozoic carbon cycle to a model of the physical climate system. We show that the drawdown of atmospheric oxygen into the ocean, as surface temperatures decline, operates so as to increase the rate of remineralization of a massive pool of dissolved organic carbon. This leads directly to an increase of atmospheric carbon dioxide, enhanced greenhouse warming of the surface of the Earth, and the prevention of a snowball state.

A migratory mantle plume on Venus: Implications for Earth?

USGS Publications Warehouse

Chapman, M.G.; Kirk, R.L.

1996-01-01

A spatially fixed or at least internally rigid hotspot reference frame has been assumed for determining relative plate motions on Earth. Recent 1:5,000,000 scale mapping of Venus, a planet without terrestrial-style plate tectonics and ocean cover, reveals a systematic age and dimensional progression of corona-like arachnoids occurring in an uncinate chain. The nonrandom associations between arachnoids indicate they likely formed from a deep-seated mantle plume in a manner similar to terrestrial hotspot features. However, absence of expected convergent "plate" margin deformation suggests that the arachnoids are the surface expression of a migratory mantle plume beneath a stationary surface. If mantle plumes are not stationary on Venus, what if any are the implications for Earth?

Clay particles as binder for earth buildings materials: a fresh look into rheology of dense clay suspensions

NASA Astrophysics Data System (ADS)

Landrou, Gnanli; Brumaud, Coralie; Habert, Guillaume

2017-06-01

In the ceramic industry and in many sectors, clay minerals are widely used. In earthen construction technique, clay plays a crucial role in the processing. The purpose of this research is to understand and modify the clay properties in earth material to propose an innovative strategy to develop a castable earth-based material. To do so, we focused on the modification of clay properties at fresh state with inorganic additives. As the rheological behaviour of clays is controlled by their surface charge, the addition of phosphate anion allows discussing deep the rheology of concentrated clay suspensions. We highlighted the thixotropic and shear thickening behaviour of a dispersed kaolinite clay suspensions. Indeed, by adding sodium hexametaphosphate the workability of clay paste increases and the behaviour is stable during time after a certain shear is applied. Moreover, we stress that the aging and the shift in critical strain in clay system are due to the re-arrangement of clay suspension and a decrease of deformation during time. The understanding of both effect: thixotropy and aging are crucial for better processing of clay-based material and for self-compacting clay concrete. Yet, studies need to pursue to better understand the mechanism.

Deep-Sea Bioluminescence Blooms after Dense Water Formation at the Ocean Surface

PubMed Central

Tamburini, Christian; Canals, Miquel; Durrieu de Madron, Xavier; Houpert, Loïc; Lefèvre, Dominique; Martini, Séverine; D'Ortenzio, Fabrizio; Robert, Anne; Testor, Pierre; Aguilar, Juan Antonio; Samarai, Imen Al; Albert, Arnaud; André, Michel; Anghinolfi, Marco; Anton, Gisela; Anvar, Shebli; Ardid, Miguel; Jesus, Ana Carolina Assis; Astraatmadja, Tri L.; Aubert, Jean-Jacques; Baret, Bruny; Basa, Stéphane; Bertin, Vincent; Biagi, Simone; Bigi, Armando; Bigongiari, Ciro; Bogazzi, Claudio; Bou-Cabo, Manuel; Bouhou, Boutayeb; Bouwhuis, Mieke C.; Brunner, Jurgen; Busto, José; Camarena, Francisco; Capone, Antonio; Cârloganu, Christina; Carminati, Giada; Carr, John; Cecchini, Stefano; Charif, Ziad; Charvis, Philippe; Chiarusi, Tommaso; Circella, Marco; Coniglione, Rosa; Costantini, Heide; Coyle, Paschal; Curtil, Christian; Decowski, Patrick; Dekeyser, Ivan; Deschamps, Anne; Donzaud, Corinne; Dornic, Damien; Dorosti, Hasankiadeh Q.; Drouhin, Doriane; Eberl, Thomas; Emanuele, Umberto; Ernenwein, Jean-Pierre; Escoffier, Stéphanie; Fermani, Paolo; Ferri, Marcelino; Flaminio, Vincenzo; Folger, Florian; Fritsch, Ulf; Fuda, Jean-Luc; Galatà, Salvatore; Gay, Pascal; Giacomelli, Giorgio; Giordano, Valentina; Gómez-González, Juan-Pablo; Graf, Kay; Guillard, Goulven; Halladjian, Garadeb; Hallewell, Gregory; van Haren, Hans; Hartman, Joris; Heijboer, Aart J.; Hello, Yann; Hernández-Rey, Juan Jose; Herold, Bjoern; Hößl, Jurgen; Hsu, Ching-Cheng; de Jong, Marteen; Kadler, Matthias; Kalekin, Oleg; Kappes, Alexander; Katz, Uli; Kavatsyuk, Oksana; Kooijman, Paul; Kopper, Claudio; Kouchner, Antoine; Kreykenbohm, Ingo; Kulikovskiy, Vladimir; Lahmann, Robert; Lamare, Patrick; Larosa, Giuseppina; Lattuada, Dario; Lim, Gordon; Presti, Domenico Lo; Loehner, Herbert; Loucatos, Sotiris; Mangano, Salvatore; Marcelin, Michel; Margiotta, Annarita; Martinez-Mora, Juan Antonio; Meli, Athina; Montaruli, Teresa; Motz, Holger; Neff, Max; Nezri, Emma nuel; Palioselitis, Dimitris; Păvălaş, Gabriela E.; Payet, Kevin; Payre, Patrice; Petrovic, Jelena; Piattelli, Paolo; Picot-Clemente, Nicolas; Popa, Vlad; Pradier, Thierry; Presani, Eleonora; Racca, Chantal; Reed, Corey; Riccobene, Giorgio; Richardt, Carsten; Richter, Roland; Rivière, Colas; Roensch, Kathrin; Rostovtsev, Andrei; Ruiz-Rivas, Joaquin; Rujoiu, Marius; Russo, Valerio G.; Salesa, Francisco; Sánchez-Losa, Augustin; Sapienza, Piera; Schöck, Friederike; Schuller, Jean-Pierre; Schussler, Fabian; Shanidze, Rezo; Simeone, Francesco; Spies, Andreas; Spurio, Maurizio; Steijger, Jos J. M.; Stolarczyk, Thierry; Taiuti, Mauro G. F.; Toscano, Simona; Vallage, Bertrand; Van Elewyck, Véronique; Vannoni, Giulia; Vecchi, Manuela; Vernin, Pascal; Wijnker, Guus; Wilms, Jorn; de Wolf, Els; Yepes, Harold; Zaborov, Dmitry; De Dios Zornoza, Juan; Zúñiga, Juan

2013-01-01

The deep ocean is the largest and least known ecosystem on Earth. It hosts numerous pelagic organisms, most of which are able to emit light. Here we present a unique data set consisting of a 2.5-year long record of light emission by deep-sea pelagic organisms, measured from December 2007 to June 2010 at the ANTARES underwater neutrino telescope in the deep NW Mediterranean Sea, jointly with synchronous hydrological records. This is the longest continuous time-series of deep-sea bioluminescence ever recorded. Our record reveals several weeks long, seasonal bioluminescence blooms with light intensity up to two orders of magnitude higher than background values, which correlate to changes in the properties of deep waters. Such changes are triggered by the winter cooling and evaporation experienced by the upper ocean layer in the Gulf of Lion that leads to the formation and subsequent sinking of dense water through a process known as “open-sea convection”. It episodically renews the deep water of the study area and conveys fresh organic matter that fuels the deep ecosystems. Luminous bacteria most likely are the main contributors to the observed deep-sea bioluminescence blooms. Our observations demonstrate a consistent and rapid connection between deep open-sea convection and bathypelagic biological activity, as expressed by bioluminescence. In a setting where dense water formation events are likely to decline under global warming scenarios enhancing ocean stratification, in situ observatories become essential as environmental sentinels for the monitoring and understanding of deep-sea ecosystem shifts. PMID:23874425

A complete tomography of the Earth's interior with floating seismometers in the oceans: the EarthScope-Oceans

NASA Astrophysics Data System (ADS)

Chen, Y. J.; Nolet, G.

2016-12-01

While the tomography techniques of imaging the earth's interior have been improved significantly over the past three decades the resolution of the resulting 3D images of the earth's interior, particularly the lower mantle, has been severely limited by the lack of seismic stations in the oceans which cover the 2/3 of the earth's surface. But this is going to be changed by the recently developed floating hydrophones called "Mermaids" which, freely floating under the sea surface, can operate as seismometers (see abstract by Nolet et al. in session DI010). These `Mermaids' have recorded (1) teleseismic waves, crucial to provide resolution for tomographic images of the deep mantle beneath oceanic areas, as well as (2) swarms of earthquakes too small to be observed on land, indicative of tectonic motions on oceanic ridges. Transmission is in quasi-real time by satellite (Iridium). A new version of the Mermaid, of much larger capacity, with a lifetime of five to six years is available for deployment. SUSTC in Shenzhen, China, in close collaboration with Geoazur (France), will launch the first stage of a large scale, global network of floating seismometers in the oceans named EarthScope-Oceans in 2017 by setting afloat 50 Mermaids in the Indian Ocean. Japan and other European nations may join the effort, which should reach 500 sensors by 2019 covering the entire world oceans. After that, the robots will be equipped with sophisticated software currently under development, which adds the capacity to juggle up to eight sensors and that has a reprogramming ability even during missions. We then expect the network to become multi-disciplinary and be able to host instruments not only for global seismology but also for biologists, oceanographers, geochemists, meteorologists and others. This new monitoring network will greatly improve our knowledge of acoustic noise pollution, of cetacean populations and their interaction with noise and meteorological conditions in all of the oceans by providing large and continuous data coverage. It will transform the discipline of seismic tomography at sea and improve our understanding of geodynamical processes operating in the deep mantle of the Earth by filling the data gap that currently exists in the oceanic domain.

Earthquakes - on the moon

NASA Technical Reports Server (NTRS)

Nakamura, Y.

1981-01-01

Information obtained with the Apollo lunar seismic stations is discussed. The four types of natural seismic sources that have been identified are described, viz., thermal moonquakes, deep moonquakes, meteoroid impacts, and shallow moonquakes. It is suggested that: (1) the thermal quakes represent the slow cracking and movement of surface rocks; (2) the deep quakes are induced by the tide-generating force of the earth's gravity; (3) the meteoroids responsible for most of the observed impacts are in the mass range from 1 to 100 kg and are clustered in groups near the earth's orbit; and (4) the shallow quakes are similar to intraplate earthquakes and indicate that the moon is as seismically active as the interior regions of the earth's tectonic plates. The structure of the lunar interior as inferred from seismic signals due to both the last three natural sources and 'artificial' impacts of used spacecraft is examined in detail.

Considering bioactivity in modelling continental growth and the Earth's evolution

NASA Astrophysics Data System (ADS)

Höning, D.; Spohn, T.

2013-09-01

The complexity of planetary evolution increases with the number of interacting reservoirs. On Earth, even the biosphere is speculated to interact with the interior. It has been argued (e.g., Rosing et al. 2006; Sleep et al, 2012) that the formation of continents could be a consequence of bioactivity harvesting solar energy through photosynthesis to help build the continents and that the mantle should carry a chemical biosignature. Through plate tectonics, the surface biosphere can impact deep subduction zone processes and the interior of the Earth. Subducted sediments are particularly important, because they influence the Earth's interior in several ways, and in turn are strongly influenced by the Earth's biosphere. In our model, we use the assumption that a thick sedimentary layer of low permeability on top of the subducting oceanic crust, caused by a biologically enhanced weathering rate, can suppress shallow dewatering. This in turn leads to greater vailability of water in the source region of andesitic partial melt, resulting in an enhanced rate of continental production and regassing rate into the mantle. Our model includes (i) mantle convection, (ii) continental erosion and production, and (iii) mantle water degassing at mid-ocean ridges and regassing at subduction zones. The mantle viscosity of our model depends on (i) the mantle water concentration and (ii) the mantle temperature, whose time dependency is given by radioactive decay of isotopes in the Earth's mantle. Boundary layer theory yields the speed of convection and the water outgassing rate of the Earth's mantle. Our results indicate that present day values of continental surface area and water content of the Earth's mantle represent an attractor in a phase plane spanned by both parameters. We show that the biologic enhancement of the continental erosion rate is important for the system to reach this fixed point. An abiotic Earth tends to reach an alternative stable fixed point with a smaller continental surface area and dryer mantle. The origin and evolution of life on Earth might be responsible for the rise of continents 3.5 billion years ago.

Investigation of North Pond crustal fluids by poised potential methods

NASA Astrophysics Data System (ADS)

Jones, R. M.; Orcutt, B.

2017-12-01

Microbes are present in the deep subsurface but their rates of activity, potential metabolisms and roles in the environment are still largely unknown. The marine deep crustal subsurface accounts for approximately 2.3x1018 m2 of the earth's volume, making this environment potentially significant to earth processes despite low productivity inherent in resource limited conditions. This has implications for geochemical cycling and exploring limits of life, linking to the `follow the energy' approach for defining habitability on earth and further afield. Most resources for life in the marine deep crust originate from rock. One subset of lithotrophic interactions involves direct transfer between electron acceptors and donors embedded in minerals and microbes. In this investigation, poised potential methods such as chronoamperometry were used to investigate mineral-microbe electron transfer interactions in the context of North Pond, a Mid-Atlantic ridge site representative of cool, sediment-covered basalts that make up the majority of the deep marine subsurface. Electrodes were poised at potentials corresponding approximately to particular lithotrophic oxidation reactions to enrich for sub-sections of North Pond deep subsurface fluid communities that were associated with direct electron transfer at these potentials.

Apparatus for advancing a wellbore using high power laser energy

DOEpatents

Zediker, Mark S.; Land, Mark S.; Rinzler, Charles C.; Faircloth, Brian O.; Koblick, Yeshaya; Moxley, Joel F.

2014-09-02

Delivering high power laser energy to form a borehole deep into the earth using laser energy. Down hole laser tools, laser systems and laser delivery techniques for advancement, workover and completion activities. A laser bottom hole assembly (LBHA) for the delivery of high power laser energy to the surfaces of a borehole, which assembly may have laser optics, a fluid path for debris removal and a mechanical means to remove earth.

76 FR 27308 - Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Space Vehicle and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-11

... created by ascending rockets launched from the KLC reach the Earth's surface over deep ocean, well past... flushing in response to the rocket noise, or the mother/pup bond could be permanently broken. However, NMFS...

Deep space communication - Past, present, and future

NASA Technical Reports Server (NTRS)

Posner, E. C.; Stevens, R.

1984-01-01

This paper reviews the progress made in deep space communication from its beginnings until now, describes the development and applications of NASA's Deep Space Network, and indicates directions for the future. Limiting factors in deep space communication are examined using the upcoming Voyager encounter with Uranus, centered on the downlink telemetry from spacecraft to earth, as an example. A link calculation for Voyager at Uranus over Australia is exhibited. Seven basic deep space communication functions are discussed, and technical aspects of spacecraft communication equipment, ground antennas, and ground electronics and processing are considered.

Quantitative Modeling of Earth Surface Processes

NASA Astrophysics Data System (ADS)

Pelletier, Jon D.

This textbook describes some of the most effective and straightforward quantitative techniques for modeling Earth surface processes. By emphasizing a core set of equations and solution techniques, the book presents state-of-the-art models currently employed in Earth surface process research, as well as a set of simple but practical research tools. Detailed case studies demonstrate application of the methods to a wide variety of processes including hillslope, fluvial, aeolian, glacial, tectonic, and climatic systems. Exercises at the end of each chapter begin with simple calculations and then progress to more sophisticated problems that require computer programming. All the necessary computer codes are available online at www.cambridge.org/9780521855976. Assuming some knowledge of calculus and basic programming experience, this quantitative textbook is designed for advanced geomorphology courses and as a reference book for professional researchers in Earth and planetary science looking for a quantitative approach to Earth surface processes.

Effective Utilization of Resources and Infrastructure for a Spaceport Network Architecture

NASA Technical Reports Server (NTRS)

Gill, Tracy; Larson, Wiley; Mueller, Robert; Roberson, Luke

2012-01-01

Providing routine, affordable access to a variety of orbital and deep space destinations requires an intricate network of ground, planetary surface, and space-based spaceports like those on Earth (land and sea), in various Earth orbits, and on other extraterrestrial surfaces. Advancements in technology and international collaboration are critical to establish a spaceport network that satisfies the requirements for private and government research, exploration, and commercial objectives. Technologies, interfaces, assembly techniques, and protocols must be adapted to enable mission critical capabilities and interoperability throughout the spaceport network. The conceptual space mission architecture must address the full range of required spaceport services, from managing propellants for a variety of spacecraft to governance structure. In order to accomplish affordability and sustainability goals, the network architecture must consider deriving propellants from in situ planetary resources to the maximum extent possible. Water on the Moon and Mars, Mars' atmospheric CO2, and O2 extracted from lunar regolith are examples of in situ resources that could be used to generate propellants for various spacecraft, orbital stages and trajectories, and the commodities to support habitation and human operations at these destinations. The ability to use in-space fuel depots containing in situ derived propellants would drastically reduce the mass required to launch long-duration or deep space missions from Earth's gravity well. Advances in transformative technologies and common capabilities, interfaces, umbilicals, commodities, protocols, and agreements will facilitate a cost-effective, safe, reliable infrastructure for a versatile network of Earth- and extraterrestrial spaceports. Defining a common infrastructure on Earth, planetary surfaces, and in space, as well as deriving propellants from in situ planetary resources to construct in-space propellant depots to serve the spaceport network, will reduce exploration costs due to standardization of infrastructure commonality and reduction in number and types of interfaces and commodities.

Deep Space Earth Observations from DSCOVR

NASA Astrophysics Data System (ADS)

Marshak, A.; Herman, J.

2018-02-01

The Deep Space Climate Observatory (DSCOVR) at Sun-Earth L1 orbit observes the full sunlit disk of Earth. There are two Earth science instruments on board DSCOVR — EPIC and NISTAR. We discuss if EPIC and NISAR-like instruments can be used in Deep Space Gateway.

Deep Reconditioning Testing for near Earth Orbits

NASA Technical Reports Server (NTRS)

Betz, F. E.; Barnes, W. L.

1984-01-01

The problems and benefits of deep reconditioning to near Earth orbit missions with high cycle life and shallow discharge depth requirements is discussed. A simple battery level approach to deep reconditioning of nickel cadmium batteries in near Earth orbit is considered. A test plan was developed to perform deep reconditioning in direct comparison with an alternative trickle charge approach. The results demonstrate that the deep reconditioning procedure described for near Earth orbit application is inferior to the alternative of trickle charging.

High-resolution lidar topography of the Puget Lowland, Washington - A bonanza for earth science

USGS Publications Warehouse

Haugerud, R.A.; Harding, D.J.; Johnson, S.Y.; Harless, J.L.; Weaver, C.S.; Sherrod, B.L.

2003-01-01

More than 10,000 km2 of high-resolution, public-domain topography acquired by the Puget Sound Lidar Consortium is revolutionizing investigations of active faulting, continental glaciation, landslides, and surficial processes in the seismically active Puget Lowland. The Lowland-the population and economic center of the Pacific Northwest-presents special problems for hazards investigations, with its young glacial topography, dense forest cover, and urbanization. Lidar mapping during leaf-off conditions has led to a detailed digital model of the landscape beneath the forest canopy. The surface thus revealed contains a rich and diverse record of previously unknown surface-rupturing faults, deep-seated landslides, uplifted Holocene and Pleistocene beaches, and subglacial and periglacial features. More than half a dozen suspected postglacial fault scarps have been identified to date. Five scarps that have been trenched show evidence of large, Holocene, surface-rupturing earthquakes.

Earth's core and inner-core resonances from analysis of VLBI nutation and superconducting gravimeter data

NASA Astrophysics Data System (ADS)

Rosat, S.; Lambert, S. B.; Gattano, C.; Calvo, M.

2017-01-01

Geophysical parameters of the deep Earth's interior can be evaluated through the resonance effects associated with the core and inner-core wobbles on the forced nutations of the Earth's figure axis, as observed by very long baseline interferometry (VLBI), or on the diurnal tidal waves, retrieved from the time-varying surface gravity recorded by superconducting gravimeters (SGs). In this paper, we inverse for the rotational mode parameters from both techniques to retrieve geophysical parameters of the deep Earth. We analyse surface gravity data from 15 SG stations and VLBI delays accumulated over the last 35 yr. We show existing correlations between several basic Earth parameters and then decide to inverse for the rotational modes parameters. We employ a Bayesian inversion based on the Metropolis-Hastings algorithm with a Markov-chain Monte Carlo method. We obtain estimates of the free core nutation resonant period and quality factor that are consistent for both techniques. We also attempt an inversion for the free inner-core nutation (FICN) resonant period from gravity data. The most probable solution gives a period close to the annual prograde term (or S1 tide). However the 95 per cent confidence interval extends the possible values between roughly 28 and 725 d for gravity, and from 362 to 414 d from nutation data, depending on the prior bounds. The precisions of the estimated long-period nutation and respective small diurnal tidal constituents are hence not accurate enough for a correct determination of the FICN complex frequency.

Exploring Asteroid Interiors: The Deep Interior Mission Concept

NASA Technical Reports Server (NTRS)

Asphaug, E.; Belton, M. J. S.; Cangahuala, A.; Keith, L.; Klaasen, K.; McFadden, L.; Neumann, G.; Ostro, S. J.; Reinert, R.; Safaeinili, A.

2003-01-01

Deep Interior is a mission to determine the geophysical properties of near-Earth objects, including the first volumetric image of the interior of an asteroid. Radio reflection tomography will image the 3D distribution of complex dielectric properties within the 1 km rendezvous target and hence map structural, density or compositional variations. Laser altimetry and visible imaging will provide high-resolution surface topography. Smart surface pods culminating in blast experiments, imaged by the high frame rate camera and scanned by lidar, will characterize active mechanical behavior and structure of surface materials, expose unweathered surface for NIR analysis, and may enable some characterization of bulk seismic response. Multiple flybys en route to this target will characterize a diversity of asteroids, probing their interiors with non-tomographic radar reflectance experiments. Deep Interior is a natural follow-up to the NEARShoemaker mission and will provide essential guidance for future in situ asteroid and comet exploration. While our goal is to learn the interior geology of small bodies and how their surfaces behave, the resulting science will enable pragmatic technologies required of hazard mitigation and resource utilization.

Tidal tomography constrains Earth's deep-mantle buoyancy.

PubMed

Lau, Harriet C P; Mitrovica, Jerry X; Davis, James L; Tromp, Jeroen; Yang, Hsin-Ying; Al-Attar, David

2017-11-15

Earth's body tide-also known as the solid Earth tide, the displacement of the solid Earth's surface caused by gravitational forces from the Moon and the Sun-is sensitive to the density of the two Large Low Shear Velocity Provinces (LLSVPs) beneath Africa and the Pacific. These massive regions extend approximately 1,000 kilometres upward from the base of the mantle and their buoyancy remains actively debated within the geophysical community. Here we use tidal tomography to constrain Earth's deep-mantle buoyancy derived from Global Positioning System (GPS)-based measurements of semi-diurnal body tide deformation. Using a probabilistic approach, we show that across the bottom two-thirds of the two LLSVPs the mean density is about 0.5 per cent higher than the average mantle density across this depth range (that is, its mean buoyancy is minus 0.5 per cent), although this anomaly may be concentrated towards the very base of the mantle. We conclude that the buoyancy of these structures is dominated by the enrichment of high-density chemical components, probably related to subducted oceanic plates or primordial material associated with Earth's formation. Because the dynamics of the mantle is driven by density variations, our result has important dynamical implications for the stability of the LLSVPs and the long-term evolution of the Earth system.

Near Earth Architectural Options for a Future Deep Space Optical Communications Network

NASA Technical Reports Server (NTRS)

Edwards, B. L.; Liebrecht, P. E.; Fitzgerald, R. J.

2004-01-01

In the near future the National Aeronautics and Space Administration anticipates a significant increase in demand for long-haul communications services from deep space to Earth. Distances will range from 0.1 to 40 AU, with data rate requirements in the 1's to 1000's of Mbits/second. The near term demand is driven by NASA's Space Science Enterprise which wishes to deploy more capable instruments onboard spacecraft and increase the number of deep space missions. The long term demand is driven by missions with extreme communications challenges such as very high data rates from the outer planets, supporting sub-surface exploration, or supporting NASA's Human Exploration and Development of Space Enterprise beyond Earth orbit. Laser communications is a revolutionary communications technology that will dramatically increase NASA's ability to transmit information across the solar system. Lasercom sends information using beams of light and optical elements, such as telescopes and optical amplifiers, rather than RF signals, amplifiers, and antennas. This paper provides an overview of different network options at Earth to meet NASA's deep space lasercom requirements. It is based mainly on work done for the Mars Laser Communications Demonstration Project, a joint project between NASA's Goddard Space Flight Center (GSFC), the Jet Propulsion Laboratory, California Institute of Technology (JPL), and the Massachusetts Institute of Technology Lincoln Laboratory (MIT/LL). It reports preliminary conclusions from the Mars Lasercom Study conducted at MIT/LL and on additional work done for the Tracking and Data Relay Satellite System Continuation Study at GSFC. A lasercom flight terminal will be flown on the Mars Telesat Orbiter (MTO) to be launched by NASA in 2009, and will be the first high rate deep space demonstration of this revolutionary technology.

Rapid change of atmosphere on the Hadean Earth: Beyond Habitable Trinity on a tightrope

NASA Astrophysics Data System (ADS)

Arai, T.; Maruyama, S.

2014-12-01

Surface environment of Hadean Earth is a key to bear life on the Earth. All of previous works assumed that high pCO2 has been decreased to a few bars in the first a few hundreds millions of years (e.g., Zhanle et al., 2011). However, this process is not easy because of material and process barriers as shown below. Four barriers are present. First, the ultra-acidic pH (<0.1) of 4.4Ga ocean prevented the precipitation of carbonates at mid-oceanic ridge through water-rock interaction after the birth of primordial ocean driven by plate tectonics or pseudo-plate tectonics system. To overcome this barrier, primordial (anorthosite + KREEP) continents must have been above sea-level to increase pH rapidly through hydrological process. Second, major cap rocks on the Hadean oceanic crust must have been komatiite with minor basaltic rocks to precipitate carbonates through water-rock interaction and transport them into mantle through subduction at higher than the intermediate P/T geotherm on the Benioff plane. If not, carbonate minerals are all decarbonated at shallower depths than the Moho plane. Komatiite production depends on mantle potential temperature which must have been rapidly decreased to yield only Fe-enriched MORB by 3.8Ga. Third, the primordial continents composed of anorthosite with subordinate amounts of KREEP basalts must have been annihilated by 4.0Ga to alter pH to be possible to precipitate carbonates by hydrothermal process. The value of pCO2 must have been decreased down to a few bars from c.a. 50 bars at TSI (total surface irradiance) = 75% under the restricted time limit. If failed, the Earth must have been Venus state which is impossible to bear life on the planet. Fourth is the role of tectonic erosion to destroy and transport the primordial continent of anorthosite into deep mantle by subduction. Anorthosite + KREEP was the mother's milk grow life on the Earth, but disappeared by 4.0Ga or even earlier, but alternatively granites were formed and accumulated on the Earth to supply nutrients for life. This is time-dependent process to increase new continents. Fifth is the water content of 3-5km thick, if the value was over, no way to bear life nor evolution afterwards. After all, the Hadean Earth has passed the really risky tightrope processes to bear life. If any of above five conditions was lost, life has not been appeared.

Invertebrate population genetics across Earth's largest habitat: The deep-sea floor.

PubMed

Taylor, M L; Roterman, C N

2017-10-01

Despite the deep sea being the largest habitat on Earth, there are just 77 population genetic studies of invertebrates (115 species) inhabiting non-chemosynthetic ecosystems on the deep-sea floor (below 200 m depth). We review and synthesize the results of these papers. Studies reveal levels of genetic diversity comparable to shallow-water species. Generally, populations at similar depths were well connected over 100s-1,000s km, but studies that sampled across depth ranges reveal population structure at much smaller scales (100s-1,000s m) consistent with isolation by adaptation across environmental gradients, or the existence of physical barriers to connectivity with depth. Few studies were ocean-wide (under 4%), and 48% were Atlantic-focused. There is strong emphasis on megafauna and commercial species with research into meiofauna, "ecosystem engineers" and other ecologically important species lacking. Only nine papers account for ~50% of the planet's surface (depths below 3,500 m). Just two species were studied below 5,000 m, a quarter of Earth's seafloor. Most studies used single-locus mitochondrial genes revealing a common pattern of non-neutrality, consistent with demographic instability or selective sweeps; similar to deep-sea hydrothermal vent fauna. The absence of a clear difference between vent and non-vent could signify that demographic instability is common in the deep sea, or that selective sweeps render single-locus mitochondrial studies demographically uninformative. The number of population genetics studies to date is miniscule in relation to the size of the deep sea. The paucity of studies constrains meta-analyses where broad inferences about deep-sea ecology could be made. © 2017 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

Application of normal mode theory to seismic source and structure problems: Seismic investigations of upper mantle lateral heterogeneity. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Okal, E. A.

1978-01-01

The theory of the normal modes of the earth is investigated and used to build synthetic seismograms in order to solve source and structural problems. A study is made of the physical properties of spheroidal modes leading to a rational classification. Two problems addressed are the observability of deep isotropic seismic sources and the investigation of the physical properties of the earth in the neighborhood of the Core-Mantle boundary, using SH waves diffracted at the core's surface. Data sets of seismic body and surface waves are used in a search for possible deep lateral heterogeneities in the mantle. In both cases, it is found that seismic data do not require structural differences between oceans and continents to extend deeper than 250 km. In general, differences between oceans and continents are found to be on the same order of magnitude as the intrinsic lateral heterogeneity in the oceanic plate brought about by the aging of the oceanic lithosphere.

The role of sea-ice albedo in the climate of slowly rotating aquaplanets

NASA Astrophysics Data System (ADS)

Salameh, Josiane; Popp, Max; Marotzke, Jochem

2018-04-01

We investigate the influence of the rotation period (P_{rot}) on the mean climate of an aquaplanet, with a focus on the role of sea-ice albedo. We perform aquaplanet simulations with the atmospheric general circulation model ECHAM6 for various rotation periods from one Earth-day to 365 Earth-days in which case the planet is synchronously rotating. The global-mean surface temperature decreases with increasing P_{rot} and sea ice expands equatorwards. The cooling of the mean climate with increasing P_{rot} is caused partly by the high surface albedo of sea ice on the dayside and partly by the high albedo of the deep convective clouds over the substellar region. The cooling caused by these deep convective clouds is weak for non-synchronous rotations compared to synchronous rotation. Sensitivity simulations with the sea-ice model switched off show that the global-mean surface temperature is up to 27 K higher than in our main simulations with sea ice and thus highlight the large influence of sea ice on the climate. We present the first estimates of the influence of the rotation period on the transition of an Earth-like climate to global glaciation. Our results suggest that global glaciation of planets with synchronous rotation occurs at substantially lower incoming solar irradiation than for planets with slow but non-synchronous rotation.

Plate tectonics on Venus

NASA Technical Reports Server (NTRS)

Anderson, D. L.

1981-01-01

The high surface temperature of Venus implies a permanently buoyant lithosphere and a thick basaltic crust. Terrestrial-style tectonics with deep subduction and crustal recycling is not possible. Overthickened basaltic crust partially melts instead of converting to eclogite. Because mantle magmas do not have convenient access to the surface the Ar-40 abundance in the atmosphere should be low. Venus may provide an analog to Archean tectonics on the earth.

Temperature profiles in the earth of importance to deep electrical conductivity models

NASA Astrophysics Data System (ADS)

Čermák, Vladimír; Laštovičková, Marcela

1987-03-01

Deep in the Earth, the electrical conductivity of geological material is extremely dependent on temperature. The knowledge of temperature is thus essential for any interpretation of magnetotelluric data in projecting lithospheric structural models. The measured values of the terrestrial heat flow, radiogenic heat production and thermal conductivity of rocks allow the extrapolation of surface observations to a greater depth and the calculation of the temperature field within the lithosphere. Various methods of deep temperature calculations are presented and discussed. Characteristic geotherms are proposed for major tectonic provinces of Europe and it is shown that the existing temperatures on the crust-upper mantle boundary may vary in a broad interval of 350 1,000°C. The present work is completed with a survey of the temperature dependence of electrical conductivity for selected crustal and upper mantle rocks within the interval 200 1,000°C. It is shown how the knowledge of the temperature field can be used in the evaluation of the deep electrical conductivity pattern by converting the conductivity-versustemperature data into the conductivity-versus-depth data.

Mantle dynamics in super-Earths: Post-perovskite rheology and self-regulation of viscosity

NASA Astrophysics Data System (ADS)

Tackley, P. J.; Ammann, M.; Brodholt, J. P.; Dobson, D. P.; Valencia, D.

2013-07-01

The discovery of extra-solar "super-Earth" planets with sizes up to twice that of Earth has prompted interest in their possible lithosphere and mantle dynamics and evolution. Simple scalings suggest that super-Earths are more likely than an equivalent Earth-sized planet to be undergoing plate tectonics. Generally, viscosity and thermal conductivity increase with pressure while thermal expansivity decreases, resulting in lower convective vigour in the deep mantle, which, if extralopated to the largest super-Earths might, according to conventional thinking, result in no convection in their deep mantles due to the very low effective Rayleigh number. Here we evaluate this. First, as the mantle of a super-Earth is made mostly of post-perovskite we here extend the density functional theory (DFT) calculations of post-perovskite activation enthalpy of to a pressure of 1 TPa, for both slowest diffusion (upper-bound rheology) and fastest diffusion (lower-bound rheology) directions. Along a 1600 K adiabat the upper-bound rheology would lead to a post-perovskite layer of a very high (˜1030 Pa s) but relatively uniform viscosity, whereas the lower-bound rheology leads to a post-perovskite viscosity increase of ˜7 orders of magnitude with depth; in both cases the deep mantle viscosity would be too high for convection. Second, we use these DFT-calculated values in statistically steady-state numerical simulations of mantle convection and lithosphere dynamics of planets with up to ten Earth masses. The models assume a compressible mantle including depth-dependence of material properties and plastic yielding induced plate-like lithospheric behaviour. Results confirm the likelihood of plate tectonics for planets with Earth-like surface conditions (temperature and water) and show a self-regulation of deep mantle temperature. The deep mantle is not adiabatic; instead feedback between internal heating, temperature and viscosity regulates the temperature such that the viscosity has the value needed to facilitate convective loss of the radiogenic heat, which results in a very hot perovskite layer for the upper-bound rheology, a super-adiabatic perovskite layer for the lower-bound rheology, and an azimuthally-averaged viscosity of no more than 1026 Pa s. Convection in large super-Earths is characterised by large upwellings (even with zero basal heating) and small, time-dependent downwellings, which for large super-Earths merge into broad downwellings. In the context of planetary evolution, if, as is likely, a super-Earth was extremely hot/molten after its formation, it is thus likely that even after billions of years its deep interior is still extremely hot and possibly substantially molten with a "super basal magma ocean" - a larger version of the proposal of Labrosse et al. (Labrosse, S., Hernlund, J.W., Coltice, N. [2007]. Nature 450, 866-869), although this depends on presently unknown melt-solid density contrast and solidus.

Planetary benchmarks. [structural design criteria for radar reference devices on planetary surfaces

NASA Technical Reports Server (NTRS)

Uphoff, C.; Staehle, R.; Kobrick, M.; Jurgens, R.; Price, H.; Slade, M.; Sonnabend, D.

1978-01-01

Design criteria and technology requirements for a system of radar reference devices to be fixed to the surfaces of the inner planets are discussed. Offshoot applications include the use of radar corner reflectors as landing beacons on the planetary surfaces and some deep space applications that may yield a greatly enhanced knowledge of the gravitational and electromagnetic structure of the solar system. Passive retroreflectors with dimensions of about 4 meters and weighing about 10 kg are feasible for use with orbiting radar at Venus and Mars. Earth-based observation of passive reflectors, however, would require very large and complex structures to be delivered to the surfaces. For Earth-based measurements, surface transponders offer a distinct advantage in accuracy over passive reflectors. A conceptual design for a high temperature transponder is presented. The design appears feasible for the Venus surface using existing electronics and power components.

Aps and Tep Chemical Characterization: Link Between The Dom and Pom Pools

NASA Astrophysics Data System (ADS)

Gogou, A.; Repeta, D. J.

The ocean inventory of dissolved organic carbon (DOC) is approximately 750 GT, comprising one of the Earth's largest carbon reservoirs on Earth. Despite its potential significance, the mechanisms that lead to DOM production and to spatial and temporal variations of DOM concentration in the world ocean are poorly understood. Chemical characterization studies show that up to 50% of HMW DOM is a structurally well-defined class of acylated polysaccharides (APS), which exhibits novel molecular-level characteris tics. Although APS synthesis occurs in the euphotic zone, a large fraction of the marine inventory of APS (appr. 10-30 GT C), resides in the deep ocean, and is approximately equal in mass to the total marine inventory of particulate organic carbon. While radiocarbon dating of deep sea DOC yields very old apparent ages (4000-6000 ybp), radiocarbon measurements made by our group on individual APS sugars shows that APS in the deep ocean has a radiocarbon value of +56 per mil, equivalent to surface water POC and DIC. This is the first clear evidence for the presence of "young" DOC in the deep ocean. One mechanism that could be important for the rapid removal of APS from surface seawater is physical removal by macroaggregates. To investigate the significance of this mechanism, we studied the chemical composition of surface-active POM (TEP) produced naturally on surface waters and in laboratory experiments, after bubbling of HMW DOM isolated from algal cultures. 1H-NMR spectral properties and molecular-level distribution of neutral sugars in natural and artificially produced TEP closely resembled those observed for cultured and oceanic HMW DOM, while they are significantly different from those of suspended particulate matter in the ocean (Gogou and Repeta, 2000). The results of these experiments provide evidence that POM with similar chemical characteristics to HMW DOM can be produced from algal-derived DOM in the surface ocean.

Slip rates and spatially variable creep on faults of the northern San Andreas system inferred through Bayesian inversion of Global Positioning System data

USGS Publications Warehouse

Murray, Jessica R.; Minson, Sarah E.; Svarc, Jerry L.

2014-01-01

Fault creep, depending on its rate and spatial extent, is thought to reduce earthquake hazard by releasing tectonic strain aseismically. We use Bayesian inversion and a newly expanded GPS data set to infer the deep slip rates below assigned locking depths on the San Andreas, Maacama, and Bartlett Springs Faults of Northern California and, for the latter two, the spatially variable interseismic creep rate above the locking depth. We estimate deep slip rates of 21.5 ± 0.5, 13.1 ± 0.8, and 7.5 ± 0.7 mm/yr below 16 km, 9 km, and 13 km on the San Andreas, Maacama, and Bartlett Springs Faults, respectively. We infer that on average the Bartlett Springs fault creeps from the Earth's surface to 13 km depth, and below 5 km the creep rate approaches the deep slip rate. This implies that microseismicity may extend below the locking depth; however, we cannot rule out the presence of locked patches in the seismogenic zone that could generate moderate earthquakes. Our estimated Maacama creep rate, while comparable to the inferred deep slip rate at the Earth's surface, decreases with depth, implying a slip deficit exists. The Maacama deep slip rate estimate, 13.1 mm/yr, exceeds long-term geologic slip rate estimates, perhaps due to distributed off-fault strain or the presence of multiple active fault strands. While our creep rate estimates are relatively insensitive to choice of model locking depth, insufficient independent information regarding locking depths is a source of epistemic uncertainty that impacts deep slip rate estimates.

Deep Learning as an Individual, Conditional, and Contextual Influence on First-Year Student Outcomes

ERIC Educational Resources Information Center

Reason, Robert D.; Cox, Bradley E.; McIntosh, Kadian; Terenzini, Patrick T.

2010-01-01

For years, educators have drawn a distinction between deep cognitive processing and surface-level cognitive processing, with the former resulting in greater learning. In recent years, researchers at NSSE have created DEEP Learning scales, which consist of items related to students' experiences which are believed to encourage deep processing. In…

Hurricane Dean

NASA Technical Reports Server (NTRS)

2007-01-01

Location: The coast of Mexico from Manzanillo to Mazatlan Categorization: Tropical Depression Sustained Winds: 35 mph (56 km/hr)

[figure removed for brevity, see original site] [figure removed for brevity, see original site] Infrared ImageMicrowave Image

[figure removed for brevity, see original site] Click on the image to access AIRS Weather Snapshot for Hurricane Dean

Infrared Images Because infrared radiation does not penetrate through clouds, AIRS infrared images show either the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the storm. In cloud-free areas the AIRS instrument will receive the infrared radiation from the surface of the Earth, resulting in the warmest temperatures (orange/red).

Microwave Images In the AIRS microwave imagery, deep blue areas in storms show where the most precipitation occurs, or where ice crystals are present in the convective cloud tops. Outside of these storm regions, deep blue areas may also occur over the sea surface due to its low radiation emissivity. On the other hand, land appears much warmer due to its high radiation emissivity.

Microwave radiation from Earth's surface and lower atmosphere penetrates most clouds to a greater or lesser extent depending upon their water vapor, liquid water and ice content. Precipitation, and ice crystals found at the cloud tops where strong convection is taking place, act as barriers to microwave radiation. Because of this barrier effect, the AIRS microwave sensor detects only the radiation arising at or above their location in the atmospheric column. Where these barriers are not present, the microwave sensor detects radiation arising throughout the air column and down to the surface. Liquid surfaces (oceans, lakes and rivers) have 'low emissivity' (the signal isn't as strong) and their radiation brightness temperature is therefore low. Thus the ocean also appears 'low temperature' in the AIRS microwave images and is assigned the color blue. Therefore deep blue areas in storms show where the most precipitation occurs, or where ice crystals are present in the convective cloud tops. Outside of these storm regions, deep blue areas may also occur over the sea surface due to its low radiation emissivity. Land appears much warmer due to its high radiation emissivity.

Visible/Near-Infrared Images The AIRS instrument suite contains a sensor that captures radiation in four bands of the visible/near-infrared portion of the electromagetic spectrum. Data from three of these bands are combined to create 'visible' images similar to a snapshot taken with your camera.

The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

Hurricane Felix

NASA Technical Reports Server (NTRS)

2007-01-01

[figure removed for brevity, see original site] Microwave Image

These infrared and microwave images were created with data retrieved by the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite, and show the remnants of the former Hurricane Felix over Central America.

Infrared Images Because infrared radiation does not penetrate through clouds, AIRS infrared images show either the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the storm. In cloud-free areas the AIRS instrument will receive the infrared radiation from the surface of the Earth, resulting in the warmest temperatures (orange/red).

Microwave Images In the AIRS microwave imagery, deep blue areas in storms show where the most precipitation occurs, or where ice crystals are present in the convective cloud tops. Outside of these storm regions, deep blue areas may also occur over the sea surface due to its low radiation emissivity. On the other hand, land appears much warmer due to its high radiation emissivity.

Microwave radiation from Earth's surface and lower atmosphere penetrates most clouds to a greater or lesser extent depending upon their water vapor, liquid water and ice content. Precipitation, and ice crystals found at the cloud tops where strong convection is taking place, act as barriers to microwave radiation. Because of this barrier effect, the AIRS microwave sensor detects only the radiation arising at or above their location in the atmospheric column. Where these barriers are not present, the microwave sensor detects radiation arising throughout the air column and down to the surface. Liquid surfaces (oceans, lakes and rivers) have 'low emissivity' (the signal isn't as strong) and their radiation brightness temperature is therefore low. Thus the ocean also appears 'low temperature' in the AIRS microwave images and is assigned the color blue. Therefore deep blue areas in storms show where the most precipitation occurs, or where ice crystals are present in the convective cloud tops. Outside of these storm regions, deep blue areas may also occur over the sea surface due to its low radiation emissivity. Land appears much warmer due to its high radiation emissivity.

Visible/Near-Infrared Images The AIRS instrument suite contains a sensor that captures radiation in four bands of the visible/near-infrared portion of the electromagetic spectrum. Data from three of these bands are combined to create 'visible' images similar to a snapshot taken with your camera.

The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

Tropical Storm Erin

NASA Technical Reports Server (NTRS)

2007-01-01

Location: The Atlantic Ocean 210 miles south of Galveston, Texas Categorization: Tropical Storm Sustained Winds: 40 mph (60 km/hr)

[figure removed for brevity, see original site] [figure removed for brevity, see original site] Infrared ImageMicrowave Image

Infrared Images Because infrared radiation does not penetrate through clouds, AIRS infrared images show either the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the storm. In cloud-free areas the AIRS instrument will receive the infrared radiation from the surface of the Earth, resulting in the warmest temperatures (orange/red).

Microwave Images In the AIRS microwave imagery, deep blue areas in storms show where the most precipitation occurs, or where ice crystals are present in the convective cloud tops. Outside of these storm regions, deep blue areas may also occur over the sea surface due to its low radiation emissivity. On the other hand, land appears much warmer due to its high radiation emissivity.

Microwave radiation from Earth's surface and lower atmosphere penetrates most clouds to a greater or lesser extent depending upon their water vapor, liquid water and ice content. Precipitation, and ice crystals found at the cloud tops where strong convection is taking place, act as barriers to microwave radiation. Because of this barrier effect, the AIRS microwave sensor detects only the radiation arising at or above their location in the atmospheric column. Where these barriers are not present, the microwave sensor detects radiation arising throughout the air column and down to the surface. Liquid surfaces (oceans, lakes and rivers) have 'low emissivity' (the signal isn't as strong) and their radiation brightness temperature is therefore low. Thus the ocean also appears 'low temperature' in the AIRS microwave images and is assigned the color blue. Therefore deep blue areas in storms show where the most precipitation occurs, or where ice crystals are present in the convective cloud tops. Outside of these storm regions, deep blue areas may also occur over the sea surface due to its low radiation emissivity. Land appears much warmer due to its high radiation emissivity.

Visible/Near-Infrared Images The AIRS instrument suite contains a sensor that captures radiation in four bands of the visible/near-infrared portion of the electromagetic spectrum. Data from three of these bands are combined to create 'visible' images similar to a snapshot taken with your camera.

The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

Major technological innovations introduced in the large antennas of the Deep Space Network

NASA Technical Reports Server (NTRS)

Imbriale, W. A.

2002-01-01

The NASA Deep Space Network (DSN) is the largest and most sensitive scientific, telecommunications and radio navigation network in the world. Its principal responsibilities are to provide communications, tracking, and science services to most of the world's spacecraft that travel beyond low Earth orbit. The network consists of three Deep Space Communications Complexes. Each of the three complexes consists of multiple large antennas equipped with ultra sensitive receiving systems. A centralized Signal Processing Center (SPC) remotely controls the antennas, generates and transmits spacecraft commands, and receives and processes the spacecraft telemetry.

Nematoda from the terrestrial deep subsurface of South Africa.

PubMed

Borgonie, G; García-Moyano, A; Litthauer, D; Bert, W; Bester, A; van Heerden, E; Möller, C; Erasmus, M; Onstott, T C

2011-06-02

Since its discovery over two decades ago, the deep subsurface biosphere has been considered to be the realm of single-cell organisms, extending over three kilometres into the Earth's crust and comprising a significant fraction of the global biosphere. The constraints of temperature, energy, dioxygen and space seemed to preclude the possibility of more-complex, multicellular organisms from surviving at these depths. Here we report species of the phylum Nematoda that have been detected in or recovered from 0.9-3.6-kilometre-deep fracture water in the deep mines of South Africa but have not been detected in the mining water. These subsurface nematodes, including a new species, Halicephalobus mephisto, tolerate high temperature, reproduce asexually and preferentially feed upon subsurface bacteria. Carbon-14 data indicate that the fracture water in which the nematodes reside is 3,000-12,000-year-old palaeometeoric water. Our data suggest that nematodes should be found in other deep hypoxic settings where temperature permits, and that they may control the microbial population density by grazing on fracture surface biofilm patches. Our results expand the known metazoan biosphere and demonstrate that deep ecosystems are more complex than previously accepted. The discovery of multicellular life in the deep subsurface of the Earth also has important implications for the search for subsurface life on other planets in our Solar System.

Geodynamic models of the deep structure of the natural disaster regions of the Earth

NASA Astrophysics Data System (ADS)

Rodnikov, A. G.; Sergeyeva, N. A.; Zabarinskaya, L. P.

2012-04-01

Investigation of the deep structure and creation of geodynamic models of natural disaster regions are important for understanding of the nature of such phenomena as earthquakes, eruptions of volcanoes, tsunami and others. Carrying out of such researches is necessary for definition of areas of potential risk, forecasting and the prevention of negative consequences of acts of nature. Research region is active continental margins of the Sea of Okhotsk, and especially the area of Neftegorsk earthquake which has occurred on May, 28th 1995 in the North Sakhalin and caused many victims and destructions. The geodynamic model of the lithosphere in the region of Neftegorsk earthquake has been constructed along the profile crossing the North Sakhalin Basin, Deryugin Basin and ophiolite complex between them. The Deryugin Basin was formed at the site of an ancient deep trench after the subduction of the Okhotsk Sea Plate under Sakhalin. The basin is located above a hot plume in the mantle at a depth of 25 km. The ophiolite belt of ultramafic magmatic rocks is an ancient (K2-Pg) paleosubduction zone separating the Deryugin basin from the North Sakhalin Basin. The thickness of the ancient seismic focal zone is 80 km. It is probably that the structures of the North Sakhalin have been formed in the following way. In the Late Cretaceous the oceanic Okhotsk Sea Plate subducted under Sakhalin, the eastern part of which was an andesite island arc. Approximately in Miocene the subduction of the plate apparently ceased. In that time the Tatar Rift Strait was formed. Ophiolite rocks of the subduction zones as a result of compression have been squeezed out on a surface. The ophiolite complex combined by the ultrabasic rocks, fixes position of ancient subduction zone. It is probable that the manifestation of the Neftegorsk earthquake was a result of activization of this ancient subduction zone. On a surface the subduction zone manifests itself as deep faults running along Sakhalin. The center of the Neftegorsk earthquake was directly formed by burst of activity of this ancient subduction zone. From a position of the ancient subduction zone under Sakhalin, which is a cause of strong earthquakes here, it follows that the region is one of seismic dangerous in Russia. Constructed on the basis of complex interpretation of the geologic-geophysical data the geodynamic models of natural disaster regions give the chance: to study a deep structure under seismic dangerous zones; to investigate a role of deep processes in the upper mantle in formation of structures of earth crust; to relate the geological features, tectonomagmatic, hydrothermal activity with the processes in the upper mantle; to plot maps in detail with zones of increasing risks to prevent active building or other economic activities in such dangerous regions.

Consequences of Atomic Oxygen Interaction With Silicone and Silicone Contamination on Surfaces in Low Earth Orbit

NASA Technical Reports Server (NTRS)

Banks, Bruce A.; deGroh, Kim K.; Rutledge, Sharon K.; Haytas, Christy A.

1999-01-01

The exposure of silicones to atomic oxygen in low Earth orbit causes oxidation of the surface, resulting in conversion of silicone to silica. This chemical conversion increases the elastic modulus of the surface and initiates the development of a tensile strain. Ultimately, with sufficient exposure, tensile strain leads to cracking of the surface enabling the underlying unexposed silicone to be converted to silica resulting in additional depth and extent of cracking. The use of silicone coatings for the protection of materials from atomic oxygen attack is limited because of the eventual exposure of underlying unprotected polymeric material due to deep tensile stress cracking of the oxidized silicone. The use of moderate to high volatility silicones in low Earth orbit has resulted in a silicone contamination arrival at surfaces which are simultaneously being bombarded with atomic oxygen, thus leading to conversion of the silicone contaminant to silica. As a result of these processes, a gradual accumulation of contamination occurs leading to deposits which at times have been up to several microns thick (as in the case of a Mir solar array after 10 years in space). The contamination species typically consist of silicon, oxygen and carbon. which in the synergistic environment of atomic oxygen and UV radiation leads to increased solar absorptance and reduced solar transmittance. A comparison of the results of atomic oxygen interaction with silicones and silicone contamination will be presented based on the LDEF, EOIM-111, Offeq-3 spacecraft and Mir solar array in-space results. The design of a contamination pin-hole camera space experiment which uses atomic oxygen to produce an image of the sources of silicone contamination will also be presented.

Controlling defects and secondary phases of CZTS by surfactant Potassium

NASA Astrophysics Data System (ADS)

Zhu, Junyi; Zhang, Yiou; Tse, Kinfai; Xiao, Xudong

Cu2ZnSnS4 (CZTS) is a promising photovoltaic absorber material with earth abundant and nontoxic elements. However, the detrimental native defects and secondary phases of CSTS will largely reduce the energy conversion efficiencies. To understand the origin of these problems during the growth of CZTS, we investigated the kinetic processes on CZTS (-1-1-2) surface, using first principles calculations. A surface Zn atom was found to occupy the subsurface Cu site easily due to a low reaction barrier, which may lead to a high ZnCu concentration and a secondary phase of ZnS. These n-type defects may create deep electron traps near the interface and become detrimental to device performance. To reduce the population of ZnCu and the secondary phase, we propose to use K as a surfactant to alter surface kinetic processes. Improvements on crystal quality and device performance based on this surfactant are consistent with early experimental observations. Computing resources were provided by the High Performance Cluster Computing Centre, Hong Kong Baptist University. This work was supported by the start-up funding at CUHK.

The biological carbon pump in the ocean: Reviewing model representations and its feedbacks on climate perturbations.

NASA Astrophysics Data System (ADS)

Hülse, Dominik; Arndt, Sandra; Ridgwell, Andy; Wilson, Jamie

2016-04-01

The ocean-sediment system, as the biggest carbon reservoir in the Earth's carbon cycle, plays a crucial role in regulating atmospheric carbon dioxide concentrations and climate. Therefore, it is essential to constrain the importance of marine carbon cycle feedbacks on global warming and ocean acidification. Arguably, the most important single component of the ocean's carbon cycle is the so-called "biological carbon pump". It transports carbon that is fixed in the light-flooded surface layer of the ocean to the deep ocean and the surface sediment, where it is degraded/dissolved or finally buried in the deep sediments. Over the past decade, progress has been made in understanding different factors that control the efficiency of the biological carbon pump and their feedbacks on the global carbon cycle and climate (i.e. ballasting = ocean acidification feedback; temperature dependant organic matter degradation = global warming feedback; organic matter sulphurisation = anoxia/euxinia feedback). Nevertheless, many uncertainties concerning the interplay of these processes and/or their relative significance remain. In addition, current Earth System Models tend to employ empirical and static parameterisations of the biological pump. As these parametric representations are derived from a limited set of present-day observations, their ability to represent carbon cycle feedbacks under changing climate conditions is limited. The aim of my research is to combine past carbon cycling information with a spatially resolved global biogeochemical model to constrain the functioning of the biological pump and to base its mathematical representation on a more mechanistic approach. Here, I will discuss important aspects that control the efficiency of the ocean's biological carbon pump, review how these processes of first order importance are mathematically represented in existing Earth system Models of Intermediate Complexity (EMIC) and distinguish different approaches to approximate biogeochemical processes in the sediments. The performance of the respective mathematical representations in constraining the importance of carbon pump feedbacks on marine biogeochemical dynamics is then compared and evaluated under different extreme climate scenarios (e.g. OAE2, Eocene) using the Earth system model 'GENIE' and proxy records. The compiled mathematical descriptions and the model results underline the lack of a complete and mechanistic framework to represent the short-term carbon cycle in most EMICs which seriously limits the ability of these models to constrain the response of the ocean's carbon cycle to past and in particular future climate change. In conclusion, this presentation will critically evaluate the approaches currently used in marine biogeochemical modelling and outline key research directions concerning model development in the future.

The Once and Future Battles of Thor and the Midgard Serpent (or the Southern Ocean's Role in Climate)

NASA Astrophysics Data System (ADS)

Russell, J. L.

2017-12-01

Floats deployed by oceanographers are giving us all ringside seats to the epic battle between the wind and the deep ocean around Antarctica which will determine the rate of global atmospheric warming over the next century. The poleward-shift and intensification of the Southern Hemisphere westerly winds has been shown to maintain the connection between the surface ocean and the atmosphere with the deep ocean even as the surface ocean warms. This "doorway" allows the vast deep ocean reservoir to play a significant role in the transient global climate response to increasing atmospheric greenhouse gases. Coupled climate and earth system models at low and high resolution all simulate poleward-shifted and intensified Southern Hemisphere surface westerly winds when subjected to an atmospheric carbon dioxide doubling. Comparisons of these simulations reveal how stratification, resolution and eddies affect the transient global climate response to increasing atmospheric greenhouse gases - and our collective fate.

Pleistocene tropical Pacific temperature sensitivity to radiative greenhouse gas forcing

NASA Astrophysics Data System (ADS)

Dyck, K. A.; Ravelo, A. C.

2011-12-01

How high will Earth's global average surface temperature ultimately rise as greenhouse gas concentrations increase in the future? One way to tackle this question is to compare contemporaneous temperature and greenhouse gas concentration data from paleoclimate records, while considering that other radiative forcing mechanisms (e.g. changes in the amount and distribution of incoming solar radiation associated with changes in the Earth's orbital configuration) also contribute to surface temperature change. Since the sensitivity of surface temperature varies with location and latitude, here we choose a central location representative of the west Pacific warm pool, far from upwelling regions or surface temperature gradients in order to minimize climate feedbacks associated with high-latitude regions or oceanic dynamics. The 'steady-state' or long-term temperature change associated with greenhouse gas radiative forcing is often labeled as equilibrium (or 'Earth system') climate sensitivity to the doubling of atmospheric greenhouse gas concentration. Climate models suggest that Earth system sensitivity does not change dramatically over times when CO2 was lower or higher than the modern atmospheric value. Thus, in our investigation of the changes in tropical SST, from the glacial to interglacial states when greenhouse gas forcing nearly doubled, we use Late Pleistocene paleoclimate records to constrain earth system sensitivity for the tropics. Here we use Mg/Ca-paleothermometry using the foraminifera G. ruber from ODP Site 871 from the past 500 kyr in the western Pacific warm pool to estimate tropical Pacific equilibrium climate sensitivity to a doubling of greenhouse gas concentrations to be ~4°C. This tropical SST sensitivity to greenhouse gas forcing is ~1-2°C higher than that predicted by climate models of past glacial periods or future warming for the tropical Pacific. Equatorial Pacific SST sensitivity may be higher than predicted by models for a number of reasons. First, models may not be adequately representing long-term deep ocean feedbacks. Second, models may incorrectly parameterize tropical cloud (or other short-term) feedback processes. Lastly, either paleo-temperature or radiative forcing may have been incorrectly estimated (e.g. through calibration of paleoclimate evidence for temperature change). Since theory suggests that surface temperature in the high latitudes is more sensitive to radiative forcing changes than surface temperature in the tropics, the results of this study also imply that globally averaged Earth system sensitivity to greenhouse gas concentrations may be higher than most climate models predict.

Long Range Effect of The M7.8 April 2015 Nepal Earth Quake on the Deep Groudwater Outflow in a Thousand-Mile-Away Geothermal Field in Southern China's Guangdong

NASA Astrophysics Data System (ADS)

Lu, G.; Yu, S.; Xu, F.; Wang, X.; Yan, K.; Yuen, D. A.

2015-12-01

Deep ground waters sustain high temperature and pressure and are susceptible to impact from an earthquake. How an earthquake would have been associated with long-range effect on geological environment of deep groundwater is a question of interest to the scientific community and general public. The massive Richter 8.1 Nepal Earthquake (on April 25, 2015) provided a rare opportunity to test the response of deep groundwater systems. Deep ground waters at elevated temperature would naturally flow to ground surface along preferential flow path such as a deep fault, forming geothermal water flows. Geothermal water flows are susceptible to stress variation and can reflect the physical conditions of supercritical hot water kilometers deep down inside the crust. This paper introduces the monitoring work on the outflow in Xijiang Geothermal Field of Xinyi City, Guangdong Province in southern China. The geothermal field is one of typical geothermal fields with deep faults in Guangdong. The geothermal spring has characteristic daily variation of up to 72% in flow rate, which results from being associated with a north-south run deep fault susceptible to earthquake event. We use year-long monitoring data to illustrate how the Nepal earthquake would have affected the flows at the field site over 2.5 thousand kilometers away. The irregularity of flow is judged by deviation from otherwise good correlation of geothermal spring flow with solid earth tidal waves. This work could potentially provide the basis for further study of deep groundwater systems and insight to earthquake prediction.

This Dynamic Planet: World map of volcanoes, earthquakes, impact craters and plate tectonics

USGS Publications Warehouse

Simkin, Tom; Tilling, Robert I.; Vogt, Peter R.; Kirby, Stephen H.; Kimberly, Paul; Stewart, David B.

2006-01-01

Our Earth is a dynamic planet, as clearly illustrated on the main map by its topography, over 1500 volcanoes, 44,000 earthquakes, and 170 impact craters. These features largely reflect the movements of Earth's major tectonic plates and many smaller plates or fragments of plates (including microplates). Volcanic eruptions and earthquakes are awe-inspiring displays of the powerful forces of nature and can be extraordinarily destructive. On average, about 60 of Earth's 550 historically active volcanoes are in eruption each year. In 2004 alone, over 160 earthquakes were magnitude 6.0 or above, some of which caused casualties and substantial damage. This map shows many of the features that have shaped--and continue to change--our dynamic planet. Most new crust forms at ocean ridge crests, is carried slowly away by plate movement, and is ultimately recycled deep into the earth--causing earthquakes and volcanism along the boundaries between moving tectonic plates. Oceans are continually opening (e.g., Red Sea, Atlantic) or closing (e.g., Mediterranean). Because continental crust is thicker and less dense than thinner, younger oceanic crust, most does not sink deep enough to be recycled, and remains largely preserved on land. Consequently, most continental bedrock is far older than the oldest oceanic bedrock. (see back of map) The earthquakes and volcanoes that mark plate boundaries are clearly shown on this map, as are craters made by impacts of extraterrestrial objects that punctuate Earth's history, some causing catastrophic ecological changes. Over geologic time, continuing plate movements, together with relentless erosion and redeposition of material, mask or obliterate traces of earlier plate-tectonic or impact processes, making the older chapters of Earth's 4,500-million-year history increasingly difficult to read. The recent activity shown on this map provides only a present-day snapshot of Earth's long history, helping to illustrate how its present surface came to be. The map is designed to show the most prominent features when viewed from a distance, and more detailed features upon closer inspection. The back of the map zooms in further, highlighting examples of fundamental features, while providing text, timelines, references, and other resources to enhance understanding of this dynamic planet. Both the front and back of this map illustrate the enormous recent growth in our knowledge of planet Earth. Yet, much remains unknown, particularly about the processes operating below the ever-shifting plates and the detailed geological history during all but the most recent stage of Earth's development.

Anomalies of rupture velocity in deep earthquakes

NASA Astrophysics Data System (ADS)

Suzuki, M.; Yagi, Y.

2010-12-01

Explaining deep seismicity is a long-standing challenge in earth science. Deeper than 300 km, the occurrence rate of earthquakes with depth remains at a low level until ~530 km depth, then rises until ~600 km, finally terminate near 700 km. Given the difficulty of estimating fracture properties and observing the stress field in the mantle transition zone (410-660 km), the seismic source processes of deep earthquakes are the most important information for understanding the distribution of deep seismicity. However, in a compilation of seismic source models of deep earthquakes, the source parameters for individual deep earthquakes are quite varied [Frohlich, 2006]. Rupture velocities for deep earthquakes estimated using seismic waveforms range from 0.3 to 0.9Vs, where Vs is the shear wave velocity, a considerably wider range than the velocities for shallow earthquakes. The uncertainty of seismic source models prevents us from determining the main characteristics of the rupture process and understanding the physical mechanisms of deep earthquakes. Recently, the back projection method has been used to derive a detailed and stable seismic source image from dense seismic network observations [e.g., Ishii et al., 2005; Walker et al., 2005]. Using this method, we can obtain an image of the seismic source process from the observed data without a priori constraints or discarding parameters. We applied the back projection method to teleseismic P-waveforms of 24 large, deep earthquakes (moment magnitude Mw ≥ 7.0, depth ≥ 300 km) recorded since 1994 by the Data Management Center of the Incorporated Research Institutions for Seismology (IRIS-DMC) and reported in the U.S. Geological Survey (USGS) catalog, and constructed seismic source models of deep earthquakes. By imaging the seismic rupture process for a set of recent deep earthquakes, we found that the rupture velocities are less than about 0.6Vs except in the depth range of 530 to 600 km. This is consistent with the depth variation of deep seismicity: it peaks between about 530 and 600 km, where the fast rupture earthquakes (greater than 0.7Vs) are observed. Similarly, aftershock productivity is particularly low from 300 to 550 km depth and increases markedly at depth greater than 550 km [e.g., Persh and Houston, 2004]. We propose that large fracture surface energy (Gc) value for deep earthquakes generally prevent the acceleration of dynamic rupture propagation and generation of earthquakes between 300 and 700 km depth, whereas small Gc value in the exceptional depth range promote dynamic rupture propagation and explain the seismicity peak near 600 km.

Aerosol-Water Cycle Interaction: A New Challenge in Monsoon Climate Research

NASA Technical Reports Server (NTRS)

Lau, William K. M.

2006-01-01

Long recognized as a major environmental hazard, aerosol is now known to have strong impacts on both regional and global climate. It has been estimated that aerosol may reduce by up to 10% of the seasonal mean solar radiation reaching the earth surface, producing a global cooling effect that opposes global warming (Climate Change 2001). This means that the potential perils that humans have committed to global warming may be far greater than what we can detect at the present. As a key component of the Earth climate system, the water cycle is profoundly affected by the presence of aerosols in the atmosphere. Through the so-called "direct effect", aerosol scatters and/or absorbs solar radiation, thus cooling the earth surface and changing the horizontal and vertical radiational heating contrast in the atmosphere. The heating contrast drives anomalous atmospheric circulation, resulting in changes in convection, clouds, and rainfall. Another way aerosol can affect the water cycle is through the so-called "indirect effects", whereby aerosol increases the number of cloud condensation nuclei, prolongs life time of clouds, and inhibits the growth of cloud drops to raindrops. This leads to more clouds, and increased reflection of solar radiation, and further cooling at the earth surface. In monsoon regions, the response of the water cycle to aerosol forcing is especially complex, not only because of presence of diverse mix of aerosol species with vastly different radiative properties, but also because the monsoon is strongly influenced by ocean and land surface processes, land use, land change, as well as regional and global greenhouse warming effects. Thus, sorting out the impacts of aerosol forcing, and interaction with the monsoon water cycle is a very challenging problem. In this talk, I will offer some insights into how aerosols may impact the Asian monsoon based on preliminary results from satellite observations and climate model experiments. Specifically, I will discuss the "elevated heat pump" hypothesis, involving atmospheric heating by absorbing aerosols (dust and black carbon) over the southern slopes of the Himalayas, and feedback with the deep convection, in modifying monsoon water cycle over South and East Asia. The role of aerosol forcing relative to those due to sea surface temperature and land surface processes, as well as observation requirements to verify such a hypothesis will also be discussed.

Aerosol-Water Cycle Interaction: A New Challenge in Monsoon Climate Research

NASA Technical Reports Server (NTRS)

Lau, William K. M.

2006-01-01

Long recognized as a major environmental hazard, aerosol is now known to have strong impacts on both regional and global climate. It has been estimated that aerosol may reduce by up to 10% of the seasonal mean solar radiation reaching the earth surface, producing a global cooling effect that opposes global warming (Climate Change 2001). This means that the potential perils that humans have committed to global warming may be far greater than what we can detect at the present. As a key component of the Earth climate system, the water cycle is profoundly affected by the presence of aerosols in the atmosphere. Through the so-called direct effect , aerosol scatters and/or absorbs solar radiation, thus cooling the earth surface and changing the horizontal and vertical radiational heating contrast in the atmosphere. The heating contrast drives anomalous atmospheric circulation, resulting in changes in convection, clouds, and rainfall. Another way aerosol can affect the water cycle is through the so-called indirect effects, whereby aerosol increases the number of cloud condensation nuclei, prolongs life time of clouds, and inhibits the growth of cloud drops to raindrops. This leads to more clouds, and increased reflection of solar radiation, and further cooling at the earth surface. In monsoon regions, the response of the water cycle to aerosol forcing is especially complex, not only because of presence of diverse mix of aerosol species with vastly different radiative properties, but also because the monsoon is strongly influenced by ocean and land surface processes, land use, land change, as well as regional and global greenhouse warming effects. Thus, sorting out the impacts of aerosol forcing, and interaction with the monsoon water cycle is a very challenging problem. In this talk, I will offer some insights into how aerosols may impact the Asian monsoon based on preliminary results from satellite observations and climate model experiments. Specifically, I will discuss the elevated heat pump hypothesis, involving atmospheric heating by absorbing aerosols (dust and black carbon) over the southern slopes of the Himalayas, and feedback with the deep convection, in modifying monsoon water cycle over South .and East Asia. The role of aerosol forcing relative to those due to sea surface temperature and land surface processes, as well as observation requirements to verify such a hypothesis will also be discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zediker, Mark S.; Land, Mark S.; Rinzler, Charles C.

A system, apparatus and methods for delivering high power laser energy to perform laser operations in oil fields and to form a borehole deep into the earth using laser energy. A laser downhole assembly for the delivery of high power laser energy to surfaces and areas in a borehole, which assembly may have laser optics and a fluid path.

Deep Charging Evaluation of Satellite Power and Communication System Components

NASA Technical Reports Server (NTRS)

Schneider, T. A.; Vaughn, J. A.; Chu, B.; Wong, F.; Gardiner, G.; Wright, K. H.; Phillips, B.

2016-01-01

Deep charging, in contrast to surface charging, focuses on electron penetration deep into insulating materials applied over conductors. A classic example of this scenario is an insulated wire. Deep charging can pose a threat to material integrity, and to sensitive electronics, when it gives rise to an electrostatic discharge or arc. With the advent of Electric Orbit Raising, which requires spiraling through Earth's radiation belts, satellites are subjected to high energy electron environments which they normally would not encounter. Beyond Earth orbit, missions to Jupiter and Saturn face deep charging concerns due to the high energy radiation environments. While predictions can be made about charging in insulating materials, it is difficult to extend those predictions to complicated geometries, such as the case of an insulating coating around a small wire, or a non-uniform silicone grouting on a bus bar. Therefore, to conclusively determine the susceptibility of a system to arcs from deep charging, experimental investigations must be carried out. This paper will describe the evaluation carried out by NASA's Marshall Space Flight Center on subscale flight-like samples developed by Space Systems/Loral, LLC. Specifically, deep charging evaluations of solar array wire coupons, a photovoltaic cell coupon, and a coaxial microwave transmission cable, will be discussed. The results of each evaluation will be benchmarked against control sample tests, as well as typical power system levels, to show no significant deep charging threat existed for this set of samples under the conditions tested.

Operational GPS Imaging System at Multiple Scales for Earth Science and Monitoring of Geohazards

NASA Astrophysics Data System (ADS)

Blewitt, Geoffrey; Hammond, William; Kreemer, Corné

2016-04-01

Toward scientific targets that range from slow deep Earth processes to geohazard rapid response, our operational GPS data analysis system produces smooth, yet detailed maps of 3-dimensional land motion with respect to our Earth's center of mass at multiple spatio-temporal scales with various latencies. "GPS Imaging" is implemented operationally as a back-end processor to our GPS data processing facility, which uses JPL's GIPSY OASIS II software to produce positions from 14,000 GPS stations in ITRF every 5 minutes, with coordinate precision that gradually improves as latency increases upward from 1 hour to 2 weeks. Our GPS Imaging system then applies sophisticated signal processing and image filtering techniques to generate images of land motion covering our Earth's continents with high levels of robustness, accuracy, spatial resolution, and temporal resolution. Techniques employed by our GPS Imaging system include: (1) similarity transformation of polyhedron coordinates to ITRF with optional common-mode filtering to enhance local transient signal to noise ratio, (2) a comprehensive database of ~100,000 potential step events based on earthquake catalogs and equipment logs, (3) an automatic, robust, and accurate non-parametric estimator of station velocity that is insensitive to prevalent step discontinuities, outliers, seasonality, and heteroscedasticity; (4) a realistic estimator of velocity error bars based on subsampling statistics; (5) image processing to create a map of land motion that is based on median spatial filtering on the Delauney triangulation, which is effective at despeckling the data while faithfully preserving edge features; (6) a velocity time series estimator to assist identification of transient behavior, such as unloading caused by drought, and (7) a method of integrating InSAR and GPS for fine-scale seamless imaging in ITRF. Our system is being used to address three main scientific focus areas, including (1) deep Earth processes, (2) anthropogenic lithospheric processes, and (3) dynamic solid Earth events. Our prototype images show that the striking, first-order signal in North America and Europe is large scale uplift and subsidence from mantle flow driven by Glacial Isostatic Adjustment. At regional scales, the images reveal that anthropogenic lithospheric processes can dominate vertical land motion in extended regions, such as the rapid subsidence of California's Central Valley (CV) exacerbated by drought. The Earth's crust is observed to rebound elastically as evidenced by uplift of surrounding mountain ranges. Images also reveal natural uplift of mountains, mantle relaxation associated with earthquakes over the last century, and uplift at plate boundaries driven by interseismic locking. Using the high-rate positions at low latency, earthquake events can be rapidly imaged, modeled, and monitored for afterslip, potential aftershocks, and subsequent deeper relaxation. Thus we are imaging deep Earth processes with unprecedented scope, resolution and accuracy. In addition to supporting these scientific focus areas, the data products are also being used to support the global reference frame (ITRF), and show potential to enhance missions such as GRACE and NISAR by providing complementary information on Earth processes.

A Critical Discussion of Deep and Surface Processing: What It Means, How It Is Measured, the Role of Context, and Model Specification

ERIC Educational Resources Information Center

Dinsmore, Daniel L.; Alexander, Patricia A.

2012-01-01

The prevailing assumption by some that deep processing promotes stronger learning outcomes while surface processing promotes weaker learning outcomes has been called into question by the inconsistency and ambiguity of results in investigations of the relation between levels of processing and performance. The purpose of this literature review is to…

An Earth Summit in a Large General Education Oceanography Class

NASA Astrophysics Data System (ADS)

Dodson, H.; Prothero, W. A.

2001-12-01

An Earth Summit approach in UCSB's undergraduate physical oceanography course has raised student interest level while it also supports the course goals of increased learner awareness of the process of science, and critical analysis of scientific claims. At the beginning of the quarter, each group of students chooses a country to represent in the Earth Summit. During the course of the quarter, these groups relate each of the class themes to their chosen country. Themes include 1) ocean basins and plate tectonics, 2) atmospheres, oceans and climate, and 3) fisheries. Students acquire and utilize Earth data to support their positions. Earth data sources include the "Our Dynamic Planet" CDROM (http://oceanography.geol.ucsb.edu/ODP_Advert/odp_onepage.htm), NOAA's ocean and climate database (http://ferret.wrc.noaa.gov/las/), WorldWatcher CD (http://www.worldwatcher.northwestern.edu/) and JPL's Seawinds web site (http://haifung.jpl.nasa.gov/index.html). During the atmospheres, oceans and climate theme, students choose from 12 mini-studies that use various kinds of on-line Earth data related to important global or regional phenomena relevant to the course. The Earth datasets that the students access for their analysis include: winds; atmospheric pressure; ocean chemistry; sea surface temperature; solar radiation; precipitation, etc. The first group of 6 mini-studies focus on atmosphere and ocean, and are: 1) global winds and surface currents, 2) atmosphere and ocean interactions, 3) stratospheric ozone depletion, 4) El Nino, 5) Indian monsoon, and 6) deep ocean circulation. The second group focus on the Earth's heat budget and climate and are: 1) influence of man's activities on the climate, 2) the greenhouse effect, 3) seasonal variation and the Earth's heat budget, 4) global warming, 5) paleoclimate, and 6) volcanoes and climate. The students use what they have learned in these mini-studies to address atmospheric and climatic issues pertinent to their specific Earth Summit countries. For example, students representing the country of Chile might model their investigations after a)winds and surface currents, b)atmosphere and ocean interactions, c) stratospheric ozone depletion, d)El Nino; and/or e)volcanoes and climate. Please join the "Oceanography" interest group of DLESE to discuss, develop, and access oceanography related mini-studies that use earth data (http://oceanography.geol.ucsb.edu/dlese/wg_oceanog/Index.html). >http://oceanography.geol.ucsb.edu/AWP/Class_Info/GS-4/Labs/Labs Index.html

EarthCube - Earth System Bridge: Spanning Scientific Communities with Interoperable Modeling Frameworks

NASA Astrophysics Data System (ADS)

Peckham, S. D.; DeLuca, C.; Gochis, D. J.; Arrigo, J.; Kelbert, A.; Choi, E.; Dunlap, R.

2014-12-01

In order to better understand and predict environmental hazards of weather/climate, ecology and deep earth processes, geoscientists develop and use physics-based computational models. These models are used widely both in academic and federal communities. Because of the large effort required to develop and test models, there is widespread interest in component-based modeling, which promotes model reuse and simplified coupling to tackle problems that often cross discipline boundaries. In component-based modeling, the goal is to make relatively small changes to models that make it easy to reuse them as "plug-and-play" components. Sophisticated modeling frameworks exist to rapidly couple these components to create new composite models. They allow component models to exchange variables while accommodating different programming languages, computational grids, time-stepping schemes, variable names and units. Modeling frameworks have arisen in many modeling communities. CSDMS (Community Surface Dynamics Modeling System) serves the academic earth surface process dynamics community, while ESMF (Earth System Modeling Framework) serves many federal Earth system modeling projects. Others exist in both the academic and federal domains and each satisfies design criteria that are determined by the community they serve. While they may use different interface standards or semantic mediation strategies, they share fundamental similarities. The purpose of the Earth System Bridge project is to develop mechanisms for interoperability between modeling frameworks, such as the ability to share a model or service component. This project has three main goals: (1) Develop a Framework Description Language (ES-FDL) that allows modeling frameworks to be described in a standard way so that their differences and similarities can be assessed. (2) Demonstrate that if a model is augmented with a framework-agnostic Basic Model Interface (BMI), then simple, universal adapters can go from BMI to a modeling framework's native component interface. (3) Create semantic mappings between modeling frameworks that support semantic mediation. This third goal involves creating a crosswalk between the CF Standard Names and the CSDMS Standard Names (a set of naming conventions). This talk will summarize progress towards these goals.

Mothership - Affordable Exploration of Planetary Bodies through Individual Nano-Sats and Swarms

NASA Astrophysics Data System (ADS)

DiCorcia, James D.; Ernst, Sebastian M.; Grace, J. Mike; Gump, David P.; Lewis, John S.; Foulds, Craig F.; Faber, Daniel R.

2015-04-01

One concept to enable broad participation in the scientific exploration of small bodies is the Mothership mission architecture which delivers third-party nano-sats, experiments, and sensors to a near Earth asteroid or comet. Deep Space Industries' Mothership service includes delivery of nano-sats, communication to Earth, and visuals of the asteroid surface and surrounding area. It allows researchers to house their instruments in a low-cost nano-sat platform that does not require the high-performance propulsion or deep space communication capabilities that otherwise would be required for a solo asteroid mission. This enables organizations with relatively low operating budgets to closely examine an asteroid with highly specialized sensors of their own choosing, while the nano-sats can be built or commissioned by a variety of smaller institutions, companies, or agencies. In addition, the Mothership and its deployed nano-sats can offer a platform for instruments which need to be distributed over multiple spacecraft. The Mothership is designed to carry 10 to 12 nano-sats, based upon a variation of the Cubesat standard, with some flexibility on the specific geometry. The Deep Space Nano-Sat reference design is a 14.5 cm cube, which accomodates the same volume as a traditional 3U Cubesat. This design was found to be more favorable for deep space due to its thermal characteristics. The CubeSat standard was originally designed with operations in low Earth orbit in mind. By deliberately breaking the standard, Deep Space Nano-Sats offer better performance with less chance of a critical malfunction in the more hostile deep space environment. The first mission can launch as early as Q4 2017, with subsequent, regular launches through the 2020's.

The Ocean's Vital Skin: Toward an Integrated Understanding of the Sea Surface Microlayer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engel, Anja; Bange, Hermann W.; Cunliffe, Michael

Despite the huge extent of the ocean’s surface, until now relatively little attention has been paid to the sea surface microlayer (SML) as the ultimate interface where heat, momentum and mass exchange between the ocean and the atmosphere takes place. Via the SML, large-scale environmental changes in the ocean such as warming, acidification, deoxygenation, and eutrophication potentially influence cloud formation, precipitation, and the global radiation balance. Due to the deep connectivity between biological, chemical, and physical processes, studies of the SML may reveal multiple sensitivities to global and regional changes. Understanding the processes at the ocean’s surface, in particular involvingmore » the SML as an important and determinant interface, could therefore provide an essential contribution to the reduction of uncertainties regarding ocean-climate feedbacks. This review identifies gaps in our current knowledge of the SML and highlights a need to develop a holistic and mechanistic understanding of the diverse biological, chemical, and physical processes occurring at the ocean-atmosphere interface. We advocate the development of strong interdisciplinary expertise and collaboration in order to bridge between ocean and atmospheric sciences. Although this will pose significant methodological challenges, such an initiative would represent a new role model for interdisciplinary research in Earth System sciences.« less

The Ocean's Vital Skin: Toward an Integrated Understanding of the Sea Surface Microlayer

DOE PAGES

Engel, Anja; Bange, Hermann W.; Cunliffe, Michael; ...

2017-05-30

Despite the huge extent of the ocean’s surface, until now relatively little attention has been paid to the sea surface microlayer (SML) as the ultimate interface where heat, momentum and mass exchange between the ocean and the atmosphere takes place. Via the SML, large-scale environmental changes in the ocean such as warming, acidification, deoxygenation, and eutrophication potentially influence cloud formation, precipitation, and the global radiation balance. Due to the deep connectivity between biological, chemical, and physical processes, studies of the SML may reveal multiple sensitivities to global and regional changes. Understanding the processes at the ocean’s surface, in particular involvingmore » the SML as an important and determinant interface, could therefore provide an essential contribution to the reduction of uncertainties regarding ocean-climate feedbacks. This review identifies gaps in our current knowledge of the SML and highlights a need to develop a holistic and mechanistic understanding of the diverse biological, chemical, and physical processes occurring at the ocean-atmosphere interface. We advocate the development of strong interdisciplinary expertise and collaboration in order to bridge between ocean and atmospheric sciences. Although this will pose significant methodological challenges, such an initiative would represent a new role model for interdisciplinary research in Earth System sciences.« less

Where microorganisms meet rocks in the Earth's Critical Zone

NASA Astrophysics Data System (ADS)

Akob, D. M.; Küsel, K.

2011-03-01

The Earth's Critical Zone (CZ) is the critical, outer shell of the Earth that provides an arena for the interplay of diverse physical, chemical, and biological processes that are fundamental for sustaining life. As microbes are the principle drivers of biogeochemical cycles, it is necessary to understand the biodiversity of the CZ unseen majority and their impact on life-sustaining processes. This review aims to summarize the factors controlling where microbes (prokaryotes and micro-eukaryotes) live within the CZ and what is known to date about their diversity and function. Microbes live in all regions of the CZ down to 5 km depth, but due to changing habitat complexity, e.g., variability in pore spaces, water, oxygen, and nutrients, their functional role changes with depth. The abundance of prokaryotes and micro-eukaryotes decreases from a maximum of 1010 or 107 cells g soil-1 up to eight orders of magnitude with depth. Symbiotic mycorrhizal fungi and free-living decomposers are best understood in soil habitats, where they are up to 103 cells g soil-1. However, little is known about their identity and impact on weathering in the deep subsurface. The relatively low abundance of micro-eukaryotes in the deep subsurface suggests that these organisms are either limited in space or nutrients or unable to cope with oxygen limitations. Since deep regions of the CZ are limited in the recent input of photosynthesis-derived carbon, microbes are dependent on deposited organic material or on chemolithoautotrophic metabolism that allows for the establishment of a complete food chain independent from the surface. However, the energy flux available might only allow cell growth over tens to thousands of years. The recent development of "omics" technologies has provided microbial ecologists with methods to link the composition and function of in situ microbial communities. We should expect new metabolic discoveries as we have a closer look utilizing a polyphasic approach into the microbial communities of the CZ. Thus, future work is still needed to link microbial biodiversity to the exact role of microbes in weathering and geochemical cycling in the CZ, especially in subsurface habitats.

Experiments Demonstrate Geothermal Heating Process

ERIC Educational Resources Information Center

Roman, Harry T.

2012-01-01

When engineers design heat-pump-based geothermal heating systems for homes and other buildings, they can use coil loops buried around the perimeter of the structure to gather low-grade heat from the earth. As an alternative approach, they can drill well casings and store the summer's heat deep in the earth, then bring it back in the winter to warm…

Where should the upper boundary of the earth's critical zone be?

NASA Astrophysics Data System (ADS)

Liu, W.; Zhang, X. J.

2017-12-01

Recently increasing attention has been paid to the study of the critical zone (CZ) of the earth. The upper boundary of the CZ is generally defined as the top of plant canopy, and the lower boundary at the bottom of deep groundwater. The question is whether the ecological, biogeochemical and hydrological processes that are the focuses of CZ research occur within the scope of such boundaries. The role of water is central in these processes as is shown by the current studies as follows. First, there exist water vapor transport strips or pathways with higher flux strength than the surrounding areas in the troposphere, known as "tropospheric rivers" or "atmospheric rivers" (Newell, et al, 1992; Zhu, et al, 1998), specially dubbed as "sky rivers" (Wang, et al, 2016). The sky rivers are connected with the surface and underground rivers by precipitation and evapotranspiration processes, forming a complete water cycle system of the earth. Second, changes in atmospheric composition, such as aerosol increases, the formation of smog, CO2 concentration rising, directly or indirectly affected solar radiation and plant growth, which to a large extent determine potential evapotranspiration and vegetation cover change. Based on the Budyko model, annual water balance at a catchment is closely related to these changes (Zhang, et al., 2001; Ning, et al., 2017). Third, the theory of evaporation complementarity holds that surface evapotranspiration can be completely determined and calculated by meteorological data. Based on the eddy covariance observation for water and heat flux in the Loess Plateau (Brutsaert, et al., 2017), the relationship between calculated and observed ET values becomes stronger from 2m to 32m, which may be related to the existence of a blending height at higher elevations above the ground. Therefore, we deem that the CZ upper boundary should be selected at the tropopause of the atmosphere. The troposphere, directly affected by the earth surface, contains 3/4 of total mass of the whole atmosphere and almost all water vapor. Such a specification of the vertical CZ will afford comprehensive, systematic and in-depth studies on the near surface layer with focus on water role and cycle. This would also help define and attack the world problems regarding resources, environment and ecological services.

Between a rock and a hot place: the core-mantle boundary.

PubMed

Wookey, James; Dobson, David P

2008-12-28

The boundary between the rocky mantle and iron core, almost 2900 km below the surface, is physically the most significant in the Earth's interior. It may be the terminus for subducted surface material, the source of mantle plumes and a control on the Earth's magnetic field. Its properties also have profound significance for the thermochemical and dynamic evolution of the solid Earth. Evidence from seismology shows that D'' (the lowermost few hundred kilometres of the mantle) has a variety of anomalous features. Understanding the origin of these observations requires an understanding of the elastic and deformation properties of the deep Earth minerals. Core-mantle boundary pressures and temperatures are achievable in the laboratory using diamond anvil cell (DAC) apparatus. Such experiments have led to the recent discovery of a new phase, 'post-perovskite', which may explain many hitherto poorly understood properties of D''. Experimental work is also done using analogue minerals at lower pressures and temperatures; these circumvent some of the limits imposed by the small sample size allowed by the DAC. A considerable contribution also comes from theoretical methods that provide a wealth of otherwise unavailable information, as well as verification and refinement of experimental results. The future of the study of the lowermost mantle will involve the linking of the ever-improving seismic observations with predictions of material properties from theoretical and experimental mineral physics in a quantitative fashion, including simulations of the dynamics of the deep Earth. This has the potential to dispel much of the mystery that still surrounds this remote but important region.

Global Long-Term SeaWiFS Deep Blue Aerosol Products available at NASA GES DISC

NASA Technical Reports Server (NTRS)

Shen, Suhung; Sayer, A. M.; Bettenhausen, Corey; Wei, Jennifer C.; Ostrenga, Dana M.; Vollmer, Bruce E.; Hsu, Nai-Yung; Kempler, Steven J.

2012-01-01

Long-term climate data records about aerosols are needed in order to improve understanding of air quality, radiative forcing, and for many other applications. The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) provides a global well-calibrated 13- year (1997-2010) record of top-of-atmosphere radiance, suitable for use in retrieval of atmospheric aerosol optical depth (AOD). Recently, global aerosol products derived from SeaWiFS with Deep Blue algorithm (SWDB) have become available for the entire mission, as part of the NASA Making Earth Science data records for Use in Research for Earth Science (MEaSUREs) program. The latest Deep Blue algorithm retrieves aerosol properties not only over bright desert surfaces, but also vegetated surfaces, oceans, and inland water bodies. Comparisons with AERONET observations have shown that the data are suitable for quantitative scientific use [1],[2]. The resolution of Level 2 pixels is 13.5x13.5 km2 at the center of the swath. Level 3 daily and monthly data are composed by using best quality level 2 pixels at resolution of both 0.5ox0.5o and 1.0ox1.0o. Focusing on the southwest Asia region, this presentation shows seasonal variations of AOD, and the result of comparisons of 5-years (2003- 2007) of AOD from SWDB (Version 3) and MODIS Aqua (Version 5.1) for Dark Target (MYD-DT) and Deep Blue (MYD-DB) algorithms.

The Potential for Low-Temperature Abiotic Hydrogen Generation and a Hydrogen-Driven Deep Biosphere

PubMed Central

Huang, Shanshan; Thorseth, Ingunn H.

2011-01-01

Abstract The release and oxidation of ferrous iron during aqueous alteration of the mineral olivine is known to reduce aqueous solutions to such extent that molecular hydrogen, H2, forms. H2 is an efficient energy carrier and is considered basal to the deep subsurface biosphere. Knowledge of the potential for H2 generation is therefore vital to understanding the deep biosphere on Earth and on extraterrestrial bodies. Here, we provide a review of factors that may reduce the potential for H2 generation with a focus on systems in the core temperature region for thermophilic to hyperthermophilic microbial life. We show that aqueous sulfate may inhibit the formation of H2, whereas redox-sensitive compounds of carbon and nitrogen are unlikely to have significant effect at low temperatures. In addition, we suggest that the rate of H2 generation is proportional to the dissolution rate of olivine and, hence, limited by factors such as reactive surface areas and the access of water to fresh surfaces. We furthermore suggest that the availability of water and pore/fracture space are the most important factors that limit the generation of H2. Our study implies that, because of large heat flows, abundant olivine-bearing rocks, large thermodynamic gradients, and reduced atmospheres, young Earth and Mars probably offered abundant systems where microbial life could possibly have emerged. Key Words: Serpentinization—Olivine—Hydrogen—Deep biosphere—Water—Mars. Astrobiology 11, 711–724. PMID:21923409

Computer Aided Process Planning for Non-Axisymmetric Deep Drawing Products

NASA Astrophysics Data System (ADS)

Park, Dong Hwan; Yarlagadda, Prasad K. D. V.

2004-06-01

In general, deep drawing products have various cross-section shapes such as cylindrical, rectangular and non-axisymmetric shapes. The application of the surface area calculation to non-axisymmetric deep drawing process has not been published yet. In this research, a surface area calculation for non-axisymmetric deep drawing products with elliptical shape was constructed for a design of blank shape of deep drawing products by using an AutoLISP function of AutoCAD software. A computer-aided process planning (CAPP) system for rotationally symmetric deep drawing products has been developed. However, the application of the system to non-axisymmetric components has not been reported yet. Thus, the CAPP system for non-axisymmetric deep drawing products with elliptical shape was constructed by using process sequence design. The system developed in this work consists of four modules. The first is recognition of shape module to recognize non-axisymmetric products. The second is a three-dimensional (3-D) modeling module to calculate the surface area for non-axisymmetric products. The third is a blank design module to create an oval-shaped blank with the identical surface area. The forth is a process planning module based on the production rules that play the best important role in an expert system for manufacturing. The production rules are generated and upgraded by interviewing field engineers. Especially, the drawing coefficient, the punch and die radii for elliptical shape products are considered as main design parameters. The suitability of this system was verified by applying to a real deep drawing product. This CAPP system constructed would be very useful to reduce lead-time for manufacturing and improve an accuracy of products.

Bedrock Exhumed from the Deep

NASA Image and Video Library

2017-01-18

Roadside bedrock outcrops are all too familiar for many who have taken a long road trip through mountainous areas on Earth. Martian craters provide what tectonic mountain building and man's TNT cannot: crater-exposed bedrock outcrops. Although crater and valley walls offer us roadside-like outcrops from just below the Martian surface, their geometry is not always conducive to orbital views. On the other hand, a crater central peak -- a collection of mountainous rocks that have been brought up from depth, but also rotated and jumbled during the cratering process -- produce some of the most spectacular views of bedrock from orbit. This color composite cutout shows an example of such bedrock that may originate from as deep as 2 miles beneath the surface. The bedrock at this scale is does not appear to be layered or made up of grains, but has a massive appearance riddled with cross-cutting fractures, some of which have been filled by dark materials and rock fragments (impact melt and breccias) generated by the impact event. A close inspection of the image shows that these light-toned bedrock blocks are partially to fully covered by sand dunes and coated with impact melt bearing breccia flows. http://photojournal.jpl.nasa.gov/catalog/PIA12291

Towards a New Framework for Interpreting Relations Between Mantle Dynamics and Processes at the Earth's Surface: A Case Study Involving the Deccan Traps

NASA Astrophysics Data System (ADS)

Glisovic, P.; Forte, A. M.

2017-12-01

An outstanding challenge in modern geodynamics is the utilization of mantle convection models and geophysical data to successfully explain geological events and processes that alter Earth's biosphere, climate, and surface. A key challenge in this modelling is the determination of the initial (and unknown) configuration of mantle heterogeneity in the geological past. The first step in addressing this challenge is recognizing that seismic tomography is our most powerful tool for mapping the present-day, internal structure of the mantle. We, therefore, implemented a new back-and-forth iterative method for time-reversed, tomography-based convection modelling to reconstruct Earth's internal 3-D structure and dynamics over the Cenozoic [Glisovic & Forte 2016 (JGR)]. This backward convection modelling also includes another key input - the depth variation of mantle viscosity inferred from joint inversions of the global convection-related observables and a suite of glacial isostatic adjustments (GIA) data [Mitrovica & Forte 2004 (EPSL), Forte et al. 2010 (EPSL)]. This state-of-the-art, time-reversed convection model is able to show that massive outpourings of basalt in west-central India, known as the Deccan Traps, about 65 million years ago can be directly linked to the presence of two different deep-mantle hotspots: Réunion and Comores [Glisovic & Forte 2017 (Science)]. This work constitutes case study showing how time-reversed convection modelling provides a new framework for interpreting the relations between mantle dynamics and changing paleogeography and it provides a roadmap for a new series of studies that will elucidate these linkages.

Axial focusing of impact energy in the Earth's interior: Proof-of-principle tests of a new hypothesis

NASA Technical Reports Server (NTRS)

Boslough, M. B.; Chael, E. P.; Trucano, T. G.; Kipp, M. E.; Crawford, D. A.

1994-01-01

A causal link between major impact events and global processes would probably require a significant change in the thermal state of the Earth's interior, presumably brought about by coupling of impact energy. One possible mechanism for such energy coupling from the surface to the deep interior would be through focusing due to axial symmetry. Antipodal focusing of surface and body waves from earthquakes is a well-known phenomenon which has previously been exploited by seismologists in studies of the Earth's deep interior. Antipodal focusing from impacts on the Moon, Mercury, and icy satellites has also been invoked by planetary scientists to explain unusual surface features opposite some of the large impact structures on these bodies. For example, 'disrupted' terrains have been observed antipodal to the Caloris impact basis on Mercury and Imbrium Basin on the Moon. Very recently there have been speculations that antipodal focusing of impact energy within the mantle may lead to flood basalt and hotspot activity, but there has not yet been an attempt at a rigorous model. A new hypothesis was proposed and preliminary proof-of-principle tests for the coupling of energy from major impacts to the mantle by axial focusing of seismic waves was performed. Because of the axial symmetry of the explosive source, the phases and amplitudes are dependent only on ray parameter (or takeoff angle) and are independent of azimuthal angle. For a symmetric and homogeneous Earth, all the seismic energy radiated by the impact at a given takeoff angle will be refocused (minus attenuation) on the axis of symmetry, regardless of the number of reflections and refractions it has experienced. Mantle material near the axis of symmetry will experience more strain cycles with much greater amplitude than elsewhere and will therefore experience more irreversible heating. The situation is very different than for a giant earthquake, which in addition to having less energy, has an asymmetric focal mechanism and a larger area. Two independent proof-of-principle approaches were used. The first makes use of seismic simulations, which are being performed with a realistic Earth model to determine the degree of focusing along the axis and to estimate the volume of material, if any, that experiences significant irreversible heating. The second involves two-dimensional hydrodynamic code simulations to determine the stress history, internal energy, and temperature rise as a function of radius along the axis.

Decay of deep water convection in CMIP5 GCMs in the North Atlantic and Southern Ocean in the 21st century

NASA Astrophysics Data System (ADS)

Molodtsov, S.; Anis, A.; Marinov, I.; Cabre, A.

2016-12-01

Contemporary changes in the climate system due to anthropogenic activity have already resulted in unprecedented melting rates of the polar ice caps. This in turn may have a significant impact on the thermohaline circulation in the future. The freshening of the surface waters increases stable stratification in regions of deep water formation, eventually triggering a weakening and, ultimately, may bring to a cessation of deep convection in these regions. Here we present comparatively an analysis of the response of deep convective processes in the North Atlantic (NA) and Southern Ocean (SO) to anthropogenic forcing using output from the latest generation of Earth System Models (ESM), part of the CMIP5 intercomparison. Our findings indicate an attenuation of deep convection by the end of the 21st century from ESM simulations under representative concentration pathways (RCP) 8.5 scenario when compared to the years under historical scenario in both NA and SO. The average depth of the mixed layer in the regions studied during March/September, the months with maximum mixed layer depths in the NA/SO, respectively, was found to decrease dramatically by the end of the 21st century. Furthermore, the increase in stratification and decrease in mixed layer depths, resulting in the decay of deep convection, leads to accumulation of excess heat, previously released during the convection events, in the ocean interior in both regions.

Lattice thermal conductivity of silicate glasses at high pressures

NASA Astrophysics Data System (ADS)

Chang, Y. Y.; Hsieh, W. P.

2016-12-01

Knowledge of the thermodynamic and transport properties of magma holds the key to understanding the thermal evolution and chemical differentiation of Earth. The discovery of the remnant of a deep magma ocean above the core mantle boundary (CMB) from seismic observations suggest that the CMB heat flux would strongly depend on the thermal conductivity, including lattice (klat) and radiative (krad) components, of dense silicate melts and major constituent minerals around the region. Recent measurements on the krad of dense silicate glasses and lower-mantle minerals show that krad of dense silicate glasses could be significantly smaller than krad of the surrounding solid mantle phases, and therefore the dense silicate melts would act as a thermal insulator in deep lower mantle. This conclusion, however, remains uncertain due to the lack of direct measurements on the lattice thermal conductivity of silicate melts under relevant pressure-temperature conditions. Besides the CMB, magmas exist in different circumstances beneath the surface of the Earth. Chemical compositions of silicate melts vary with geological and geodynamic settings of the melts and have strong influences on their thermal properties. In order to have a better view of heat transport within the Earth, it is important to study compositional and pressure dependences of thermal properties of silicate melts. Here we report experimental results on lattice thermal conductivities of silicate glasses with basaltic and rhyolitic compositions up to Earth's lower mantle pressures using time-domain thermoreflectance coupled with diamond-anvil cell techniques. This study not only provides new data for the thermal conductivity of silicate melts in the Earth's deep interior, but is crucial for further understanding of the evolution of Earth's complex internal structure.

AIDA: the Asteroid Impact & Deflection Assessment mission

NASA Astrophysics Data System (ADS)

Vincent, Jean-Baptiste

2016-07-01

The Asteroid Impact & Deflection Assessment (AIDA) mission is a joint cooperation between European and US space agencies that consists of two separate and independent spacecraft that will be launched to a binary asteroid system, the near-Earth asteroid Didymos, to assess the possibility of deflecting an asteroid trajectory by using a kinetic impactor. The European Asteroid Impact Mission (AIM) is under Phase A/B1 study at ESA from March 2015 until summer 2016. AIM is set to rendez-vous with the asteroid system a few months prior to the impact by the US Double Asteroid Redirection Test (DART) spacecraft to fully characterize the smaller of the two binary components. AIM is a unique mission as it will be the first time that a spacecraft will investigate the surface, subsurface, and internal properties of a small binary near Earth asteroid. In addition it will perform various important technology demonstrations that can serve other space missions: AIM will release a set of CubeSats in deep space and a lander on the surface of the smaller asteroid and for the first time, deep-space inter-satellite linking will be demonstrated between the main spacecraft, the CubeSats, and the lander, and data will also be transmitted from interplanetary space to Earth by a laser communication system. The knowledge obtained by this mission will have great implications for our understanding of the history of the Solar System. Small asteroids are believed to result from collisions and other processes (e.g., spinup, shaking) that made them what they are now. Having direct information on their surface and internal properties will allow us to understand how these processes work and transform these small bodies as well as, for this particular case, how a binary system forms. So far, our understanding of the collisional process and the validation of numerical simulations of the impact process rely on impact experiments at laboratory scales. With DART, thanks to the characterization of the target by AIM, the mission will be the first fully documented impact experiment at asteroid scale, which will include the characterization of the target's properties and the outcome of the impact. By comparing our in situ measurements with ground-based data from telescopes, we can calibrate better the remote observations and improve our data interpretation of other systems. Therefore, AIDA offers a unique opportunity to test and refine our understanding and models at the actual scale of an asteroid. This will allow feeding small-body collisional evolution models with more realistic parameters to draw a more reliable story of the Solar System formation and evolution. Moreover, it will offer a first check of the validity of the kinetic impactor concept to deflect a small body trajectory and lead to improved efficiency for future kinetic impactor designs.

Modelling the Impact of Life on Continental Growth - Mechanisms and Results

NASA Astrophysics Data System (ADS)

Höning, D.; Spohn, T.

2013-12-01

The complexity of planetary evolution increases with the number of interacting reservoirs. On Earth, even the biosphere is speculated to interact with the interior. It has been argued (e.g., Rosing et al. 2006; Sleep et al, 2012) that the formation of continents could be a consequence of bioactivity harvesting solar energy through photosynthesis to help build the continents and that the mantle should carry a chemical biosignature. Through plate tectonics, the surface biosphere can impact deep subduction zone processes and the interior of the Earth. Subducted sediments are particularly important, because they influence the Earth's interior in several ways, and in turn are strongly influenced by the Earth's biosphere. In our model, we use the assumption that a thick sedimentary layer of low permeability on top of the subducting oceanic crust, caused by a biologically enhanced weathering rate, can suppress shallow dewatering. This in turn leads to greater availability of water in the source region of andesitic partial melt, resulting in an enhanced rate of continental production and regassing rate into the mantle. Our model includes (i) mantle convection, (ii) continental erosion and production, and (iii) mantle water degassing at mid-ocean ridges and regassing at subduction zones. The mantle viscosity of our model depends on (i) the mantle water concentration and (ii) the mantle temperature, whose time dependency is given by radioactive decay of isotopes in the Earth's mantle. Boundary layer theory yields the speed of convection and the water outgassing rate of the Earth's mantle. Our results indicate that present day values of continental surface area and water content of the Earth's mantle represent an attractor in a phase plane spanned by both parameters. We show that the biologic enhancement of the continental erosion rate is important for the system to reach this fixed point. An abiotic Earth tends to reach an alternative stable fixed point with a smaller continental surface area and dryer mantle. The origin and evolution of life on Earth might be responsible for the rise of continents 3.5 billion years ago. References: [1] N. H. Sleep et al., Annu. Rev. Earth Planet. Sci. 40, 277-300, 2012 [2] M. T. Rosing et al., Paleo3 232, 90-113, 2006

In situ determination of crystal structure and chemistry of minerals at Earth's deep lower mantle conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Hongsheng; Zhang, Li

Recent advances in experimental techniques and data processing allow in situ determination of mineral crystal structure and chemistry up to Mbar pressures in a laser-heated diamond anvil cell (DAC), providing the fundamental information of the mineralogical constitution of our Earth's interior. This work highlights several recent breakthroughs in the field of high-pressure mineral crystallography, including the stability of bridgmanite, the single-crystal structure studies of post-perovskite and H-phase as well as the identification of hydrous minerals and iron oxides in the deep lower mantle. The future development of high-pressure crystallography is also discussed.

Hydrocarbon degassing of the earth and origin of oil-gas fields (isotope-geochemical and geodynamic aspects)

NASA Astrophysics Data System (ADS)

Valyaev, Boris; Dremin, Ivan

2016-04-01

More than half a century ago, Academician PN Kropotkin substantiated the relationship of the formation and distribution of oil and gas fields with the processes of emanation hydrocarbon degassing of the Earth. Over the years, the concept of PN Kropotkin received further development and recognition of studies based on new factual material. Of particular importance are the following factors: a) the results of studies on global and regional uneven processes of traditional oil and gas and the role of deep faults in controlling the spread of oil and gas fields; b) the results of the research on gigantic volumes and localization of the discharges of hydrocarbon fluids (mud volcanoes, seeps) on land and into the atmosphere and through the bottom of the World ocean; c) the results of the studies on grand volumes of the spread of unconventional hydrocarbon resources in their non-traditional fields, especially on near-surface interval of unconventional oil and gas accumulation with gas hydrates, heavy oil and bitumen, as well as extraordinary resources of oil and gas in the shale and tight rocks. Deep mantle-crust nature of oil and gas in traditional and nontraditional deposits thus received further substantiation of geological and geophysical data and research results. However, isotopic and geochemical data are still interpreted in favor of the concept of the genesis of oil and gas in the processes of thermal catalytic conversion of organic matter of sedimentary rocks, at temperatures up to 200°C. In this report an alternative interpretation of the isotope carbon-hydrogen system (δ13C-δD) for gas and of oil deposits, isotope carbon system for methane and carbon dioxide (δ13C1-δ13C0) will be presented. An alternative interpretation will also be presented for the data on carbon-helium isotope geochemical system for oil and gas fields, volcanoes and mud volcanoes. These constructions agree with the geological data on the nature of deep hydrocarbon fluids involved in the formation of traditional and nontraditional hydrocarbon accumulations. The genesis of hydrocarbon fluids turn up to be associated with a hydrocarbon branch of deep degassing and recycling of crustal materials and processes of crust-mantle interaction [1,2,3]. The study was supported by the Russian Foundation for Basic Research (RFBR), grant № 14-05-00869. 1. Valyaev B.M., Dremin I.S. Deep Roots of the Fluid Systems and Oil-Gas Fields (Isotope Geochemical and Geodynamic Aspects) // International Conference Goldschmidt2015, Prague, Czech Republic, August 16-21, 2015. Abstracts. P. 3221. 2. Valyaev B., Dremin I. Recycling of crustal matter and the processes of mantle-crust interaction in the genesis of hydrocarbon fluids // International Conference on Gas Geochemistry 2013, Patras, Greece, 1-7 September 2013, Book of abstracts. P. 32. 3. Degassing of the Earth: Geotectonics, Geodynamics, Geofluids; Oil and Gas; Hydrocarbon and Life. Proceedings of the all-Russian with International Participation Conference, devoted the centenary of Academician P.N. Kropotkin, October 18-22, 2010, Moscow. Responsible editors: Academician A.N. Dmitrievsky, senior doctorate B.M. Valyaev. -Moscow: GEOS, 2010. 712 p.

Predator-guided sampling reveals biotic structure in the bathypelagic.

PubMed

Benoit-Bird, Kelly J; Southall, Brandon L; Moline, Mark A

2016-02-24

We targeted a habitat used differentially by deep-diving, air-breathing predators to empirically sample their prey's distributions off southern California. Fine-scale measurements of the spatial variability of potential prey animals from the surface to 1,200 m were obtained using conventional fisheries echosounders aboard a surface ship and uniquely integrated into a deep-diving autonomous vehicle. Significant spatial variability in the size, composition, total biomass, and spatial organization of biota was evident over all spatial scales examined and was consistent with the general distribution patterns of foraging Cuvier's beaked whales (Ziphius cavirostris) observed in separate studies. Striking differences found in prey characteristics between regions at depth, however, did not reflect differences observed in surface layers. These differences in deep pelagic structure horizontally and relative to surface structure, absent clear physical differences, change our long-held views of this habitat as uniform. The revelation that animals deep in the water column are so spatially heterogeneous at scales from 10 m to 50 km critically affects our understanding of the processes driving predator-prey interactions, energy transfer, biogeochemical cycling, and other ecological processes in the deep sea, and the connections between the productive surface mixed layer and the deep-water column. © 2016 The Author(s).

Trophic dynamics of deep-sea megabenthos are mediated by surface productivity.

PubMed

Tecchio, Samuele; van Oevelen, Dick; Soetaert, Karline; Navarro, Joan; Ramírez-Llodra, Eva

2013-01-01

Most deep-sea benthic ecosystems are food limited and, in the majority of cases, are driven by the organic matter falling from the surface or advected downslope. Species may adapt to this scarceness by applying a wide variety of responses, such as feeding specialisation, niche width variation, and reduction in metabolic rates. The Mediterranean Sea hosts a gradient of food availability at the deep seafloor over its wide longitudinal transect. In the Mediterranean, broad regional studies on trophic habits are almost absent, and the response of deep-sea benthos to different trophic conditions is still speculative. Here, we show that both primary and secondary production processes taking place at surface layers are key drivers of deep-sea food web structuring. By employing an innovative statistical tool, we interpreted bulk-tissue δ(13)C and δ(15)N isotope ratios in benthic megafauna, and associated surface and mesopelagic components from the 3 basins of the Mediterranean Sea at 3 different depths (1200, 2000, and 3000 m). The trophic niche width and the amplitude of primary carbon sources were positively correlated with both primary and secondary surface production indicators. Moreover, mesopelagic organic matter utilization processes showed an intermediate position between surface and deep benthic components. These results shed light on the understanding of deep-sea ecosystems functioning and, at the same time, they demand further investigation.

Trophic Dynamics of Deep-Sea Megabenthos Are Mediated by Surface Productivity

PubMed Central

Tecchio, Samuele; van Oevelen, Dick; Soetaert, Karline; Navarro, Joan; Ramírez-Llodra, Eva

2013-01-01

Most deep-sea benthic ecosystems are food limited and, in the majority of cases, are driven by the organic matter falling from the surface or advected downslope. Species may adapt to this scarceness by applying a wide variety of responses, such as feeding specialisation, niche width variation, and reduction in metabolic rates. The Mediterranean Sea hosts a gradient of food availability at the deep seafloor over its wide longitudinal transect. In the Mediterranean, broad regional studies on trophic habits are almost absent, and the response of deep-sea benthos to different trophic conditions is still speculative. Here, we show that both primary and secondary production processes taking place at surface layers are key drivers of deep-sea food web structuring. By employing an innovative statistical tool, we interpreted bulk-tissue δ13C and δ15N isotope ratios in benthic megafauna, and associated surface and mesopelagic components from the 3 basins of the Mediterranean Sea at 3 different depths (1200, 2000, and 3000 m). The trophic niche width and the amplitude of primary carbon sources were positively correlated with both primary and secondary surface production indicators. Moreover, mesopelagic organic matter utilization processes showed an intermediate position between surface and deep benthic components. These results shed light on the understanding of deep-sea ecosystems functioning and, at the same time, they demand further investigation. PMID:23691098

Influence of Tidal Forces on the Triggering of Seismic Events

NASA Astrophysics Data System (ADS)

Varga, Péter; Grafarend, Erik

2018-05-01

Tidal stresses are generated in any three-dimensional body influenced by an external inhomogeneous gravity field of rotating planets or moons. In this paper, as a special case, stresses caused within the solid Earth by the body tides are discussed from viewpoint of their influence on seismic activity. The earthquake triggering effects of the Moon and Sun are usually investigated by statistical comparison of tidal variations and temporal distribution of earthquake activity, or with the use of mathematical or experimental modelling of physical processes in earthquake prone structures. In this study, the magnitude of the lunisolar stress tensor in terms of its components along the latitude of the spherical surface of the Earth as well as inside the Earth (up to the core-mantle boundary) were calculated for the PREM (Dziewonski and Anderson in Phys Earth Planet Inter 25(4):297-356, 1981). Results of calculations prove that stress increases as a function of depth reaching a value around some kPa at the depth of 900-1500 km, well below the zone of deep earthquakes. At the depth of the overwhelming part of seismic energy accumulation (around 50 km) the stresses of lunisolar origin are only (0.0-1.0)·103 Pa. Despite the fact that these values are much smaller than the earthquake stress drops (1-30 MPa) (Kanamori in Annu Rev Earth Planet Sci 22:207-237, 1994) this does not exclude the possibility of an impact of tidal forces on outbreak of seismic events. Since the tidal potential and its derivatives are coordinate dependent and the zonal, tesseral and sectorial tides have different distributions from the surface down to the CMB, the lunisolar stress cannot influence the break-out of every seismological event in the same degree. The influencing lunisolar effect of the solid earth tides on earthquake occurrences is connected first of all with stress components acting parallel to the surface of the Earth. The influence of load tides is limited to the loaded area and its immediate vicinity.

Influence of Tidal Forces on the Triggering of Seismic Events

NASA Astrophysics Data System (ADS)

Varga, Péter; Grafarend, Erik

2017-05-01

Tidal stresses are generated in any three-dimensional body influenced by an external inhomogeneous gravity field of rotating planets or moons. In this paper, as a special case, stresses caused within the solid Earth by the body tides are discussed from viewpoint of their influence on seismic activity. The earthquake triggering effects of the Moon and Sun are usually investigated by statistical comparison of tidal variations and temporal distribution of earthquake activity, or with the use of mathematical or experimental modelling of physical processes in earthquake prone structures. In this study, the magnitude of the lunisolar stress tensor in terms of its components along the latitude of the spherical surface of the Earth as well as inside the Earth (up to the core-mantle boundary) were calculated for the PREM (Dziewonski and Anderson in Phys Earth Planet Inter 25(4):297-356, 1981). Results of calculations prove that stress increases as a function of depth reaching a value around some kPa at the depth of 900-1500 km, well below the zone of deep earthquakes. At the depth of the overwhelming part of seismic energy accumulation (around 50 km) the stresses of lunisolar origin are only (0.0-1.0)·103 Pa. Despite the fact that these values are much smaller than the earthquake stress drops (1-30 MPa) (Kanamori in Annu Rev Earth Planet Sci 22:207-237, 1994) this does not exclude the possibility of an impact of tidal forces on outbreak of seismic events. Since the tidal potential and its derivatives are coordinate dependent and the zonal, tesseral and sectorial tides have different distributions from the surface down to the CMB, the lunisolar stress cannot influence the break-out of every seismological event in the same degree. The influencing lunisolar effect of the solid earth tides on earthquake occurrences is connected first of all with stress components acting parallel to the surface of the Earth. The influence of load tides is limited to the loaded area and its immediate vicinity.

A new multi-proxy reconstruction of Atlantic deep ocean circulation during the warm mid-Pliocene

NASA Astrophysics Data System (ADS)

Riesselman, C. R.; Dowsett, H. J.; Scher, H. D.; Robinson, M. M.

2011-12-01

The mid-Pliocene (3.264 - 3.025 Ma) is the most recent interval in Earth's history with sustained global temperatures in the range of warming predicted for the 21st century, providing an appealing analog with which to examine the Earth system changes we might encounter in the coming century. Ongoing sea surface and deep ocean temperature reconstructions and coupled ocean-atmosphere general circulation model simulations by the USGS PRISM (Pliocene Research Interpretation and Synoptic Mapping) Group identify a dramatic North Atlantic warm anomaly coupled with increased evaporation in the mid-Pliocene, possibly driving enhanced meridional overturning circulation and North Atlantic Deep Water production. However deep ocean temperature is not a conclusive proxy for water mass, and most coupled model simulations predict transient decreases in North Atlantic Deep Water production in 21st century, presenting a contrasting picture of future warmer worlds. Here, we present early results from a new multi-proxy reconstruction of Atlantic deep ocean circulation during the warm mid-Pliocene, using δ13C of benthic foraminifera as a proxy for water mass age and the neodymium isotopic imprint on fossil fish teeth as a proxy for water mass source region along a three-site depth transect from the Walvis Ridge (subtropical South Atlantic). The deep ocean circulation reconstructions resulting from this project will add a new dimension to the PRISM effort and will be useful for both initialization and evaluation of future model simulations.

In-situ measurements of rare earth elements in deep sea sediments using nuclear methods.

PubMed

Obhođaš, Jasmina; Sudac, Davorin; Meric, Ilker; Pettersen, Helge E S; Uroić, Milivoj; Nađ, Karlo; Valković, Vlado

2018-03-21

The prospecting activities for finding new rare earth elements (REE) sources have increased greatly in recent years. One of the main discoveries was announced in 2011 by Japanese researchers who found large quantities of REE on the ocean seafloor at the sea depths greater than 4,000 m. The classic approach to investigate REE in deep sea sediments is to obtain sediment samples by drilling that is followed by laborious laboratory analysis. This is very expensive, time consuming and not appropriate for exploring vast areas. In order to efficiently explore the ocean floor for REE deposits, the further development of affordable sensors is needed. Here, we propose two nuclear techniques for exploring REE in surface deep sea sediments: i) Passive measurement of lutetium-176 radioactivity, appropriate if long-term in-situ measurements are possible, and ii) The use of the neutron sensor attached to a remotely operated vehicle for rapid in-situ measurement of gadolinium by thermal neutron-capture. Since concentrations of lutetium and gadolinium show strong linear correlation to the total REE concentrations in deep sea sediments, it is possible to deduce the total REE content by measuring Lu or Gd concentrations only.

Comparing Vesta's Surface Roughness to the Moon Using Bistatic Radar Observations by the Dawn Mission

NASA Astrophysics Data System (ADS)

Palmer, E. M.; Heggy, E.; Kofman, W. W.; Moghaddam, M.

2015-12-01

The first orbital bistatic radar (BSR) observations of a small body have been conducted opportunistically by NASA's Dawn spacecraft at Asteroid Vesta using the telecommunications antenna aboard Dawn to transmit and the Deep Space Network 70-meter antennas on Earth to receive. Dawn's high-gain communications antenna continuously transmitted right-hand circularly polarized radio waves (4-cm wavelength), and due to the opportunistic nature of the experiment, remained in a fixed orientation pointed toward Earth throughout each BSR observation. As a consequence, Dawn's transmitted radio waves scattered from Vesta's surface just before and after each occultation of the Dawn spacecraft behind Vesta, resulting in surface echoes at highly oblique incidence angles of greater than 85 degrees, and a small Doppler shift of ~2 Hz between the carrier signal and surface echoes from Vesta. We analyze the power and Doppler spreading of Vesta's surface echoes to assess surface roughness, and find that Vesta's area-normalized radar cross section ranges from -8 to -17 dB, which is notably much stronger than backscatter radar cross section values reported for the Moon's limbs (-20 to -35 dB). However, our measurements correspond to the forward scattering regime--such that at high incidence, radar waves are expected to scatter more weakly from a rough surface in the backscatter direction than that which is scattered forward. Using scattering models of rough surfaces observed at high incidence, we report on the relative roughness of Vesta's surface as compared to the Moon and icy Galilean satellites. Through this, we assess the dominant processes that have influenced Vesta's surface roughness at centimeter and decimeter scales, which are in turn applicable to assisting future landing, sampling and orbital missions of other small bodies.

Empirical links between the local runaway greenhouse, super-greenhouse, and deep convection in Earth's tropics

NASA Astrophysics Data System (ADS)

Dewey, M. C.; Goldblatt, C.

2017-12-01

Energy balance requires that energy absorbed and emitted at the top of the atmosphere equal; this is maintained via the Planck feedback whereby outgoing longwave radiation (OLR) increases as surface temperature increases. There are two cases where this breaks down: the runaway greenhouse (known from planetary sciences theory) characterized by an asymptotic limit on OLR from moist atmospheres, and the super-greenhouse (known from tropical meteorology observations) where OLR decreases with surface temperature when the atmosphere is moist aloft. Here we show that the runaway greenhouse limit can be empirically observed and constrained in Earth's tropics, that the runaway and super-greenhouse occur as part of the same physical phenomenon, and that the transition through the super-greenhouse to a local runaway greenhouse is intimately linked to the onset of deep convection. A runaway greenhouse occurs when water vapour causes the troposphere to become optically thick to thermal radiation from the surface and a limit on OLR emerges as thermal emission is from a constant temperature level aloft. This limit is modelled as 282 W/m/m [Goldblatt et al, 2013]. Using satellite data from Earth's tropics, we find an empirical value of this limit of 280 W/m/m, in excellent agreement with the model.A column transitioning to a runaway greenhouse typically overshoots the runaway limit and then OLR decreases with increasing surface temperature until the runaway limit is reached after which OLR remains constant. The term super-greenhouse effect (SGE) has been used to describe OLR decreasing with surface warming, observed in these satellite measurements. We show the SGE is one and the same as the transition to a local runaway greenhouse, and represents a fundamental shift in the radiation response of the earth system, rather than simply an extension of water vapour feedback. This transition via SGE from an optically thin to optically thick troposphere is facilitated by enhanced moistening of the upper troposphere through active convection. That convection itself may be initiated by the changes to the atmospheric optical depth and consequent need for adjustment of the surface energy budget.Refs: Goldblatt et al., 2013, Nature Geoscience, 6, 661-667, doi:10.1038/NGEO1892.

The case for a deep-atmospheric in situ mission to address the highest priority Decadal Survey questions for Venus (Invited)

NASA Astrophysics Data System (ADS)

Atreya, S. K.; Garvin, J. B.; Glaze, L. S.; Campbell, B. A.; Fisher, M. E.; Flores, A.; Gilmore, M. S.; Johnson, N.; Kiefer, W. S.; Lorenz, R. D.; Mahaffy, P. R.; Ravine, M. A.; Webster, C. R.; Zolotov, M. Y.

2013-12-01

Current understanding of Venus lags behind that for Mars, with a major disparity of information concerning noble and trace gases and the small scale surface processes needed for comparative studies of terrestrial planet evolution. Despite global surface mapping by Magellan, discoveries by Venera landers, and ongoing atmospheric observations by the Venus Express (VEx) orbiter, significant questions about Venus remain unanswered. To place Venus into its proper context with respect to Mars and Earth, it is necessary to obtain new measurements that address top issues identified in the National Research Council (NRC) Solar System Decadal Survey: (1) evolution of the atmosphere, history of climate, and evidence of past hydrologic cycles; (2) history of volatiles and sedimentary cycles; and (3) planetary surface evolution. To answer these questions, new measurements are needed. First and foremost, in situ noble gas measurements are needed to constrain solar system formation and Venus evolution. In particular, the isotopic ratios of Xe and Kr can provide unique insights into planetary accretion. Isotopic measurements of nitrogen (15N/14N) will place important constraints on atmospheric loss processes. Current knowledge of this ratio has a substantial uncertainty of ×20%. VEx observations of hydrogen isotopes indicate the D/H ratio above the clouds is substantially greater than measured by Pioneer Venus, and varies with height. High precision measurements of the vertical distribution of the D/H isotopic ratio below the cloud layers will provide constraints on models of the climate history of water on Venus. The majority of atmospheric mass is located below the clouds. Current data suggest intense interaction among atmospheric gases down to the surface. The haze within the cloud region of unknown composition plays a central role in the radiative balance. Photochemically-derived species (H2SO4, OCS, CO, Sn) are subjected to thermochemical reactions below the clouds, especially within 30 km of the surface. Competing temperature-pressure dependent reactions and atmospheric circulation may cause vertical and latitudinal gradients of chemically-active trace gases (e.g., SO2, H2S, OCS, CO). Measurements of the chemical composition of the near-surface atmosphere can be used to evaluate the stability of primary and secondary minerals and can help to understand chemistry of atmosphere-surface interactions. However, concentrations of many trace species have never been measured below ~30 km, and multiple in situ measurements are required to evaluate chemical processes and cycles of volatiles, which can only be accomplished with deep entry probes. Current lack of understanding about Venus not only limits our understanding of evolutionary pathways Earth could experience, but also suggests that we are ill-equipped to understand the evolution of star systems with similar-sized planets.

The Time Series Technique for Aerosol Retrievals over Land from MODIS: Algorithm MAIAC

NASA Technical Reports Server (NTRS)

Lyapustin, Alexei; Wang, Yujie

2008-01-01

Atmospheric aerosols interact with sun light by scattering and absorbing radiation. By changing irradiance of the Earth surface, modifying cloud fractional cover and microphysical properties and a number of other mechanisms, they affect the energy balance, hydrological cycle, and planetary climate [IPCC, 2007]. In many world regions there is a growing impact of aerosols on air quality and human health. The Earth Observing System [NASA, 1999] initiated high quality global Earth observations and operational aerosol retrievals over land. With the wide swath (2300 km) of MODIS instrument, the MODIS Dark Target algorithm [Kaufman et al., 1997; Remer et al., 2005; Levy et al., 2007] currently complemented with the Deep Blue method [Hsu et al., 2004] provides daily global view of planetary atmospheric aerosol. The MISR algorithm [Martonchik et al., 1998; Diner et al., 2005] makes high quality aerosol retrievals in 300 km swaths covering the globe in 8 days. With MODIS aerosol program being very successful, there are still several unresolved issues in the retrieval algorithms. The current processing is pixel-based and relies on a single-orbit data. Such an approach produces a single measurement for every pixel characterized by two main unknowns, aerosol optical thickness (AOT) and surface reflectance (SR). This lack of information constitutes a fundamental problem of the remote sensing which cannot be resolved without a priori information. For example, MODIS Dark Target algorithm makes spectral assumptions about surface reflectance, whereas the Deep Blue method uses ancillary global database of surface reflectance composed from minimal monthly measurements with Rayleigh correction. Both algorithms use Lambertian surface model. The surface-related assumptions in the aerosol retrievals may affect subsequent atmospheric correction in unintended way. For example, the Dark Target algorithm uses an empirical relationship to predict SR in the Blue (B3) and Red (B1) bands from the 2.1 m channel (B7) for the purpose of aerosol retrieval. Obviously, the subsequent atmospheric correction will produce the same SR in the red and blue bands as predicted, i.e. an empirical function of 2.1. In other words, the spectral, spatial and temporal variability of surface reflectance in the Blue and Red bands appears borrowed from band B7. This may have certain implications for the vegetation and global carbon analysis because the chlorophyll-sensing bands B1, B3 are effectively substituted in terms of variability by band B7, which is sensitive to the plant liquid water. This chapter describes a new recently developed generic aerosol-surface retrieval algorithm for MODIS. The Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm simultaneously retrieves AOT and surface bi-directional reflection factor (BRF) using the time series of MODIS measurements.

Enhanced deep ocean ventilation and oxygenation with global warming

NASA Astrophysics Data System (ADS)

Froelicher, T. L.; Jaccard, S.; Dunne, J. P.; Paynter, D.; Gruber, N.

2014-12-01

Twenty-first century coupled climate model simulations, observations from the recent past, and theoretical arguments suggest a consistent trend towards warmer ocean temperatures and fresher polar surface oceans in response to increased radiative forcing resulting in increased upper ocean stratification and reduced ventilation and oxygenation of the deep ocean. Paleo-proxy records of the warming at the end of the last ice age, however, suggests a different outcome, namely a better ventilated and oxygenated deep ocean with global warming. Here we use a four thousand year global warming simulation from a comprehensive Earth System Model (GFDL ESM2M) to show that this conundrum is a consequence of different rates of warming and that the deep ocean is actually better ventilated and oxygenated in a future warmer equilibrated climate consistent with paleo-proxy records. The enhanced deep ocean ventilation in the Southern Ocean occurs in spite of increased positive surface buoyancy fluxes and a constancy of the Southern Hemisphere westerly winds - circumstances that would otherwise be expected to lead to a reduction in deep ocean ventilation. This ventilation recovery occurs through a global scale interaction of the Atlantic Meridional Overturning Circulation undergoing a multi-centennial recovery after an initial century of transient decrease and transports salinity-rich waters inform the subtropical surface ocean to the Southern Ocean interior on multi-century timescales. The subsequent upwelling of salinity-rich waters in the Southern Ocean strips away the freshwater cap that maintains vertical stability and increases open ocean convection and the formation of Antarctic Bottom Waters. As a result, the global ocean oxygen content and the nutrient supply from the deep ocean to the surface are higher in a warmer ocean. The implications for past and future changes in ocean heat and carbon storage will be discussed.

Advanced Microelectronics Technologies for Future Small Satellite Systems

NASA Technical Reports Server (NTRS)

Alkalai, Leon

1999-01-01

Future small satellite systems for both Earth observation as well as deep-space exploration are greatly enabled by the technological advances in deep sub-micron microelectronics technologies. Whereas these technological advances are being fueled by the commercial (non-space) industries, more recently there has been an exciting new synergism evolving between the two otherwise disjointed markets. In other words, both the commercial and space industries are enabled by advances in low-power, highly integrated, miniaturized (low-volume), lightweight, and reliable real-time embedded systems. Recent announcements by commercial semiconductor manufacturers to introduce Silicon On Insulator (SOI) technology into their commercial product lines is driven by the need for high-performance low-power integrated devices. Moreover, SOI has been the technology of choice for many space semiconductor manufacturers where radiation requirements are critical. This technology has inherent radiation latch-up immunity built into the process, which makes it very attractive to space applications. In this paper, we describe the advanced microelectronics and avionics technologies under development by NASA's Deep Space Systems Technology Program (also known as X2000). These technologies are of significant benefit to both the commercial satellite as well as the deep-space and Earth orbiting science missions. Such a synergistic technology roadmap may truly enable quick turn-around, low-cost, and highly capable small satellite systems for both Earth observation as well as deep-space missions.

Ecohydrology of Deep Fractured Rocks at Homestake DUSEL

NASA Astrophysics Data System (ADS)

Kieft, T. L.; Boutt, D. F.; Murdoch, L. C.; Wang, H. F.

2009-12-01

The Deep Underground Science and Engineering Laboratory (DUSEL) at Homestake in SD will provide an unprecedented opportunity to study the terrestrial subsurface. Such a study could fundamentally change the way we view the origin and early evolution of life on Earth, the search for novel materials, and the generation of energy. Knowledge of subsurface life has come from only a few boreholes and deep mines. DUSEL will enable the first detailed study of a deep ecosystem in the context of the hydrology, geochemistry, and rock system state that sustain it. We are guided by the over-arching question: What controls the distribution and evolution of subsurface life? Our hypothesis is that these controls are dominated by processes related to geology, geochemistry, geomechanics, and hydrology. Themes of scaling and the development of facies, or zones of similar characteristics cut across all the processes. The ecohydrologic setting of DUSEL Homestake is characterized by a vast expanse of fractured metamorphic rock cut by 100s of km of tunnels and boreholes. Many km3 of the region have been highly affected by mining activities; adjacent regions are partially desaturated; and more distal regions are pristine and presumed to harbor indigenous microbial ecosystems. Simulations along with descriptions of the mine suggest division into zones, or ecohydrologic facies, where essential characteristics related to the requirements for life are expected to be similar. These ecohydrologic facies are a primary organizing principle for our investigation. The Deep EcoHydrology Experiment will consist of field studies supported by numerical simulations. The experimental activities include a particularly exciting opportunity to probe the lower limits of the biosphere using deep drilling technology deployed from the lowest reaches of the facility (2440 m below the surface). The use of the flooding/dewatering event as a tracer combined with hydrologic and mechanical stressors form a theme that cuts across many of the experimental activities. Five key experimental activities have been identified that will enable motivating hypotheses to be tested: 1) Initial Characterization, 2) Flow System, 3) Stress and Deformation, 4) Exploration, and 5) Cross-cutting activities. The International Continental Drilling Program has approved a preproposal for an ICDP ecohydrology project at DUSEL. The development of a long-term deep geosciences observatory at the Homestake DUSEL will revolutionize the field of deep sub-surface ecohydrology. The opportunities for young scientists and international participation in such a facility will be tremendous. Results from the work will have wide ranging implications as 20% of the current earth’s surface consists of a similar geologic setting. DUSEL will also facilitate experiential learning for K-12 through graduate school students working alongside world-class geoscientists.

Deep sub-seafloor prokaryotes stimulated at interfaces over geological time.

PubMed

Parkes, R John; Webster, Gordon; Cragg, Barry A; Weightman, Andrew J; Newberry, Carole J; Ferdelman, Timothy G; Kallmeyer, Jens; Jørgensen, Bo B; Aiello, Ivano W; Fry, John C

2005-07-21

The sub-seafloor biosphere is the largest prokaryotic habitat on Earth but also a habitat with the lowest metabolic rates. Modelled activity rates are very low, indicating that most prokaryotes may be inactive or have extraordinarily slow metabolism. Here we present results from two Pacific Ocean sites, margin and open ocean, both of which have deep, subsurface stimulation of prokaryotic processes associated with geochemical and/or sedimentary interfaces. At 90 m depth in the margin site, stimulation was such that prokaryote numbers were higher (about 13-fold) and activity rates higher than or similar to near-surface values. Analysis of high-molecular-mass DNA confirmed the presence of viable prokaryotes and showed changes in biodiversity with depth that were coupled to geochemistry, including a marked community change at the 90-m interface. At the open ocean site, increases in numbers of prokaryotes at depth were more restricted but also corresponded to increased activity; however, this time they were associated with repeating layers of diatom-rich sediments (about 9 Myr old). These results show that deep sedimentary prokaryotes can have high activity, have changing diversity associated with interfaces and are active over geological timescales.

Shallow outgassing changes disrupt steady lava lake activity, Kilauea Volcano

NASA Astrophysics Data System (ADS)

Patrick, M. R.; Orr, T. R.; Swanson, D. A.; Lev, E.

2015-12-01

Persistent lava lakes are a testament to sustained magma supply and outgassing in basaltic systems, and the surface activity of lava lakes has been used to infer processes in the underlying magmatic system. At Kilauea Volcano, Hawai`i, the lava lake in Halema`uma`u Crater has been closely studied for several years with webcam imagery, geophysical, petrological and gas emission techniques. The lava lake in Halema`uma`u is now the second largest on Earth, and provides an unprecedented opportunity for detailed observations of lava lake outgassing processes. We observe that steady activity is characterized by continuous southward motion of the lake's surface and slow changes in lava level, seismic tremor and gas emissions. This normal, steady activity can be abruptly interrupted by the appearance of spattering - sometimes triggered by rockfalls - on the lake surface, which abruptly shifts the lake surface motion, lava level and gas emissions to a more variable, unstable regime. The lake commonly alternates between this a) normal, steady activity and b) unstable behavior several times per day. The spattering represents outgassing of shallowly accumulated gas in the lake. Therefore, although steady lava lake behavior at Halema`uma`u may be deeply driven by upwelling of magma, we argue that the sporadic interruptions to this behavior are the result of shallow processes occurring near the lake surface. These observations provide a cautionary note that some lava lake behavior is not representative of deep-seated processes. This behavior also highlights the complex and dynamic nature of lava lake activity.

Record of Cyclical Massive Upwellings from the Pacific Large Low Shear Velocity Province in the Mesozoic

NASA Astrophysics Data System (ADS)

Gazel, E.; Madrigal, P.; Flores, K. E.; Bizimis, M.; Jicha, B. R.

2016-12-01

Global tomography and numerical models suggest that mantle plume occurrences are closely linked to the margins of the large low shear velocity provinces (LLSVPs). In these locations the ascent of material from the core-mantle boundary connects the deep Earth with surface processes through mantle plume activity, forming large igneous provinces (LIPs) and some of the modern hotspot volcanoes. Petrological and geodynamic evidence suggest a link between the formation of oceanic plateaus and the interactions of mantle plumes and mid-ocean ridges (MOR). Therefore, it is possible to trace the potential interactions between MORs and deep mantle plume upwellings by referencing the tectonic and magmatic evolution of the Pacific Plate in time to the current location of the LLSVP, considering the long-lived ( 500 Ma) existence of these thermochemical anomalies. We identified episodic upwellings of the Pacific LLSVP during the Mesozoic separated by 10 to 20 Ma, by reconstructing the kinematic evolution of the Pacific Plate in the last 170 Ma. The fact that the bulk emplacement of LIPs ( 120-80 Ma) in the Pacific coincides with the timing of the Cretaceous Normal Superchron, that can be related to fluctuations of mantle-core heat fluxes further supports the hypothesis of deep mantle origin for LIPs. The potential cyclicity of LIP emplacement could be tied to core heat fluctuations interacting with the lower mantle, the rheology contrast of material crossing the transition zone (either upwelling hot material or downgoing dense slabs as mantle avalanches), the rate of entrainment of recycled materials, or a combination of the processes mentioned. Recognizing patterns and possible cycles is crucial to the link between deep processes and life as these pulses impacted the marine biota resulting in episodes of anoxia and mass extinctions shortly after their eruption.

Hydrogen-bearing iron peroxide and its implications to the deep Earth

NASA Astrophysics Data System (ADS)

Liu, J.; Hu, Q.; Kim, D. Y.; Wu, Z.; Wang, W.; Alp, E. E.; Yang, L.; Xiao, Y.; Meng, Y.; Chow, P.; Greenberg, E.; Prakapenka, V. B.; Mao, H. K.; Mao, W. L.

2017-12-01

Hydrous materials subducted into the deep mantle may play a significant role in the geophysical and geochemical processes of the lower mantle through geological time, but their roles have not become clear yet in the region. Hydrogen-bearing iron peroxide (FeO2Hx) was recently discovered to form through dehydrogenation of goethite (e.g., FeOOH) and the reaction between hematite (Fe2O3) and water under deep lower mantle conditions. We conducted synchrotron Mössbauer, X-ray absorption, and X-ray emission spectroscopy measurements to investigate the electronic spin and valence states of iron in hydrogen-bearing iron peroxide (FeO2Hx) in-situ at high pressures. Combined with theoretical calculations and other high-pressure experiments (i.e., nuclear resonant inelastic x-ray scattering spectroscopy and X-ray diffraction coupled with laser-heated diamond-anvil cell techniques), we find that the intriguing properties of FeO2Hx could shed light on the origin of a number of the observed geochemical and geophysical anomalies in the deep Earth.

Ion propulsion engine installed on Deep Space 1 at CCAS

NASA Technical Reports Server (NTRS)

1998-01-01

Workers at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station (CCAS), attach a strap during installation of the ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS, in October.

Ion propulsion engine installed on Deep Space 1 at CCAS

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Defense Satellite Communications Systems Processing Facility (DPF) at Cape Canaveral Air Station (CCAS) finish installing the ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched Oct. 25 aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS.

Ion propulsion engine installed on Deep Space 1 at CCAS

NASA Technical Reports Server (NTRS)

1998-01-01

Workers at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station (CCAS), maneuver the ion propulsion engine into place before installation on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight- tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS, in October.

Ion propulsion engine installed on Deep Space 1 at CCAS

NASA Technical Reports Server (NTRS)

1998-01-01

Workers at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station (CCAS), install an ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS, in October.

Ion propulsion engine installed on Deep Space 1 at CCAS

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Defense Satellite Communications Systems Processing Facility (DPF) at Cape Canaveral Air Station (CCAS) make adjustments while installing the ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight- tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched Oct. 25 aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS.

Ion propulsion engine installed on Deep Space 1 at CCAS

NASA Technical Reports Server (NTRS)

1998-01-01

Workers at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station (CCAS), make adjustments while installing the ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight- tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS, in October.

Deep Space 1 is prepared for transport to launch pad

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Defense Satellite Communication Systems Processing Facility (DPF), Cape Canaveral Air Station (CCAS), move to the workstand the second conical section leaf of the payload transportation container for Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS.

Hydrothermal systems are a sink for dissolved black carbon in the deep ocean

NASA Astrophysics Data System (ADS)

Niggemann, J.; Hawkes, J. A.; Rossel, P. E.; Stubbins, A.; Dittmar, T.

2016-02-01

Exposure to heat during fires on land or geothermal processes in Earth's crust induces modifications in the molecular structure of organic matter. The products of this thermogenesis are collectively termed black carbon. Dissolved black carbon (DBC) is a significant component of the oceanic dissolved organic carbon (DOC) pool. In the deep ocean, DBC accounts for 2% of DOC and has an apparent radiocarbon age of 18,000 years. Thus, DBC is much older than the bulk DOC pool, suggesting that DBC is highly refractory. Recently, it has been shown that recalcitrant deep-ocean DOC is efficiently removed during hydrothermal circulation. Here, we hypothesize that hydrothermal circulation is also a net sink for deep ocean DBC. We analyzed DBC in samples collected at different vent sites in the Atlantic, Pacific and Southern oceans. DBC was quantified in solid-phase extracts as benzenepolycarboxylic acids (BPCAs) following nitric acid digestion. Concentrations of DBC were much lower in hydrothermal fluids than in surrounding deep ocean seawater, confirming that hydrothermal circulation acts as a net sink for oceanic DBC. The relative contribution of DBC to bulk DOC did not change during hydrothermal circulation, indicating that DBC is removed at similar rates as bulk DOC. The ratio of the oxidation products benzenehexacarboxylic acid (B6CA) to benzenepentacarboxylic acid (B5CA) was significantly higher in hydrothermally altered samples compared to ratios typically found in the deep ocean, reflecting a higher degree of condensation of DBC molecules after hydrothermal circulation. Our study identified hydrothermal circulation as a quantitatively important sink for refractory DBC in the deep ocean. In contrast to photodegradation of DBC at the sea surface, which is more efficient for more condensed DBC, i.e. decreasing the B6CA/B5CA ratio, hydrothermal processing increases the B6CA/B5CA ratio, introducing a characteristic hydrothermal DBC signature.

Metabolic Potential of Microbial Genomes Reconstructed from a Deep-Sea Oligotrophic Sediment Metagenome

NASA Astrophysics Data System (ADS)

Tully, B. J.; Huber, J. A.; Heidelberg, J. F.

2016-02-01

The South Pacific Gyre (SPG) possesses the lowest rates of sedimentation, surface chlorophyll concentration and primary productivity in the global oceans, making it one of the most oligotrophic environments on earth. As a direct result of the low-standing biomass in surface waters, deep-sea sediments are thin and contain small amount of labile organic carbon. It was recently shown that the sediment column within the SPG is fully oxic through to the underlying basalt basement and may be representative of 9-37% of the global marine environment. In addition, it appears that approximately 50% of the total organic carbon is removed from the oligotrophic sediments within the first 20 centimeters beneath the sea floor (cmbsf). To understand the microbial processes that contribute to the removal of the labile organic matter, metagenomic sequencing and analysis was carried out on a sample of sediment collected from 0-5 cmbsf from SPG site 10 (U1369). Analysis of 9 partially reconstructed environmental genomes revealed that the members of the SPG surface sediment microbial community are phylogenetically distinct from surface/upper ocean organisms, with deep branches within the Alpha- and Gammaproteobacteria, Nitrospirae, Nitrospina, the phylum NC10, and several unique phylogenetic groups. Within these partially complete genomes there is evidence for microbially mediated metal (iron/manganese) oxidation and carbon fixation linked to the nitrification. Additionally, despite low sedimentation and hypothesized energy-limitation, members of the SPG microbial community had motility and chemotactic genes and possessed mechanisms for the utilization of high molecular weight organic matter, including exoproteases and peptide specific membrane transporters. Simultaneously, the SPG genomes showed a limited potential for the degradation of recalcitrant carbon compounds. Finally, the presence of putative genes with functions involved with denitrification and the consumption of C1 compounds suggest that there may be microenvironments in the surface sediments were microbes can deplete oxygen concentrations to hypoxic/anoxic levels. This study represents an important first analysis in understanding how microorganisms in oligotrophic sediments impact deep-sea carbon transformations.

Development of a Model of Geophysical and Geochemical Controls on Abiotic Carbon Cycling on Earth-Like Planets

NASA Astrophysics Data System (ADS)

Neveu, M.; Felton, R.; Domagal-Goldman, S. D.; Desch, S. J.; Arney, G. N.

2017-12-01

About 20 Earth-sized planets (0.6-1.6 Earth masses and radii) have now been discovered beyond our solar system [1]. Although such planets are prime targets in the upcoming search for atmospheric biosignatures, their composition, geology, and climate are essentially unconstrained. Yet, developing an understanding of how these factors influence planetary evolution through time and space is essential to establishing abiotic backgrounds against which any deviations can provide evidence for biological activity. To this end, we are building coupled geophysical-geochemical models of abiotic carbon cycling on such planets. Our models are controlled by atmospheric factors such as temperature and composition, and compute interior inputs to atmospheric species. They account for crustal weathering, ocean-atmosphere equilibria, and exchange with the deep interior as a function of planet composition and size (and, eventually, age).Planets in other solar systems differ from the Earth not only in their bulk physical properties, but also likely in their bulk chemical composition [2], which influences key parameters such as the vigor of mantle convection and the near-surface redox state. Therefore, simulating how variations in such parameters affect carbon cycling requires us to simulate the above processes from first principles, rather than by using arbitrary parameterizations derived from observations as is often done with models of carbon cycling on Earth [3] or extrapolations thereof [4]. As a first step, we have developed a kinetic model of crustal weathering using the PHREEQC code [5] and kinetic data from [6]. We will present the ability of such a model to replicate Earth's carbon cycle using, for the time being, parameterizations for surface-interior-atmosphere exchange processes such as volcanism (e.g., [7]).[1] exoplanet.eu, 7/28/2017.[2] Young et al. (2014) Astrobiology 14, 603-626.[3] Lerman & Wu (2008) Kinetics of Global Geochemical Cycles. In Kinetics of Water-Rock Interaction (Brantley et al., eds.), Springer, New York.[4] Edson et al. (2012) Astrobiology 12, 562-571.[5] Parkhurst & Appelo (2013) USGS Techniques and Methods 6-A43.[6] Palandri & Kharaka (2008) USGS Report 2004-1068.[7] Kite et al. (2009) ApJ 700, 1732-1749.

Quaternary of Himalaya

NASA Astrophysics Data System (ADS)

Srivastava, Pradeep; Singh, Vimal

2017-05-01

Tectonically active Himalayan mountains evolves via feedbacks from deep earth and surface processes; the complex interaction of various processes results into the landscape which is dynamic both at longer and shorter time scales. The extreme hydrological events that possibly ride over a long term climate cycle bring the changes in the landscape that impact human societies more closely. These events in the Himalaya frequently cause huge damage to economy and human lives. The geologist community under the umbrella of Himalaya-Karakorum-Tibet (HKT) workshop in its 30th edition convened a special session and deliberated on the subject. This special issue "Quaternary of Himalaya" is an outcome of papers presented and discussion held during this session; it consists of 18 papers in three sub-themes (i) Extreme Events in Himalaya (ii) Paleoglaciation in Himalaya and (iii) Expressions of climate and neotectonics in Himalaya.

Publications of the Western Earth Surface Processes Team 2006

USGS Publications Warehouse

Powell, Charles L.; Stone, Paul

2007-01-01

The Western Earth Surface Processes Team (WESPT) of the U.S. Geological Survey (USGS) conducts geologic mapping, earth-surface process investigations, and related topical earth science studies in the western United States. This work is focused on areas where modern geologic maps and associated earth-science data are needed to address key societal and environmental issues such as ground-water quality, landslides and other potential geologic hazards, and land-use decisions. Areas of primary emphasis in 2006 included southern California, the San Francisco Bay region, the Mojave Desert, the Colorado Plateau region of northern Arizona, and the Pacific Northwest. The team has its headquarters in Menlo Park, California, and maintains smaller field offices at several other locations in the western United States. This compilation gives the bibliographical citations for 123 new publications, most of which are available online using the hyperlinks provided.

Preferences for Deep-Surface Learning: A Vocational Education Case Study Using a Multimedia Assessment Activity

ERIC Educational Resources Information Center

Hamm, Simon; Robertson, Ian

2010-01-01

This research tests the proposition that the integration of a multimedia assessment activity into a Diploma of Events Management program promotes a deep learning approach. Firstly, learners' preferences for deep or surface learning were evaluated using the revised two-factor Study Process Questionnaire. Secondly, after completion of an assessment…

Harnessing Big Data to Represent 30-meter Spatial Heterogeneity in Earth System Models

NASA Astrophysics Data System (ADS)

Chaney, N.; Shevliakova, E.; Malyshev, S.; Van Huijgevoort, M.; Milly, C.; Sulman, B. N.

2016-12-01

Terrestrial land surface processes play a critical role in the Earth system; they have a profound impact on the global climate, food and energy production, freshwater resources, and biodiversity. One of the most fascinating yet challenging aspects of characterizing terrestrial ecosystems is their field-scale (˜30 m) spatial heterogeneity. It has been observed repeatedly that the water, energy, and biogeochemical cycles at multiple temporal and spatial scales have deep ties to an ecosystem's spatial structure. Current Earth system models largely disregard this important relationship leading to an inadequate representation of ecosystem dynamics. In this presentation, we will show how existing global environmental datasets can be harnessed to explicitly represent field-scale spatial heterogeneity in Earth system models. For each macroscale grid cell, these environmental data are clustered according to their field-scale soil and topographic attributes to define unique sub-grid tiles. The state-of-the-art Geophysical Fluid Dynamics Laboratory (GFDL) land model is then used to simulate these tiles and their spatial interactions via the exchange of water, energy, and nutrients along explicit topographic gradients. Using historical simulations over the contiguous United States, we will show how a robust representation of field-scale spatial heterogeneity impacts modeled ecosystem dynamics including the water, energy, and biogeochemical cycles as well as vegetation composition and distribution.

Production and recycling of oceanic crust in the early Earth

NASA Astrophysics Data System (ADS)

van Thienen, P.; van den Berg, A. P.; Vlaar, N. J.

2004-08-01

Because of the strongly different conditions in the mantle of the early Earth regarding temperature and viscosity, present-day geodynamics cannot simply be extrapolated back to the early history of the Earth. We use numerical thermochemical convection models including partial melting and a simple mechanism for melt segregation and oceanic crust production to investigate an alternative suite of dynamics which may have been in operation in the early Earth. Our modelling results show three processes that may have played an important role in the production and recycling of oceanic crust: (1) Small-scale ( x×100 km) convection involving the lower crust and shallow upper mantle. Partial melting and thus crustal production takes place in the upwelling limb and delamination of the eclogitic lower crust in the downwelling limb. (2) Large-scale resurfacing events in which (nearly) the complete crust sinks into the (eventually lower) mantle, thereby forming a stable reservoir enriched in incompatible elements in the deep mantle. New crust is simultaneously formed at the surface from segregating melt. (3) Intrusion of lower mantle diapirs with a high excess temperature (about 250 K) into the upper mantle, causing massive melting and crustal growth. This allows for plumes in the Archean upper mantle with a much higher excess temperature than previously expected from theoretical considerations.

Planetary Protection Progress of Hayabusa2 and Its Piggyback PROCYON: Launch, Earth Swingby and Outbound Cruising Phases

NASA Astrophysics Data System (ADS)

Yano, Hajime; Yoshikawa, Makoto; Sarli, Bruno; Ozaki, Naoya; Funase, Ryu; Tsuda, Yuichi; Chujo, Toshihiro; Ariu, Kaito

2016-07-01

Hayabusa-2 is Japan's second asteroid sample return mission which was successfully launched into the planned Earth departure trajectory with the H-IIA rocket on December 3rd, 2014, together with a group of its interplanetary piggyback micro- spacecraft, including the PROCYON(Proximate Object Close flYby with Optical Navigation)spacecraft, the world's first 50 kg-class deep space micro-spacecraft developed by the University of Tokyo and the Japan Aerospace Exploration Agency. The Hayabusa-2 spacecraft will go to Rug, a C-type NEO, and attempt surface investigations with daughter rovers (MINERVA-II series and MASCOT), artificial impact cratering experiment (SCI) and both surface and sub-surface sampling (Sampler) in 2018-2019 and plans to return to the Earth in December 2020. The PROCYON mission objective was to demonstrate a micro-spacecraft bus technology for deep space exploration and proximity flyby to asteroids performing optical measurements. Both of the above missions were fully evaluated by the COSPAR Planetary Protection Panel at the dedicated COSPAR colloquium and scientific assembly in 2014 and the COSPAR PPP has endorsed the Category-2 for their outbound trajectories and the non-restricted Earth return for the inbound trajectory of Hayabusa-2. As a part of the fulfillments of the Category-2 classification, both spacecraft must be compliant with the COSPAR PPP requirements of non-impact probability to Mars since they would have enough energy to reach and beyond the orbit of Mars, due to the Earth swing-by and ion engine operations for their outbound cruising. As for the Hayabusa-2 spacecraft, it successfully performed its Earth gravity assist in December 2015, resulting on accurate orbit determination for the post-swing-by orbit to be ready to restart the ion engine operation. Thus the non-impact probability to Mars did not change from the estimate given by Chujo, et al. (2015). As for the PROCYON spacecraft after the completion of the bus system demonstration, it started deep space maneuver using the ion engines so that the spacecraft would be injected into an asteroid flyby trajectory via the Earth swing-by scheduled in December 2015. However, malfunction of the PROCYON high voltage system in the thruster occurred in March 2015, and the operation of the ion thruster stopped after 223 hours of successful continuous operation. Due to this anomaly, PROCYON gave up reaching its final destination (NEO "2000 DP107"); thus it now can be said that the spacecraft will never impact on Mars. In this paper, we summarize the mission status of the both projects in terms of the COSPAR PPP perspectives.

Time travel and chemical evolution - A look at the outer solar system

NASA Astrophysics Data System (ADS)

Owen, T.

1987-12-01

It has been hypothesized that the chemical conditions today on the planets and moons of the outer solar system are similar to conditions on earth soon after it formed. If this is so, much can be learned about the chemistry that led to life on earth. While Jupiter is a poor terrestrial analog, its satellite Europa has a smooth icy surface that may cover a layer of liquid water tens of kilometers deep. It is possible that sunlight could filter through cracks in the ice, providing energy to drive chemical reactions in the water below the ice. It is noted that the surface of Titan may include lakes or oceans of ethane and that Triton may also have liquids on its surface. Studies of cometary nuclei will be undertaken during the Comet Rendezvous-Asteroid Flyby mission.

Surface and deep structures in graphics comprehension.

PubMed

Schnotz, Wolfgang; Baadte, Christiane

2015-05-01

Comprehension of graphics can be considered as a process of schema-mediated structure mapping from external graphics on internal mental models. Two experiments were conducted to test the hypothesis that graphics possess a perceptible surface structure as well as a semantic deep structure both of which affect mental model construction. The same content was presented to different groups of learners by graphics from different perspectives with different surface structures but the same deep structure. Deep structures were complementary: major features of the learning content in one experiment became minor features in the other experiment, and vice versa. Text was held constant. Participants were asked to read, understand, and memorize the learning material. Furthermore, they were either instructed to process the material from the perspective supported by the graphic or from an alternative perspective, or they received no further instruction. After learning, they were asked to recall the learning content from different perspectives by completing graphs of different formats as accurately as possible. Learners' recall was more accurate if the format of recall was the same as the learning format which indicates surface structure influences. However, participants also showed more accurate recall when they remembered the content from a perspective emphasizing the deep structure, regardless of the graphics format presented before. This included better recall of what they had not seen than of what they really had seen before. That is, deep structure effects overrode surface effects. Depending on context conditions, stimulation of additional cognitive processing by instruction had partially positive and partially negative effects.

Seismic refraction studies of volcanic crust in Costa Rica and of critical zones in the southern Sierra Nevada, California and Laramie Range, Wyoming

NASA Astrophysics Data System (ADS)

Hayes, Jorden L.

This work demonstrates the utility of seismic refraction surveys to understanding geologic processes at a range of scales. Each chapter presents subsurface maps of seismic p-wave velocities, which vary due to contrasts in elastic material properties. In the following chapters we examine seismic p-wave velocity variations that result from volcanic and tectonic processes within Earth's crust and chemical and physical weathering processes within Earth's near-surface environment. Chapter one presents results from an across-arc wide-angle seismic refraction survey of the Costa Rican volcanic front. These results support the hypothesis that juvenile continental crust may form along volcanic island arcs if built upon relatively thick substrates (i.e., large igneous provinces). Comparisons of velocity-depth functions show that velocities within the active arc of Costa Rica are lower than other modern island arcs (i.e., volcanic arcs built upon oceanic crust) and within the high-velocity extreme of bulk continental crust. Chapter two shows that physical processes can dominate over chemical processes in generating porosity in the deep critical zone and outlines a new framework for interpreting subsurface chemical and physical weathering at the landscape scale. Direct measurements of saprolite from boreholes at the Southern Sierra Nevada Critical Zone Observatory show that, contrary to convention, saprolite may experience high levels of volumetric strain (>35%) and uniform mass loss in the upper 11 m. By combining observations from boreholes and seismic refraction surveys we create a map of volumetric strain across the landscape. Variations in inferred volumetric strain are consistent with opening-mode fracture patterns predicted by topographic and tectonic stress models. Chapter three is a characterization of fracture distribution in the deep critical zone from geophysical and borehole observations in the Laramie Mountains, Wyoming. Data from core and down-hole acoustic televiewer images show that fracture density not only decreases with depth but also varies with topography. Comparisons of seismic p-wave velocities and fracture density show that increases in seismic velocity at our site (i.e., from 1-4 km/s) correspond to decreasing fracture density. Observations of a seismological boundary layer coupled with weathering interpreted in borehole images suggest a significant change in chemical weathering with depth. These results emphasize the complex interplay of chemical and physical processes in the deep critical zone.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

NASA's Deep Space 1 spacecraft waits in the Payload Hazardous Servicing Facility for prelaunch processing. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

KSC-05PD-0116

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. At Ball Aerospace in Boulder, Colo., the impactor on the Deep Impact spacecraft is tested. Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing a 3- by 3-foot projectile (impactor) to crash onto the surface, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measuring the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. The impactor will separate from the flyby spacecraft 24 hours before it impacts the surface of Tempel 1's nucleus. The impactor delivers 19 Gigajoules (that's 4.8 tons of TNT) of kinetic energy to excavate the crater. This kinetic energy is generated by the combination of the mass of the impactor and its velocity when it impacts. To accomplish this feat, the impactor uses a high-precision star tracker, the Impactor Target Sensor (ITS), and Auto-Navigation algorithms developed by Jet Propulsion Laboratory to guide it to the target. Deep Impact is a NASA Discovery mission. Launch of Deep Impact is scheduled for Jan. 12 from Launch Pad 17-B, Cape Canaveral Air Force Station, Fla.

Geoscience Education and Global Development

ERIC Educational Resources Information Center

Locke, Sharon; Libarkin, Julie; Chang, Chun-Yen

2012-01-01

A fundamental goal of geoscience education is ensuring that all inhabitants of the planet have knowledge of the natural processes that shape the physical environment, and understand how the actions of humans have an impact on the Earth on local, regional, and global scales. Geoscientists accept that deep understanding of natural processes requires…

Future Visions for Scientific Human Exploration

NASA Technical Reports Server (NTRS)

Garvin, James

2005-01-01

Today, humans explore deep-space locations such as Mars, asteroids, and beyond, vicariously here on Earth, with noteworthy success. However, to achieve the revolutionary breakthroughs that have punctuated the history of science since the dawn of the Space Age has always required humans as "the discoverers," as Daniel Boorstin contends in this book of the same name. During Apollo 17, human explorers on the lunar surface discovered the "genesis rock," orange glass, and humans in space revamped the optically crippled Hubble Space Telescope to enable some of the greatest astronomical discoveries of all time. Science-driven human exploration is about developing the opportunities for such events, perhaps associated with challenging problems such as whether we can identify life beyond Earth within the universe. At issue, however, is how to safely insert humans and the spaceflight systems required to allow humans to operate as they do best in the hostile environment of deep space. The first issue is minimizing the problems associated with human adaptation to the most challenging aspects of deep space space radiation and microgravity (or non-Earth gravity). One solution path is to develop technologies that allow for minimization of the exposure time of people to deep space, as was accomplished in Apollo. For a mission to the planet Mars, this might entail new technological solutions for in-space propulsion that would make possible time-minimized transfers to and from Mars. The problem of rapid, reliable in-space transportation is challenged by the celestial mechanics of moving in space and the so-called "rocket equation." To travel to Mars from Earth in less than the time fuel-minimizing trajectories allow (i.e., Hohmann transfers) requires an exponential increase in the amount of fuel. Thus, month-long transits would require a mass of fuel as large as the dry mass of the ISS, assuming the existence of continuous acceleration engines. This raises the largest technological stumbling block to moving humans on site as deep-space explorers, delivering the masses required for human spaceflight systems to LEO or other Earth orbital vantage points using the existing or projected fleet of Earth-to-orbit (ETO) launch vehicles. Without a return to Saturn V-class boosters or an alternate path, one cannot imagine emplacing the masses that would be required for any deep-space voyage without a prohibitive number of Shuttle-class launches. One futurist solution might involve mass launch systems that could be used to move the consumables, including fuel, water, food, and building materials, to LEO in pieces rather than launching integrated systems. This approach would necessitate the development of robotic assembly and fuel-storage systems in Earth orbit, but could provide for a natural separation of low-value cargo (e.g., fuel, water).

Art Rocks with Rock Art!

ERIC Educational Resources Information Center

Bickett, Marianne

2011-01-01

This article discusses rock art which was the very first "art." Rock art, such as the images created on the stone surfaces of the caves of Lascaux and Altimira, is the true origin of the canvas, paintbrush, and painting media. For there, within caverns deep in the earth, the first artists mixed animal fat, urine, and saliva with powdered minerals…

Deep space communication - A one billion mile noisy channel

NASA Technical Reports Server (NTRS)

Smith, J. G.

1982-01-01

Deep space exploration is concerned with the study of natural phenomena in the solar system with the aid of measurements made at spacecraft on deep space missions. Deep space communication refers to communication between earth and spacecraft in deep space. The Deep Space Network is an earth-based facility employed for deep space communication. It includes a network of large tracking antennas located at various positions around the earth. The goals and achievements of deep space exploration over the past 20 years are discussed along with the broad functional requirements of deep space missions. Attention is given to the differences in space loss between communication satellites and deep space vehicles, effects of the long round-trip light time on spacecraft autonomy, requirements for the use of massive nuclear power plants on spacecraft at large distances from the sun, and the kinds of scientific return provided by a deep space mission. Problems concerning a deep space link of one billion miles are also explored.

A role for subducted super-hydrated kaolinite in Earth’s deep water cycle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hwang, Huijeong; Seoung, Donghoon; Lee, Yongjae

Water is the most abundant volatile component in the Earth. It continuously enters the mantle through subduction zones, where it reduces the melting temperature of rocks to generate magmas. The dehydration process in subduction zones, which determines whether water is released from the slab or transported into the deeper mantle, is an essential component of the deep water cycle. Here we use in situ and time-resolved high-pressure/high-temperature synchrotron X-ray diffraction and infrared spectra to characterize the structural and chemical changes of the clay mineral kaolinite. At conditions corresponding to a depth of about 75 km in a cold subducting slabmore » (2.7 GPa and 200 °C), and in the presence of water, we observe the pressure-induced insertion of water into kaolinite. This super-hydrated phase has a unit cell volume that is about 31% larger, a density that is about 8.4% lower than the original kaolinite and, with 29 wt% H2O, the highest water content of any known aluminosilicate mineral in the Earth. As pressure and temperature approach 19 GPa and about 800 °C, we observe the sequential breakdown of super-hydrated kaolinite. The formation and subsequent breakdown of super-hydrated kaolinite in cold slabs subducted below 200 km leads to the release of water that may affect seismicity and help fuel arc volcanism at the surface.« less

Ocean Biological Pump Sensitivities and Implications for Climate Change Impacts

NASA Technical Reports Server (NTRS)

Romanou, Anastasia

2013-01-01

The ocean is one of the principal reservoirs of CO2, a greenhouse gas, and therefore plays a crucial role in regulating Earth's climate. Currently, the ocean sequesters about a third of anthropogenic CO2 emissions, mitigating the human impact on climate. At the same time, the deeper ocean represents the largest carbon pool in the Earth System and processes that describe the transfer of carbon from the surface of the ocean to depth are intimately linked to the effectiveness of carbon sequestration.The ocean biological pump (OBP), which involves several biogeochemical processes, is a major pathway for transfer of carbon from the surface mixed layer into the ocean interior. About 75 of the carbon vertical gradient is due to the carbon pump with only 25 attributed to the solubility pump. However, the relative importance and role of the two pumps is poorly constrained. OBP is further divided to the organic carbon pump (soft tissue pump) and the carbonate pump, with the former exporting about 10 times more carbon than the latter through processes like remineralization.Major uncertainties about OBP, and hence in the carbon uptake and sequestration, stem from uncertainties in processes involved in OBP such as particulate organicinorganic carbon sinkingsettling, remineralization, microbial degradation of DOC and uptakegrowth rate changes of the ocean biology. The deep ocean is a major sink of atmospheric CO2 in scales of hundreds to thousands of years, but how the export efficiency (i.e. the fraction of total carbon fixation at the surface that is transported at depth) is affected by climate change remains largely undetermined. These processes affect the ocean chemistry (alkalinity, pH, DIC, particulate and dissolved organic carbon) as well as the ecology (biodiversity, functional groups and their interactions) in the ocean. It is important to have a rigorous, quantitative understanding of the uncertainties involved in the observational measurements, the models and the projections of future changes.

Deep and persistent melt layer in the Archaean mantle

NASA Astrophysics Data System (ADS)

Andrault, Denis; Pesce, Giacomo; Manthilake, Geeth; Monteux, Julien; Bolfan-Casanova, Nathalie; Chantel, Julien; Novella, Davide; Guignot, Nicolas; King, Andrew; Itié, Jean-Paul; Hennet, Louis

2018-02-01

The transition from the Archaean to the Proterozoic eon ended a period of great instability at the Earth's surface. The origin of this transition could be a change in the dynamic regime of the Earth's interior. Here we use laboratory experiments to investigate the solidus of samples representative of the Archaean upper mantle. Our two complementary in situ measurements of the melting curve reveal a solidus that is 200-250 K lower than previously reported at depths higher than about 100 km. Such a lower solidus temperature makes partial melting today easier than previously thought, particularly in the presence of volatiles (H2O and CO2). A lower solidus could also account for the early high production of melts such as komatiites. For an Archaean mantle that was 200-300 K hotter than today, significant melting is expected at depths from 100-150 km to more than 400 km. Thus, a persistent layer of melt may have existed in the Archaean upper mantle. This shell of molten material may have progressively disappeared because of secular cooling of the mantle. Crystallization would have increased the upper mantle viscosity and could have enhanced mechanical coupling between the lithosphere and the asthenosphere. Such a change might explain the transition from surface dynamics dominated by a stagnant lid on the early Earth to modern-like plate tectonics with deep slab subduction.

The esa earth explorer land surface processes and interactions mission

NASA Astrophysics Data System (ADS)

Labandibar, Jean-Yves; Jubineau, Franck; Silvestrin, Pierluigi; Del Bello, Umberto

2017-11-01

The European Space Agency (ESA) is defining candidate missions for Earth Observation. In the class of the Earth Explorer missions, dedicated to research and pre-operational demonstration, the Land Surface Processes and Interactions Mission (LSPIM) will acquire the accurate quantitative measurements needed to improve our understanding of the nature and evolution of biosphere-atmosphere interactions and to contribute significantly to a solution of the scaling problems for energy, water and carbon fluxes at the Earth's surface. The mission is intended to provide detailed observations of the surface of the Earth and to collect data related to ecosystem processes and radiation balance. It is also intended to address a range of issues important for environmental monitoring, renewable resources assessment and climate models. The mission involves a dedicated maneuvering satellite which provides multi-directional observations for systematic measurement of Land Surface BRDF (BiDirectional Reflectance Distribution Function) of selected sites on Earth. The satellite carries an optical payload : PRISM (Processes Research by an Imaging Space Mission), a multispectral imager providing reasonably high spatial resolution images (50 m over 50 km swath) in the whole optical spectral domain (from 450 nm to 2.35 μm with a resolution close to 10 nm, and two thermal bands from 8.1 to 9.1 μm). This paper presents the results of the Phase A study awarded by ESA, led by ALCATEL Space Industries and concerning the design of LSPIM.

Putting the Deep Biosphere on the Map for Oceanography Courses: Gas Hydrates As a Case Study for the Deep Biosphere

NASA Astrophysics Data System (ADS)

Sikorski, J. J.; Briggs, B. R.

2014-12-01

The ocean is essential for life on our planet. It covers 71% of the Earth's surface, is the source of the water we drink, the air we breathe, and the food we eat. Yet, the exponential growth in human population is putting the ocean and thus life on our planet at risk. However, based on student evaluations from our introductory oceanography course it is clear that our students have deficiencies in ocean literacy that impact their ability to recognize that the ocean and humans are inextricably connected. Furthermore, life present in deep subsurface marine environments is also interconnected to the study of the ocean, yet the deep biosphere is not typically covered in undergraduate oceanography courses. In an effort to improve student ocean literacy we developed an instructional module on the deep biosphere focused on gas hydrate deposits. Specifically, our module utilizes Google Earth and cutting edge research about microbial life in the ocean to support three inquiry-based activities that each explore different facets of gas hydrates (i.e. environmental controls, biologic controls, and societal implications). The relevant nature of the proposed module also makes it possible for instructors of introductory geology courses to modify module components to discuss related topics, such as climate, energy, and geologic hazards. This work, which will be available online as a free download, is a solid contribution toward increasing the available teaching resources focused on the deep biosphere for geoscience educators.

Effect of inversion layer at iron pyrite surface on photovoltaic device

NASA Astrophysics Data System (ADS)

Uchiyama, Shunsuke; Ishikawa, Yasuaki; Uraoka, Yukiharu

2018-03-01

Iron pyrite has great potential as a thin-film solar cell material because it has high optical absorption, low cost, and is earth-abundant. However, previously reported iron pyrite solar cells showed poor photovoltaic characteristics. Here, we have numerically simulated its photovoltaic characteristics and band structures by utilizing a two-dimensional (2D) device simulator, ATLAS, to evaluate the effects of an inversion layer at the surface and a high density of deep donor defect states in the bulk. We found that previous device structures did not consider the inversion layer at the surface region of iron pyrite, which made it difficult to obtain the conversion efficiency. Therefore, we remodeled the device structure and suggested that removing the inversion layer and reducing the density of deep donor defect states would lead to a high conversion efficiency of iron pyrite solar cells.

Infragravity waves in the ocean as a source of acoustic-gravity waves in the atmosphere

NASA Astrophysics Data System (ADS)

Zabotin, Nikolay A.; Godin, Oleg A.

2013-04-01

Infragravity waves (IGWs) are surface gravity waves in the ocean with periods longer than the longest periods (~30s) of wind-generated waves. IGWs propagate transoceanic distances with very little attenuation in deep water and, because of their long wavelengths (from ~1 km to hundreds of km), provide a mechanism for coupling wave processes in the ocean, ice shelves, the atmosphere, and the solid Earth. Here, we build on recent advances in understanding spectral and spatial variability of background infragravity waves in deep ocean to evaluate the IGW manifestations in the atmosphere. Water compressibility has a minor effect on IGWs. On the contrary, much larger compressibility and vertical extent of the atmosphere makes it necessary to treat IGW extension into the atmosphere as acoustic-gravity waves. There exist two distinct regimes of IGW penetration into the atmosphere. At higher frequencies, one has surface waves in the atmosphere propagating horizontally along the ocean surface and prominent up to heights of the order of the wavelength. At lower frequencies, IGWs are leaky waves, which continuously radiate their energy into the upper atmosphere. The transition between the two regimes occurs at a frequency of the order of 3 mHz, with the exact value of the transition frequency being a function of the ocean depth, the direction of IGW propagation and the vertical profiles of temperature and wind velocity. The transition frequency decreases with increasing ocean depth. Using recently obtained semi-empirical model of power spectra the IGWs over varying bathymetry [Godin O. A., Zabotin N. A., Sheehan A. F., Yang Z., and Collins J. A. Power spectra of infragravity waves in a deep ocean, Geophys. Res. Lett., under review (2012)], we derive an estimate of the flux of the mechanical energy from the deep ocean into the atmosphere due to IGWs. Significance will be discussed of the IGW contributions into the field of acoustic-gravity waves in the atmosphere.

Electromagnetic deep-probing (100-1000 KMS) of the Earth's interior from artificial satellites: Constraints on the regional emplacement of crustal resources

NASA Technical Reports Server (NTRS)

Hermance, J. F. (Principal Investigator)

1981-01-01

An algorithm was developed to address the problem of electromagnetic coupling of ionospheric current systems to both a homogeneous Earth having finite conductivity, and to an Earth having gross lateral variations in its conductivity structure, e.g., the ocean-land interface. Typical results from the model simulation for ionospheric currents flowing parallel to a representative geologic discontinuity are shown. Although the total magnetic field component at the satellite altitude is an order of magnitude smaller than at the Earth's surface (because of cancellation effects from the source current), the anomalous behavior of the satellite observations as the vehicle passes over the geologic contact is relatively more important pronounced. The results discriminate among gross lithospheric structures because of difference in electrical conductivity.

Error Budgets for the Exoplanet Starshade (exo-s) Probe-Class Mission Study

NASA Technical Reports Server (NTRS)

Shaklan, Stuart B.; Marchen, Luis; Cady, Eric; Ames, William; Lisman, P. Douglas; Martin, Stefan R.; Thomson, Mark; Regehr, Martin

2015-01-01

Exo-S is a probe-class mission study that includes the Dedicated mission, a 30 millimeters starshade co-launched with a 1.1 millimeter commercial telescope in an Earth-leading deep-space orbit, and the Rendezvous mission, a 34 millimeter starshade intended to work with a 2.4 millimeters telescope in an Earth-Sun L2 orbit. A third design, referred to as the Rendezvous Earth Finder mission, is based on a 40 millimeter starshade and is currently under study. This paper presents error budgets for the detection of Earth-like planets with each of these missions. The budgets include manufacture and deployment tolerances, the allowed thermal fluctuations and dynamic motions, formation flying alignment requirements, surface and edge reflectivity requirements, and the allowed transmission due to micrometeoroid damage.

Error budgets for the Exoplanet Starshade (Exo-S) probe-class mission study

NASA Astrophysics Data System (ADS)

Shaklan, Stuart B.; Marchen, Luis; Cady, Eric; Ames, William; Lisman, P. Douglas; Martin, Stefan R.; Thomson, Mark; Regehr, Martin

2015-09-01

Exo-S is a probe-class mission study that includes the Dedicated mission, a 30 m starshade co-launched with a 1.1 m commercial telescope in an Earth-leading deep-space orbit, and the Rendezvous mission, a 34 m starshade intended to work with a 2.4 m telescope in an Earth-Sun L2 orbit. A third design, referred to as the Rendezvous Earth Finder mission, is based on a 40 m starshade and is currently under study. This paper presents error budgets for the detection of Earth-like planets with each of these missions. The budgets include manufacture and deployment tolerances, the allowed thermal fluctuations and dynamic motions, formation flying alignment requirements, surface and edge reflectivity requirements, and the allowed transmission due to micrometeoroid damage.

Performance of deep geothermal energy systems

NASA Astrophysics Data System (ADS)

Manikonda, Nikhil

Geothermal energy is an important source of clean and renewable energy. This project deals with the study of deep geothermal power plants for the generation of electricity. The design involves the extraction of heat from the Earth and its conversion into electricity. This is performed by allowing fluid deep into the Earth where it gets heated due to the surrounding rock. The fluid gets vaporized and returns to the surface in a heat pipe. Finally, the energy of the fluid is converted into electricity using turbine or organic rankine cycle (ORC). The main feature of the system is the employment of side channels to increase the amount of thermal energy extracted. A finite difference computer model is developed to solve the heat transport equation. The numerical model was employed to evaluate the performance of the design. The major goal was to optimize the output power as a function of parameters such as thermal diffusivity of the rock, depth of the main well, number and length of lateral channels. The sustainable lifetime of the system for a target output power of 2 MW has been calculated for deep geothermal systems with drilling depths of 8000 and 10000 meters, and a financial analysis has been performed to evaluate the economic feasibility of the system for a practical range of geothermal parameters. Results show promising an outlook for deep geothermal systems for practical applications.

From Prime to Extended Mission: Evolution of the MER Tactical Uplink Process

NASA Technical Reports Server (NTRS)

Mishkin, Andrew H.; Laubach, Sharon

2006-01-01

To support a 90-day surface mission for two robotic rovers, the Mars Exploration Rover mission designed and implemented an intensive tactical operations process, enabling daily commanding of each rover. Using a combination of new processes, custom software tools, a Mars-time staffing schedule, and seven-day-a-week operations, the MER team was able to compress the traditional weeks-long command-turnaround for a deep space robotic mission to about 18 hours. However, the pace of this process was never intended to be continued indefinitely. Even before the end of the three-month prime mission, MER operations began evolving towards greater sustainability. A combination of continued software tool development, increasing team experience, and availability of reusable sequences first reduced the mean process duration to approximately 11 hours. The number of workshifts required to perform the process dropped, and the team returned to a modified 'Earth-time' schedule. Additional process and tool adaptation eventually provided the option of planning multiple Martian days of activity within a single workshift, making 5-day-a-week operations possible. The vast majority of the science team returned to their home institutions, continuing to participate fully in the tactical operations process remotely. MER has continued to operate for over two Earth-years as many of its key personnel have moved on to other projects, the operations team and budget have shrunk, and the rovers have begun to exhibit symptoms of aging.

Lunar Navigation Determination System - LaNDS

NASA Technical Reports Server (NTRS)

Quinn, David; Talabac, Stephen

2012-01-01

A portable comprehensive navigational system has been developed that both robotic and human explorers can use to determine their location, attitude, and heading anywhere on the lunar surface independent of external infrastructure (needs no Lunar satellite network, line of sight to the Sun or Earth, etc.). The system combines robust processing power with an extensive topographical database to create a real-time atlas (GIS Geospatial Information System) that is able to autonomously control and monitor both single unmanned rovers and fleets of rovers, as well as science payload stations. The system includes provisions for teleoperation and tele-presence. The system accepts (but does not require) inputs from a wide range of sensors. A means was needed to establish a location when the search is taken deep in a crater (looking for water ice) and out of view of Earth or any other references. A star camera can be employed to determine the user's attitude in menial space and stellar map in body space. A local nadir reference (e.g., an accelerometer that orients the nadir vector in body space) can be used in conjunction with a digital ephemeris and gravity model of the Moon to isolate the latitude, longitude, and azimuth of the user on the surface. That information can be used in conjunction with a Lunar GIS and advanced navigation planning algorithms to aid astronauts (or other assets) to navigate on the Lunar surface.

Silicon solar cell characterization at low temperatures and low illumination as a function of particulate irradiation

NASA Technical Reports Server (NTRS)

Whitaker, A. F.; Little, S. A.; Peacock, C. L., Jr.

1983-01-01

Various configurations of back surface reflector silicon solar cells including small (2 x 2) cm and large (approx. 6 x 6) cm cells with conventional and wraparound contacts were subjected to 1 MeV electron irradiation and characterized under both Earth orbital and deep space conditions of temperatures and illuminations. Current-Voltage (I-V) data were generated from +65 C to -150 C and at incident illuminations from 135.3 mW/sq cm to 5.4 mW/sq cm for these cells. Degradation in cell performance which is manifested only under deep space conditions is emphasized. In addition, the effect of particle irradiation on the high temperature and high intensity and low temperature and low intensity performance of the cells is described. The cells with wraparound contacts were found to have lower efficiencies at Earth orbital conditions than the cells with conventional contacts.

Deep Space Network and Lunar Network Communication Coverage of the Moon

NASA Technical Reports Server (NTRS)

Lee, Charles H.; Cheung, Kar-Ming

2006-01-01

In this article, we describe the communication coverage analysis for the lunar network and the Earth ground stations. The first part of this article focuses on the direct communication coverage of the Moon from the Earth's ground stations. In particular, we assess the coverage performance of the Moon based on the existing Deep Space Network (DSN) antennas and the complimentary coverage of other potential stations at Hartebeesthoek, South Africa and at Santiago, Chile. We also address the coverage sensitivity based on different DSN antenna scenarios and their capability to provide single and redundant coverage of the Moon. The second part of this article focuses on the framework of the constrained optimization scheme to seek a stable constellation six relay satellites in two planes that not only can provide continuous communication coverage to any users on the Moon surface, but can also deliver data throughput in a highly efficient manner.

Seismic anisotropy from crust to core: a mineral and rock physics perspective

NASA Astrophysics Data System (ADS)

Mainprice, David

2014-05-01

Since the early work of Hess and co-works for mantle in the 1960s and Poupinet et al. in 1980s for the inner core, we know that seismic anisotropy is a global phenomenon. Progress in seismology has led to a much more complete image of the Earth's interior in terms of heterogeneity and anisotropy. The interpretation of the seismic anisotropy requires a multidisciplinary effort to unravel the geodynamic scenario recorded in today's seismological snapshot. Progress in mineral physics on the experimental measurement of elastic properties at extreme conditions are now completed by ab initio atomic modelling for the full range of temperatures and pressures of the Earth's interior. The new data on the elastic constants of wider range minerals enables more realistic petrology for seismic anisotropy models. Experimental plastic deformation of polycrystalline samples at deep Earth conditions allows the direct study of crystal preferred orientation (CPO) and these studies are completed by ab initio atomic modelling of dislocations and other defects that control plasticity. Finally, polycrystalline plasticity codes allow the simulation of CPO reported by experimentalists and the modelling of more complex strain paths required for geodynamic models. The CPO of crustal and mantle rocks from the Earth's surface or recovered as xenoliths, provides a geological verification of the CPOs present in the Earth. The systematic use of CPO measured by U-stage for field studies all over the world for last 40 years has now been intensified in last 15 years by the use of electron back-scattered diffraction (EBSD) to study of CPO and the associated digital microstructure. It is an appropriate time to analysis CPO databases of olivine and other minerals, which represents the work of our group, both present and former members, as well as collaborating colleagues. It is also interesting to compare the natural record as illustrated by our databases in the light of recent experimental results. Information on CPO together with single crystal elastic constants and the equation of state allow the modelling of seismic anisotropy due to plasticity at any PT condition, and the connection with geodynamic processes related to large-scale flow in the deep Earth.

A brief geologic history of Volusia County, Florida

USGS Publications Warehouse

German, Edward R.

2009-01-01

Volusia County is in a unique and beautiful setting. This Florida landscape is characterized by low coastal plains bordered by upland areas of sandy ridges and many lakes. Beautiful streams and springs abound within the vicinity. Underneath the land surface is a deep layer of limestone rocks that stores fresh, clean water used to serve drinking and other needs. However, the landscape and the subsurface rocks have not always been as they appear today. These features are the result of environmental forces and processes that began millions of years ago and are still ongoing. This fact sheet provides a brief geologic history of the Earth, Florida, and Volusia County, with an emphasis on explaining why the Volusia County landscape and geologic structure exists as it does today.

Deep-ocean ferromanganese crusts and nodules

USGS Publications Warehouse

Hein, James R.; Koschinsky, Andrea

2014-01-01

Ferromanganese crusts and nodules may provide a future resource for a large variety of metals, including many that are essential for emerging high- and green-technology applications. A brief review of nodules and crusts provides a setting for a discussion on the latest (past 10 years) research related to the geochemistry of sequestration of metals from seawater. Special attention is given to cobalt, nickel, titanium, rare earth elements and yttrium, bismuth, platinum, tungsten, tantalum, hafnium, tellurium, molybdenum, niobium, zirconium, and lithium. Sequestration from seawater by sorption, surface oxidation, substitution, and precipitation of discrete phases is discussed. Mechanisms of metal enrichment reflect modes of formation of the crusts and nodules, such as hydrogenetic (from seawater), diagenetic (from porewaters), and mixed diagenetic–hydrogenetic processes.

KSC-05PD-0114

NASA Technical Reports Server (NTRS)

2005-01-01

the Fischer Assembly building at Ball Aerospace in Boulder, Colo. Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing a 3- by 3- foot projectile (impactor) to crash onto the surface, Deep Impacts flyby spacecraft will collect pictures and data of how the crater forms, measuring the craters depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determining the changes in natural outgassing produced by the impact. The impactor will separate from the flyby spacecraft 24 hours before it impacts the surface of Tempel 1's nucleus. The impactor delivers 19 Gigajoules (that's 4.8 tons of TNT) of kinetic energy to excavate the crater. This kinetic energy is generated by the combination of the mass of the impactor and its velocity when it impacts. To accomplish this feat, the impactor uses a high-precision star tracker, the Impactor Target Sensor (ITS), and Auto-Navigation algorithms developed by Jet Propulsion Laboratory to guide it to the target. Deep Impact is a NASA Discovery mission. Launch of Deep Impact is scheduled for Jan. 12 from Launch Pad 17-B, Cape Canaveral Air Force Station, Fla.

Properties of the moon, Mars, Martian satellites, and near-earth asteroids

NASA Technical Reports Server (NTRS)

Taylor, Jeffrey G.

1989-01-01

Environments and surface properties of the moon, Mars, Martian satellites, and near-earth asteroids are discussed. Topics include gravity, atmospheres, surface properties, surface compositions, seismicity, radiation environment, degradation, use of robotics, and environmental impacts. Gravity fields vary from large fractions of the earth's field such as 1/3 on Mars and 1/6 on the moon to smaller fractions of 0.0004 g on an asteroid 1 km in diameter. Spectral data and the analogy with meteor compositions suggest that near-earth asteroids may contain many resources such as water-rich carbonaceous materials and iron-rich metallic bodies. It is concluded that future mining and materials processing operations from extraterrestrial bodies require an investment now in both (1) missions to the moon, Mars, Phobos, Deimos, and near-earth asteroids and (2) earth-based laboratory research in materials and processing.

Demandite, lunar materials and space industrialization

NASA Technical Reports Server (NTRS)

Criswell, D. R.

1977-01-01

Terrestrial industry consumes a wide range of elements in producing the outputs which support and make industrial societies possible. 'Demandite' is a conceptual or synthetic molecule which is composed of the weight fractions of the major elements consumed by industry. Demandite needed for mature industrial activities in space will differ from the terrestrial composition because solar energy must replace hydrocarbon-energy, lunar and asteroidal bulk compositions are different from mineral deposits on the earth, and the major bulk processing in space will be the creation of radiation shielding for human habitats to provide real estate in space complete with water, atmosphere and life-stock elements. Demandite cost may be dominated by earth to deep space transport cost of minor elemental constituents depleted in the lunar soils unless careful attention is given to substitution of materials, searches of the moon (polar regions) and asteroids for the depleted elements, and continuing lowering of earth to deep space transport costs.

Decomposing Worldwide Complete Spherical Bouguer Gravity Anomaly Using 2-D Empirical Method

NASA Astrophysics Data System (ADS)

Firdaus, Ruhul; Mey Ekawati, Gestin

2017-04-01

Currently available worldwide gravity anomaly data provides a high-resolution (2’×2’) of Complete Spherical Bouguer Anomaly (CSBA) based on the available information of the Earth gravity field from surface and satellite measurements. The data has not only been provided and processed thoroughly but it also has been claimed to be appropriate for various geophysical applications. Therefore, the analysis of gravity anomaly is becoming increasingly significant for the earth sciences as a whole and assisting both shallow and deep geological problems. Earth gravity anomaly has to be analyzed carefully as it has very complex data due to anomaly mixing of the density masses spread over the Earth horizontally and vertically. The bigger the spatial coverage of data (e.g. global scale data), the more severe the data from anomaly mixing due to various wavelength. BEMD is an empirical method supposedly suitable with highly oscillation-mixing data. It can effectively isolate each local anomaly in details and is analogized as successively reverse moving average with local windowing. BEMD is designed to reduce multi-component, non-linear gravity field data to a series of single local anomaly contributions. Anomaly from a single body was assumed as a mono-component signal. The main advantage of BEMD processing techniques is to present the subtle details in the data which are not clearly identified in anomaly maps, without specifying any prior information about the nature of the source bodies. As the result, we have identified regional anomalies due to the drift of continental and oceanic masses considered as crust-regional anomaly (CRA). We remove the CRA from the CBA to provide surface-residual anomaly (SRA) where shallow geologic bodies reveal. Meanwhile, the CRA itself can be used as reference to reduce this high magnitude anomaly from any measurement data to exhibit only shallow body anomaly. Further analysis can be carried out to build a general understanding of the details and parameters of the shallower or deeper causative body distributions.

Non-Seismic Pre-Earthquake Phenomena and their Effects on the Biosphere

NASA Astrophysics Data System (ADS)

Freund, Friedemann; Stolc, Viktor

2013-04-01

Earthquakes occur when tectonic stresses build up deep in the Earth and reach the threshold of catastrophic rupture. During the build-up of stress, long before rupture, processes occur in the Earth crust that lead to the activation of highly mobile electronic charge carriers. One remarkable property of these charge carriers is that they are able to flow out of the stressed rock volume into surrounding rocks. Such an outflow constitutes an electric current, which generates electromagnetic (EM) signals. If the outflow occurs in bursts, the EM signals will consist of short EM pulses. If the outflow is continuous, the currents are likely to fluctuate, generating EM emissions over a wide frequency range. Only the ultralow and extremely low frequency (ULF/ELF) waves can travel through kilometers of rock and reach the Earth surface. These ULF/ELF emissions can last for hours or days. In a companion poster we report on their effects on crucial biochemical reactions in living organisms. Another remarkable property of the outflowing charge carriers is that they are (i) positively charged and (ii) highly oxidizing. When they reach the Earth surface from below, they build up microscopic but very steep electric fields, strong enough to field-ionize air molecules, i.e. rip an electron off air molecules. As a result the air above the epicenter of an impending major earthquake often becomes heavily laden with positive airborne ions. Medical research has long shown that positive airborne ions cause changes in the stress hormone level in animals and humans. Therefore, positive airborne ions are a likely cause for unusual reactions among animals and humans. When the outflowing charge carriers cross from rocks into water, they oxidize the water to hydrogen peroxide. This process, plus oxidation reactions involving dissolved organic compounds in the ground water, are likely candidates for causing behavioral changes, even death, among aquatic animals.

Exchange processes from the deep interior to the surface of icy moons

NASA Astrophysics Data System (ADS)

Grasset, O.

Space exploration provides outstanding images of planetary surfaces. Galileo space- craft around Jupiter, and now Cassini in the saturnian system have revealed to us the variety of icy surfaces in the solar system. While Europa, Enceladus, and maybe Titan present past or even active tectonic and volcanic activities, many other moons have been dead worlds for more than 3 billions years. Composition of ices is also complex and it is now commonly admitted that icy surfaces are never composed of pure ices. Water ice can be mixed with salts (Europa?), with hydrocarbons (Titan?) or with silicates (Callisto). The present surfaces of icy moons are the results of both internal (tectonic; volcanism; mantle composition; magnetic field; . . . ) and external processes (radiations, atmospheres, impacts, . . . ). Internal activity (past or present) is almost unknown. While the surfaces indicate clearly that an important activity existed (Ganymede, Europa, Titan, . . . ) or still exists (Enceladus, Titan?, . . . ), volcanic and tectonic processes within icy mantles are still very poorly understood. This project proposes some key studies for improving our knowledge of exchange processes within icy moons, which are: 1) Surface compositions: Interpretation of mapping spectrometer data. It addresses the interpretation of remote sensing data. These data are difficult to understand and a debate between people involved in Galileo and those who are now trying to interpret Cassini data might be fruitful. As an example, interpretation of Galileo data on Europa are still controversial. It is impossible to affirm that the "non-icy" material which does not present the classic infrared signature of pure ice is due to the presence of magnesium hydrates, sodium hydrates, magnesium sulfurs, "clays", or even altered water ice. Discussion on the subject are still needed. On Titan, the presence of the atmosphere impedes to link IR data from Cassini to the composition of the surface. 2) Past and present dynamics of icy surfaces: erosion, tectonics and cryovolcanism. This second topic is devoted to the description of the surface features. A synthesis of what has been seen in the jovian system and a presentation of what is now discovered in the saturnian system might be useful. 3) Internal processes: dynamics of icy mantles. Many works have been done specifically for icy moons (rheology of icy mantles, heating modes, effect of ice composition, internal activity of small moons, internal oceans,. . . ). Icy mantles present so many different convective processes, depending on parameters such as the ice composition, the heating mode, . . . , that a full review of the recent progress on the subject is required. 4) Physics and chemistry of ices: experimental constraints on hydrates, clathrates and organics. Nothing can be done without experimental data. Thermodynamical constraints, phase diagrams, but also mechanical properties of icy materials are required for constraining all models. Many progress have been made these last five years, especially for clathrate structures so important in the case of Titan. A review of these progresses is required. 5) Earth analogs: a tool for understanding surface/ internal features. Tectonic and volcanic features on icy moons are sometimes confronted to Earth structures. This procedure is very interesting. While materials are different (on Earth the melt is lighter than the rock, but on icy moons it is the contrary), tectonic and volcanic features can be very similar. Our good understanding of the Earth can be very useful for describing the processes responsible of tectonic/volcanic features on the moons. Discussing around the five themes described above may provide some constraints on open questions such as the characteristics of liquid layers within icy moons, the cryovolcanism on Titan, the resurfacing of Europa, the composition of Titan's surface, and the activity on Enceladus. 2

Using The Global Positioning System For Earth Orbiter and Deep Space Network

NASA Technical Reports Server (NTRS)

Lichten, Stephen M.; Haines, Bruce J.; Young, Lawrence E.; Dunn, Charles; Srinivasan, Jeff; Sweeney, Dennis; Nandi, Sumita; Spitzmesser, Don

1994-01-01

The Global Positioning System (GPS) can play a major role in supporting orbit and trajectory determination for spacecraft in a wide range of applications, including low-Earth, high-earth, and even deep space (interplanetary) tracking.

Toward Microsatellite Based Space Situational Awareness

NASA Astrophysics Data System (ADS)

Scott, L.; Wallace, B.; Sale, M.; Thorsteinson, S.

2013-09-01

The NEOSSat microsatellite is a dual mission space telescope which will perform asteroid detection and Space Situational Awareness (SSA) observation experiments on deep space, earth orbiting objects. NEOSSat was launched on 25 February 2013 into a 800 dawn-dusk sun synchronous orbit and is currently undergoing satellite commissioning. The microsatellite consists of a small aperture optical telescope, GPS receiver, high performance attitude control system, and stray light rejection baffle designed to reject stray light from the Sun while searching for asteroids with elongations 45 degrees along the ecliptic. The SSA experimental mission, referred to as HEOSS (High Earth Orbit Space Surveillance), will focus on objects in deep space orbits. The HEOSS mission objective is to evaluate the utility of microsatellites to perform catalog maintenance observations of resident space objects in a manner consistent with the needs of the Canadian Forces. The advantages of placing a space surveillance sensor in low Earth orbit are that the observer can conduct observations without the day-night interruption cycle experienced by ground based telescopes, the telescope is insensitive to adverse weather and the system has visibility to deep space resident space objects which are not normally visible from ground based sensors. Also, from a photometric standpoint, the microsatellite is able to conduct observations on objects with a rapidly changing observer position. The possibility of spin axis estimation on geostationary satellites may be possible and an experiment characterize spin axis of distant resident space objects is being planned. Also, HEOSS offers the ability to conduct observations of satellites at high phase angles which can potentially extend the trackable portion of space in which deep space objects' orbits can be monitored. In this paper we describe the HEOSS SSA experimental data processing system and the preliminary findings of the catalog maintenance experiments. The placement of a space based space surveillance sensor in low Earth orbit introduces tasking and image processing complexities such as cosmic ray rejection, scattered light from Earth's limb and unique scheduling limitations due to the observer's rapid positional change and we describe first-look microsatellite space surveillance lessons from this unique orbital vantage point..

Local surface plasmon enhanced polarization and internal quantum efficiency of deep ultraviolet emissions from AlGaN-based quantum wells.

PubMed

Zhang, Cai; Tang, Ning; Shang, Liangliang; Fu, Lei; Wang, Weiying; Xu, Fujun; Wang, Xinqiang; Ge, Weikun; Shen, Bo

2017-05-24

We report the enhancement of the polarization and internal quantum efficiency (IQE) of deep-UV LEDs by evaporating Al nanoparticles on the device surface to induce localized surface plasmons (LSPs). The deep-UV LEDs polarization is improved due to part of TM emission turns into TE emission through LSPs coupling. The significantly enhanced IQE is attributed to LSPs coupling, which suppress the participation of delocalized and dissociated excitons to non-radiative recombination process.

Deep water recycling through time

PubMed Central

Magni, Valentina; Bouilhol, Pierre; van Hunen, Jeroen

2014-01-01

We investigate the dehydration processes in subduction zones and their implications for the water cycle throughout Earth's history. We use a numerical tool that combines thermo-mechanical models with a thermodynamic database to examine slab dehydration for present-day and early Earth settings and its consequences for the deep water recycling. We investigate the reactions responsible for releasing water from the crust and the hydrated lithospheric mantle and how they change with subduction velocity (vs), slab age (a) and mantle temperature (Tm). Our results show that faster slabs dehydrate over a wide area: they start dehydrating shallower and they carry water deeper into the mantle. We parameterize the amount of water that can be carried deep into the mantle, W (×105 kg/m2), as a function of vs (cm/yr), a (Myrs), and Tm (°C):. We generally observe that a 1) 100°C increase in the mantle temperature, or 2) ∼15 Myr decrease of plate age, or 3) decrease in subduction velocity of ∼2 cm/yr all have the same effect on the amount of water retained in the slab at depth, corresponding to a decrease of ∼2.2×105 kg/m2 of H2O. We estimate that for present-day conditions ∼26% of the global influx water, or 7×108 Tg/Myr of H2O, is recycled into the mantle. Using a realistic distribution of subduction parameters, we illustrate that deep water recycling might still be possible in early Earth conditions, although its efficiency would generally decrease. Indeed, 0.5–3.7 × 108 Tg/Myr of H2O could still be recycled in the mantle at 2.8 Ga. Key Points Deep water recycling might be possible even in early Earth conditions We provide a scaling law to estimate the amount of H2O flux deep into the mantle Subduction velocity has a a major control on the crustal dehydration pattern PMID:26321881

Deep water recycling through time.

PubMed

Magni, Valentina; Bouilhol, Pierre; van Hunen, Jeroen

2014-11-01

We investigate the dehydration processes in subduction zones and their implications for the water cycle throughout Earth's history. We use a numerical tool that combines thermo-mechanical models with a thermodynamic database to examine slab dehydration for present-day and early Earth settings and its consequences for the deep water recycling. We investigate the reactions responsible for releasing water from the crust and the hydrated lithospheric mantle and how they change with subduction velocity ( v s ), slab age ( a ) and mantle temperature (T m ). Our results show that faster slabs dehydrate over a wide area: they start dehydrating shallower and they carry water deeper into the mantle. We parameterize the amount of water that can be carried deep into the mantle, W (×10 5 kg/m 2 ), as a function of v s (cm/yr), a (Myrs), and T m (°C):[Formula: see text]. We generally observe that a 1) 100°C increase in the mantle temperature, or 2) ∼15 Myr decrease of plate age, or 3) decrease in subduction velocity of ∼2 cm/yr all have the same effect on the amount of water retained in the slab at depth, corresponding to a decrease of ∼2.2×10 5 kg/m 2 of H 2 O. We estimate that for present-day conditions ∼26% of the global influx water, or 7×10 8 Tg/Myr of H 2 O, is recycled into the mantle. Using a realistic distribution of subduction parameters, we illustrate that deep water recycling might still be possible in early Earth conditions, although its efficiency would generally decrease. Indeed, 0.5-3.7 × 10 8 Tg/Myr of H 2 O could still be recycled in the mantle at 2.8 Ga. Deep water recycling might be possible even in early Earth conditions We provide a scaling law to estimate the amount of H 2 O flux deep into the mantle Subduction velocity has a a major control on the crustal dehydration pattern.

Global water cycle and the coevolution of the Earth's interior and surface environment.

PubMed

Korenaga, Jun; Planavsky, Noah J; Evans, David A D

2017-05-28

The bulk Earth composition contains probably less than 0.3% of water, but this trace amount of water can affect the long-term evolution of the Earth in a number of different ways. The foremost issue is the occurrence of plate tectonics, which governs almost all aspects of the Earth system, and the presence of water could either promote or hinder the operation of plate tectonics, depending on where water resides. The global water cycle, which circulates surface water into the deep mantle and back to the surface again, could thus have played a critical role in the Earth's history. In this contribution, we first review the present-day water cycle and discuss its uncertainty as well as its secular variation. If the continental freeboard has been roughly constant since the Early Proterozoic, model results suggest long-term net water influx from the surface to the mantle, which is estimated to be 3-4.5×10 14  g yr -1 on the billion years time scale. We survey geological and geochemical observations relevant to the emergence of continents above the sea level as well as the nature of Precambrian plate tectonics. The global water cycle is suggested to have been dominated by regassing, and its implications for geochemical cycles and atmospheric evolution are also discussed.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'. © 2017 The Author(s).

MT+, integrating magnetotellurics to determine earth structure, physical state, and processes

USGS Publications Warehouse

Bedrosian, P.A.

2007-01-01

As one of the few deep-earth imaging techniques, magnetotellurics provides information on both the structure and physical state of the crust and upper mantle. Magnetotellurics is sensitive to electrical conductivity, which varies within the earth by many orders of magnitude and is modified by a range of earth processes. As with all geophysical techniques, magnetotellurics has a non-unique inverse problem and has limitations in resolution and sensitivity. As such, an integrated approach, either via the joint interpretation of independent geophysical models, or through the simultaneous inversion of independent data sets is valuable, and at times essential to an accurate interpretation. Magnetotelluric data and models are increasingly integrated with geological, geophysical and geochemical information. This review considers recent studies that illustrate the ways in which such information is combined, from qualitative comparisons to statistical correlation studies to multi-property inversions. Also emphasized are the range of problems addressed by these integrated approaches, and their value in elucidating earth structure, physical state, and processes. ?? Springer Science+Business Media B.V. 2007.

The Link Between Rare-Earth Peak Formation and the Astrophysical Site of the R Process

DOE PAGES

Mumpower, Matthew R.; McLaughlin, Gail C.; Surman, Rebecca; ...

2016-12-20

The primary astrophysical source of the rare-earth elements is the rapid neutron capture process (r process). The rare-earth peak that is seen in the solar r-process residuals has been proposed to originate as a pile-up of nuclei during the end of the r process. Here, we introduce a new method utilizing Monte Carlo studies of nuclear masses in the rare-earth region, that includes self-consistently adjusting β-decay rates and neutron capture rates, to find the mass surfaces necessary for the formation of the rare-earth peak. We demonstrate our method with two types of astrophysical scenario, one corresponding to conditions typical ofmore » hot winds from core-collapse supernovae and stellar-mass accretion disks, and one corresponding to conditions typical of the ejection of the material from the tidal tails of neutron star mergers. In each type of astrophysical condition, this method successfully locates a region of enhanced stability in the mass surface that is responsible for the rare-earth peak. Finally, for each scenario, we find that the change in the mass surface has qualitatively different features, thus future measurements can shed light on the type of environment in which the r process occurred.« less

The Link Between Rare-Earth Peak Formation and the Astrophysical Site of the R Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mumpower, Matthew R.; McLaughlin, Gail C.; Surman, Rebecca

The primary astrophysical source of the rare-earth elements is the rapid neutron capture process (r process). The rare-earth peak that is seen in the solar r-process residuals has been proposed to originate as a pile-up of nuclei during the end of the r process. Here, we introduce a new method utilizing Monte Carlo studies of nuclear masses in the rare-earth region, that includes self-consistently adjusting β-decay rates and neutron capture rates, to find the mass surfaces necessary for the formation of the rare-earth peak. We demonstrate our method with two types of astrophysical scenario, one corresponding to conditions typical ofmore » hot winds from core-collapse supernovae and stellar-mass accretion disks, and one corresponding to conditions typical of the ejection of the material from the tidal tails of neutron star mergers. In each type of astrophysical condition, this method successfully locates a region of enhanced stability in the mass surface that is responsible for the rare-earth peak. Finally, for each scenario, we find that the change in the mass surface has qualitatively different features, thus future measurements can shed light on the type of environment in which the r process occurred.« less

THE LINK BETWEEN RARE-EARTH PEAK FORMATION AND THE ASTROPHYSICAL SITE OF THE R PROCESS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mumpower, Matthew R.; McLaughlin, Gail C.; Surman, Rebecca

The primary astrophysical source of the rare-earth elements is the rapid neutron capture process ( r process). The rare-earth peak that is seen in the solar r -process residuals has been proposed to originate as a pile-up of nuclei during the end of the r process. We introduce a new method utilizing Monte Carlo studies of nuclear masses in the rare-earth region, that includes self-consistently adjusting β -decay rates and neutron capture rates, to find the mass surfaces necessary for the formation of the rare-earth peak. We demonstrate our method with two types of astrophysical scenario, one corresponding to conditionsmore » typical of hot winds from core-collapse supernovae and stellar-mass accretion disks, and one corresponding to conditions typical of the ejection of the material from the tidal tails of neutron star mergers. In each type of astrophysical condition, this method successfully locates a region of enhanced stability in the mass surface that is responsible for the rare-earth peak. For each scenario, we find that the change in the mass surface has qualitatively different features, thus future measurements can shed light on the type of environment in which the r process occurred.« less

Sedimentary Geology Context and Challenges for Cyberinfrastructure Data Management

NASA Astrophysics Data System (ADS)

Chan, M. A.; Budd, D. A.

2014-12-01

A cyberinfrastructure data management system for sedimentary geology is crucial to multiple facets of interdisciplinary Earth science research, as sedimentary systems form the deep-time framework for many geoscience communities. The breadth and depth of the sedimentary field spans research on the processes that form, shape and affect the Earth's sedimentary crust and distribute resources such as hydrocarbons, coal, and water. The sedimentary record is used by Earth scientists to explore questions such as the continental crust evolution, dynamics of Earth's past climates and oceans, evolution of the biosphere, and the human interface with Earth surface processes. Major challenges to a data management system for sedimentary geology are the volume and diversity of field, analytical, and experimental data, along with many types of physical objects. Objects include rock samples, biological specimens, cores, and photographs. Field data runs the gamut from discrete location and spatial orientation to vertical records of bed thickness, textures, color, sedimentary structures, and grain types. Ex situ information can include geochemistry, mineralogy, petrophysics, chronologic, and paleobiologic data. All data types cover multiple order-of-magnitude scales, often requiring correlation of the multiple scales with varying degrees of resolution. The stratigraphic framework needs dimensional context with locality, time, space, and depth relationships. A significant challenge is that physical objects represent discrete values at specific points, but measured stratigraphic sections are continuous. In many cases, field data is not easily quantified, and determining uncertainty can be difficult. Despite many possible hurdles, the sedimentary community is anxious to embrace geoinformatic resources that can provide better tools to integrate the many data types, create better search capabilities, and equip our communities to conduct high-impact science at unprecedented levels.

Spatial Patterns in the Efficiency of the Biological Pump: What Controls Export Ratios at the Global Scale?

NASA Astrophysics Data System (ADS)

Moore, J. K.

2016-02-01

The efficiency of the biological pump is influenced by complex interactions between chemical, biological, and physical processes. The efficiency of export out of surface waters and down through the water column to the deep ocean has been linked to a number of factors including biota community composition, production of mineral ballast components, physical aggregation and disaggregation processes, and ocean oxygen concentrations. I will examine spatial patterns in the export ratio and the efficiency of the biological pump at the global scale using the Community Earth System Model (CESM). There are strong spatial variations in the export efficiency as simulated by the CESM, which are strongly correlated with new nutrient inputs to the euphotic zone and their impacts on phytoplankton community structure. I will compare CESM simulations that include dynamic, variable export ratios driven by the phytoplankton community structure, with simulations that impose a near-constant export ratio to examine the effects of export efficiency on nutrient and surface chlorophyll distributions. The model predicted export ratios will also be compared with recent satellite-based estimates.

A Review of Global Satellite-Derived Snow Products

NASA Technical Reports Server (NTRS)

Frei, Allan; Tedesco, Marco; Lee, Shihyan; Foster, James; Hall, Dorothy K.; Kelly, Richard; Robinson, David A.

2011-01-01

Snow cover over the Northern Hemisphere plays a crucial role in the Earth s hydrology and surface energy balance, and modulates feedbacks that control variations of global climate. While many of these variations are associated with exchanges of energy and mass between the land surface and the atmosphere, other expected changes are likely to propagate downstream and affect oceanic processes in coastal zones. For example, a large component of the freshwater flux into the Arctic Ocean comes from snow melt. The timing and magnitude of this flux affects biological and thermodynamic processes in the Arctic Ocean, and potentially across the globe through their impact on North Atlantic Deep Water formation. Several recent global remotely sensed products provide information at unprecedented temporal, spatial, and spectral resolutions. In this article we review the theoretical underpinnings and characteristics of three key products. We also demonstrate the seasonal and spatial patterns of agreement and disagreement amongst them, and discuss current and future directions in their application and development. Though there is general agreement amongst these products, there can be disagreement over certain geographic regions and under conditions of ephemeral, patchy and melting snow

A Review of Global Satellite-Derived Snow Products

NASA Technical Reports Server (NTRS)

Frei, Allan; Tedesco, Marco; Lee, Shihyan; Foster, James; Hall, Dorothy K.; Kelly, Richard; Robinson, David A.

2011-01-01

Snow cover over the Northern Hemisphere plays a crucial role in the Earth's hydrology and surface energy balance, and modulates feedbacks that control variations of global climate. While many of these variations are associated with exchanges of energy and mass between the land surface and the atmosphere, other expected changes are likely to propagate downstream and affect oceanic processes in coastal zones. For example, a large component of the freshwater flux into the Arctic Ocean comes from snow melt. The timing and magnitude of this flux affects biological and thermodynamic processes in the Arctic Ocean, and potentially across the globe through their impact on North Atlantic Deep Water formation. Several recent global remotely sensed products provide information at unprecedented temporal, spatial, and spectral resolutions. In this article we review the theoretical underpinnings and characteristics of three key products. We also demonstrate the seasonal and spatial patterns of agreement and disagreement amongst them, and discuss current and future directions in their application and development. Though there is general agreement amongst these products, there can be disagreement over certain geographic regions and under conditions of ephemeral, patchy and melting snow.

A Review of Global Satellite-derived Snow Products

NASA Technical Reports Server (NTRS)

Frei, Allan; Tedesco, Marco; Lee, Shihyan; Foster, James; Hall, Dorothy K.; Kelly, Richard; Robinson, David A.

2012-01-01

Snow cover over the Northern Hemisphere plays a crucial role in the Earth's hydrology and surface energy balance, and modulates feedbacks that control variations of global climate. While many of these variations are associated with exchanges of energy and mass between the land surface and the atmosphere, other expected changes are likely to propagate downstream and affect oceanic processes in coastal zones. For example, a large component of the freshwater flux into the Arctic Ocean comes from snow melt. The timing and magnitude of this flux affects biological and thermodynamic processes in the Arctic Ocean, and potentially across the globe through their impact on North Atlantic Deep Water formation. Several recent global remotely sensed products provide information at unprecedented temporal, spatial, and spectral resolutions. In this article we review the theoretical underpinnings and characteristics of three key products. We also demonstrate the seasonal and spatial patterns of agreement and disagreement amongst them, and discuss current and future directions in their application and development. Though there is general agreement amongst these products, there can be disagreement over certain geographic regions and under conditions of ephemeral, patchy and melting snow.

Chemical evolution on Titan: comparisons to the prebiotic earth.

PubMed

Clarke, D W; Ferris, J P

1997-06-01

Models for the origin of Titan's atmosphere, the processing of the atmosphere and surface and its exobiological role are reviewed. Titan has gained widespread acceptance in the origin of life field as a model for the types of evolutionary processes that could have occurred on prebiotic Earth. Both Titan and Earth possess significant atmospheres (> or = 1 atm) composed mainly of molecular nitrogen with smaller amounts of more reactive species. Both of these atmospheres are processed primarily by solar ultraviolet light with high energy particles interactions contributing to a lesser extent. The products of these reactions condense or are dissolved in other atmospheric species (aerosols/clouds) and fall to the surface. There these products may have been further processed on Titan and the primitive Earth by impacting comets and meteorites. While the low temperatures on Titan (approximately 72-180 K) preclude the presence of permanent liquid water on the surface, it has been suggested that tectonic activity or impacts by meteors and comets could produce liquid water pools on the surface for thousands of years. Hydrolysis and oligomerization reactions in these pools might form chemicals of prebiological significance. Other direct comparisons between the conditions on present day Titan and those proposed for prebiotic Earth are also presented.

Mapping the Iron Oxidation State in Martian Meteorites

NASA Technical Reports Server (NTRS)

Martin, A. M.; Treimann, A. H.; Righter, K.

2017-01-01

Several types of Martian igneous meteorites have been identified: clinopyroxenites (nakhlites), basaltic shergottites, peridotitic shergottites, dunites (chassignites) and orthopyroxenites [1,2]. In order to constrain the heterogeneity of the Martian mantle and crust, and their evolution through time, numerous studies have been performed on the iron oxidation state of these meteorites [3,4,5,6,7,8,9]. The calculated fO2 values all lie within the FMQ-5 to FMQ+0.5 range (FMQ representing the Fayalite = Magnetite + Quartz buffer); however, discrepancies appear between the various studies, which are either attributed to the choice of the minerals/melts used, or to the precision of the analytical/calculation method. The redox record in volcanic samples is primarily related to the oxidation state in the mantle source(s). However, it is also influenced by several deep processes: melting, crystallization, magma mixing [10], assimilation and degassing [11]. In addition, the oxidation state in Martian meteorites is potentially affected by several surface processes: assimilation of sediment/ crust during lava flowing at Mars' surface, low temperature micro-crystallization [10], weathering at the surface of Mars and low temperature reequilibration, impact processes (i.e. high pressure phase transitions, mechanical mixing, shock degassing and melting), space weathering, and weathering on Earth (at atmospheric conditions different from Mars). Decoding the redox record of Martian meteorites, therefore, requires large-scale quantitative analysis methods, as well as a perfect understanding of oxidation processes.

NASA Technology Area 07: Human Exploration Destination Systems Roadmap

NASA Technical Reports Server (NTRS)

Kennedy, Kriss J.; Alexander, Leslie; Landis, Rob; Linne, Diane; Mclemore, Carole; Santiago-Maldonado, Edgardo; Brown, David L.

2011-01-01

This paper gives an overview of the National Aeronautics and Space Administration (NASA) Office of Chief Technologist (OCT) led Space Technology Roadmap definition efforts. This paper will given an executive summary of the technology area 07 (TA07) Human Exploration Destination Systems (HEDS). These are draft roadmaps being reviewed and updated by the National Research Council. Deep-space human exploration missions will require many game changing technologies to enable safe missions, become more independent, and enable intelligent autonomous operations and take advantage of the local resources to become self-sufficient thereby meeting the goal of sustained human presence in space. Taking advantage of in-situ resources enhances and enables revolutionary robotic and human missions beyond the traditional mission architectures and launch vehicle capabilities. Mobility systems will include in-space flying, surface roving, and Extra-vehicular Activity/Extravehicular Robotics (EVA/EVR) mobility. These push missions will take advantage of sustainability and supportability technologies that will allow mission independence to conduct human mission operations either on or near the Earth, in deep space, in the vicinity of Mars, or on the Martian surface while opening up commercialization opportunities in low Earth orbit (LEO) for research, industrial development, academia, and entertainment space industries. The Human Exploration Destination Systems (HEDS) Technology Area (TA) 7 Team has been chartered by the Office of the Chief Technologist (OCT) to strategically roadmap technology investments that will enable sustained human exploration and support NASA s missions and goals for at least the next 25 years. HEDS technologies will enable a sustained human presence for exploring destinations such as remote sites on Earth and beyond including, but not limited to, LaGrange points, low Earth orbit (LEO), high Earth orbit (HEO), geosynchronous orbit (GEO), the Moon, near-Earth objects (NEOs), which > 95% are asteroidal bodies, Phobos, Deimos, Mars, and beyond. The HEDS technology roadmap will strategically guide NASA and other U.S. Government agency technology investments that will result in capabilities enabling human exploration missions to diverse destinations generating high returns on investments.

Reducing the Risk of Human Missions to Mars Through Testing

NASA Astrophysics Data System (ADS)

Drake, Bret G.

2007-07-01

The NASA Deputy Administrator charted an internal NASA planning group to develop the rationale for exploration beyond low-Earth orbit. This team, termed the Exploration Blueprint, performed architecture analyses to develop roadmaps for how to accomplish the first steps beyond Low-Earth Orbit through the human exploration of Mars. Following the results of the Exploration Blueprint study, the NASA Administrator asked for a recommendation on the next steps in human and robotic exploration. Much of the focus during this period was on integrating the results from the previous studies into more concrete implementation strategies in order to understand the relationship between NASA programs, timing, and resulting budgetary implications. This resulted in an integrated approach including lunar surface operations to retire risk of human Mars missions, maximum use of common and modular systems including what was termed the exploration transfer vehicle, Earth orbit and lunar surface demonstrations of long-life systems, collaboration of human and robotic missions to vastly increase mission return, and high-efficiency transportation systems (nuclear) for deep-space transportation and power. The data provided in this summary presentation was developed to begin to address one of the key elements of the emerging implementation strategy, namely how lunar missions help retire risk of human missions to Mars. During this process the scope of the activity broadened into the issue of how testing in general, in various venues including the moon, can help reduce the risk for Mars missions.

Applying a Hidden Markov Model-Based Event Detection and Classification Algorithm to Apollo Lunar Seismic Data

NASA Astrophysics Data System (ADS)

Knapmeyer-Endrun, B.; Hammer, C.

2014-12-01

The seismometers that the Apollo astronauts deployed on the Moon provide the only recordings of seismic events from any extra-terrestrial body so far. These lunar events are significantly different from ones recorded on Earth, in terms of both signal shape and source processes. Thus they are a valuable test case for any experiment in planetary seismology. In this study, we analyze Apollo 16 data with a single-station event detection and classification algorithm in view of NASA's upcoming InSight mission to Mars. InSight, scheduled for launch in early 2016, has the goal to investigate Mars' internal structure by deploying a seismometer on its surface. As the mission does not feature any orbiter, continuous data will be relayed to Earth at a reduced rate. Full range data will only be available by requesting specific time-windows within a few days after the receipt of the original transmission. We apply a recently introduced algorithm based on hidden Markov models that requires only a single example waveform of each event class for training appropriate models. After constructing the prototypes we detect and classify impacts and deep and shallow moonquakes. Initial results for 1972 (year of station installation with 8 months of data) indicate a high detection rate of over 95% for impacts, of which more than 80% are classified correctly. Deep moonquakes, which occur in large amounts, but often show only very weak signals, are detected with less certainty (~70%). As there is only one weak shallow moonquake covered, results for this event class are not statistically significant. Daily adjustments of the background noise model help to reduce false alarms, which are mainly erroneous deep moonquake detections, by about 25%. The algorithm enables us to classify events that were previously listed in the catalog without classification, and, through the combined use of long period and short period data, identify some unlisted local impacts as well as at least two yet unreported deep moonquakes.

Deep Space 1 is prepared for transport to launch pad

NASA Technical Reports Server (NTRS)

1998-01-01

Workers in the Defense Satellite Communication Systems Processing Facility (DPF), Cape Canaveral Air Station (CCAS), begin attaching the conical section leaves of the payload transportation container on Deep Space 1 before launch, targeted for Oct. 25 aboard a Boeing Delta 7326 rocket from Launch Pad 17A. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight- tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

KSC-98pc1261

NASA Image and Video Library

1998-10-07

KENNEDY SPACE CENTER, FLA. -- Workers at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station (CCAS), attach a strap during installation of the ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS, in October

KSC-98pc1262

NASA Image and Video Library

1998-10-07

KENNEDY SPACE CENTER, FLA. -- Workers at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station (CCAS), make adjustments while installing the ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS, in October

KSC-98pc1264

NASA Image and Video Library

1998-10-07

KENNEDY SPACE CENTER, FLA. -- Workers in the Defense Satellite Communications Systems Processing Facility (DPF) at Cape Canaveral Air Station (CCAS) make adjustments while installing the ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched Oct. 25 aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS

KSC-98pc1260

NASA Image and Video Library

1998-10-07

KENNEDY SPACE CENTER, FLA. -- Workers at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station (CCAS), install an ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS, in October

KSC-98pc1265

NASA Image and Video Library

1998-10-07

KENNEDY SPACE CENTER, FLA. -- Workers in the Defense Satellite Communications Systems Processing Facility (DPF) at Cape Canaveral Air Station (CCAS) finish installing the ion propulsion engine on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched Oct. 25 aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS

KSC-98pc1263

NASA Image and Video Library

1998-10-07

KENNEDY SPACE CENTER, FLA. -- Workers at the Defense Satellite Communications System Processing Facility (DPF), Cape Canaveral Air Station (CCAS), maneuver the ion propulsion engine into place before installation on Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS, in October

KSC-98pc1314

NASA Image and Video Library

1998-10-10

KENNEDY SPACE CENTER, FLA. -- Workers in the Defense Satellite Communication Systems Processing Facility (DPF), Cape Canaveral Air Station (CCAS), move to the workstand the second conical section leaf of the payload transportation container for Deep Space 1. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS

Science Syllabus for Middle and Junior High Schools. Block D, The Earth's Changing Surface.

ERIC Educational Resources Information Center

New York State Education Dept., Albany. Bureau of General Education Curriculum Development.

This syllabus begins with a list of program objectives and performance criteria for the study of three general topic areas in earth science and a list of 22 science processes. Following this information is a listing of concepts and understandings for subtopics within the general topic areas: (1) the earth's surface--surface features, rock…

High power laser downhole cutting tools and systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O

Downhole cutting systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser cutting operations within a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform cutting operations in such boreholes deep within the earth.

Electromagnetic deep-probing (100-1000 KMS) of the Earth's interior from artificial satellites: Constraints on the regional emplacement of crustal resources

NASA Technical Reports Server (NTRS)

Hermance, J. F. (Principal Investigator)

1981-01-01

Model simulations show that induction in a spherical Earth by distant magnetospheric sources can contribute magnetic field fluctuations at MAGSAT altitudes which are 30 to 40 percent of the external field amplitudes. When the characteristic dimensions (e.g. depth of penetration, etc) of a particular situations are small compared with the Earth's radius, the Earth can be approximated by a plane horizontal half space. In this case, electromagnetic energy is reflected with close to 100 percent efficiency from the Earth's surface. This implies that the total horizontal field is twice the source field when the source is above the satellite, but is reduced to values which are much smaller than the source field when the source is below the satellite. This latter effect tends to enhance the signature of gross electrical discontinuities in the lithosphere when observed at satellite altitudes.

Electromagnetic deep-probing (100-1000 kms) of the Earth's interior from artificial satellites: Constraints on the regional emplacement of crustal resources

NASA Technical Reports Server (NTRS)

Hermance, J. F.

1983-01-01

The reconnaissance phase of using satellite observtions to studying electromagnetic induction in the solid earth is summarized. Several points are made: (1) satellite data apparently suffer far less from the effects of near surface lateral heterogeneities in the earth than do ground-based data; (2) zonal ionospheric currents during the recovery phase of major magnetic storms appear to be minimal, at least in the dawn and dusk sectors wher MAGSAT was flown; hence the internal contributions that satellites observe during these times is in fact due primarily to induction in the Earth with little or no contribution from ionospheric currents; and (3) the interpretation of satellite data in terms of primitive electromagnetic response functions, while grossly over-simplified, results in a surprisingly well-resolved radius for an equivalent super-conductor representing the conductivity region of the Earth's interior (5,370 + or - 120 km).

Deep Space 1 is prepared for transport to launch pad

NASA Technical Reports Server (NTRS)

1998-01-01

In the Defense Satellite Communications Systems Processing Facility (DPF), Cape Canaveral Air Station (CCAS), workers place an anti-static blanket over the lower portion of Deep Space 1, to protect the spacecraft during transport to the launch pad. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS.

Deep Space 1 is prepared for transport to launch pad

NASA Technical Reports Server (NTRS)

1998-01-01

In the Defense Satellite Communications Systems Processing Facility (DPF), Cape Canaveral Air Station (CCAS), after covering the lower portion of Deep Space 1, workers adjust the anti-static blanket covering the upper portion. The blanket will protect the spacecraft during transport to the launch pad. Deep Space 1 is the first flight in NASA's New Millennium Program, and is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS.

Coseismic Gravity and Displacement Signatures Induced by the 2013 Okhotsk Mw8.3 Earthquake.

PubMed

Zhang, Guoqing; Shen, Wenbin; Xu, Changyi; Zhu, Yiqing

2016-09-01

In this study, Gravity Recovery and Climate Experiment (GRACE) RL05 data from January 2003 to October 2014 were used to extract the coseismic gravity changes induced by the 24 May 2013 Okhotsk Mw8.3 deep-focus earthquake using the difference and least square fitting methods. The gravity changes obtained from GRACE data agreed well with those from dislocation theory in both magnitude and spatial pattern. Positive and negative gravity changes appeared on both sides of the epicenter. The positive signature appeared on the western side, and the peak value was approximately 0.4 microgal (1 microgal = 10(-8) m/s²), whereas on the eastern side, the gravity signature was negative, and the peak value was approximately -1.1 microgal. It demonstrates that deep-focus earthquakes Mw ≤ 8.5 are detectable by GRACE observations. Moreover, the coseismic displacements of 20 Global Positioning System (GPS) stations on the Earth's surface were simulated using an elastic dislocation theory in a spherical earth model, and the results are consistent with the GPS results, especially the near-field results. We also estimated the gravity contributions from the coseismic vertical displacements and density changes, analyzed the proportion of these two gravity change factors (based on an elastic dislocation theory in a spherical earth model) in this deep-focus earthquake. The gravity effect from vertical displacement is four times larger than that caused by density redistribution.

Biodiversity's big wet secret: the global distribution of marine biological records reveals chronic under-exploration of the deep pelagic ocean.

PubMed

Webb, Thomas J; Vanden Berghe, Edward; O'Dor, Ron

2010-08-02

Understanding the distribution of marine biodiversity is a crucial first step towards the effective and sustainable management of marine ecosystems. Recent efforts to collate location records from marine surveys enable us to assemble a global picture of recorded marine biodiversity. They also effectively highlight gaps in our knowledge of particular marine regions. In particular, the deep pelagic ocean--the largest biome on Earth--is chronically under-represented in global databases of marine biodiversity. We use data from the Ocean Biogeographic Information System to plot the position in the water column of ca 7 million records of marine species occurrences. Records from relatively shallow waters dominate this global picture of recorded marine biodiversity. In addition, standardising the number of records from regions of the ocean differing in depth reveals that regardless of ocean depth, most records come either from surface waters or the sea bed. Midwater biodiversity is drastically under-represented. The deep pelagic ocean is the largest habitat by volume on Earth, yet it remains biodiversity's big wet secret, as it is hugely under-represented in global databases of marine biological records. Given both its value in the provision of a range of ecosystem services, and its vulnerability to threats including overfishing and climate change, there is a pressing need to increase our knowledge of Earth's largest ecosystem.

Continental degassing of 4He by surficial discharge of deep groundwater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aggarwal, Pradeep K.; Matsumoto, Takuya; Sturchio, Neil C.

2014-12-01

Radiogenic He-4 is produced by the decay of uranium and thorium in the Earths mantle and crust. From here, it is degassed to the atmosphere(1-5) and eventually escapes to space(1,5,6). Assuming that all of the He-4 produced is degassed, about 70% of the total He-4 degassed from Earth comes from the continental crust(2,-5,7). However, the outgoing flux of crustal He-4 has not been directly measured at the Earths surface(2) and the migration pathways are poorly understood(2-4,7,8). Here we present measurements of helium isotopes and the long-lived cosmogenic radio-isotope Kr-81 in the deep, continental-scale Guarani aquifer in Brazil and show thatmore » crustal He-4 reaches the atmosphere primarily by the surficial discharge of deep groundwater. We estimate that He-4 in Guarani groundwater discharge accounts for about 20% of the assumed global flux from continental crust, and that other large aquifers may account for about 33%. Old groundwater ages suggest that He-4 in the Guarani aquifer accumulates over half- to one-million-year timescales. We conclude that He-4 degassing from the continents is regulated by groundwater discharge, rather than episodic tectonic events, and suggest that the assumed steady state between crustal production and degassing of He-4, and its resulting atmospheric residence time, should be re-examined« less

The Critical Zone: A Necessary Framework for Understanding Surface Earth Processes

NASA Astrophysics Data System (ADS)

Dietrich, W. E.

2016-12-01

One definition of the critical zone is: the thin veneer of Earth that extends from the top of the vegetation to the base of weathered bedrock. With this definition we can envision the critical zone as a distinct entity with a well-defined top and a fairly well-defined bottom that is distributed across terrestrial earth landscapes. It is a zone of co-evolving processes and, importantly, much of this zone is well below the soil mantle (and commonly more than 10 times thicker than the soil). Weathering advance into fresh bedrock creates a hydrologically-conductive skin that mediates runoff and solute chemistry, stores water used by vegetation, releases water as baseflow to streams, influences soil production and hillslope evolution, and feeds gasses to the atmosphere. Especially in seasonally dry environments, rock moisture in the critical zone, i.e. moisture that is exchangeable and potentially mobile in the matrix and fractures of the bedrock, can be a significant source of water to plants and is a previously unrecognized large component of the water budget that matters to climate models. First observations on the systematic variation of the critical zone across hillslopes have led to four distinct theories representing four distinct processes for what controls the depth to fresh bedrock (and thus the thickness of this zone across a hillslope). These theories are motivating geophysical surveys, deep drilling, and other actions to parameterize and explore the power of these models. Studies at the NSF-supported Critical Zone Observatories have taught us that the critical zone is an entity and that enduring field studies reveal key processes. A challenge we now face is how to include this emerging understanding of the critical zone into models of reactive transport, hydrologic processes and water supply, critical zone structure, landscape evolution, and climate.

Dynamic Linkages Between the Transition Zone & Surface Plate Motions in 2D Models of Subduction

NASA Astrophysics Data System (ADS)

Arredondo, K.; Billen, M. I.

2013-12-01

While slab pull is considered the dominant force controlling plate motion and speed, its magnitude is controlled by slab behavior in the mantle, where tomographic studies show a wide range of possibilities from direct penetration to folding, or stagnation directly above the lower mantle (e.g. Fukao et al., 2009). Geodynamic studies have investigated various parameters, such as plate age and two phase transitions, to recreate observed behavior (e.g. Běhounková and Cízková, 2008). However, past geodynamic models have left out known slab characteristics that may have a large impact on slab behavior and our understanding of subduction processes. Mineral experiments and seismic observations have indicated the existence of additional phase transitions in the mantle transition zone that may produce buoyancy forces large enough to affect the descent of a subducting slab (e.g. Ricard et al., 2005). The current study systematically tests different common assumptions used in geodynamic models: kinematic versus free-slip boundary conditions, the effects of adiabatic heating, viscous dissipation and latent heat, compositional layering and a more complete suite of phase transitions. Final models have a complete energy equation, with eclogite, harzburgite and pyrolite lithosphere compositional layers, and seven composition-dependent phase transitions within the olivine, pyroxene and garnet polymorph minerals. Results show important feedback loops between different assumptions and new behavior from the most complete models. Kinematic models show slab weakening or breaking above the 660 km boundary and between compositional layers. The behavior in dynamic models with a free-moving trench and overriding plate is compared to the more commonly found kinematic models. The new behavior may have important implications for the depth distribution of deep earthquakes within the slab. Though the thermodynamic parameters of certain phase transitions may be uncertain, their presence and feedback to other added processes remain important, which could encourage mineralogical research into multiphase systems. Feedback from the compositionally complex slab to the dynamic trench may improve understanding on the mechanics of slab behavior in the upper and lower mantle and surface behavior of the subducting and overriding plates. Běhounková, M., and H. Cízková, Long-wavelength character of subducted slabs in the lower mantle, Earth and Planetary Science Letters, 275, 43-53, 2008. Fukao, Y., M. Obayashi, T. Nakakuki, and the Deep Slab Project Group, Stagnant slab: A review, Annual Reviews of Earth and Planetary Science, 37, 19-46, 2009. Ricard, Y., E. Mattern, and J. Matas, Synthetic tomographic images of slabs from mineral physics, in Earth's Deep Mantle: Structure, Composition, and Evolution, Geophysical Monograph Series, vol. 160, American Geophysical Union, 2005.

Differentiating biotic from abiotic methane genesis in hydrothermally active planetary surfaces

PubMed Central

Oze, Christopher; Jones, L. Camille; Goldsmith, Jonas I.; Rosenbauer, Robert J.

2012-01-01

Molecular hydrogen (H2) is derived from the hydrothermal alteration of olivine-rich planetary crust. Abiotic and biotic processes consume H2 to produce methane (CH4); however, the extent of either process is unknown. Here, we assess the temporal dependence and limit of abiotic CH4 related to the presence and formation of mineral catalysts during olivine hydrolysis (i.e., serpentinization) at 200 °C and 0.03 gigapascal. Results indicate that the rate of CH4 production increases to a maximum value related to magnetite catalyzation. By identifying the dynamics of CH4 production, we kinetically model how the H2 to CH4 ratio may be used to assess the origin of CH4 in deep subsurface serpentinization systems on Earth and Mars. Based on our model and available field data, low H2/CH4 ratios (less than approximately 40) indicate that life is likely present and active. PMID:22679287

Differentiating biotic from abiotic methane genesis in hydrothermally active planetary surfaces.

PubMed

Oze, Christopher; Jones, L Camille; Goldsmith, Jonas I; Rosenbauer, Robert J

2012-06-19

Molecular hydrogen (H(2)) is derived from the hydrothermal alteration of olivine-rich planetary crust. Abiotic and biotic processes consume H(2) to produce methane (CH(4)); however, the extent of either process is unknown. Here, we assess the temporal dependence and limit of abiotic CH(4) related to the presence and formation of mineral catalysts during olivine hydrolysis (i.e., serpentinization) at 200 °C and 0.03 gigapascal. Results indicate that the rate of CH(4) production increases to a maximum value related to magnetite catalyzation. By identifying the dynamics of CH(4) production, we kinetically model how the H(2) to CH(4) ratio may be used to assess the origin of CH(4) in deep subsurface serpentinization systems on Earth and Mars. Based on our model and available field data, low H(2)/CH(4) ratios (less than approximately 40) indicate that life is likely present and active.

When a Slowly Rotating Aquaplanet is Coupled to a Dynamical Ocean

NASA Astrophysics Data System (ADS)

Salameh, J.; Marotzke, J.

2017-12-01

Planets orbiting in close distance from their stars have a high probability to be detected, and are expected to be slowly rotating due to strong tidal forces. By increasing the rotation period from 1 Earth-day to 365 Earth-days, we previously found that the global-mean surface temperature of an aquaplanet with a static mixed-layer ocean decreases by up to 27 K. The cooling is attributed to an increase of the planetary albedo with the rotation period, which is associated with the different distributions of the sea ice and the deep convective clouds. However, we had there assumed a fixed mixed-layer depth and a zero oceanic heat transport in the aquaplanet configuration. The limitations of these assumptions in such exotic climates are still unclear. We therefore perform coupled atmosphere-ocean aquaplanet simulations with the general circulation model ICON for various rotation periods ranging from 1 Earth-day to 365 Earth-days. We investigate how the underlying oceanic circulation modifies the mean climate of slowly rotating aquaplanets, and whether the day-to-night oceanic heat transport reduces the surface-temperature gradients and the sea-ice extent.

Communications technology

NASA Astrophysics Data System (ADS)

Sokoloski, Martin M.

1988-09-01

The objective of the Communications Technology Program is to enable data transmission to and from low Earth orbit, geostationary orbit, and solar and deep space missions. This can be achieved by maintaining an effective, balances effort in basic, applied, and demonstration prototype communications technology through work in theory, experimentation, and components. The program consists of three major research and development discipline areas which are: microwave and millimeter wave tube components; solid state monolithic integrated circuit; and free space laser communications components and devices. The research ranges from basic research in surface physics (to study the mechanisms of surface degradation from under high temperature and voltage operating conditions which impacts cathode tube reliability and lifetime) to generic research on the dynamics of electron beams and circuits (for exploitation in various micro- and millimeter wave tube devices). Work is also performed on advanced III-V semiconductor materials and devices for use in monolithic integrated analog circuits (used in adaptive, programmable phased arrays for microwave antenna feeds and receivers) - on the use of electromagnetic theory in antennas and on technology necessary for eventual employment of lasers for free space communications for future low earth, geostationary, and deep space missions requiring high data rates with corresponding directivity and reliability.

Communications technology

NASA Technical Reports Server (NTRS)

Sokoloski, Martin M.

1988-01-01

The objective of the Communications Technology Program is to enable data transmission to and from low Earth orbit, geostationary orbit, and solar and deep space missions. This can be achieved by maintaining an effective, balances effort in basic, applied, and demonstration prototype communications technology through work in theory, experimentation, and components. The program consists of three major research and development discipline areas which are: microwave and millimeter wave tube components; solid state monolithic integrated circuit; and free space laser communications components and devices. The research ranges from basic research in surface physics (to study the mechanisms of surface degradation from under high temperature and voltage operating conditions which impacts cathode tube reliability and lifetime) to generic research on the dynamics of electron beams and circuits (for exploitation in various micro- and millimeter wave tube devices). Work is also performed on advanced III-V semiconductor materials and devices for use in monolithic integrated analog circuits (used in adaptive, programmable phased arrays for microwave antenna feeds and receivers) - on the use of electromagnetic theory in antennas and on technology necessary for eventual employment of lasers for free space communications for future low earth, geostationary, and deep space missions requiring high data rates with corresponding directivity and reliability.

Two-dimensional magnetotelluric model of deep resistivity structure in the Bodie-Aurora district of California

USGS Publications Warehouse

Sampson, Jay A.

2006-01-01

Introduction: Magnetotelluric data were acquired during October 2001 by the U.S. Geological Survey (USGS) as part of a study to examine the structural nature of basins in the transition zone between the Sierra Nevada Mountains of California and the Basin and Range province of Nevada. Magnetotelluric (MT) geophysical studies assist the mapping of geologic structure and the inference of lithologic packages that are concealed beneath the Earth's surface. The Basin and Range province has a complicated geologic history, which includes extension and compression of the Earth's crust to form the basins and ranges that blanket much of Nevada. The basins and ranges in the vicinity of this study trend northeastward and are bounded by steeply dipping strike slip faults. Interestingly, deep east-west magnetic trends occur in the aeromagnetic data of this study area indicating that the northeast-trending basins and ranges represent only thin-skinned deformation at the surface with an underlying east-west structure. To investigate this issue, MT data were acquired at seven stations in eastern California, 20 km east of Mono Lake. The purpose of this report is to present a two-dimensional apparent resistivity model of the MT data acquired for this study.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

Wearing special protective suits, workers ready NASA's Deep Space 1 spacecraft for prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

Wearing special protective suits, workers look over NASA's Deep Space 1 spacecraft before prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

Wearing special protective suits, workers maneuver NASA's Deep Space 1 spacecraft into place for prelaunch processing in the Payload Hazardous Servicing Facility at KSC. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

Wearing special protective suits, workers move NASA's Deep Space 1 spacecraft into another room in the Payload Hazardous Servicing Facility for prelaunch processing . Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

How strange was the Strangelove Ocean? New insights from Boron Isotopes.

NASA Astrophysics Data System (ADS)

Henehan, M. J.; Ridgwell, A.; Thomas, E.; Zhang, S.; Planavsky, N.; Alegret, L.; Schmidt, D. N.; Rae, J. W. B.; Foster, G. L.; Huber, B. T.; Hull, P. M.

2016-12-01

The idea of the `Strangelove Ocean'1 has captured the imagination of palaeoceanographers (and the public) since it was posited to explain the collapse or reverse in surface-deep ocean δ13C gradients after the Cretaceous-Palaeogene (K-Pg) boundary1. It describes a post-extinction ocean where primary productivity was drastically reduced, eliminating the surface-to-deep carbon isotope gradient produced by the biological pump. Survival of benthic foraminifera across the K-Pg (suggesting a persistent supply of organic matter to the deep) is difficult to reconcile with this ideae.g. 2. Geochemical proxies also suggest that severe export productivity reductions were at most regional3. This mismatch between patterns in δ13C and other indicators has thus been interpreted as a signal of changing vital effects in post-extinction pelagic calcifiers, toward lighter δ13C e.g. 2. However, it may be that vital effects in earliest Palaeocene foraminiferal survivors can account for only part of the convergence in δ13C between surface and deep ocean.4 In addition, analysis of carbonate preservation after the K-Pg boundary indicates large-scale carbonate system/ocean pH shifts at this time5, which could have produced secular changes in carbon isotope signals. Here we present new paired benthic and planktic boron isotope measurements that allow us to examine surface to deep ocean pH gradients (which in today's ocean are driven largely by biological activity) across the K-Pg boundary interval and into the early Palaeocene. We then couple these to model simulations to untangle the carbon cycle drivers, both physical and biological, that could have caused these changes in ocean pH gradients. We discuss implications for our understanding of this important interval in Earth history, with reference to the mechanisms of Earth system recovery following mass extinction. References:1. Hsü, K. J. & McKenzie, J. A., 1985. AGU Geophysical Monograph Series 32. doi:10.1029/GM032p0487 2. Alegret, L., et al., 2012. PNAS 109, 728-732. doi:10.1073/pnas.1110601109 3. Hull, P.M. & Norris, R.D., 2011. Paleoceanography 26, PA3205. doi:10.1029/2010PA002082 4. Birch, H.S., et al., 2016. Geology 44, 287-290. doi:10.1130/G37581.1 5. Henehan et al., 2016. Phil. Trans. Roy. Soc. B. 371, 20150510. doi:10.1098/rstb.2015.0510

Hotspots and sunspots - Surface tracers of deep mantle convection in the earth and sun

NASA Technical Reports Server (NTRS)

Stothers, Richard B.

1993-01-01

The evolution of the hot-spot distribution on earth in time and space is investigated using available age data. The statistics of continental flood basalt eruptions suggests the formation of a total of about 40 hot spots worldwide during the Cenozoic and Mesozoic, with no true antipodal pairs found. It was found that hot spots tend to concentrate mainly in mid-latitudes, but the pattern of new appearances of hot spots may migrate from high to low latitudes in both hemispheres in long cycles, and may also drift in longitude, although much more slowly prograde.

Tidal calibration of Plate Boundary Observatory borehole strainmeters: Roles of vertical and shear coupling

USGS Publications Warehouse

Roeloffs, Evelyn

2010-01-01

A multicomponent borehole strainmeter directly measures changes in the diameter of its cylindrical housing at several azimuths. To transform these measurements to formation strains requires a calibration matrix, which must be estimated by analyzing the installed strainmeter's response to known strains. Typically, theoretical calculations of Earth tidal strains serve as the known strains. This paper carries out such an analysis for 12 Plate Boundary Observatory (PBO) borehole strainmeters, postulating that each of the strainmeters' four gauges responds ("couples") to all three horizontal components of the formation strain tensor, as well as to vertical strain. Orientation corrections are also estimated. The fourth extensometer in each PBO strainmeter provides redundant information used to reduce the chance that coupling coefficients could be misleadingly fit to inappropriate theoretical tides. Satisfactory fits between observed and theoretically calculated tides were obtained for three PBO strainmeters in California, where the calculated tides are corroborated by other instrumentation, as well as for six strainmeters in Oregon and Washington, where no other instruments have ever recorded Earth tidal strain. Several strainmeters have unexpectedly large coupling coefficients for vertical strain, which increases the strainmeter's response to atmospheric pressure. Vertical coupling diminishes, or even changes the sign of, the apparent response to areal strain caused by Earth tides or deep Earth processes because near the free surface, vertical strains are opposite in sign to areal strain. Vertical coupling does not impair the shear strain response, however. PBO borehole strainmeters can provide calibrated shear strain time series of transient strain associated with tectonic or magmatic processes.

Geothermal energy control system and method

DOEpatents

Matthews, Hugh B.

1976-01-01

A geothermal energy transfer and utilization system makes use of thermal energy stored in hot solute-bearing well water to generate super-heated steam from an injected flow of clean water; the super-heated steam is then used for operating a turbine-driven pump at the well bottom for pumping the hot solute-bearing water at high pressure and in liquid state to the earth's surface, where it is used by transfer of its heat to a closed-loop boiler-turbine-alternator combination for the generation of electrical or other power. Residual concentrated solute-bearing water is pumped back into the earth. The clean cooled water is regenerated at the surface-located system and is returned to the deep well pumping system also for lubrication of a novel bearing arrangement supporting the turbine-driven pump system.

Towards ecosystem based management and monitoring of the deep Mediterranean, North-East Atlantic and Beyond

NASA Astrophysics Data System (ADS)

Grehan, Anthony J.; Arnaud-Haond, Sophie; D'Onghia, Gianfranco; Savini, Alessandra; Yesson, Chris

2017-11-01

The deep sea covers 65% of the earth's surface and 95% of the biosphere but only a very small fraction (less than 0.0001%) of this has been explored (Rogers et al., 2015; Taylor and Roterman, 2017). However, current knowledge indicates that the deep ocean is characterized by a high level of biodiversity and by the presence of important biological and non-renewable resources. As well as vast flat and muddy plains, the topography of the deep ocean contains a variety of complex and heterogeneous seafloor features, such as canyons, seamounts, cold seeps, hydrothermal vents and biogenic (deep-water coral) reefs and sponge bioherms that harbour an unquantified and diverse array of organisms. The deep sea, despite its remoteness, provides a variety of supporting, provisioning, regulating and cultural, ecosystem goods and services (Thurber et al., 2014). The recent push for 'Blue Growth', to unlock the potential of seas and oceans (European Commission, 2017) has increased the focus on the potential to exploit resources in the deep-sea and consequently the need for improved management (Thurber et al., 2014).

REASON for Europa

NASA Astrophysics Data System (ADS)

Patterson, Gerald Wesley; Blankenship, Don; Moussessian, Alina; Plaut, Jeffrey; Gim, Yonggyu; Schroeder, Dustin; Soderlund, Krista; Grima, Cyril; Chapin, Elaine

2015-11-01

The science goal of the Europa multiple flyby mission is to “explore Europa to investigate its habitability”. One of the primary instruments selected for the scientific payload is a multi-frequency, multi-channel ice penetrating radar system. This “Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON)” would revolutionize our understanding of Europa’s ice shell by providing the first direct measurements of its surface character and subsurface structure. REASON will address key questions regarding Europa’s habitability, including the existence of any liquid water, through the innovative use of radar sounding, altimetry, reflectometry, and plasma/particles analyses. These investigations require a dual-frequency radar (HF and VHF frequencies) instrument with simultaneous shallow and deep sounding that is designed for performance robustness in the challenging environment of Europa. The flyby-centric mission configuration is an opportunity to collect and transmit minimally processed data back to Earth and exploit advanced processing approaches developed for terrestrial airborne data sets. The observation and characterization of subsurface features beneath Europa’s chaotic surface requires discriminating abundant surface clutter from a relatively weak subsurface signal. Finally, the mission plan also includes using REASON as a nadir altimeter capable of measuring tides to test ice shell and ocean hypotheses as well as characterizing roughness across the surface statistically to identify potential follow-on landing sites. We will present a variety of measurement concepts for addressing these challenges.

REASON for Europa

NASA Astrophysics Data System (ADS)

Moussessian, A.; Blankenship, D. D.; Plaut, J. J.; Patterson, G. W.; Gim, Y.; Schroeder, D. M.; Soderlund, K. M.; Grima, C.; Young, D. A.; Chapin, E.

2015-12-01

The science goal of the Europa multiple flyby mission is to "explore Europa to investigate its habitability". One of the primary instruments selected for the scientific payload is a multi-frequency, multi-channel ice penetrating radar system. This "Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON)" would revolutionize our understanding of Europa's ice shell by providing the first direct measurements of its surface character and subsurface structure. REASON addresses key questions regarding Europa's habitability, including the existence of any liquid water, through the innovative use of radar sounding, altimetry, reflectometry, and plasma/particles analyses. These investigations require a dual-frequency radar (HF and VHF frequencies) instrument with concurrent shallow and deep sounding that is designed for performance robustness in the challenging environment of Europa. The flyby-centric mission configuration is an opportunity to collect and transmit minimally processed data back to Earth and exploit advanced processing approaches developed for terrestrial airborne data sets. The observation and characterization of subsurface features beneath Europa's chaotic surface require discriminating abundant surface clutter from a relatively weak subsurface signal. Finally, the mission plan also includes using REASON as a nadir altimeter capable of measuring tides to test ice shell and ocean hypotheses as well as characterizing roughness across the surface statistically to identify potential follow-on landing sites. We will present a variety of measurement concepts for addressing these challenges.

Identification and Removal of Contaminant Sequences From Ribosomal Gene Databases: Lessons From the Census of Deep Life.

PubMed

Sheik, Cody S; Reese, Brandi Kiel; Twing, Katrina I; Sylvan, Jason B; Grim, Sharon L; Schrenk, Matthew O; Sogin, Mitchell L; Colwell, Frederick S

2018-01-01

Earth's subsurface environment is one of the largest, yet least studied, biomes on Earth, and many questions remain regarding what microorganisms are indigenous to the subsurface. Through the activity of the Census of Deep Life (CoDL) and the Deep Carbon Observatory, an open access 16S ribosomal RNA gene sequence database from diverse subsurface environments has been compiled. However, due to low quantities of biomass in the deep subsurface, the potential for incorporation of contaminants from reagents used during sample collection, processing, and/or sequencing is high. Thus, to understand the ecology of subsurface microorganisms (i.e., the distribution, richness, or survival), it is necessary to minimize, identify, and remove contaminant sequences that will skew the relative abundances of all taxa in the sample. In this meta-analysis, we identify putative contaminants associated with the CoDL dataset, recommend best practices for removing contaminants from samples, and propose a series of best practices for subsurface microbiology sampling. The most abundant putative contaminant genera observed, independent of evenness across samples, were Propionibacterium , Aquabacterium , Ralstonia , and Acinetobacter . While the top five most frequently observed genera were Pseudomonas , Propionibacterium , Acinetobacter , Ralstonia , and Sphingomonas . The majority of the most frequently observed genera (high evenness) were associated with reagent or potential human contamination. Additionally, in DNA extraction blanks, we observed potential archaeal contaminants, including methanogens, which have not been discussed in previous contamination studies. Such contaminants would directly affect the interpretation of subsurface molecular studies, as methanogenesis is an important subsurface biogeochemical process. Utilizing previously identified contaminant genera, we found that ∼27% of the total dataset were identified as contaminant sequences that likely originate from DNA extraction and DNA cleanup methods. Thus, controls must be taken at every step of the collection and processing procedure when working with low biomass environments such as, but not limited to, portions of Earth's deep subsurface. Taken together, we stress that the CoDL dataset is an incredible resource for the broader research community interested in subsurface life, and steps to remove contamination derived sequences must be taken prior to using this dataset.

Calderas produced by hydromagmatic eruptions through permafrost in northwest Alaska

NASA Technical Reports Server (NTRS)

Beget, J. E.

1993-01-01

Most hydromagmatic eruptions on Earth are generated by interactions of lava and ground or surface water. This eruptive process typically produces craters 0.1-1 km in diameter, although a few as large as 1-2 km were described. In contrast, a series of Pleistocene hydromagmatic eruptions through 80-100-m-thick permafrost on the Seward Peninsula of Alaska produced four craters 3-8 km in diameter. These craters, called the Espenberg maars, are the four largest maars known on Earth. The thermodynamic properties of ground ice influence the rate and amount of water melted during the course of the eruption. Large quantities of water are present, but only small amounts can be melted at any time to interact with magma. This would tend to produce sustained and highly explosive low water/magma (fuel-coolant) ratios during the eruptions. An area of 400 km(sub 2) around the Alaskan maars shows strong reductions in the density of thaw lakes, ground ice, and other surface manifestations of permafrost because of deep burial by coeval tephra falls. The unusually large Espenberg maars are the first examples of calderas produced by hydromagmatic eruptions. These distinctive landforms can apparently be used as an indicator of the presence of permafrost at the time of eruption.

Structure and dynamics of Earth's lower mantle.

PubMed

Garnero, Edward J; McNamara, Allen K

2008-05-02

Processes within the lowest several hundred kilometers of Earth's rocky mantle play a critical role in the evolution of the planet. Understanding Earth's lower mantle requires putting recent seismic and mineral physics discoveries into a self-consistent, geodynamically feasible context. Two nearly antipodal large low-shear-velocity provinces in the deep mantle likely represent chemically distinct and denser material. High-resolution seismological studies have revealed laterally varying seismic velocity discontinuities in the deepest few hundred kilometers, consistent with a phase transition from perovskite to post-perovskite. In the deepest tens of kilometers of the mantle, isolated pockets of ultralow seismic velocities may denote Earth's deepest magma chamber.

Method and apparatus for delivering high power laser energy over long distances

DOEpatents

Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

2015-04-07

Systems, devices and methods for the transmission and delivery of high power laser energy deep into the earth and for the suppression of associated nonlinear phenomena. Systems, devices and methods for the laser drilling of a borehole in the earth. These systems can deliver high power laser energy down a deep borehole, while maintaining the high power to advance such boreholes deep into the earth and at highly efficient advancement rates.

Recycling of crustal materials through study of ultrahigh-pressure minerals in collisional orogens, ophiolites, and mantle xenoliths: A review

NASA Astrophysics Data System (ADS)

Liou, Juhn G.; Tsujimori, Tatsuki; Yang, Jingsui; Zhang, R. Y.; Ernst, W. G.

2014-12-01

Newly recognized occurrences of ultrahigh-pressure (UHP) minerals including diamonds in ultrahigh-temperature (UHT) felsic granulites of orogenic belts, in chromitites associated with ophiolitic complexes, and in mantle xenoliths suggest the recycling of crustal materials through deep subduction, mantle upwelling, and return to the Earth's surface. This circulation process is supported by crust-derived mineral inclusions in deep-seated zircons, chromites, and diamonds from collision-type orogens, from eclogitic xenoliths in kimberlites, and from chromitities of several Alpine-Himalayan and Polar Ural ophiolites; some of these minerals contain low-atomic number elements typified by crustal isotopic signatures. Ophiolite-type diamonds in placer deposits and as inclusions in chromitites together with numerous highly reduced minerals and alloys appear to have formed near the mantle transition zone. In addition to ringwoodite and inferred stishovite, a number of nanometric minerals have been identified as inclusions employing state-of-the-art analytical tools. Reconstitution of now-exsolved precursor UHP phases and recognition of subtle decompression microstructures produced during exhumation reflect earlier UHP conditions. For example, Tibetan chromites containing exsolution lamellae of coesite + diopside suggest that the original chromitites formed at P > 9-10 GPa at depths of >250-300 km. The precursor phase most likely had a Ca-ferrite or a Ca-titanite structure; both are polymorphs of chromite and (at 2000 °C) would have formed at minimum pressures of P > 12.5 or 20 GPa respectively. Some podiform chromitites and host peridotites contain rare minerals of undoubted crustal origin, including zircon, feldspars, garnet, kyanite, andalusite, quartz, and rutile; the zircons possess much older U-Pb ages than the time of ophiolite formation. These UHP mineral-bearing chromitite hosts evidently had a deep-seated evolution prior to extensional mantle upwelling and partial melting at shallow depths to form the overlying ophiolite complexes. These new findings together with stable isotopic and inclusion characteristics of diamonds provide compelling evidence for profound underflow of both oceanic and continental lithosphere, recycling of surface 'organic' carbon into the lower mantle, and ascent to the Earth's surface through mantle upwelling. Intensified study of UHP granulite-facies lower crustal basement and ophiolitic chromitites should allow a better understanding of the geodynamics of subduction and crustal cycling.

Evolving Oxygen Landscape of the Early Atmosphere and Oceans

NASA Astrophysics Data System (ADS)

Lyons, T. W.; Reinhard, C. T.; Planavsky, N. J.

2013-12-01

The past decade has witnessed remarkable advances in our understanding of oxygen on the early Earth, and a new framework, the topic of this presentation, is now in place to address the controls on spatiotemporal distributions of oxygen and their potential relationships to deep-Earth processes. Recent challenges to the Archean biomarker record have put an added burden on inorganic geochemistry to fingerprint and quantify the early production, accumulation, and variation of biospheric oxygen. Fortunately, a wide variety of techniques now point convincingly to photosynthetic oxygen production and dynamic accumulation well before the canonical Great Oxidation Event (GOE). Recent modeling of sulfur recycling over this interval allows for transient oxygen accumulation in the atmosphere without the disappearance of non-mass-dependent (NMD) sulfur isotope anomalies from the stratigraphic record and further allows for persistent accumulation in the atmosphere well before the permanent disappearance of NMD signals. This recent work suggests that the initial rise of oxygen may have occurred in fits and starts rather than a single step, and that once permanently present in the atmosphere, oxygen likely rose to high levels and then plummeted, in phase with the Paleoproterozoic Lomagundi positive carbon isotope excursion. More than a billion years of oxygen-free conditions in the deep ocean followed and set a challenging course for life, including limited abundances and diversity of eukaryotic organisms. Despite this widespread anoxia, sulfidic (euxinic) conditions were likely limited to productive ocean margins. Nevertheless, euxinia was sufficiently widespread to impact redox-dependent nutrient relationships, particularly the availability of bioessential trace metals critical in the nitrogen cycle, which spawned feedbacks that likely maintained oxygen at very low levels in the ocean and atmosphere and delayed the arrival of animals. Then, in the mid, pre-glacial Neoproterozoic we see evidence for an oxygenation event that significantly predated recent evidence for ocean ventilation in the post-glacial Ediacaran ocean. The trigger that facilitated the transition out of the oxygen-lean ';boring billion' is an area of active study. Additional evidence points to the likelihood of rising and falling oxygen levels through the later Neoproterozoic, which would have had a strong impact on early animal diversification and development of oxygen-demanding ecologies marked by large animals with complex trophic relationships. These observations now provide a context for interpreting the cause-and-effect relationships among the late Proterozoic rise in oxygen, the onset and dynamics of global-scale Neoproterozoic glaciation, metazoan diversification, and large-scale tectonic processes as surface expressions of deep-Earth processes.

[Search for life in deep biospheres].

PubMed

Naganuma, Takeshi

2003-12-01

The life in deep biospheres bridges conventional biology and future exobiology. This review focuses the microbiological studies from the selected deep biospheres, i.e., deep-sea hydrothermal vents, sub-hydrothermal vents, terrestrial subsurface and a sub-glacier lake. The dark biospheres facilitate the emergence of organisms and communities dependent on chemolithoautotrophy, which are overwhelmed by photoautotrophy (photosynthesis) in the surface biospheres. The life at deep-sea hydrothermal vents owes much to chemolithoautotrophy based on the oxidation of sulfide emitted from the vents. It is likely that similarly active bodies such as the Jovian satellite Europa may have hydrothermal vents and associated biological communities. Anoxic or anaerobic condition is characteristic of deep subsurface biospheres. Subsurface microorganisms exploit available oxidants, or terminal electron acceptors (TEA), for anaerobic respiration. Sulfate, nitrate, iron (III) and CO2 are the representative TEAs in the deep subsurface. Below the 3000-4000 m-thick glacier on Antarctica, there have been >70 lakes with liquid water located. One of such sub-glacial lakes, Lake Vostok, is about to be drill-penetrated for microbiological studies. These deep biosphere "platforms" provide new knowledge about the diversity and potential of the Earth's life. The expertise obtained from the deep biosphere expeditions will facilitate the capability of exobiologial exploration.

Exponential decline of deep-sea ecosystem functioning linked to benthic biodiversity loss.

PubMed

Danovaro, Roberto; Gambi, Cristina; Dell'Anno, Antonio; Corinaldesi, Cinzia; Fraschetti, Simonetta; Vanreusel, Ann; Vincx, Magda; Gooday, Andrew J

2008-01-08

Recent investigations suggest that biodiversity loss might impair the functioning and sustainability of ecosystems. Although deep-sea ecosystems are the most extensive on Earth, represent the largest reservoir of biomass, and host a large proportion of undiscovered biodiversity, the data needed to evaluate the consequences of biodiversity loss on the ocean floor are completely lacking. Here, we present a global-scale study based on 116 deep-sea sites that relates benthic biodiversity to several independent indicators of ecosystem functioning and efficiency. We show that deep-sea ecosystem functioning is exponentially related to deep-sea biodiversity and that ecosystem efficiency is also exponentially linked to functional biodiversity. These results suggest that a higher biodiversity supports higher rates of ecosystem processes and an increased efficiency with which these processes are performed. The exponential relationships presented here, being consistent across a wide range of deep-sea ecosystems, suggest that mutually positive functional interactions (ecological facilitation) can be common in the largest biome of our biosphere. Our results suggest that a biodiversity loss in deep-sea ecosystems might be associated with exponential reductions of their functions. Because the deep sea plays a key role in ecological and biogeochemical processes at a global scale, this study provides scientific evidence that the conservation of deep-sea biodiversity is a priority for a sustainable functioning of the worlds' oceans.

On the feasibility of borehole-to-surface electromagnetics for monitoring CO2 sequestration

NASA Astrophysics Data System (ADS)

Wilson, G. A.; Zhdanov, M. S.; Hibbs, A. D.; Black, N.; Gribenko, A. V.; Cuma, M.; Agundes, A.; Eiskamp, G.

2012-12-01

Carbon capture and storage (CCS) projects rely on storing supercritical CO2 in deep saline reservoirs where buoyancy forces drive the injected CO2 upward into the aquifer until a seal is reached. The permanence of the sequestration depends entirely on the long-term geological integrity of the seal. Active geophysical monitoring of the sequestration is critical for informing CO2 monitoring, accounting and verification (MVA) decisions. During injection, there exists a correlation between the changes in CO2 and water saturations in a saline reservoir. Dissolved salts react with the CO2 to precipitate out as carbonates, thereby generally decreasing the electrical resistivity. As a result, there is a correlation between the change in fluid saturation and measured electromagnetic (EM) fields. The challenge is to design an EM survey appropriate for monitoring large, deep reservoirs. Borehole-to-surface electromagnetic (BSEM) surveys consist of borehole-deployed galvanic transmitters and a surface-based array of electric and magnetic field sensors. During a recent field trial, it was demonstrated that BSEM could successfully identify the oil-water contact in the water-injection zone of a carbonate reservoir. We review the BSEM methodology, and perform full-field BSEM modeling. The 3D resistivity models used in this study are based on dynamic reservoir simulations of CO2 injection into a saline reservoir. Although the electric field response at the earth's surface is low, we demonstrate that it can be accurately measured and processed with novel methods of noise cancellation and sufficient stacking over the period of monitoring to increase the signal-to-noise ratio for subsequent seismic- and well-constrained 3D inversion. For long-term or permanent monitoring, we discuss the deployment of novel electric field sensors with chemically inert electrodes that couple to earth in a capacitive manner. This capacitive coupling is a purely EM phenomenon, which, to first order, has no temperature, ionic concentration or corrosion effects and has unprecedented fidelity. This makes the capacitive E-field sensor ideal for CCS applications which require very stable operation over a wide range of ground temperature and moisture level variation, for extended periods of time.

Impact of volcanic ash on anammox communities in deep sea sediments.

PubMed

Song, Bongkeun; Buckner, Caroline T; Hembury, Deborah J; Mills, Rachel A; Palmer, Martin R

2014-04-01

Subaerial explosive volcanism contributes substantial amounts of material to the oceans, but little is known about the impact of volcanic ash on sedimentary microbial activity. We have studied anammox communities in deep sea sediments near the volcanically active island of Montserrat, Lesser Antilles. The rates of anammox and denitrification in the sediments were measured using (15)N isotope pairing incubation experiments, while 16S rRNA genes were used to examine anammox community structures. The higher anammox rates were measured in sediment containing the lower accumulation of volcanic ash in the surface sediments, while the lowest activities were found in sediments with the highest ash deposit. 16S rRNA gene analysis revealed the presence of 'Candidatus Scalindua spp.' in the sediments. The lowest diversity of anammox bacteria was observed in the sediments with the highest ash deposit. Overall, this study demonstrates that the deposition of volcanic material in deep sea sediments has negative impacts on activity and diversity of the anammox community. Since anammox may account for up to 79% of N2 production in marine ecosystems, periods of extensive explosive volcanism in Earth history may have had a hitherto unrecognized negative impact on the sedimentary nitrogen removal processes. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

Processes governing transient responses of the deep ocean buoyancy budget to a doubling of CO2

NASA Astrophysics Data System (ADS)

Palter, J. B.; Griffies, S. M.; Hunter Samuels, B. L.; Galbraith, E. D.; Gnanadesikan, A.

2012-12-01

Recent observational analyses suggest there is a temporal trend and high-frequency variability in deep ocean buoyancy in the last twenty years, a phenomenon reproduced even in low-mixing models. Here we use an earth system model (GFDL's ESM2M) to evaluate physical processes that influence buoyancy (and thus steric sea level) budget of the deep ocean in quasi-steady state and under a doubling of CO2. A new suite of model diagnostics allows us to quantitatively assess every process that influences the buoyancy budget and its temporal evolution, revealing surprising dynamics governing both the equilibrium budget and its transient response to climate change. The results suggest that the temporal evolution of the deep ocean contribution to sea level rise is due to a diversity of processes at high latitudes, whose net effect is then advected in the Eulerian mean flow to mid and low latitudes. In the Southern Ocean, a slowdown in convection and spin up of the residual mean advection are approximately equal players in the deep steric sea level rise. In the North Atlantic, the region of greatest deep steric sea level variability in our simulations, a decrease in mixing of cold, dense waters from the marginal seas and a reduction in open ocean convection causes an accumulation of buoyancy in the deep subpolar gyre, which is then advected equatorward.

The surface of Mars: An unusual laboratory that preserves a record of catastrophic and unusual events

USGS Publications Warehouse

Chapman, M.G.

2009-01-01

Catastrophic and unusual events on Earth such as bolide impacts, megafloods, supereruptions, flood volcanism, and subice volcanism may have devastating effects when they occur. Although these processes have unique characteristics and form distinctive features and deposits, we have diffi culties identifying them and measuring the magnitude of their effects. Our diffi culties with interpreting these processes and identifying their consequences are understandable considering their infrequency on Earth, combined with the low preservation potential of their deposits in the terrestrial rock record. Although we know these events do happen, they are infrequent enough that the deposits are poorly preserved on the geologically active face of the Earth, where erosion, volcanism, and tectonism constantly change the surface. Unlike the Earth, on Mars catastrophic and unusual features are well preserved because of the slow modifi cation of the surface. Signifi cant precipitation has not occurred on Mars for billions of years and there appears to be no discrete crustal plates to have undergone subduction and destruction. Therefore the ancient surface of Mars preserves geologic features and deposits that result from these extraordinary events. Also, unlike the other planets, Mars is the most similar to our own, having an atmosphere, surface ice, volcanism, and evidence of onceflowing water. So although our understanding of precursors, processes, and possible biological effects of catastrophic and unusual processes is limited on Earth, some of these mysteries may be better understood through investigating the surface of Mars. ?? 2009 The Geological Society of America.

Japanese Exploration to Solar System Small Bodies: Rewriting a Planetary Formation Theory with Astromaterial Connection (Invited)

NASA Astrophysics Data System (ADS)

Yano, H.

2013-12-01

Three decades ago, Japan's deep space exploration started with Sakigake and Suisei, twin flyby probes to P/Halley. Since then, the Solar System small bodies have been one of focused destinations to the Japanese solar system studies even today. Only one year after the Halley armada launch, the very first meeting was held for an asteroid sample return mission at ISAS, which after 25 years, materialized as the successful Earth return of Hayabusa , an engineering verification mission for sample return from surfaces of an NEO for the first time in the history. Launched in 2003 and returned in 2010, Hayabusa became the first to visit a sub-km, rubble-pile potentially hazardous asteroid in near Earth space. Its returned samples solved S-type asteroid - ordinary chondrite paradox by proving space weathering evidences in sub-micron scale. Between the Halley missions and Hayabusa, SOCCER concept by M-V rocket was jointly studied between ISAS and NASA; yet it was not realized due to insufficient delta-V for intact capture by decelerating flyby/encounter velocity to a cometary coma. The SOCCER later became reality as Stardust, NASA Discovery mission for cometary coma dust sample return in1999-2006. Japan has collected the second largest collection of the Antarctic meteorites and micrometeorites of the world and asteromaterial scientists are eager to collaborate with space missions. Also Japan enjoyed a long history of collaborations between professional astronomers and high-end amateur observers in the area of observational studies of asteroids, comets and meteors. Having these academic foundations, Japan has an emphasis on programmatic approach to sample returns of Solar System small bodies in future prospects. The immediate follow-on to Hayabusa is Hayabusa-2 mission to sample return with an artificial impactor from 1999 JU3, a C-type NEO in 2014-2020. Following successful demonstration of deep space solar sail technique by IKAROS in 2010-2013, the solar power sail is a deep space probe with hybrid propulsion of solar photon sail and ion engine system that will enable Japan to reach out deep interplanetary space beyond the main asteroid belt. Since 2002, Japanese scientists and engineers have been investigating the solar power sail mission to Jupiter Trojans and interdisciplinary cruising science, such as infrared observation of zodiacal light due to cosmic dust, which at the same time hit a large cross section of the solar sail membrane dust detector, concentrating inside the main asteroid belt. Now the mission design has extended from cruising and fly-by only to rendezvous and sample return options from Jupiter Trojan asteroids. Major scientific goal of Jupiter Trojan exploration is to constrain its origin between two competing hypothesis such as remnants of building blocks the Jovian system as the classic model and the second generation captured EKBOs as the planetary migration models, in which several theories are in deep discussion. Also important is to better understand mixing process of material and structure of the early Solar System just beyond snow line. The current plan involves its launch and both solar photon and IES accelerations combined with Earth and Jupiter gravity assists in 2020's, detailed rendezvous investigation of a few 10-km sized D-type asteroid among Jupiter Trojans in early 2030's and an optional sample return of its surface materials to the Earth in late 2030's.

Habitation Concepts for Human Missions Beyond Low-Earth-Orbit

NASA Technical Reports Server (NTRS)

Smitherman, David V.

2016-01-01

The Advanced Concepts Office at the NASA Marshall Space Flight Center has been engaged for several years in a variety of study activities to help define various options for deep space habitation. This work includes study activities supporting asteroid, lunar and Mars mission activities for the Human spaceflight Architecture Team (HAT), the Deep Space Habitat (DSH) project, and the Exploration Augmentation Module (EAM) project through the NASA Advanced Exploration Systems (AES) Program. The missions under consideration required human habitation beyond low-Earth-orbit (LEO) including deep space habitation in the lunar vicinity to support asteroid retrieval missions, human and robotic lunar surface missions, deep space research facilities, Mars vehicle servicing, and Mars transit missions. Additional considerations included international interest and near term capabilities through the International Space Station (ISS) and Space Launch System (SLS) programs. A variety of habitat layouts have been considered, including those derived from the existing ISS systems, those that could be fabricated from SLS components, and other approaches. This paper presents an overview of several leading designs explored in late fiscal year (FY) 2015 for asteroid, lunar, and Mars mission habitats and identifies some of the known advantages and disadvantages inherent in each. Key findings indicate that module diameters larger than those used for ISS can offer lighter structures per unit volume, and sufficient volume to accommodate consumables for long-duration missions in deep space. The information provided with the findings includes mass and volume data that should be helpful to future exploration mission planning and deep space habitat design efforts.

DECADE web portal: toward the integration of MaGa, EarthChem and VOTW data systems to further the knowledge on Earth degassing

NASA Astrophysics Data System (ADS)

Cardellini, Carlo; Frigeri, Alessandro; Lehnert, Kerstin; Ash, Jason; McCormick, Brendan; Chiodini, Giovanni; Fischer, Tobias; Cottrell, Elizabeth

2015-04-01

The release of volatiles from the Earth's interior takes place in both volcanic and non-volcanic areas of the planet. The comprehension of such complex process and the improvement of the current estimates of global carbon emissions, will greatly benefit from the integration of geochemical, petrological and volcanological data. At present, major online data repositories relevant to studies of degassing are not linked and interoperable. In the framework of the Deep Earth Carbon Degassing (DECADE) initiative of the Deep Carbon Observatory (DCO), we are developing interoperability between three data systems that will make their data accessible via the DECADE portal: (1) the Smithsonian Institutionian's Global Volcanism Program database (VOTW) of volcanic activity data, (2) EarthChem databases for geochemical and geochronological data of rocks and melt inclusions, and (3) the MaGa database (Mapping Gas emissions) which contains compositional and flux data of gases released at volcanic and non-volcanic degassing sites. The DECADE web portal will create a powerful search engine of these databases from a single entry point and will return comprehensive multi-component datasets. A user will be able, for example, to obtain data relating to compositions of emitted gases, compositions and age of the erupted products and coincident activity, of a specific volcano. This level of capability requires a complete synergy between the databases, including availability of standard-based web services (WMS, WFS) at all data systems. Data and metadata can thus be extracted from each system without interfering with each database's local schema or being replicated to achieve integration at the DECADE web portal. The DECADE portal will enable new synoptic perspectives on the Earth degassing process allowing to explore Earth degassing related datasets over previously unexplored spatial or temporal ranges.

Genomic Evidence of Chemotrophic Metabolisms in Deep-Dwelling Chloroflexi Conferred by Ancient Horizontal Gene Transfer Events

NASA Astrophysics Data System (ADS)

Momper, L. M.; Magnabosco, C.; Amend, J.; Osburn, M. R.; Fournier, G. P.

2017-12-01

The marine and terrestrial subsurface biospheres represent quite likely the largest reservoirs for life on Earth, directly impacting surface processes and global cycles throughout Earth's history. In the deep subsurface biosphere (DSB) organic carbon and energy are often extremely scarce. However, archaea and bacteria are able to persist in the DSB to at least 3.5 km below surface [1]. Understanding how they persist, and by what metabolisms they subsist, are key questions in this biosphere. To address these questions we investigated 5 global DSB environments: one legacy mine in South Dakota, USA, 3 mines in South Africa and marine fluids circulating beneath the Juan de Fuca Ridge. Boreholes within these mines provided access to fluids buried beneath the earth's surface and sampled depths down to 3.1 km. Geochemical data were collected concomitantly with DNA for metagenomic sequencing. We examined genomes of the ancient and deeply branching Chloroflexi for metabolic capabilities and interrogated the geochemical drivers behind those metabolisms with in situ thermodynamic modeling of reaction energetics. In total, 23 Chloroflexi genomes were identified and analyzed from the 5 subsurface sites. Genes for nitrate reduction (nar) and sulfite reduction (dsr) were found in many of the South Africa Chloroflexi but were absent from genomes collected in South Dakota. Indeed, nitrate reduction was among the most energetically favorable reactions in South African fluids (10-14 kJ cell-1 sec -1 per mol of reactant) and sulfur reduction with Fe2+ or H2 was also exergonic [2]. Conversely, genes for nitrite and nitrous oxide reduction (nrf, nir and nos) were found in genomes collected in South Dakota and Juan de Fuca, but not South Africa. We examined the origin of genes conferring these metabolisms in the Chloroflexi genomes. We discovered evidence for horizontal gene transfer (HGT) for all of these putative metabolisms. Retention of these genes in Chloroflexi lineages indicates HGT may have conferred an advantageous metabolism in DSB environments. We are using molecular dating techniques to constrain the timing of these HGT events on geologic timescales. [1] Baker J. B. et al. (2003) Environ Microbiol., 5, 267-277. [2] Magnabosco C. et al. (2016) ISME J, 10(3), 730-741.

Method and apparatus for delivering high power laser energy over long distances

DOEpatents

Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

2013-08-20

Systems, devices and methods for the transmission of 1 kW or more of laser energy deep into the earth and for the suppression of associated nonlinear phenomena. Systems, devices and methods for the laser drilling of a borehole in the earth. These systems can deliver high power laser energy down a deep borehole, while maintaining the high power to advance such boreholes deep into the earth and at highly efficient advancement rates.

Methods for enhancing the efficiency of creating a borehole using high power laser systems

DOEpatents

Zediker, Mark S.; Rinzler, Charles C.; Faircloth, Brian O.; Koblick, Yeshaya; Moxley, Joel F.

2014-06-24

Methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena to enhance the formation of Boreholes. Methods for the laser operations to reduce the critical path for forming a borehole in the earth. These methods can deliver high power laser energy down a deep borehole, while maintaining the high power to perform operations in such boreholes deep within the earth.

High power laser workover and completion tools and systems

DOEpatents

Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

2014-10-28

Workover and completion systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser workover and completion of a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform laser workover and completion operations in such boreholes deep within the earth.

Water masses transform at mid-depths over the Antarctic Continental Slope

NASA Astrophysics Data System (ADS)

Mead Silvester, Jess; Lenn, Yueng-Djern; Polton, Jeffrey; Phillips, Helen E.; Morales Maqueda, Miguel

2017-04-01

The Meridional Overturning Circulation (MOC) controls the oceans' latitudinal heat distribution, helping to regulate the Earth's climate. The Southern Ocean is the primary place where cool, deep waters return to the surface to complete this global circulation. While water mass transformations intrinsic to this process predominantly take place at the surface following upwelling, recent studies implicate vertical mixing in allowing transformation at mid-depths over the Antarctic continental slope. We deployed an EM-Apex float near Elephant Island, north of the Antarctic Peninsula's tip, to profile along the slope and use potential vorticity to diagnose observed instabilities. The float captures direct heat exchange between a lens of Upper Circumpolar Deep Water (UCDW) and surrounding Lower Circumpolar Deep Waters (LCDW) at mid-depths and over the course of several days. Heat fluxes peak across the top and bottom boundaries of the UCDW lens and peak diffusivities across the bottom boundary are associated with shear instability. Estimates of diffusivity from shear-strain finestructure parameterisation and heat fluxes are found to be in reasonable agreement. The two-dimensional Ertel potential vorticity is elevated both inside the UCDW lens and along its bottom boundary, with a strong contribution from the shear term in these regions and instabilities are associated with gravitational and symmetric forcing. Thus, shear instabilities are driving turbulent mixing across the lower boundary between these two water masses, leading to the observed heat exchange and transformation at mid-depths over the Antarctic continental slope. This has implications for our understanding of the rates of upwelling and ocean-atmosphere exchanges of heat and carbon at this critical location.

Europa's surface radiation environment and considerations for in-situ sampling and biosignature detection

NASA Astrophysics Data System (ADS)

Nordheim, T.; Paranicas, C.; Hand, K. P.

2017-12-01

Jupiter's moon Europa is embedded deep within the Jovian magnetosphere and is thus exposed to bombardment by charged particles, from thermal plasma to more energetic particles at radiation belt energies. In particular, energetic charged particles are capable of affecting the uppermost layer of surface material on Europa, in some cases down to depths of several meters (Johnson et al., 2004; Paranicas et al., 2009, 2002). Examples of radiation-induced surface alteration include sputtering, radiolysis and grain sintering; processes that are capable of significantly altering the physical properties of surface material. Radiolysis of surface ices containing sulfur-bearing contaminants from Io has been invoked as a possible explanation for hydrated sulfuric acid detected on Europa's surface (Carlson et al., 2002, 1999) and radiolytic production of oxidants represents a potential source of energy for life that could reside within Europa's sub-surface ocean (Chyba, 2000; Hand et al., 2007; Johnson et al., 2003; Vance et al., 2016). Accurate knowledge of Europa's surface radiation environment is essential to the interpretation of space and Earth-based observations of Europa's surface and exosphere. Furthermore, future landed missions may seek to sample endogenic material emplaced on Europa's surface to investigate its chemical composition and to search for biosignatures contained within. Such material would likely be sampled from the shallow sub-surface, and thus, it becomes crucial to know to which degree this material is expected to have been radiation processed.Here we will present modeling results of energetic electron and proton bombardment of Europa's surface, including interactions between these particles and surface material. In addition, we will present predictions for biosignature destruction at different geographical locations and burial depths and discuss the implications of these results for surface sampling by future missions to Europa's surface.

Melting curve of compressed barium carbonate from in situ ionic conductivity measurements: Implications for the melting behavior of alkaline earth carbonates in Earth's deep carbon cycle

NASA Astrophysics Data System (ADS)

Dong, J.; Li, J.; Zhu, F.; Li, Z.; Farawi, R.

2017-12-01

The whereabouts of subducted carbonates place a major constraint on the Earth's deep carbon cycle, but the fraction of carbon retained in the slab and transported into the deep mantle, compared to that released from the slab and recycled to the surface, is still under debate. Knowledge of the stability of carbonated mantle rocks is pivotal for assessing the ability of slabs to carry carbonates into the deep mantle. Determination and systematic comparison of the melting curves of alkali and alkaline earth carbonates at high pressure can help construct thermodynamic models to predict the melting behavior of complex carbonated mantle rocks. Among alkaline earth carbonates, the melting behavior of barium carbonate (BaCO3) has not been adequately understood. The reported melting point of BaCO3at 1 bar differ by nearly 800 °C and constraints on the melting curve of BaCO3 at high pressure are not available. In this study, the melting temperatures of BaCO3 were determined up to 11 GPa from in situ ionic conductivity measurements using the multi-anvil apparatus at the University of Michigan. The solid-liquid boundary at high pressure was detected on the basis of a steep rise in conductivity through the sample upon melting. The melting point of BaCO3 was found to drop from 1797 °C at 3.3 GPa to 1600 °C at 5.5 GPa and then rise with pressure to 2180 °C at 11 GPa. The observed melting depression point at 5.5 GPa corresponds to the phase transition of BaCO3 from the aragonite structure (Pmcn) to post-aragonite structure (Pmmn) at 6.3 GPa, 877 °C and 8.0 GPa, 727 °C, determined from synchrotron X-ray diffraction measurements using laser-heated DAC experiments at the Advanced Photon Source, Argonne National Laboratory. These results are also compared with ex situ falling marker experiments, and the three methods together place tight constraints on the melting curve of BaCO3 and elucidates the effect of structural phase transitions on its melting behavior.

Recent distribution of lead in the Indian Ocean reflects the impact of regional emissions.

PubMed

Echegoyen, Yolanda; Boyle, Edward A; Lee, Jong-Mi; Gamo, Toshitaka; Obata, Hajime; Norisuye, Kazuhiro

2014-10-28

Humans have injected lead (Pb) massively into the earth surface environment in a temporally and spatially evolving pattern. A significant fraction is transported by the atmosphere into the surface ocean where we can observe its transport by ocean currents and sinking particles. This study of the Indian Ocean documents high Pb concentrations in the northern and tropical surface waters and extremely low Pb levels in the deep water. North of 20°S, dissolved Pb concentrations decrease from 42 to 82 pmol/kg in surface waters to 1.5-3.3 pmol/kg in deep waters. South of 20°S, surface water Pb concentrations decrease from 21 pmol/kg at 31°S to 7 pmol/kg at 62°S. This surface Pb concentration gradient reflects a southward decrease in anthropogenic Pb emissions. The upper waters of the north and central Indian Ocean have high Pb concentrations resulting from recent regional rapid industrialization and a late phase-out of leaded gasoline, and these concentrations are now higher than currently seen in the central North Pacific and North Atlantic oceans. The Antarctic sector of the Indian Ocean shows very low concentrations due to limited regional anthropogenic Pb emissions, high scavenging rates, and rapid vertical mixing, but Pb still occurs at higher levels than would have existed centuries ago. Penetration of Pb into the northern and central Indian Ocean thermocline waters is minimized by limited ventilation. Pb concentrations in the deep Indian Ocean are comparable to the other oceans at the same latitude, and deep waters of the central Indian Ocean match the lowest observed oceanic Pb concentrations.

Ejecta from Ocean Impacts

NASA Technical Reports Server (NTRS)

Kyte, Frank T.

2003-01-01

Numerical simulations of deep-ocean impact provide some limits on the size of a projectile that will not mix with the ocean floor during a deep-ocean impact. For a vertical impact at asteroidal velocities (approx. 20 km/s), mixing is only likely when the projectile diameter is greater than 112 of the water depth. For oblique impacts, even larger projectiles will not mix with ocean floor silicates. Given the typical water depths of 4 to 5 km in deep-ocean basins, asteroidal projectiles with diameters as large as 2 or 3 km may commonly produce silicate ejecta that is composed only of meteoritic materials and seawater salts. However, the compressed water column beneath the projectile can still disrupt and shock metamorphose the ocean floor. Therefore, production of a separate, terrestrial ejecta component is not ruled out in the most extreme case. With increasing projectile size (or energy) relative to water depths, there must be a gradation between oceanic impacts and more conventional continental impacts. Given that 60% of the Earth's surface is covered by oceanic lithosphere and 500 m projectiles impact the Earth on 10(exp 5) y timescales, there must be hundreds of oceanic impact deposits in the sediment record awaiting discovery.

Investigating Continental Margins: An Activity to Help Students Better Understand the Continental Margins of North America

ERIC Educational Resources Information Center

Poli, Maria-Serena; Capodivacca, Marco

2011-01-01

Continental margins are an important part of the ocean floor. They separate the land above sea level from the deep ocean basins below and occupy about 11% of Earth's surface. They are also economically important, as they harbor both mineral resources and some of the most valuable fisheries in the world. In this article students investigate North…

Estimating ionospheric currents by inversion from ground-based geomagnetic data and calculating geoelectric fields for studies of geomagnetically induced currents

NASA Astrophysics Data System (ADS)

de Villiers, J. S.; Pirjola, R. J.; Cilliers, P. J.

2016-09-01

This research focuses on the inversion of geomagnetic variation field measurements to obtain the source currents in the ionosphere and magnetosphere, and to determine the geoelectric fields at the Earth's surface. During geomagnetic storms, the geoelectric fields create geomagnetically induced currents (GIC) in power networks. These GIC may disturb the operation of power systems, cause damage to power transformers, and even result in power blackouts. In this model, line currents running east-west along given latitudes are postulated to exist at a certain height above the Earth's surface. This physical arrangement results in the fields on the ground being composed of a zero magnetic east component and a nonzero electric east component. The line current parameters are estimated by inverting Fourier integrals (over wavenumber) of elementary geomagnetic fields using the Levenberg-Marquardt technique. The output parameters of the model are the ionospheric current strength and the geoelectric east component at the Earth's surface. A conductivity profile of the Earth is adapted from a shallow layered-Earth model for one observatory, together with a deep-layer model derived from satellite observations. This profile is used to obtain the ground surface impedance and therefore the reflection coefficient in the integrals. The inputs for the model are a spectrum of the geomagnetic data for 31 May 2013. The output parameters of the model are spectrums of the ionospheric current strength and of the surface geoelectric field. The inverse Fourier transforms of these spectra provide the time variations on the same day. The geoelectric field data can be used as a proxy for GIC in the prediction of GIC for power utilities. The current strength data can assist in the interpretation of upstream solar wind behaviour.

Redox variations in Mauna Kea lavas, the oxygen fugacity of the Hawaiian plume, and the role of volcanic gases in Earth's oxygenation.

PubMed

Brounce, Maryjo; Stolper, Edward; Eiler, John

2017-08-22

The behavior of C, H, and S in the solid Earth depends on their oxidation states, which are related to oxygen fugacity ( f O 2 ). Volcanic degassing is a source of these elements to Earth's surface; therefore, variations in mantle f O 2 may influence the f O 2 at Earth's surface. However, degassing can impact magmatic f O 2 before or during eruption, potentially obscuring relationships between the f O 2 of the solid Earth and of emitted gases and their impact on surface f O 2 We show that low-pressure degassing resulted in reduction of the f O 2 of Mauna Kea magmas by more than an order of magnitude. The least degassed magmas from Mauna Kea are more oxidized than midocean ridge basalt (MORB) magmas, suggesting that the upper mantle sources of Hawaiian magmas have higher f O 2 than MORB sources. One explanation for this difference is recycling of material from the oxidized surface to the deep mantle, which is then returned to the surface as a component of buoyant plumes. It has been proposed that a decreasing pressure of volcanic eruptions led to the oxygenation of the atmosphere. Extension of our findings via modeling of degassing trends suggests that a decrease in eruption pressure would not produce this effect. If degassing of basalts were responsible for the rise in oxygen, it requires that Archean magmas had at least two orders of magnitude lower f O 2 than modern magmas. Estimates of f O 2 of Archean magmas are not this low, arguing for alternative explanations for the oxygenation of the atmosphere.

Suppression of Lateral Diffusion and Surface Leakage Currents in nBn Photodetectors Using an Inverted Design

NASA Astrophysics Data System (ADS)

Du, X.; Savich, G. R.; Marozas, B. T.; Wicks, G. W.

2018-02-01

Surface leakage and lateral diffusion currents in InAs-based nBn photodetectors have been investigated. Devices fabricated using a shallow etch processing scheme that etches through the top contact and stops at the barrier exhibited large lateral diffusion current but undetectably low surface leakage. Such large lateral diffusion current significantly increased the dark current, especially in small devices, and causes pixel-to-pixel crosstalk in detector arrays. To eliminate the lateral diffusion current, two different approaches were examined. The conventional solution utilized a deep etch process, which etches through the top contact, barrier, and absorber. This deep etch processing scheme eliminated lateral diffusion, but introduced high surface current along the device mesa sidewalls, increasing the dark current. High device failure rate was also observed in deep-etched nBn structures. An alternative approach to limit lateral diffusion used an inverted nBn structure that has its absorber grown above the barrier. Like the shallow etch process on conventional nBn structures, the inverted nBn devices were fabricated with a processing scheme that only etches the top layer (the absorber, in this case) but avoids etching through the barrier. The results show that inverted nBn devices have the advantage of eliminating the lateral diffusion current without introducing elevated surface current.

Understanding the Effects of Collisional Evolution and Spacecraft Impact Experiments on Comets and Asteroids

NASA Technical Reports Server (NTRS)

Lederer, S.M.; Jensen, E.A.; Fane, M.; Smith, D.C.; Holmes, J.; Keller, L.P.; Lindsay, S.S.; Wooden, D.H.; Whizin, A.; Cintala, M.J.;

VAFB-20180329-PH_CNW01_0019

NASA Image and Video Library

2018-03-29

In the Astrotech facility at Vandenberg Air Force Base in California, the heatshield is lifted for placement on NASA's Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, or InSight, Mars lander. InSight will be the first mission to look deep beneath the Martian surface. It will study the planet's interior by measuring its heat output and listen for marsquakes. The spacecraft will use the seismic waves generated by marsquakes to develop a map of the planet’s deep interior. The resulting insight into Mars’ formation will provide a better understanding of how other rocky planets, including Earth, were created. InSight is scheduled for liftoff May 5, 2018.

VAFB-20180329-PH_CNW01_0031

NASA Image and Video Library

2018-03-29

In the Astrotech facility at Vandenberg Air Force Base in California, the heatshield is placed on NASA's Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, or InSight, Mars lander. InSight will be the first mission to look deep beneath the Martian surface. It will study the planet's interior by measuring its heat output and listen for marsquakes. The spacecraft will use the seismic waves generated by marsquakes to develop a map of the planet’s deep interior. The resulting insight into Mars’ formation will provide a better understanding of how other rocky planets, including Earth, were created. InSight is scheduled for liftoff May 5, 2018.

InSight Encapsulation

NASA Image and Video Library

2018-04-16

In the Astrotech facility at Vandenberg Air Force Base in California, NASA's Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, or InSight, Mars lander is encapsulated in its payload fairing. InSight will be the first mission to look deep beneath the Martian surface. It will study the planet's interior by measuring its heat output and listen for marsquakes. The spacecraft will use the seismic waves generated by marsquakes to develop a map of the planet’s deep interior. The resulting insight into Mars’ formation will provide a better understanding of how other rocky planets, including Earth, were created. InSight is scheduled for liftoff May 5, 2018.

InSight Encapsulation

NASA Image and Video Library

2018-04-16

In the Astrotech facility at Vandenberg Air Force Base in California, technicians and engineers encapsulate NASA's Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, or InSight, Mars lander in its payload fairing. InSight will be the first mission to look deep beneath the Martian surface. It will study the planet's interior by measuring its heat output and listen for marsquakes. The spacecraft will use the seismic waves generated by marsquakes to develop a map of the planet’s deep interior. The resulting insight into Mars’ formation will provide a better understanding of how other rocky planets, including Earth, were created. InSight is scheduled for liftoff May 5, 2018.

InSight Rollout to Pad

NASA Image and Video Library

2018-04-23

Encapsulated in its payload fairing, NASA's Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, or InSight, Mars lander is transported to Space Launch Complex 3 at Vandenberg Air Force Base in California. InSight will be the first mission to look deep beneath the Martian surface. It will study the planet's interior by measuring its heat output and listen for marsquakes. The spacecraft will use the seismic waves generated by marsquakes to develop a map of the planet’s deep interior. The resulting insight into Mars’ formation will provide a better understanding of how other rocky planets, including Earth, were created. InSight is scheduled for liftoff May 5, 2018.

InSight Rollout to Pad

NASA Image and Video Library

2018-04-23

Encapsulated in its payload fairing NASA's Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, or InSight, Mars lander arrives at Space Launch Complex 3 at Vandenberg Air Force Base in California. InSight will be the first mission to look deep beneath the Martian surface. It will study the planet's interior by measuring its heat output and listen for marsquakes. The spacecraft will use the seismic waves generated by marsquakes to develop a map of the planet’s deep interior. The resulting insight into Mars’ formation will provide a better understanding of how other rocky planets, including Earth, were created. InSight is scheduled for liftoff May 5, 2018.

InSight Rollout to Pad

NASA Image and Video Library

2018-04-23

Encapsulated in its payload fairing NASA's Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, or InSight, Mars lander is transported to Space Launch Complex 3 at Vandenberg Air Force Base in California. InSight will be the first mission to look deep beneath the Martian surface. It will study the planet's interior by measuring its heat output and listen for marsquakes. The spacecraft will use the seismic waves generated by marsquakes to develop a map of the planet’s deep interior. The resulting insight into Mars’ formation will provide a better understanding of how other rocky planets, including Earth, were created. InSight is scheduled for liftoff May 5, 2018.

InSight Lift & Mate

NASA Image and Video Library

2018-04-23

Encapsulated in its payload fairing NASA's Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, or InSight, Mars lander is prepared for transport to Space Launch Complex 3 at Vandenberg Air Force Base in California. InSight will be the first mission to look deep beneath the Martian surface. It will study the planet's interior by measuring its heat output and listen for marsquakes. The spacecraft will use the seismic waves generated by marsquakes to develop a map of the planet’s deep interior. The resulting insight into Mars’ formation will provide a better understanding of how other rocky planets, including Earth, were created. InSight is scheduled for liftoff May 5, 2018.

InSight Battery Installation

NASA Image and Video Library

2018-04-20

In the gantry at Space Launch Complex 3 at Vandenberg Air Force Base in California, a technician prepares batteries for installation in NASA's Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, or InSight, Mars lander. InSight will be the first mission to look deep beneath the Martian surface. It will study the planet's interior by measuring its heat output and listen for marsquakes. The spacecraft will use the seismic waves generated by marsquakes to develop a map of the planet’s deep interior. The resulting insight into Mars’ formation will provide a better understanding of how other rocky planets, including Earth, were created. InSight is scheduled for liftoff May 5, 2018.

A new technique for in situ measurement of the composition of neutral gas in interplanetary space

NASA Technical Reports Server (NTRS)

Gruntman, Michael A.

1993-01-01

Neutral atoms in interplanetary space play an important role in many processes relevant to the formation and evolution of the Solar System. An experimental approach is proposed for in situ atom detection based on the conversion of neutral atoms to negative ions at a specially prepared sensitive surface. Negative ions are subsequently analyzed and detected in an essentially noise-free mode. The use of the technique for in situ study of the composition of neutral interstellar atoms is considered. It is shown that interstellar H, D, and O atoms and possibly H2 molecules can be measured by the proposed technique. The experiment can be performed from a high-apogee Earth-orbiting satellite or from a deep space probe. Possible applications of the technique are discussed.

Designing a network of critical zone observatories to explore the living skin of the terrestrial Earth

NASA Astrophysics Data System (ADS)

Brantley, Susan L.; McDowell, William H.; Dietrich, William E.; White, Timothy S.; Kumar, Praveen; Anderson, Suzanne P.; Chorover, Jon; Lohse, Kathleen Ann; Bales, Roger C.; Richter, Daniel D.; Grant, Gordon; Gaillardet, Jérôme

2017-12-01

The critical zone (CZ), the dynamic living skin of the Earth, extends from the top of the vegetative canopy through the soil and down to fresh bedrock and the bottom of the groundwater. All humans live in and depend on the CZ. This zone has three co-evolving surfaces: the top of the vegetative canopy, the ground surface, and a deep subsurface below which Earth's materials are unweathered. The network of nine CZ observatories supported by the US National Science Foundation has made advances in three broad areas of CZ research relating to the co-evolving surfaces. First, monitoring has revealed how natural and anthropogenic inputs at the vegetation canopy and ground surface cause subsurface responses in water, regolith structure, minerals, and biotic activity to considerable depths. This response, in turn, impacts aboveground biota and climate. Second, drilling and geophysical imaging now reveal how the deep subsurface of the CZ varies across landscapes, which in turn influences aboveground ecosystems. Third, several new mechanistic models now provide quantitative predictions of the spatial structure of the subsurface of the CZ.Many countries fund critical zone observatories (CZOs) to measure the fluxes of solutes, water, energy, gases, and sediments in the CZ and some relate these observations to the histories of those fluxes recorded in landforms, biota, soils, sediments, and rocks. Each US observatory has succeeded in (i) synthesizing research across disciplines into convergent approaches; (ii) providing long-term measurements to compare across sites; (iii) testing and developing models; (iv) collecting and measuring baseline data for comparison to catastrophic events; (v) stimulating new process-based hypotheses; (vi) catalyzing development of new techniques and instrumentation; (vii) informing the public about the CZ; (viii) mentoring students and teaching about emerging multidisciplinary CZ science; and (ix) discovering new insights about the CZ. Many of these activities can only be accomplished with observatories. Here we review the CZO enterprise in the United States and identify how such observatories could operate in the future as a network designed to generate critical scientific insights. Specifically, we recognize the need for the network to study network-level questions, expand the environments under investigation, accommodate both hypothesis testing and monitoring, and involve more stakeholders. We propose a driving question for future CZ science and a hubs-and-campaigns model to address that question and target the CZ as one unit. Only with such integrative efforts will we learn to steward the life-sustaining critical zone now and into the future.

A role for subducted super-hydrated kaolinite in Earth’s deep water cycle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hwang, Huijeong; Seoung, Donghoon; Lee, Yongjae

Water is the most abundant volatile component in the Earth. It continuously enters the mantle through subduction zones, where it reduces the melting temperature of rocks to generate magmas. The dehydration process in subduction zones, which determines whether water is released from the slab or transported into the deeper mantle, is an essential component of the deep water cycle. Here in this paper we use in situ and time-resolved high-pressure/high-temperature synchrotron X-ray diffraction and infrared spectra to characterize the structural and chemical changes of the clay mineral kaolinite. At conditions corresponding to a depth of about 75 km in amore » cold subducting slab (2.7 GPa and 200 °C), and in the presence of water, we observe the pressure-induced insertion of water into kaolinite. This super-hydrated phase has a unit cell volume that is about 31% larger, a density that is about 8.4% lower than the original kaolinite and, with 29 wt% H 2O, the highest water content of any known aluminosilicate mineral in the Earth. As pressure and temperature approach 19 GPa and about 800 °C, we observe the sequential breakdown of super-hydrated kaolinite. The formation and subsequent breakdown of super-hydrated kaolinite in cold slabs subducted below 200 km leads to the release of water that may affect seismicity and help fuel arc volcanism at the surface.« less

A role for subducted super-hydrated kaolinite in Earth’s deep water cycle

DOE PAGES

Hwang, Huijeong; Seoung, Donghoon; Lee, Yongjae; ...

2017-11-20

Water is the most abundant volatile component in the Earth. It continuously enters the mantle through subduction zones, where it reduces the melting temperature of rocks to generate magmas. The dehydration process in subduction zones, which determines whether water is released from the slab or transported into the deeper mantle, is an essential component of the deep water cycle. Here in this paper we use in situ and time-resolved high-pressure/high-temperature synchrotron X-ray diffraction and infrared spectra to characterize the structural and chemical changes of the clay mineral kaolinite. At conditions corresponding to a depth of about 75 km in amore » cold subducting slab (2.7 GPa and 200 °C), and in the presence of water, we observe the pressure-induced insertion of water into kaolinite. This super-hydrated phase has a unit cell volume that is about 31% larger, a density that is about 8.4% lower than the original kaolinite and, with 29 wt% H 2O, the highest water content of any known aluminosilicate mineral in the Earth. As pressure and temperature approach 19 GPa and about 800 °C, we observe the sequential breakdown of super-hydrated kaolinite. The formation and subsequent breakdown of super-hydrated kaolinite in cold slabs subducted below 200 km leads to the release of water that may affect seismicity and help fuel arc volcanism at the surface.« less

Deep Space 1 arrives at KSC and processing begins in the PHSF

NASA Technical Reports Server (NTRS)

1998-01-01

Wearing special protective suits, workers remove the protective covering from NASA's Deep Space 1 spacecraft in the Payload Hazardous Servicing Facility at KSC to prepare it for prelaunch processing. Targeted for launch on a Boeing Delta 7326 rocket on Oct. 15, 1998, the first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Tremor-tide correlations and near-lithostatic pore pressure on the deep San Andreas fault.

PubMed

Thomas, Amanda M; Nadeau, Robert M; Bürgmann, Roland

2009-12-24

Since its initial discovery nearly a decade ago, non-volcanic tremor has provided information about a region of the Earth that was previously thought incapable of generating seismic radiation. A thorough explanation of the geologic process responsible for tremor generation has, however, yet to be determined. Owing to their location at the plate interface, temporal correlation with geodetically measured slow-slip events and dominant shear wave energy, tremor observations in southwest Japan have been interpreted as a superposition of many low-frequency earthquakes that represent slip on a fault surface. Fluids may also be fundamental to the failure process in subduction zone environments, as teleseismic and tidal modulation of tremor in Cascadia and Japan and high Poisson ratios in both source regions are indicative of pressurized pore fluids. Here we identify a robust correlation between extremely small, tidally induced shear stress parallel to the San Andreas fault and non-volcanic tremor activity near Parkfield, California. We suggest that this tremor represents shear failure on a critically stressed fault in the presence of near-lithostatic pore pressure. There are a number of similarities between tremor in subduction zone environments, such as Cascadia and Japan, and tremor on the deep San Andreas transform, suggesting that the results presented here may also be applicable in other tectonic settings.

Packing, Scheduling and Covering Problems in a Game-Theoretic Perspective

NASA Astrophysics Data System (ADS)

Karlstrom, Leif

Magma transport pathways through Earth's crust span 12--15 orders of magnitude in time and space, with unsteadiness at all scales. However emergent organization of this system is widespread, recorded by spatial loci of volcanism at the surface and large-scale, rapid outpourings of magma throughout the geologic record. This thesis explores several mechanisms for the organization and time evolution of magma transport, from the deep crust to the surface. A primary focus (Chapters 2--5) is the filling, stability and drainage of magma chambers, structures which function both as reservoirs feeding individual volcanic eruptions and as stalling points in the crust where magma accumulates and differentiation occurs. We show that magma chambers may dictate the spatio-temporal organization of magma rising through crust (Chapters 2--3), control the surface eruptive progression of extreme mantle melting events (Chapter 4), and actively set the size of calderas that form during shallow, crystal rich eruptions (Chapter 5). Each of these chapters explores variations on a hypothesis: interactions between magma chamber stresses and the rheology of surrounding crustal materials evolve during magma transport and this unsteady process helps determine the magnitude, location, and timing of surface eruptions. The last part of this thesis (Chapters 6--7) focuses on surface transport processes, the meandering of melt channels on the surface of glaciers and lava flows. We show that the meandering instability is a generic feature of flow over an erodable substrate, despite significantly different fluid characteristics and erosion mechanics.

A Novel Approach to Model Earth Fissure Caused by Extensive Aquifer Exploitation and its Application to the Wuxi Case, China

NASA Astrophysics Data System (ADS)

Ye, Shujun; Franceschini, Andrea; Zhang, Yan; Janna, Carlo; Gong, Xulong; Yu, Jun; Teatini, Pietro

2018-03-01

Initially observed in the semiarid basins of southwestern USA, earth fissures due to aquifer over-exploitation are presently threatening a large number of subsiding basins in various countries worldwide. Different mechanics have been proposed to explain this process, such as differential compaction, horizontal movements, and fault reactivation. Numerical modeling and prediction of this major geohazard caused by overuse of groundwater resources are challenging because of two main requirements: shifting from the classical continuous to discontinuous geomechanics and incorporating two-dimensional features (the earth fissures) into large three-dimensional (3-D) modeling domain (the subsiding basin). In this work, we proposed a novel modeling approach to simulate earth fissure generation and propagation in 3-D complex geological settings. A nested two-scale approach associated with an original nonlinear elastoplastic finite element/interface element simulator allows modeling the mechanics of earth discontinuities, in terms of both sliding and opening. The model is applied on a case study in Wuxi, China, where groundwater pumping between 1985 and 2004 has caused land subsidence larger than 2 m. The model outcomes highlight that the presence of a shallow (˜80 m deep) bedrock ridge crossing the Yangtze River delta is the key factor triggering the earth fissure development in this area. Bending of the alluvial deposits around the ridge tip and shear stress due to the uneven piezometric change and asymmetrical shape of the bedrock have caused the earth fissure to onset at the land surface and propagate downward to a maximum depth of about 20-30 m. Maximum sliding and opening are computed in the range of 10-40 cm, in agreement with the order of magnitude estimated in the field.

The GPS Topex/Poseidon precise orbit determination experiment - Implications for design of GPS global networks

NASA Technical Reports Server (NTRS)

Lindqwister, Ulf J.; Lichten, Stephen M.; Davis, Edgar S.; Theiss, Harold L.

1993-01-01

Topex/Poseidon, a cooperative satellite mission between United States and France, aims to determine global ocean circulation patterns and to study their influence on world climate through precise measurements of sea surface height above the geoid with an on-board altimeter. To achieve the mission science aims, a goal of 13-cm orbit altitude accuracy was set. Topex/Poseidon includes a Global Positioning System (GPS) precise orbit determination (POD) system that has now demonstrated altitude accuracy better than 5 cm. The GPS POD system includes an on-board GPS receiver and a 6-station GPS global tracking network. This paper reviews early GPS results and discusses multi-mission capabilities available from a future enhanced global GPS network, which would provide ground-based geodetic and atmospheric calibrations needed for NASA deep space missions while also supplying tracking data for future low Earth orbiters. Benefits of the enhanced global GPS network include lower operations costs for deep space tracking and many scientific and societal benefits from the low Earth orbiter missions, including improved understanding of ocean circulation, ocean-weather interactions, the El Nino effect, the Earth thermal balance, and weather forecasting.

An Integrated Strategy for Promoting Geoscience Education and Research in Developing Countries through International Cooperation

NASA Astrophysics Data System (ADS)

Aswathanarayana, U.

2007-12-01

Geoscience education and research in Developing countries should aim at achieving food, water and environmental security, and disaster preparedness, based on the synergetic application of earth (including atmospheric and oceanic realms), space and information sciences through economically-viable, ecologically- sustainable and people-participatory management of natural resources. The proposed strategy involves the integration of the following three principal elements: (i) What needs to be taught: Geoscience needs to be taught as earth system science incorporating geophysical, geochemical and geobiological approaches, with focus (say, 80 % of time) on surficial processes (e.g. dynamics of water, wind and waves, surface and groundwater, soil moisture, geomorphology, landuse, crops), and surficial materials (e.g. soils, water, industrial minerals, sediments, biota). Subjects such as the origin, structure and evolution of the earth, and deep-seated processes (e.g. dynamics of the crust-mantle interaction, plate tectonics) could be taught by way of background knowledge (say, 20 % of the time), (ii) How jobs are to be created: Jobs are to be created by merging geoscience knowledge with economic instruments (say, micro enterprises), and management structures at different levels (Policy level, Technology Transfer level and Implementation level), customized to the local biophysical and socioeconomic situations, and (iii) International cooperation: Web-based instruction (e.g. education portals, virtual laboratories) through South - South and North - South cooperation, customized to the local biophysical and socioeconomic situations, with the help of (say) UNDP, UNESCO, World Bank, etc.

The Chesapeake Bay Crater: Geology and geophysics of a Late Eocene submarine impact structure

USGS Publications Warehouse

Poag, C. Wylie; Koeberl, Christian; Reimold, Wolf Uwe

2004-01-01

The list of impact craters documented on Earth is short. Only about 165 genuine impact structures have been identified to date (Table 1.1). Even so, the number is steadily increasing at the rate of ∼3–5 per year (Grieve et al. 1995; Earth Impact Database at http://www.unb.ca/passc/Impact/Database/). In stark contrast, most other rocky planets and satellites of our solar system are pockmarked by thousands to hundreds of thousands of impact features (Beatty et al. 1999). Nevertheless, impact specialists acknowledge that Earth, too, has undergone billions of years of bolide bombardment (Melosh 1989; Schoenberg et al. 2002). The most intense bombardment, however, took place during Earth’s earliest history (∼3.8–4 Ga; Ryder 1990; Cohen et al. 2000; Ryder et al. 2000). Traces of most terrestrial impacts have been completely erased or strongly altered by the dynamic processes of a thick atmosphere, deep ocean, and mobile crust, a combination unique to our planet. Planetary geologists now recognize that processes associated with bolide impacts are fundamental to planetary accretion and surface modification (Melosh 1989; Peucker-Ehrenbrink and Schmitz 2001). Incoming meteorites may have been primary sources for Earth’s water, and, perhaps, even organic life as we know it (Thomas et al. 1997; Kring 2000). There is little doubt that impacts played a major role in the evolution of Earth’s biota (Ryder et al. 1996; Hart 1996).

Deep and Surface Processing of Instructor's Feedback in an Online Course

ERIC Educational Resources Information Center

Huang, Kun; Ge, Xun; Law, Victor

2017-01-01

This study investigated the characteristics of deep and surface approaches to learning in online students' responses to instructor's qualitative feedback given to a multi-stage, ill-structured design project. Further, the study examined the relationships between approaches to learning and two learner characteristics: epistemic beliefs (EB) and…

Getting Inside Knowledge: The Application of Entwistle's Model of Surface/Deep Processing in Producing Open Learning Materials.

ERIC Educational Resources Information Center

Evans, Barbara; Honour, Leslie

1997-01-01

Reports on a study that required student teachers training in business education to produce open learning materials on intercultural communication. Analysis of stages and responses to this assignment revealed a distinction between "deep" and "surface" learning. Includes charts delineating the characteristics of these two types…

Multifunctional Interface Facility for Receiving and Processing Planetary Surface Materials for Science Investigation and Resource Evaluation at the Deep Space Gateway

NASA Astrophysics Data System (ADS)

Sibille, L.; Mantovani, J. G.; Townsend, I. I.; Mueller, R. P.

2018-02-01

The concepts describe hardware and instrumentation for the study of planetary surface materials at the Deep Space Gateway as a progressive evolution of capabilities for eliminating the need for special handling and Planetary Protection (PP) protocols inside the habitats.

Onboard Detection of Active Canadian Sulfur Springs: A Europa Analogue

NASA Technical Reports Server (NTRS)

Castano, Rebecca; Wagstaff, Kiri; Gleeson, Damhnait; Pappalardo, Robert; Chien, Steve; Tran, Daniel; Scharenbroich, Lucas; Moghaddam, Baback; Tang, Benyang; Bue, Brian;

Deep Space 1 is prepared for transport to launch pad

NASA Technical Reports Server (NTRS)

1998-01-01

Wrapped in an anti-static blanket for protection, Deep Space 1 is moved out of the Defense Satellite Communications Systems Processing Facility (DPF) at Cape Canaveral Air Station (CCAS) for its trip to Launch Pad 17A. The spacecraft will be launched aboard a Boeing Delta 7326 rocket on Oct. 25. Deep Space 1 is the first flight in NASA's New Millennium Program, and is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Semantically-enabled Knowledge Discovery in the Deep Carbon Observatory

NASA Astrophysics Data System (ADS)

Wang, H.; Chen, Y.; Ma, X.; Erickson, J. S.; West, P.; Fox, P. A.

2013-12-01

The Deep Carbon Observatory (DCO) is a decadal effort aimed at transforming scientific and public understanding of carbon in the complex deep earth system from the perspectives of Deep Energy, Deep Life, Extreme Physics and Chemistry, and Reservoirs and Fluxes. Over the course of the decade DCO scientific activities will generate a massive volume of data across a variety of disciplines, presenting significant challenges in terms of data integration, management, analysis and visualization, and ultimately limiting the ability of scientists across disciplines to make insights and unlock new knowledge. The DCO Data Science Team (DCO-DS) is applying Semantic Web methodologies to construct a knowledge representation focused on the DCO Earth science disciplines, and use it together with other technologies (e.g. natural language processing and data mining) to create a more expressive representation of the distributed corpus of DCO artifacts including datasets, metadata, instruments, sensors, platforms, deployments, researchers, organizations, funding agencies, grants and various awards. The embodiment of this knowledge representation is the DCO Data Science Infrastructure, in which unique entities within the DCO domain and the relations between them are recognized and explicitly identified. The DCO-DS Infrastructure will serve as a platform for more efficient and reliable searching, discovery, access, and publication of information and knowledge for the DCO scientific community and beyond.

Deep Space 1 is prepared for transport to launch pad

NASA Technical Reports Server (NTRS)

1998-01-01

In the Defense Satellite Communications Systems Processing Facility (DPF), Cape Canaveral Air Station (CCAS), the lower part of Deep Space 1 is enclosed with the conical section leaves of the payload transportation container prior to its move to Launch Pad 17A. The spacecraft is targeted for launch Oct. 25 aboard a Boeing Delta 7326 rocket. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

KSC-98pc1316

NASA Image and Video Library

1998-10-10

KENNEDY SPACE CENTER, FLA. -- In the Defense Satellite Communications Systems Processing Facility (DPF), Cape Canaveral Air Station (CCAS), after covering the lower portion of Deep Space 1, workers adjust the anti-static blanket covering the upper portion. The blanket will protect the spacecraft during transport to the launch pad. Deep Space 1 is the first flight in NASA's New Millennium Program, and is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS

KSC-98pc1317

NASA Image and Video Library

1998-10-10

KENNEDY SPACE CENTER, FLA. -- In the Defense Satellite Communications Systems Processing Facility (DPF), Cape Canaveral Air Station (CCAS), workers place an anti-static blanket over the lower portion of Deep Space 1, to protect the spacecraft during transport to the launch pad. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1 will be launched aboard a Boeing Delta 7326 rocket from Launch Pad 17A, CCAS

The Chlorine Isotope Composition of Earth’s Mantle

NASA Astrophysics Data System (ADS)

Bonifacie, M.; Jendrzejewski, N.; Agrinier, P.; Humler, E.; Coleman, M.; Javoy, M.

2008-03-01

Chlorine stable isotope compositions (δ37Cl) of 22 mid-ocean ridge basalts (MORBs) correlate with Cl content. The high-δ37Cl, Cl-rich basalts are highly contaminated by Cl-rich materials (seawater, brines, or altered rocks). The low-δ37Cl, Cl-poor basalts approach the composition of uncontaminated, mantle-derived magmas. Thus, most or all oceanic lavas are contaminated to some extent during their emplacement. MORB-source mantle has δ37Cl ≤ 1.6 per mil (‰), which is significantly lower than that of surface reservoirs (~ 0‰). This isotopic difference between the surface and deep Earth results from net Cl isotopic fractionation (associated with removal of Cl from the mantle and its return by subduction over Earth history) and/or the addition (to external reservoirs) of a late volatile supply that is 37Cl-enriched.

Method of Remotely Constructing a Room

DOEpatents

Michie, J. D.; De Hart, R. C.

1971-10-05

The testing of nuclear devices of high explosive yield has required that cavities of relatively large size be provided at considerable distances below the surface of the earth for the pre-detonation emplacement of the device. The construction of an essentially watertight chamber or room in the cavity is generally required for the actual emplacement of the device. A method is described of constructing such a room deep within the earth by personnel at the surface. A dual wall bladder of a watertight, pliable fabric material is lowered down a shaft into a selected position. The bladder is filled with a concrete grout while a heavy fluid having essentially the same density as the grout is maintained on both sides of the bladder, to facilitate complete deployment of the bladder by the grout to form a room of desired configuration. (10 claims)

Method of remotely constructing a room

DOEpatents

Michie, J.D.; De Hart, R.C.

1971-10-05

The testing of nuclear devices of high explosive yield has required that cavities of relatively large size be provided at considerable distances below the surface of the earth for the pre-detonation emplacement of the device. The construction of an essentially watertight chamber or room in the cavity is generally required for the actual emplacement of the device. A method is described of constructing such a room deep within the earth by personnel at the surface. A dual wall bladder of a watertight, pliable fabric material is lowered down a shaft into a selected position. The bladder is filled with a concrete grout while a heavy fluid having essentially the same density as the grout is maintained on both sides of the bladder, to facilitate complete deployment of the bladder by the grout to form a room of desired configuration. (10 claims)

A Comparison of Microbial Communities from Deep Igneous Crust

NASA Astrophysics Data System (ADS)

Smith, A. R.; Flores, G. E.; Fisk, M. R.; Colwell, F. S.; Thurber, A. R.; Mason, O. U.; Popa, R.

2013-12-01

Recent investigations of life in Earth's crust have revealed common themes in organism function, taxonomy, and diversity. Capacities for hydrogen oxidation, carbon fixation, methanogenesis and methanotrophy, iron and sulfur metabolisms, and hydrocarbon degradation often predominate in deep life communities, and crustal mineralogy has been hypothesized as a driving force for determining deep life community assemblages. Recently, we found that minerals characteristic of the igneous crust harbored unique communities when incubated in the Juan de Fuca Ridge flank borehole IODP 1301A. Here we present attached mineral biofilm morphologies and a comparison of our mineral communities to those from a variety of locations, contamination states, and igneous crustal or mineralogical types. We found that differences in borehole mineral communities were reflected in biofilm morphologies. Olivine biofilms were thick, carbon-rich films with embedded cells of uniform size and shape and often contained secondary minerals. Encrusted cells, spherical and rod-shaped cells, and tubes were indicative of glass surfaces. We also found that the attached communities from incubated borehole minerals were taxonomically more similar to native, attached communities from marine and continental crust than to communities from the aquifer water that seeded it. Our findings further support the hypothesis that mineralogy selects for microbial communities that have distinct phylogenetic, morphological, and potentially functional, signatures. This has important implications for resolving ecosystem function and microbial distributions in igneous crust, the largest deep habitat on Earth.

Duration of the hydrocarbon fluid formation under thermobaric conditions of the Earth's upper mantle

NASA Astrophysics Data System (ADS)

Mukhina, Elena; Kolesnikov, Anton; Kutcherov, Vladimir

2016-04-01

Deep abiogenic formation of hydrocarbons is an inherent part of the Earth's global carbon cycle. It was experimentally confirmed that natural gas could be formed from inorganic carbon and hydrogen containing minerals at pressure and temperature corresponding to the Earth's upper mantle conditions. Reaction between calcite, wustite and water in the large volume device was studied in several works. It was previously proposed that reaction is possible only after 40 minutes of exposure at high pressure and temperature. In this work similar experiment at P = 60 kbar and T = 1200 K were carried out in "Toroid" type chamber with the 5 seconds duration of thermobaric exposure. Gas chromatographic analysis of the reaction products has shown the presence of hydrocarbon mixture comparable to 5 minutes and 6 hours exposure experiments. Based on this fact it is possible to conclude that the reaction of natural gas formation is instant at least at given thermobaric conditions. This experiment will help to better understand the process of deep hydrocarbon generation, particularly its kinetics.

Using the Global Positioning System for Earth Orbiter and Deep Space Tracking

NASA Technical Reports Server (NTRS)

Lichten, Stephen M.

1994-01-01

The Global Positioning System (GPS) can play a major role in supporting orbit and trajectory determination for spacecraft in a wide range of applications, including low-Earth, high-Earth, and even deep space (interplanetary) tracking. This paper summarizes recent results demonstrating these unique and far-ranging applications of GPS.

Southern Mariana OBS Experiment and Preliminary Results of Passive-Source Investigations

NASA Astrophysics Data System (ADS)

Le, B. M.; Lin, J.; Yang, T.; Shiyan 3, S. P. O. R.

2017-12-01

The Southern Mariana OBS Experiment (SMOE) was one of the first seismic experiments targeting the deepest part of Earth's surface. During the Phase I experiment in December 2016, an array of OBS instruments were deployed across the Challenger Deep that recorded both active-source and passive-source data. During the Phase II experiment in December 2016-June 2017, passive-source data were recorded. We have retrieved earthquake signals and processed the waveforms from the recorded global, regional and local events, respectively, during the Phase I experiment. Most of the waveforms recorded by the OBS array have fairly good quality with discernible main phases. Rayleigh waves from many earthquakes were analyzed using the frequency-time analysis and their group velocities at different periods were obtained. The dispersion curves from different Rayleigh wave propagating paths would be valuable for inverting the structure of the subducting Pacific and overriding Philippine Sea plates. Furthermore, we applied the ambient noise cross-correlation method and retrieved high-quality coherence surface wave waveforms. With its relatively high frequencies, the surface waves can be used to study the crustal structure of the region. Together with the Phase II data, we expect that this seismic experiment will provide unprecedented constraints on the structure and geodynamic processes of the southern Mariana trench.

Mantle circulation models with variational data assimilation: Inferring past mantle flow and structure from plate motion histories and seismic tomography

NASA Astrophysics Data System (ADS)

Bunge, Hans-Peter

2002-08-01

Earth's mantle overturns itself about once every 200 Million years (myrs). Prima facie evidence for this overturn is the motion of tectonic plates at the surface of the Earth driving the geologic activity of our planet. Supporting evidence also comes from seismic tomograms of the Earth's interior that reveal the convective currents in remarkable clarity. Much has been learned about the physics of solid state mantle convection over the past two decades aided primarily by sophisticated computer simulations. Such simulations are reaching the threshold of fully resolving the convective system globally. In this talk we will review recent progress in mantle dynamics studies. We will then turn our attention to the fundamental question of whether it is possible to explicitly reconstruct mantle flow back in time. This is a classic problem of history matching, amenable to control theory and data assimilation. The technical advances that make such approach feasible are dramatically increasing compute resources, represented for example through Beowulf clusters, and new observational initiatives, represented for example through the US-Array effort that should lead to an order-of-magnitude improvement in our ability to resolve Earth structure seismically below North America. In fact, new observational constraints on deep Earth structure illustrate the growing importance of of improving our data assimilation skills in deep Earth models. We will explore data assimilation through high resolution global adjoint models of mantle circulation and conclude that it is feasible to reconstruct mantle flow back in time for at least the past 100 myrs.

SenSyF Experience on Integration of EO Services in a Generic, Cloud-Based EO Exploitation Platform

NASA Astrophysics Data System (ADS)

Almeida, Nuno; Catarino, Nuno; Gutierrez, Antonio; Grosso, Nuno; Andrade, Joao; Caumont, Herve; Goncalves, Pedro; Villa, Guillermo; Mangin, Antoine; Serra, Romain; Johnsen, Harald; Grydeland, Tom; Emsley, Stephen; Jauch, Eduardo; Moreno, Jose; Ruiz, Antonio

2016-08-01

SenSyF is a cloud-based data processing framework for EO- based services. It has been pioneer in addressing Big Data issues from the Earth Observation point of view, and is a precursor of several of the technologies and methodologies that will be deployed in ESA's Thematic Exploitation Platforms and other related systems.The SenSyF system focuses on developing fully automated data management, together with access to a processing and exploitation framework, including Earth Observation specific tools. SenSyF is both a development and validation platform for data intensive applications using Earth Observation data. With SenSyF, scientific, institutional or commercial institutions developing EO- based applications and services can take advantage of distributed computational and storage resources, tailored for applications dependent on big Earth Observation data, and without resorting to deep infrastructure and technological investments.This paper describes the integration process and the experience gathered from different EO Service providers during the project.

Constraints from Earth's heat budget on mantle dynamics

NASA Astrophysics Data System (ADS)

Kellogg, L. H.; Ferrachat, S.

2006-12-01

Recent years have seen an increase in the number of proposed models to explain Earth's mantle dynamics: while two end-members, pure layered convection with the upper and lower mantle convecting separately from each other, and pure, whole mantle convection, appear not to satisfy all the observations, several addition models have been proposed. These models include and attempt to characterize least one reservoir that is enriched in radiogenic elements relative to the mid-ocean ridge basalt (MORB) source, as is required to account for most current estimates of the Earth's heat budget. This reservoir would also be responsible for the geochemical signature in some ocean island basalts (OIBs) like Hawaii, but must be rarely sampled at the surface. Our current knowledge of the mass- and heat-budget for the bulk silicate Earth from geochemical, cosmochemical and geodynamical observations and constraints enables us to quantify the radiogenic heat enrichment required to balance the heat budget. Without assuming any particular model for the structure of the reservoir, we first determine the inherent trade-off between heat production rate and mass of the reservoir. Using these constraints, we then investigate the dynamical inferences of the heat budget, assuming that the additional heat is produced within a deep layer above the core-mantle boundary. We carry out dynamical models of layered convection using four different fixed reservoir volumes, corresponding to deep layers of thicknesses 150, 500 1000 and 1600 km, respectively, and including both temperature-dependent viscosity and an instrinsic viscosity jump between upper and lower mantle. We then assess the viability of these cases against 5 criteria: stability of the deep layer through time, topography of the interface, effective density profile, intrinsic chemical density and the heat flux at the CMB.

Hot-field tectonics

NASA Astrophysics Data System (ADS)

Zonenshain, L. P.; Kuzmin, M. I.; Bocharova, N. Yu.

1991-12-01

Intraplate, hot spot related volcanic occurrences do not have a random distribution on the Earth's surface. They are concentrated in two large regions (up to 10,000 km in diameter), the Pacific and the African, and two smaller areas (2000-3000 km in diameter), the Central Asian and the Tasmanian. These regions are considered as manifestations of hot fields in the mantle, whereas the regions lying in between are expressions of cold fields in the mantle. Large-scale anomalies coincide with the hot fields: topographic swells, geoid highs, uplifts of the "asthenospheric table", inferred heated regions in the lowermost mantle according to seismic tomographic images, geochemical anomalies showing the origin of volcanics from undepleted mantle sources. Hot fields are relatively stable features, having remained in the same position on the Earth's surface during the last 120 Ma, although they have other configurations and other positions in the Late Paleozoic and Early Mesozoic. Available data show that two main hot fields (Pacific and African) are possibly moving one with respect to the other, converging along the Eastern Pacific subduction system and diverging along that of the Western Pacific. If so, well-known differences between these subduction systems can also be connected with related displacement of the hot fields. Hot fields are assumed to correspond to upwelling branches of mantle and rather deep mantle convection, and cold fields to downwelling branches. Thus, hot fields can be regarded as expressions of deeper tectonics, comparative to the plate tectonics, which is operating in the upper layers of the Earth. We call it hot-field tectonics. Plate tectonics is responsible for the opening and closure of oceans and for the formation of orogenic belts, whereas hot-field tectonics accounts for a larger cyclicity of the Earth's evolution and for amalgamation and break up of Pangea-type supercontinents. Hot-field tectonics seems to be the only process to have existed on all of the terrestrial planets. We speculate that hot-field tectonics governs the global geodynamics of the Earth.

The Deep-Sea and Sub-Seafloor Frontier initiative - a key to link EC research and international scientific ocean drilling

NASA Astrophysics Data System (ADS)

Kopf, A.

2009-04-01

The Deep-Sea and Sub-Seafloor Frontiers project, DS3F, represents the continuation of the DSF roadmap towards the sustainable management of oceanic resources on a European scale. It will develop strategies for sub-seafloor sampling to contribute to a better understanding of deep-sea and sub-seafloor processes by connecting marine research in life and geosciences, climate and environmental change, as well as socio-economic issues and policy building. We propose to establish a long-lived research approach that considers (i) the need for a sustainable management of the ocean, and particularly the deep sea with enhanced activity (fishery, hydrocarbon exploration), (ii) the necessity to unravel deep-seated geological processes that drive seafloor ecosystems, and (iii) the value of seabed archives for the reconstruction of paleo-environmental conditions and the improved prediction of future climate change. Sub-seafloor drilling and sampling can provide two key components in understanding how deep-sea ecosystems function at present, and how they will respond to global change: (a) an inventory of present subsurface processes and biospheres, and their links to surface ecosystems, including seafloor observation and baseline studies, and (b) a high resolution archive of past variations in environmental conditions and biodiversity. For both components, an international effort is needed to share knowledge, methods and technologies, including mission-specific platforms to increase the efficiency, coverage and accuracy of sub-seafloor sampling and exploration. The deep biosphere has been discovered only within the past two decades and comprises the last major frontier for biological exploration. We lack fundamental knowledge of composition, diversity, distribution and metabolism in sub-seafloor biological communities at Earth's extremes, and their repercussions on seafloor ecosystems and life in the deep sea. There is equally an emerging need to shed light on geodynamic processes fuelling biological activity, and how such processes tie into the emission of geofuels and the formation of hydrocarbons and other resources. In addition, geodynamic processes may be cause natural hazards such as earthquake slip, submarine landslides, or tsunamis with a profound effect for humans and ecosystems. Their governing principles and potential triggers are poorly understood and often related to the sub-seafloor environment. In summary, the three main research areas in the Integrated Ocean Drilling Program (IODP; see Initial Science Plan www.iodp.org/isp/), i.e. geodynamics, climate and deep biosphere, as well as the goals of DS3F show a strong overlap and suggest an emerging need to join forces. This will result in the most efficient use of sub-seafloor sampling techniques and existing marine infrastructure to study the geosystem and its effects on biosphere and marine ecosystems. The DS3F initiative aims at providing a comprehensive "white paper" for a sustainable use of the oceans, an European Maritime Policy, and a strong link between European mission-specific drilling projects including IODP, IMAGES, ESF-EuroMARC and EC campaigns.

Episodic processes, invasion and faunal mosaics in evolutionary and ecological time

USDA-ARS?s Scientific Manuscript database

Episodes of ecological perturbation and faunal turnover represent crises for global biodiversity and have occurred periodically across Earth history on a continuum linking deep evolutionary and shallow ecological time. Major extinction events and biodiversity crises across the 540 milion years of th...

The telecommunications and data acquisition report

NASA Technical Reports Server (NTRS)

Renzetti, N. A. (Editor)

1981-01-01

Developments in Earth-based ratio technology as applied to the Deep Space Network are reported. Topics include ratio astronomy and spacecraft tracking networks. Telemetric methods and instrumentation are described. Station control and system technology for space communication is discussed. Special emphasis is placed on network data processing.

Biodiversity's Big Wet Secret: The Global Distribution of Marine Biological Records Reveals Chronic Under-Exploration of the Deep Pelagic Ocean

PubMed Central

Webb, Thomas J.; Vanden Berghe, Edward; O'Dor, Ron

2010-01-01

Background Understanding the distribution of marine biodiversity is a crucial first step towards the effective and sustainable management of marine ecosystems. Recent efforts to collate location records from marine surveys enable us to assemble a global picture of recorded marine biodiversity. They also effectively highlight gaps in our knowledge of particular marine regions. In particular, the deep pelagic ocean – the largest biome on Earth – is chronically under-represented in global databases of marine biodiversity. Methodology/Principal Findings We use data from the Ocean Biogeographic Information System to plot the position in the water column of ca 7 million records of marine species occurrences. Records from relatively shallow waters dominate this global picture of recorded marine biodiversity. In addition, standardising the number of records from regions of the ocean differing in depth reveals that regardless of ocean depth, most records come either from surface waters or the sea bed. Midwater biodiversity is drastically under-represented. Conclusions/Significance The deep pelagic ocean is the largest habitat by volume on Earth, yet it remains biodiversity's big wet secret, as it is hugely under-represented in global databases of marine biological records. Given both its value in the provision of a range of ecosystem services, and its vulnerability to threats including overfishing and climate change, there is a pressing need to increase our knowledge of Earth's largest ecosystem. PMID:20689845

Coring the deep critical zone in the Jemez River Basin Critical Zone Observatory, Valles Caldera National Preserve, Northern New Mexico

NASA Astrophysics Data System (ADS)

Moravec, B. G.; White, A. M.; Paras, B.; Sanchez, A.; McGuffy, C.; Fairbanks, D.; McIntosh, J. C.; Pelletier, J. D.; Gallery, R. E.; Rasmussen, C.; Carr, B.; Holbrook, W. S.; Chorover, J.

2016-12-01

The Critical Zone (CZ) is the focus of current interdisciplinary Earth surface science research that aims to describe the interactions between geological and biological processes that influence ecosystem function, soil formation, nutrient and carbon cycling, hydrologic partitioning, biological activity and diversity, and mineral weathering. Prior research at the Catalina-Jemez (C-J) CZO has focused on the CZ near-surface, including remote sensing, and sampling/analysis of vegetation and soil microbiota, soils and saprolite, and surface water. However, the extent to which weathering, water/rock interaction, and solute mobility along flowpaths in the deep CZ respond to near surface CZ processes (i.e. water, energy, and mass fluxes) is not well understood. The goal of the present research is to understand depth-dependent trends in weathering dynamics from the mobile soil to unweathered bedrock in relation to landscape position (hillslope aspect and downgradient hollow). We used diamond core drilling techniques to excavate three boreholes to depths of 18.9, 41.8, and 46.3 meters in an instrumented forested sub-catchment of the C-J CZO in northern New Mexico. Here we present field methodology and preliminary data collected during the field campaign conducted during summer 2016. Element concentrations were measured during core extractions using portable X-ray fluorescence (XRF), which was subsequently validated against bench-scale XRF. Depth-dependent trends in both regolith depth and chemical depletion patterns show significant variation with landscape position. All three boreholes show complex weathering profiles with differences potentially due to textural controls on weathering, development of preferential flowpaths, and differing hydrologic base levels. Preliminary data indicate that chemical depletion patterns are not monotonic, but rather comprise large excursions that are being investigated for their relation to variation in local mineralogical composition and incongruent weathering reactions.

A Participative Tool for Sharing, Annotating and Archiving Submarine Video Data

NASA Astrophysics Data System (ADS)

Marcon, Y.; Kottmann, R.; Ratmeyer, V.; Boetius, A.

2016-02-01

Oceans cover more than 70 percent of the Earth's surface and are known to play an essential role on all of the Earth systems and cycles. However, less than 5 percent of the ocean bottom has been explored and many aspects of the deep-sea world remain poorly understood. Increasing our ocean literacy is a necessity in order for specialists and non-specialists to better grasp the roles of the ocean on the Earth's system, its resources, and the impact of human activities on it. Due to technological advances, deep-sea research produces ever-increasing amounts of scientific video data. However, using such data for science communication and public outreach purposes remains difficult as tools for accessing/sharing such scientific data are often lacking. Indeed, there is no common solution for the management and analysis of marine video data, which are often scattered across multiple research institutes or working groups and it is difficult to get an overview of the whereabouts of those data. The VIDLIB Deep-Sea Video Platform is a web-based tool for sharing/annotating time-coded deep-sea video data. VIDLIB provides a participatory way to share and analyze video data. Scientists can share expert knowledge for video analysis without the need to upload/download large video files. Also, VIDLIB offers streaming capabilities and has potential for participatory science and science communication in that non-specialists can ask questions on what they see and get answers from scientists. Such a tool is highly valuable in terms of scientific public outreach and popular science. Video data are by far the most efficient way to communicate scientific findings to a non-expert public. VIDLIB is being used for studying the impact of deep-sea mining on benthic communities as well as for exploration in polar regions. We will present the structure and workflow of VIDLIB as well as an example of video analysis. VIDLIB (http://vidlib.marum.de) is funded by the EU EUROFLEET project and the Helmholtz Alliance ROBEX.

Influence of gravity on deformation of blocks in Earth's crust

NASA Astrophysics Data System (ADS)

Tataurova, A. A.; Stefanov, Yu. P.; Bakeev, R. A.

2017-12-01

The article presents the results of numerical calculations of deformation using an Earth's crust model fragment under the influence of gravitational force. It is shown that plastic deformation in low-strength blocks changes the stress-strain state in the medium and produces a surface deflection which is hundred meters deep. The deflection is defined by the properties of the medium, its extent, and conditions at the lateral boundaries. The order of load application beyond the elastic limit affects the development of deformation, which should be taken into account when formulating problems and performing numerical simulations. The problem has been solved using a two-dimensional elastoplastic approach.

Deep-water Circulation: Processes & Products (16-18 June 2010, Baiona): introduction and future challenges

NASA Astrophysics Data System (ADS)

Hernández-Molina, Francisco Javier; Stow, Dorrik A. V.; Llave, Estefanía; Rebesco, Michele; Ercilla, Gemma; van Rooij, David; Mena, Anxo; Vázquez, Juan-Tomás; Voelker, Antje H. L.

2011-12-01

Deep-water circulation is a critical part of the global conveyor belt that regulates Earth's climate. The bottom (contour)-current component of this circulation is of key significance in shaping the deep seafloor through erosion, transport, and deposition. As a result, there exists a high variety of large-scale erosional and depositional features (drifts) that together form more complex contourite depositional systems on continental slopes and rises as well as in ocean basins, generated by different water masses flowing at different depths and at different speeds either in the same or in opposite directions. Yet, the nature of these deep-water processes and the deposited contourites is still poorly understood in detail. Their ultimate decoding will undoubtedly yield information of fundamental importance to the earth and ocean sciences. The international congress Deep-water Circulation: Processes & Products was held from 16-18 June 2010 in Baiona, Spain, hosted by the University of Vigo. Volume 31(5/6) of Geo-Marine Letters is a special double issue containing 17 selected contributions from the congress, guest edited by F.J. Hernández-Molina, D.A.V. Stow, E. Llave, M. Rebesco, G. Ercilla, D. Van Rooij, A. Mena, J.-T. Vázquez and A.H.L. Voelker. The papers and discussions at the congress and the articles in this special issue provide a truly multidisciplinary perspective of interest to both academic and industrial participants, contributing to the advancement of knowledge on deep-water bottom circulation and related processes, as well as contourite sedimentation. The multidisciplinary contributions (including geomorphology, tectonics, stratigraphy, sedimentology, paleoceanography, physical oceanography, and deep-water ecology) have demonstrated that advances in paleoceanographic reconstructions and our understanding of the ocean's role in the global climate system depend largely on the feedbacks among disciplines. New insights into the link between the biota of deep-water ecosystems and bottom currents confirm the need for this field to be investigated and mapped in detail. Likewise, it is confirmed that deep-water contourites are not only of academic interest but also potential resources of economic value. Cumulatively, both the congress and the present volume serve to demonstrate that the role of bottom currents in shaping the seafloor has to date been generally underestimated, and that our understanding of such systems is still in its infancy. Future research on contourites, using new and more advanced techniques, should focus on a more detailed visualization of water-mass circulation and its variability, in order to decipher the physical processes involved and the associations between drifts and other common bedforms. Moreover, contourite facies models should be better established, including their associations with other deep-water sedimentary environments both in modern and ancient submarine domains. The rapid increase in deep-water exploration and the new deep-water technologies available to the oil industry and academic institutions will undoubtedly lead to spectacular advances in contourite research in terms of processes, morphology, sediment stacking patterns, facies, and their relationships with other deep-marine depositional systems.

Microbial Diversity in Surface Iron-Rich Aqueous Environments: Implications for Seeking Signs of Life on Mars

NASA Technical Reports Server (NTRS)

Brown, I. I.; Allen, C. C.; Tringe, S. G.; Klatt, C. G.; Bryant, D. A.; Sarkisova, S. A.; Garrison, D. H.; McKay, D. S.

2010-01-01

The success of selecting future landing sites on Mars to discover extinct and/or extant extraterrestrial life is dependent on the correct approximation of available knowledge about terrestrial paleogeochemistry and life evolution to Martian (paleo) geology and geochemistry. It is well known that both Earth and Mars are Fe rich. This widespread occurrence suggests that Fe may have played a key role in early life forms, where it probably served as a key constituent in early prosthetic moieties in many proteins of ancient microbes on Earth and likely Mars. The second critical idea is the premise that Life on Mars could most likely have developed when Mars experienced tectonic activity [1] which dramatically decreased around 1 bin years after Martian creation. After that Martian life could have gone extinct or hibernated in the deep subsurface, which would be expensive to reach in contrast to the successful work of Martian surface rovers. Here we analyze the diversity of microbes in several terrestrial Fe rich surface environments in conjunction with the phylogeny and molecular timing of emergence of those microbes on Earth. Anticipated results should help evaluate future landing sites on Mars in searches for biosignatures.

The Hadean-Archaean Environment

PubMed Central

Sleep, Norman H.

2010-01-01

A sparse geological record combined with physics and molecular phylogeny constrains the environmental conditions on the early Earth. The Earth began hot after the moon-forming impact and cooled to the point where liquid water was present in ∼10 million years Subsequently, a few asteroid impacts may have briefly heated surface environments, leaving only thermophile survivors in kilometer-deep rocks. A warm 500 K, 100 bar CO2 greenhouse persisted until subducted oceanic crust sequestered CO2 into the mantle. It is not known whether the Earth's surface lingered in a ∼70°C thermophile environment well into the Archaean or cooled to clement or freezing conditions in the Hadean. Recently discovered ∼4.3 Ga rocks near Hudson Bay may have formed during the warm greenhouse. Alkalic rocks in India indicate carbonate subduction by 4.26 Ga. The presence of 3.8 Ga black shales in Greenland indicates that S-based photosynthesis had evolved in the oceans and likely Fe-based photosynthesis and efficient chemical weathering on land. Overall, mantle derived rocks, especially kimberlites and similar CO2-rich magmas, preserve evidence of subducted upper oceanic crust, ancient surface environments, and biosignatures of photosynthesis. PMID:20516134

The isolated 678-km deep 30 May 2015 MW 7.9 Ogasawara (Bonin) Islands earthquake

NASA Astrophysics Data System (ADS)

Ye, L.; Lay, T.; Zhan, Z.; Kanamori, H.; Hao, J.

2015-12-01

Deep-focus earthquakes, located 300 to 700 km below the Earth's surface within sinking slabs of relatively cold oceanic lithosphere, are mysterious phenomena. Seismic radiation from deep events is essentially indistinguishable from that for shallow stick-slip frictional-sliding earthquakes, but the confining pressure and temperature are so high for deep-focus events that a distinct process is likely needed to account for their abrupt energy release. The largest recorded deep-focus earthquake (MW 7.9) in the Izu-Bonin slab struck on 30 May 2015 beneath the Ogasawara (Bonin) Islands, isolated from prior seismicity by over 100 km in depth, and followed by only 2 small aftershocks. Globally, this is the deepest (678 km) major (MW > 7) earthquake in the seismological record. Seismicity indicates along-strike contortion of the Izu-Bonin slab, with horizontal flattening near a depth of 550 km in the Izu region and progressive steepening to near-vertical toward the south above the location of the 2015 event. Analyses of a large global data set of P, SH and pP seismic phases using short-period back-projection, subevent directivity, and broadband finite-fault inversion indicate that the mainshock ruptured a shallowly-dipping fault plane with patchy slip that spread over a distance of ~40 km with variable expansion rate (~5 km/s down-dip initially, ~3 km/s up-dip later). During the 17 s rupture duration the radiated energy was ~3.3 x 1016 J and the stress drop was ~38 MPa. The radiation efficiency is moderate (0.34), intermediate to that of the 1994 Bolivia and 2013 Sea of Okhotsk MW 8.3 earthquakes, indicating a continuum of processes. The isolated occurrence of the event suggests that localized stress concentration associated with the pronounced deformation of the Izu-Bonin slab likely played a role in generating this major earthquake.

Particle Radiation Sources, Propagation and Interactions in Deep Space, at Earth, the Moon, Mars, and Beyond: Examples of Radiation Interactions and Effects

NASA Astrophysics Data System (ADS)

Schwadron, Nathan A.; Cooper, John F.; Desai, Mihir; Downs, Cooper; Gorby, Matt; Jordan, Andrew P.; Joyce, Colin J.; Kozarev, Kamen; Linker, Jon A.; Mikíc, Zoran; Riley, Pete; Spence, Harlan E.; Török, Tibor; Townsend, Lawrence W.; Wilson, Jody K.; Zeitlin, Cary

2017-11-01

Particle radiation has significant effects for astronauts, satellites and planetary bodies throughout the Solar System. Acute space radiation hazards pose risks to human and robotic exploration. This radiation also naturally weathers the exposed surface regolith of the Moon, the two moons of Mars, and other airless bodies, and contributes to chemical evolution of planetary atmospheres at Earth, Mars, Venus, Titan, and Pluto. We provide a select review of recent areas of research covering the origin of SEPs from coronal mass ejections low in the corona, propagation of events through the solar system during the anomalously weak solar cycle 24 and important examples of radiation interactions for Earth, other planets and airless bodies such as the Moon.

Results from On-Orbit Testing of the Fram Memory Test Experiment on the Fastsat Micro-Satellite

NASA Technical Reports Server (NTRS)

MacLeod, Todd C.; Sims, W. Herb; Varnavas, Kosta A.; Ho, Fat D.

2011-01-01

NASA is planning on going beyond Low Earth orbit with manned exploration missions. The radiation environment for most Low Earth orbit missions is harsher than at the Earth's surface but much less harsh than deep space. Development of new electronics is needed to meet the requirements of high performance, radiation tolerance, and reliability. The need for both Volatile and Non-volatile memory has been identified. Emerging Non-volatile memory technologies (FRAM, C-RAM,M-RAM, R-RAM, Radiation Tolerant FLASH, SONOS, etc.) need to be investigated for use in Space missions. An opportunity arose to fly a small memory experiment on a high inclination satellite (FASTSAT). An off-the-shelf 512K Ramtron FRAM was chosen to be tested in the experiment.

Rare earth element scavenging in seawater

NASA Astrophysics Data System (ADS)

Byrne, Robert H.; Kim, Ki-Hyun

1990-10-01

Examinations of rare earth element (REE) adsorption in seawater, using a variety of surface-types, indicated that, for most surfaces, light rare earth elements (LREEs) are preferentially adsorbed compared to the heavy rare earths (HREEs). Exceptions to this behavior were observed only for silica phases (glass surfaces, acid-cleaned diatomaceous earth, and synthetic SiO 2). The affinity of the rare earths for surfaces can be strongly affected by thin organic coatings. Glass surfaces which acquired an organic coating through immersion in Tampa Bay exhibited adsorptive behavior typical of organic-rich, rather than glass, surfaces. Models of rare earth distributions between seawater and carboxylate-rich surfaces indicate that scavenging processes which involve such surfaces should exhibit a strong dependence on pH and carbonate complexation. Scavenging models involving carboxylate surfaces produce relative REE abundance patterns in good general agreement with observed shale-normalized REE abundances in seawater. Scavenging by carboxylate-rich surfaces should produce HREE enrichments in seawater relative to the LREEs and may produce enrichments of lanthanum relative to its immediate trivalent neighbors. Due to the origin of distribution coefficients as a difference between REE solution complexation (which increases strongly with atomic number) and surface complexation (which apparently also increases with atomic number) the relative solution abundance patterns of the REEs produced by scavenging reactions can be quite complex.

Investigating melting induced mantle heterogeneities in plate driven mantle convection models

NASA Astrophysics Data System (ADS)

Price, M.; Davies, H.; Panton, J.

2017-12-01

Observations from geochemistry and seismology continue to suggest a range of complex heterogeneity in Earth's mantle. In the deep mantle, two large low velocity provinces (LLVPs) have been regularly observed in seismic studies, with their longevity, composition and density compared to the surrounding mantle debated. The cause of these observed LLVPs is equally uncertain, with previous studies advocating either thermal or thermo-chemical causes. There is also evidence that these structures could provide chemically distinct reservoirs within the mantle, with recent studies also suggesting there may be additional reservoirs in the mantle, such as bridgmanite-enriched ancient mantle structures (BEAMS). One way to test these hypotheses is using computational models of the mantle, with models that capture the full 3D system being both complex and computationally expensive. Here we present results from our global mantle model TERRA. Using our model, we can track compositional variations in the convecting mantle that are generated by self-consistent, evolving melting zones. Alongside the melting, we track trace elements and other volatiles which can be partitioned during melting events, and expelled and recycled at the surface. Utilising plate reconstruction models as a boundary condition, the models generate the tectonic features observed at Earth's surface, while also organising the lower mantle into recognisable degree-two structures. This results in our models generating basaltic `oceanic' crusts which are then brought into the mantle at tectonic boundaries, providing additional chemical heterogeneity in the mantle volume. Finally, by utilising thermodynamic lookup tables to convert the final outputs from the model to seismic structures, together with resolution filters for global tomography models, we are able to make direct comparisons between our results and observations. By varying the parameters of the model, we investigate a range of current hypotheses for heterogeneity in the mantle. Our work attempts to reconcile the many proposed current ideas for the deep mantle, giving additional insight from modelling on the latest observations from other Deep Earth disciplines.

Convectively driven decadal zonal accelerations in Earth's fluid core

NASA Astrophysics Data System (ADS)

More, Colin; Dumberry, Mathieu

2018-04-01

Azimuthal accelerations of cylindrical surfaces co-axial with the rotation axis have been inferred to exist in Earth's fluid core on the basis of magnetic field observations and changes in the length-of-day. These accelerations have a typical timescale of decades. However, the physical mechanism causing the accelerations is not well understood. Scaling arguments suggest that the leading order torque averaged over cylindrical surfaces should arise from the Lorentz force. Decadal fluctuations in the magnetic field inside the core, driven by convective flows, could then force decadal changes in the Lorentz torque and generate zonal accelerations. We test this hypothesis by constructing a quasi-geostrophic model of magnetoconvection, with thermally driven flows perturbing a steady, imposed background magnetic field. We show that when the Alfvén number in our model is similar to that in Earth's fluid core, temporal fluctuations in the torque balance are dominated by the Lorentz torque, with the latter generating mean zonal accelerations. Our model reproduces both fast, free Alfvén waves and slow, forced accelerations, with ratios of relative strength and relative timescale similar to those inferred for the Earth's core. The temporal changes in the magnetic field which drive the time-varying Lorentz torque are produced by the underlying convective flows, shearing and advecting the magnetic field on a timescale associated with convective eddies. Our results support the hypothesis that temporal changes in the magnetic field deep inside Earth's fluid core drive the observed decadal zonal accelerations of cylindrical surfaces through the Lorentz torque.

Issues and Design Drivers for Deep Space Habitats

NASA Technical Reports Server (NTRS)

Rucker, Michelle A.; Anderson, Molly

2012-01-01

A cross-disciplinary team of scientists and engineers applied expertise gained in Lunar Lander development to the conceptual design of a long-duration, deep space habitat for Near Earth Asteroid (NEA) missions. The design reference mission involved two launches to assemble 5-modules for a 380-day round trip mission carrying 4 crew members. The conceptual design process yielded a number of interesting debates, some of which could be significant design drivers in a detailed Deep Space Habitat (DSH) design. These issues included: Design to minimize crew radiation exposure, launch loads, communications challenges, docking system and hatch commonality, pointing and visibility, consumables, and design for contingency operations.

Surface morphology of erbium silicide

NASA Technical Reports Server (NTRS)

Lau, S. S.; Pai, C. S.; Wu, C. S.; Kuech, T. F.; Liu, B. X.

1982-01-01

The surface of rare-earth silicides (Er, Tb, etc.), formed by the reaction of thin-film metal layers with a silicon substrate, is typically dominated by deep penetrating, regularly shaped pits. These pits may have a detrimental effect on the electronic performance of low Schottky barrier height diodes utilizing such silicides on n-type Si. This study suggests that contamination at the metal-Si or silicide-Si interface is the primary cause of surface pitting. Surface pits may be reduced in density or eliminated entirely through either the use of Si substrate surfaces prepared under ultrahigh vacuum conditions prior to metal deposition and silicide formation or by means of ion irradiation techniques. Silicide layers formed by these techniques possess an almost planar morphology.

KSC-98pc1328

NASA Image and Video Library

1998-10-12

KENNEDY SPACE CENTER, FLA. -- Wrapped in an anti-static blanket for protection, Deep Space 1 is moved out of the Defense Satellite Communications Systems Processing Facility (DPF) at Cape Canaveral Air Station (CCAS) for its trip to Launch Pad 17A. The spacecraft will be launched aboard a Boeing Delta 7326 rocket on Oct. 25. Deep Space 1 is the first flight in NASA's New Millennium Program, and is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

KSC-98pc1318

NASA Image and Video Library

1998-10-10

KENNEDY SPACE CENTER, FLA. - Wrapped in an antistatic blanket for protection, Deep Space 1 is moved out of the Defense Satellite Communications System Processing Facility (DPF) at Cape Canaveral Air Station (CCAS) for its trip to Launch Pad 17A. The spacecraft will be launched aboard Boeing's Delta 7326 rocket in October. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including an ion propulsion engine. Propelled by the gas xenon, the engine is being flight tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include softwre that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the firs two months, but will also make a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

KSC-98pc1313

NASA Image and Video Library

1998-10-10

KENNEDY SPACE CENTER, FLA. -- Workers in the Defense Satellite Communication Systems Processing Facility (DPF), Cape Canaveral Air Station (CCAS), begin attaching the conical section leaves of the payload transportation container on Deep Space 1 before launch, targeted for Oct. 25 aboard a Boeing Delta 7326 rocket from Launch Pad 17A. The first flight in NASA's New Millennium Program, Deep Space 1 is designed to validate 12 new technologies for scientific space missions of the next century, including the engine. Propelled by the gas xenon, the engine is being flight-tested for future deep space and Earth-orbiting missions. Deceptively powerful, the ion drive emits only an eerie blue glow as ionized atoms of xenon are pushed out of the engine. While slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Other onboard experiments include software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months, but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999

Potential for hydrogen-oxidizing chemolithoautotrophic and diazotrophic populations to initiate biofilm formation in oligotrophic, deep terrestrial subsurface waters.

PubMed

Wu, Xiaofen; Pedersen, Karsten; Edlund, Johanna; Eriksson, Lena; Åström, Mats; Andersson, Anders F; Bertilsson, Stefan; Dopson, Mark

2017-03-23

Deep terrestrial biosphere waters are separated from the light-driven surface by the time required to percolate to the subsurface. Despite biofilms being the dominant form of microbial life in many natural environments, they have received little attention in the oligotrophic and anaerobic waters found in deep bedrock fractures. This study is the first to use community DNA sequencing to describe biofilm formation under in situ conditions in the deep terrestrial biosphere. In this study, flow cells were attached to boreholes containing either "modern marine" or "old saline" waters of different origin and degree of isolation from the light-driven surface of the earth. Using 16S rRNA gene sequencing, we showed that planktonic and attached populations were dissimilar while gene frequencies in the metagenomes suggested that hydrogen-fed, carbon dioxide- and nitrogen-fixing populations were responsible for biofilm formation across the two aquifers. Metagenome analyses further suggested that only a subset of the populations were able to attach and produce an extracellular polysaccharide matrix. Initial biofilm formation is thus likely to be mediated by a few bacterial populations which were similar to Epsilonproteobacteria, Deltaproteobacteria, Betaproteobacteria, Verrucomicrobia, and unclassified bacteria. Populations potentially capable of attaching to a surface and to produce extracellular polysaccharide matrix for attachment were identified in the terrestrial deep biosphere. Our results suggest that the biofilm populations were taxonomically distinct from the planktonic community and were enriched in populations with a chemolithoautotrophic and diazotrophic metabolism coupling hydrogen oxidation to energy conservation under oligotrophic conditions.

Partitioning experiments in the laser-heated diamond anvil cell: volatile content in the Earth's core.

PubMed

Jephcoat, Andrew P; Bouhifd, M Ali; Porcelli, Don

2008-11-28

The present state of the Earth evolved from energetic events that were determined early in the history of the Solar System. A key process in reconciling this state and the observable mantle composition with models of the original formation relies on understanding the planetary processing that has taken place over the past 4.5Ga. Planetary size plays a key role and ultimately determines the pressure and temperature conditions at which the materials of the early solar nebular segregated. We summarize recent developments with the laser-heated diamond anvil cell that have made possible extension of the conventional pressure limit for partitioning experiments as well as the study of volatile trace elements. In particular, we discuss liquid-liquid, metal-silicate (M-Sil) partitioning results for several elements in a synthetic chondritic mixture, spanning a wide range of atomic number-helium to iodine. We examine the role of the core as a possible host of both siderophile and trace elements and the implications that early segregation processes at deep magma ocean conditions have for current mantle signatures, both compositional and isotopic. The results provide some of the first experimental evidence that the core is the obvious replacement for the long-sought, deep mantle reservoir. If so, they also indicate the need to understand the detailed nature and scale of core-mantle exchange processes, from atomic to macroscopic, throughout the age of the Earth to the present day.

The first stage of Boeing's Delta 7326 arrives at Pad 17A, CCAS, in preparation for the Deep Space 1

NASA Technical Reports Server (NTRS)

1998-01-01

The first stage of Boeing's Delta 7326 rocket, which will be used to launch the Deep Space 1 spacecraft, is lifted into place above the surface of Pad 17A at Cape Canaveral Air Station. Targeted for launch on Oct. 15, 1998, this first flight in NASA's New Millennium Program is designed to validate 12 new technologies for scientific space missions of the next century. Onboard experiments include an ion propulsion engine and software that tracks celestial bodies so the spacecraft can make its own navigation decisions without the intervention of ground controllers. Deep Space 1 will complete most of its mission objectives within the first two months but will also do a flyby of a near-Earth asteroid, 1992 KD, in July 1999.

Structure-Property-Environmental Relations in Glass and Glass-Ceramics.

DTIC Science & Technology

1980-03-01

dense Al203 result in a deep surface layer of preferred orientation detection by RKS methods. ii: C Mv CL.ASSIFICAIC S . e .. fa " " p h D e TABLE OF...distribution and decreases the isoelectric point of the powders. Variations in processing of dense Al 203 result in a deep surface layer of preferred...by their surfaces, it is essential that we learn how to predict the surface chemistry of these materials in order to optimize their performance. The

Interplay between solid Earth and biological evolution

NASA Astrophysics Data System (ADS)

Höning, Dennis; Spohn, Tilman

2017-04-01

Major shifts in Earth's evolution led to progressive adaptations of the biosphere. Particularly the emergence of continents permitted efficient use of solar energy. However, the widespread evolution of the biosphere fed back to the Earth system, often argued as a cause for the great oxidation event or as an important component in stabilizing Earth's climate. Furthermore, biologically enhanced weathering rates alter the flux of sediments in subduction zones, establishing a potential link to the deep interior. Stably bound water within subducting sediments not only enhances partial melting but further affects the mantle rheology. The mantle responds by enhancing its rates of convection, water outgassing, and subduction. How crucial is the emergence and evolution of life on Earth to these processes, and how would Earth have been evolved without the emergence of life? We here discuss concepts and present models addressing these questions and discuss the biosphere as a major component in evolving Earth system feedback cycles.

The Deep South Clouds & Aerosols project: Improving the modelling of clouds in the Southern Ocean region

NASA Astrophysics Data System (ADS)

Morgenstern, Olaf; McDonald, Adrian; Harvey, Mike; Davies, Roger; Katurji, Marwan; Varma, Vidya; Williams, Jonny

2016-04-01

Southern-Hemisphere climate projections are subject to persistent climate model biases affecting the large majority of contemporary climate models, which degrade the reliability of these projections, particularly at the regional scale. Southern-Hemisphere specific problems include the fact that satellite-based observations comparisons with model output indicate that cloud occurrence above the Southern Ocean is substantially underestimated, with consequences for the radiation balance, sea surface temperatures, sea ice, and the position of storm tracks. The Southern-Ocean and Antarctic region is generally characterized by an acute paucity of surface-based and airborne observations, further complicating the situation. In recognition of this and other Southern-Hemisphere specific problems with climate modelling, the New Zealand Government has launched the Deep South National Science Challenge, whose purpose is to develop a new Earth System Model which reduces these very large radiative forcing problems associated with erroneous clouds. The plan is to conduct a campaign of targeted observations in the Southern Ocean region, leveraging off international measurement campaigns in this area, and using these and existing measurements of cloud and aerosol properties to improve the representation of clouds in the nascent New Zealand Earth System Model. Observations and model development will target aerosol physics and chemistry, particularly sulphate, sea salt, and non-sulphate organic aerosol, its interactions with clouds, and cloud microphysics. The hypothesis is that the cloud schemes in most GCMs are trained on Northern-Hemisphere data characterized by substantial anthropogenic or terrestrial aerosol-related influences which are almost completely absent in the Deep South.

Preliminary evidence for validity of the Bahasa Indonesian version of Study Process Questionnaire.

PubMed

Liem, Arief Darmanegara; Prasetya, Paulus Hidajat

2007-02-01

This study provides preliminary evidence for the validity of the Bahasa Indonesian version of the Study Process Questionnaire (BI-SPQ) from a sample of 147 psychology students (22 men and 125 women; M age = 21.8 yr., SD = 1.3). The internal consistency alpha of the BI-SPQ subscales were found to range from .46 (Surface Strategy) to .77 (Deep Strategy), with a median of .67. Principal component analysis indicated a two-factor solution, where the Deep and Achieving subscales loaded onto Factor 1 and the Surface subscales loaded on Factor 2. Students' GPAs were associated negatively with Surface Motive (r = -.24) and were associated positively with Deep and Achieving Motives (rs = .20). Further studies with larger samples involving students majoring in other disciplines are needed to provide further evidence of the validity of the BI-SPQ.

A nucleosynthetic origin for the Earth's anomalous (142)Nd composition.

PubMed

Burkhardt, C; Borg, L E; Brennecka, G A; Shollenberger, Q R; Dauphas, N; Kleine, T

2016-09-15

A long-standing paradigm assumes that the chemical and isotopic compositions of many elements in the bulk silicate Earth are the same as in chondrites. However, the accessible Earth has a greater (142)Nd/(144)Nd ratio than do chondrites. Because (142)Nd is the decay product of the now-extinct (146)Sm (which has a half-life of 103 million years), this (142)Nd difference seems to require a higher-than-chondritic Sm/Nd ratio for the accessible Earth. This must have been acquired during global silicate differentiation within the first 30 million years of Solar System formation and implies the formation of a complementary (142)Nd-depleted reservoir that either is hidden in the deep Earth, or lost to space by impact erosion. Whether this complementary reservoir existed, and whether or not it has been lost from Earth, is a matter of debate, and has implications for determining the bulk composition of Earth, its heat content and structure, as well as for constraining the modes and timescales of its geodynamical evolution. Here we show that, compared with chondrites, Earth's precursor bodies were enriched in neodymium that was produced by the slow neutron capture process (s-process) of nucleosynthesis. This s-process excess leads to higher (142)Nd/(144)Nd ratios; after correction for this effect, the (142)Nd/(144)Nd ratios of chondrites and the accessible Earth are indistinguishable within five parts per million. The (142)Nd offset between the accessible silicate Earth and chondrites therefore reflects a higher proportion of s-process neodymium in the Earth, and not early differentiation processes. As such, our results obviate the need for hidden-reservoir or super-chondritic Earth models and imply a chondritic Sm/Nd ratio for the bulk Earth. Although chondrites formed at greater heliocentric distances and contain a different mix of presolar components than Earth, they nevertheless are suitable proxies for Earth's bulk chemical composition.

The Oceanic Flux Program: A three decade time-series of particle flux in the deep Sargasso Sea

NASA Astrophysics Data System (ADS)

Weber, J. C.; Conte, M. H.

2010-12-01

The Oceanic Flux Program (OFP), 75 km SE of Bermuda, is the longest running time-series of its kind. Initiated in 1978, the OFP has produced an unsurpassed, nearly continuous record of temporal variability in deep ocean fluxes, with a >90% temporal coverage at 3200m depth. The OFP, in conjunction with the co-located Bermuda-Atlantic Time Series (BATS) and the Bermuda Testbed Mooring (BTM) time-series, has provided key observations enabling detailed assessment of how seasonal and non-seasonal variability in the deep ocean is linked with the overlying physical and biogeochemical environment. This talk will focus on the short-term flux variability that overlies the seasonal flux pattern in the Sargasso Sea, emphasizing episodic extreme flux events. Extreme flux events are responsible for much of the year-to-year variability in mean annual flux and are most often observed during early winter and late spring when surface stratification is weak or transient. In addition to biological phenomena (e.g. salp blooms), passage of productive meso-scale features such as eddies, which alter surface water mixing characteristics and surface export fluxes, may initiate some extreme flux events. Yet other productive eddies show a minimal influence on the deep flux, underscoring the importance of upper ocean ecosystem structure and midwater processes on the coupling between the surface ocean environment and deep fluxes. Using key organic and inorganic tracers, causative processes that influence deep flux generation and the strength of the coupling with the surface ocean environment can be identified.

FeO2 and FeOOH under deep lower-mantle conditions and Earth's oxygen-hydrogen cycles.

PubMed

Hu, Qingyang; Kim, Duck Young; Yang, Wenge; Yang, Liuxiang; Meng, Yue; Zhang, Li; Mao, Ho-Kwang

2016-06-09

The distribution, accumulation and circulation of oxygen and hydrogen in Earth's interior dictate the geochemical evolution of the hydrosphere, atmosphere and biosphere. The oxygen-rich atmosphere and iron-rich core represent two end-members of the oxygen-iron (O-Fe) system, overlapping with the entire pressure-temperature-composition range of the planet. The extreme pressure and temperature conditions of the deep interior alter the oxidation states, spin states and phase stabilities of iron oxides, creating new stoichiometries, such as Fe4O5 (ref. 5) and Fe5O6 (ref. 6). Such interactions between O and Fe dictate Earth's formation, the separation of the core and mantle, and the evolution of the atmosphere. Iron, in its multiple oxidation states, controls the oxygen fugacity and oxygen budget, with hydrogen having a key role in the reaction of Fe and O (causing iron to rust in humid air). Here we use first-principles calculations and experiments to identify a highly stable, pyrite-structured iron oxide (FeO2) at 76 gigapascals and 1,800 kelvin that holds an excessive amount of oxygen. We show that the mineral goethite, FeOOH, which exists ubiquitously as 'rust' and is concentrated in bog iron ore, decomposes under the deep lower-mantle conditions to form FeO2 and release H2. The reaction could cause accumulation of the heavy FeO2-bearing patches in the deep lower mantle, upward migration of hydrogen, and separation of the oxygen and hydrogen cycles. This process provides an alternative interpretation for the origin of seismic and geochemical anomalies in the deep lower mantle, as well as a sporadic O2 source for the Great Oxidation Event over two billion years ago that created the present oxygen-rich atmosphere.

CubeX: The CubeSAT X-ray Telescope for Elemental Abundance Mapping of Airless Bodies and X-ray Pulsar Navigation

NASA Astrophysics Data System (ADS)

Nittler, L. R.; Hong, J.; Kenter, A.; Romaine, S.; Allen, B.; Kraft, R.; Masterson, R.; Elvis, M.; Gendreau, K.; Crawford, I.; Binzel, R.; Boynton, W. V.; Grindlay, J.; Ramsey, B.

2017-12-01

The surface elemental composition of a planetary body provides crucial information about its origin, geological evolution, and surface processing, all of which can in turn provide information about solar system evolution as a whole. Remote sensing X-ray fluorescence (XRF) spectroscopy has been used successfully to probe the major-element compositions of airless bodies in the inner solar system, including the Moon, near-Earth asteroids, and Mercury. The CubeSAT X-ray Telescope (CubeX) is a concept for a 6U planetary X-ray telescope (36U with S/C), which utilizes Miniature Wolter-I X-ray optics (MiXO), monolithic CMOS and SDD X-ray sensors for the focal plane, and a Solar X-ray Monitor (heritage from the REXIS XRF instrument on NASA's OSIRIS-REx mission). CubeX will map the surface elemental composition of diverse airless bodies by spectral measurement of XRF excited by solar X-rays. The lightweight ( 1 kg) MiXO optics provide sub-arcminute resolution with low background, while the inherently rad-hard CMOS detectors provide improved spectral resolution ( 150 eV) at 0 °C. CubeX will also demonstrate X-ray pulsar timing based deep space navigation (XNAV). Successful XNAV will enable autonomous deep navigation with little to no support from the Deep Space Network, hence lowering the operation cost for many more planetary missions. Recently selected by NASA Planetary Science Deep Space SmallSat Studies, the first CubeX concept, designed to rideshare to the Moon as a secondary spacecraft on a primary mission, is under study in collaboration with the Mission Design Center at NASA Ames Research Center. From high altitude ( 6,000 km) frozen polar circular orbits, CubeX will study > 8 regions ( 110 km) of geological interest on the Moon over one year to produce a high resolution ( 2-3 km) elemental abundance map of each region. The novel focal plane design of CubeX also allows us to evaluate the performance of absolute navigation by sequential observations of several millisecond pulsars without moving parts.

The deep, hot biosphere.

PubMed

Gold, T

1992-07-01

There are strong indications that microbial life is widespread at depth in the crust of the Earth, just as such life has been identified in numerous ocean vents. This life is not dependent on solar energy and photosynthesis for its primary energy supply, and it is essentially independent of the surface circumstances. Its energy supply comes from chemical sources, due to fluids that migrate upward from deeper levels in the Earth. In mass and volume it may be comparable with all surface life. Such microbial life may account for the presence of biological molecules in all carbonaceous materials in the outer crust, and the inference that these materials must have derived from biological deposits accumulated at the surface is therefore not necessarily valid. Subsurface life may be widespread among the planetary bodies of our solar system, since many of them have equally suitable conditions below, while having totally inhospitable surfaces. One may even speculate that such life may be widely disseminated in the universe, since planetary type bodies with similar subsurface conditions may be common as solitary objects in space, as well as in other solar-type systems.

Stratigraphy of two conjugate margins (Gulf of Lion and West Sardinia): modeling of vertical movements and sediment budgets

NASA Astrophysics Data System (ADS)

Leroux, Estelle; Gorini, Christian; Aslanian, Daniel; Rabineau, Marina; Blanpied, Christian; Rubino, Jean-Loup; Robin, Cécile; Granjeon, Didier; Taillepierre, Rachel

2016-04-01

The post-rift (~20-0 Ma) vertical movements of the Provence Basin (West Mediterranean) are quantified on its both conjugate (the Gulf of Lion and the West Sardinia) margins. This work is based on the stratigraphic study of sedimentary markers using a large 3D grid of seismic data, correlations with existing drillings and refraction data. The post-rift subsidence is measured by the direct use of sedimentary geometries analysed in 3D [Gorini et al., 2015; Rabineau et al., 2014] and validated by numerical stratigraphic modelling. Three domains were found: on the platform (1) and slope (2), the subsidence takes the form of a seaward tilting with different amplitudes, whereas the deep basin (3) subsides purely vertically [Leroux et al., 2015a]. These domains correspond to the deeper crustal domains respectively highlighted by wide angle seismic data. The continental crust (1) and the thinned continental crust (2) are tilted, whereas the intermediate crust, identified as lower continental exhumed crust [Moulin et al., 2015, Afhilado et al., 2015] (3) sagged. The post-break-up subsidence re-uses the initial hinge lines of the rifting phase. This striking correlation between surface geologic processes and deep earth dynamic processes emphasizes that the sedimentary record and sedimentary markers is a window into deep geodynamic processes and dynamic topography. Pliocene-Pleistocene seismic markers enabled high resolution quantification of sediment budgets over the past 6 Myr [Leroux et al., in press]. Sediment budget history is here completed on the Miocene interval. Thus, the controlling factors (climate, tectonics and eustasy) are discussed. Afilhado, A., Moulin, M., Aslanian, D., Schnürle, P., Klingelhoefer, F., Nouzé, H., Rabineau, M., Leroux, E. & Beslier, M.-O. (2015). Deep crustal structure across a young 1 passive margin from wide-angle and reflection seismic data (The SARDINIA Experiment) - II. Sardinia's margin. Bull. Soc. géol. France, 186, ILP Spec. issue, 4-5, 331-351. Gorini, C., Montadert, L., Rabineau, M., (2015) New imaging of the salinity crisis: Dual Messinian lowstand megasequences recorded in the deep basin of both the eastern and western Mediterranean, Marine and Petroleum Geology (2015), doi: 10.1016/j.marpetgeo.2015.01.009. Leroux, E., Aslanian, D., Rabineau, M., Moulin, M., Granjeon, D., Gorini C. & Droz, L. (2015a). Sedimentary markers in the Provençal basin (Western Mediterranean): a window into deep geodynamic processes. Terra Nova, 27(2), 122-129. Leroux, E., Rabineau, M., Aslanian, D., Gorini, C., Molliex, S., Bache, F., Robin, C., Droz, L., Moulin, M., Poort, J., Rubino, J.-L. & Suc, J.P. (2016, in press). High resolution evolution of terrigenous sediment yields in the Provence Basin during the last 6 Ma: relation with climate and tectonic. Basin Research, xx, xx-xx (ID: 4759575-1545130). Moulin, M., Klingelhoefer, F., Afiladho, A., Aslanian, D., Schnürle, P., Nouze, H., Beslier, M.-O. & Feld, A. (2015). Deep crustal structure across an young passive margin from wide-angle and reflection seismic data (The SARDINIA Experiment) - I. Gulf of Lion's margin, Bull. Soc. géol. France., 186, ILP Spec. issue, 4-5,309-330. Rabineau, M., Leroux, E., Aslanian, D., Bache, F., Gorini, C., Moulin, M., Molliex, S., Droz, L., Reis, T. D., Rubino, J.-L., Guillocheau, F. & Olivet, J.-L. (2014). Quantifying subsidence and isostatic readjustment using sedimentary markers (example in the Gulf of Lion). Earth and Planetary Science Letters, 388, 1-14.

Forecasting the response of Earth's surface to future climatic and land use changes: A review of methods and research needs

DOE PAGES

Pelletier, Jon D.; Murray, A. Brad; Pierce, Jennifer L.; ...

2015-07-14

In the future, Earth will be warmer, precipitation events will be more extreme, global mean sea level will rise, and many arid and semiarid regions will be drier. Human modifications of landscapes will also occur at an accelerated rate as developed areas increase in size and population density. We now have gridded global forecasts, being continually improved, of the climatic and land use changes (C&LUC) that are likely to occur in the coming decades. However, besides a few exceptions, consensus forecasts do not exist for how these C&LUC will likely impact Earth-surface processes and hazards. In some cases, we havemore » the tools to forecast the geomorphic responses to likely future C&LUC. Fully exploiting these models and utilizing these tools will require close collaboration among Earth-surface scientists and Earth-system modelers. This paper assesses the state-of-the-art tools and data that are being used or could be used to forecast changes in the state of Earth's surface as a result of likely future C&LUC. We also propose strategies for filling key knowledge gaps, emphasizing where additional basic research and/or collaboration across disciplines are necessary. The main body of the paper addresses cross-cutting issues, including the importance of nonlinear/threshold-dominated interactions among topography, vegetation, and sediment transport, as well as the importance of alternate stable states and extreme, rare events for understanding and forecasting Earth-surface response to C&LUC. Five supplements delve into different scales or process zones (global-scale assessments and fluvial, aeolian, glacial/periglacial, and coastal process zones) in detail.« less