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Sample records for alaska earthquake information

  1. 1964 Great Alaska Earthquake: a photographic tour of Anchorage, Alaska

    USGS Publications Warehouse

    Thoms, Evan E.; Haeussler, Peter J.; Anderson, Rebecca D.; McGimsey, Robert G.

    2014-01-01

    On March 27, 1964, at 5:36 p.m., a magnitude 9.2 earthquake, the largest recorded earthquake in U.S. history, struck southcentral Alaska (fig. 1). The Great Alaska Earthquake (also known as the Good Friday Earthquake) occurred at a pivotal time in the history of earth science, and helped lead to the acceptance of plate tectonic theory (Cox, 1973; Brocher and others, 2014). All large subduction zone earthquakes are understood through insights learned from the 1964 event, and observations and interpretations of the earthquake have influenced the design of infrastructure and seismic monitoring systems now in place. The earthquake caused extensive damage across the State, and triggered local tsunamis that devastated the Alaskan towns of Whittier, Valdez, and Seward. In Anchorage, the main cause of damage was ground shaking, which lasted approximately 4.5 minutes. Many buildings could not withstand this motion and were damaged or collapsed even though their foundations remained intact. More significantly, ground shaking triggered a number of landslides along coastal and drainage valley bluffs underlain by the Bootlegger Cove Formation, a composite of facies containing variably mixed gravel, sand, silt, and clay which were deposited over much of upper Cook Inlet during the Late Pleistocene (Ulery and others, 1983). Cyclic (or strain) softening of the more sensitive clay facies caused overlying blocks of soil to slide sideways along surfaces dipping by only a few degrees. This guide is the document version of an interactive web map that was created as part of the commemoration events for the 50th anniversary of the 1964 Great Alaska Earthquake. It is accessible at the U.S. Geological Survey (USGS) Alaska Science Center website: http://alaska.usgs.gov/announcements/news/1964Earthquake/. The website features a map display with suggested tour stops in Anchorage, historical photographs taken shortly after the earthquake, repeat photography of selected sites, scanned documents

  2. Earthquake Hazard and Risk in Alaska

    NASA Astrophysics Data System (ADS)

    Black Porto, N.; Nyst, M.

    2014-12-01

    Alaska is one of the most seismically active and tectonically diverse regions in the United States. To examine risk, we have updated the seismic hazard model in Alaska. The current RMS Alaska hazard model is based on the 2007 probabilistic seismic hazard maps for Alaska (Wesson et al., 2007; Boyd et al., 2007). The 2015 RMS model will update several key source parameters, including: extending the earthquake catalog, implementing a new set of crustal faults, updating the subduction zone geometry and reoccurrence rate. First, we extend the earthquake catalog to 2013; decluster the catalog, and compute new background rates. We then create a crustal fault model, based on the Alaska 2012 fault and fold database. This new model increased the number of crustal faults from ten in 2007, to 91 faults in the 2015 model. This includes the addition of: the western Denali, Cook Inlet folds near Anchorage, and thrust faults near Fairbanks. Previously the subduction zone was modeled at a uniform depth. In this update, we model the intraslab as a series of deep stepping events. We also use the best available data, such as Slab 1.0, to update the geometry of the subduction zone. The city of Anchorage represents 80% of the risk exposure in Alaska. In the 2007 model, the hazard in Alaska was dominated by the frequent rate of magnitude 7 to 8 events (Gutenberg-Richter distribution), and large magnitude 8+ events had a low reoccurrence rate (Characteristic) and therefore didn't contribute as highly to the overall risk. We will review these reoccurrence rates, and will present the results and impact to Anchorage. We will compare our hazard update to the 2007 USGS hazard map, and discuss the changes and drivers for these changes. Finally, we will examine the impact model changes have on Alaska earthquake risk. Consider risk metrics include average annual loss, an annualized expected loss level used by insurers to determine the costs of earthquake insurance (and premium levels), and the

  3. ERTS-1, earthquakes, and tectonic evolution in Alaska

    NASA Technical Reports Server (NTRS)

    Gedney, L.; Vanwormer, J.

    1974-01-01

    In comparing seismicity patterns in Alaska with ERTS-1 imagery, it is striking to see the frequency with which earthquake epicenters fall on, or near, lineaments visible on the imagery. Often these lineaments prove to be tectonics faults which have been mapped in the field. But equally as often, existing geologic and tectonic maps show no evidence of these features. The remoteness and inaccessibility of most of Alaska is responsible, in large part, for the inadequacy of the mapping. ERTS-1 imagery is filling a vital need in providing much of the missing information, and is pointing out many areas of potential earthquake hazard. Earthquakes in central and south-central Alaska result when the northeastern corner of the north Pacific lithospheric plate underthrusts the continent. North of Mt. McKinley, the seismicity is continental in nature and of shallow origin, with earthquakes occurring on lineaments, and frequently at intersections of lineaments. The shallower events tend to align themselves with lineaments visible on the imagery.

  4. The Alaska earthquake, March 27, 1964: lessons and conclusions

    USGS Publications Warehouse

    Eckel, Edwin B.

    1970-01-01

    subsidence was superimposed on regional tectonic subsidence to heighten the flooding damage. Ground and surface waters were measurably affected by the earthquake, not only in Alaska but throughout the world. Expectably, local geologic conditions largely controlled the extent of structural damage, whether caused directly by seismic vibrations or by secondary effects such as those just described. Intensity was greatest in areas underlain by thick saturated unconsolidated deposits, least on indurated bedrock or permanently frozen ground, and intermediate on coarse well-drained gravel, on morainal deposits, or on moderately indurated sedimentary rocks. Local and even regional geology also controlled the distribution and extent of the earthquake's effects on hydrologic systems. In the conterminous United States, for example, seiches in wells and bodies of surface water were controlled by geologic structures of regional dimension. Devastating as the earthquake was, it had many long-term beneficial effects. Many of these were socioeconomic or engineering in nature; others were of scientific value. Much new and corroborative basic geologic and hydrologic information was accumulated in the course of the earthquake studies, and many new or improved investigative techniques were developed. Chief among these, perhaps, were the recognition that lakes can be used as giant tiltmeters, the refinement of methods for measuring land-level changes by observing displacements of barnacles and other sessile organisms, and the relating of hydrology to seismology by worldwide study of hydroseisms in surface-water bodies and in wells. The geologic and hydrologic lessons learned from studies of the Alaska earthquake also lead directly to better definition of the research needed to further our understanding of earthquakes and of how to avoid or lessen the effects of future ones. Research is needed on the origins and mechanisms of earthquakes, on crustal structure, and on the generation of tsunamis and

  5. The 1987 1992 Gulf of Alaska earthquakes

    NASA Astrophysics Data System (ADS)

    Pegler, G.; Das, S.

    1996-06-01

    We present a study of the 1987-1992 Gulf of Alaska earthquake sequence using relocated seismicity data together with body wave analysis of selected larger events. Most of the sequence is located on a N-S-trending fault, directly south of the Yakataga seismic gap and consists of four main events of Mw = 7.2, 7.8, 7.7 and 6.8 and associated aftershocks. The first earthquake is of left-lateral strike-slip type on an ENE-WSW-trending fault. The second event is a right-lateral strike-slip earthquake on the N-S-trending fault. The fault plane of the third strike-slip event was identified as an ENE-WSW-trending fault, located to the south of that for the first event, in a previous study using body wave analysis. We show that though the body wave study cannot unambiguously identify the fault plane, the temporal development of the seismicity together with the pattern of aftershock distribution on the conjugate fault suggests that this event also occurred on the N-S-trending fault and is of right-lateral type. The seismicity on the conjugate fault is interpreted as being triggered by the increase of the shear stress in the direction of the normal to the fault plane due to the main shock. The occurrence of the fourth main shock, a right-lateral strike-slip event in 1992, which itself can be considered an aftershock of the 1987-1988 sequence with epicentres distributed along a N-S-trending fault, favours this conclusion. The first three events of the sequence have been described in earlier studies as having too short a rupture length for their seismic moment. If the rupture lengths inferred from the aftershock zones in this study are used we find that this is not the case. The events in the 1987-1992 sequence lie along magnetic anomaly 13 and related conjugate fracture zones, indicating that the oceanic crust is rupturing along pre-existing zones of weakness in response to plate boundary stresses. At the southern end, the seismic activity terminates near a seamount, which

  6. Earthquake source studies and seismic imaging in Alaska

    NASA Astrophysics Data System (ADS)

    Tape, C.; Silwal, V.

    2015-12-01

    Alaska is one of the world's most seismically and tectonically active regions. Its enhanced seismicity, including slab seismicity down to 180 km, provides opportunities (1) to characterize pervasive crustal faulting and slab deformation through the estimation of moment tensors and (2) to image subsurface structures to help understand the tectonic evolution of Alaska. Most previous studies of earthquakes and seismic imaging in Alaska have emphasized earthquake locations and body-wave travel-time tomography. In the past decade, catalogs of seismic moment tensors have been established, while seismic surface waves, active-source data, and potential field data have been used to improve models of seismic structure. We have developed moment tensor catalogs in the regions of two of the largest sedimentary basins in Alaska: Cook Inlet forearc basin, west of Anchorage, and Nenana basin, west of Fairbanks. Our moment tensor solutions near Nenana basin suggest a transtensional tectonic setting, with the basin developing in a stepover of a left-lateral strike-slip fault system. We explore the effects of seismic wave propagation from point-source and finite-source earthquake models by performing three-dimensional wavefield simulations using seismic velocity models that include major sedimentary basins. We will use our catalog of moment tensors within an adjoint-based, iterative inversion to improve the three-dimensional tomographic model of Alaska.

  7. Survey of Alaska Information Systems.

    ERIC Educational Resources Information Center

    Allen, Anda; Sokolov, Barbara J.

    This survey by the Arctic Environmental Information and Data Center at the University of Alaska identifies and describes information and data collections within Alaskan libraries and agency offices which pertain to fish and wildlife or their habitat. Included in the survey are descriptions of the location, characteristics, and availability of…

  8. Why the 1964 Great Alaska Earthquake matters 50 years later

    USGS Publications Warehouse

    West, Michael E.; Haeussler, Peter J.; Ruppert, Natalia A.; Freymueller, Jeffrey T.; ,

    2014-01-01

    Spring was returning to Alaska on Friday 27 March 1964. A two‐week cold snap had just ended, and people were getting ready for the Easter weekend. At 5:36 p.m., an earthquake initiated 12 km beneath Prince William Sound, near the eastern end of what is now recognized as the Alaska‐Aleutian subduction zone. No one was expecting this earthquake that would radically alter the coastal landscape, influence the direction of science, and indelibly mark the growth of a burgeoning state.

  9. Revisiting Notable Earthquakes and Seismic Patterns of the Past Decade in Alaska

    NASA Astrophysics Data System (ADS)

    Ruppert, N. A.; Macpherson, K. A.; Holtkamp, S. G.

    2015-12-01

    Alaska, the most seismically active region of the United States, has produced five earthquakes with magnitudes greater than seven since 2005. The 2007 M7.2 and 2013 M7.0 Andreanof Islands earthquakes were representative of the most common source of significant seismic activity in the region, the Alaska-Aleutian megathrust. The 2013 M7.5 Craig earthquake, a strike-slip event on the Queen-Charlotte fault, occurred along the transform plate boundary in southeast Alaska. The largest earthquake of the past decade, the 2014 M7.9 Little Sitkin event in the western Aleutians, occurred at an intermediate depth and ruptured along a gently dipping fault through nearly the entire thickness of the subducted Pacific plate. Along with these major earthquakes, the Alaska Earthquake Center reported over 250,000 seismic events in the state over the last decade, and its earthquake catalog surpassed 500,000 events in mid-2015. Improvements in monitoring networks and processing techniques allowed an unprecedented glimpse into earthquake patterns in Alaska. Some notable recent earthquake sequences include the 2008 Kasatochi eruption, the 2006-2008 M6+ crustal earthquakes in the central and western Aleutians, the 2010 and 2015 Bering Sea earthquakes, the 2014 Noatak swarm, and the 2014 Minto earthquake sequence. In 2013, the Earthscope USArray project made its way into Alaska. There are now almost 40 new Transportable Array stations in Alaska along with over 20 upgraded sites. This project is changing the earthquake-monitoring scene in Alaska, lowering magnitude of completeness across large, newly instrumented parts of the state.

  10. Geotechnical reconnaissance of the 2002 Denali fault, Alaska, earthquake

    USGS Publications Warehouse

    Kayen, R.; Thompson, E.; Minasian, D.; Moss, R.E.S.; Collins, B.D.; Sitar, N.; Dreger, D.; Carver, G.

    2004-01-01

    The 2002 M7.9 Denali fault earthquake resulted in 340 km of ruptures along three separate faults, causing widespread liquefaction in the fluvial deposits of the alpine valleys of the Alaska Range and eastern lowlands of the Tanana River. Areas affected by liquefaction are largely confined to Holocene alluvial deposits, man-made embankments, and backfills. Liquefaction damage, sparse surrounding the fault rupture in the western region, was abundant and severe on the eastern rivers: the Robertson, Slana, Tok, Chisana, Nabesna and Tanana Rivers. Synthetic seismograms from a kinematic source model suggest that the eastern region of the rupture zone had elevated strong-motion levels due to rupture directivity, supporting observations of elevated geotechnical damage. We use augered soil samples and shear-wave velocity profiles made with a portable apparatus for the spectral analysis of surface waves (SASW) to characterize soil properties and stiffness at liquefaction sites and three trans-Alaska pipeline pump station accelerometer locations. ?? 2004, Earthquake Engineering Research Institute.

  11. Seismicity trends and potential for large earthquakes in the Alaska-Aleutian region

    USGS Publications Warehouse

    Bufe, C.G.; Nishenko, S.P.; Varnes, D.J.

    1994-01-01

    The high likelihood of a gap-filling thrust earthquake in the Alaska subduction zone within this decade is indicated by two independent methods: analysis of historic earthquake recurrence data and time-to-failure analysis applied to recent decades of instrumental data. Recent (May 1993) earthquake activity in the Shumagin Islands gap is consistent with previous projections of increases in seismic release, indicating that this segment, along with the Alaska Peninsula segment, is approaching failure. Based on this pattern of accelerating seismic release, we project the occurrence of one or more M???7.3 earthquakes in the Shumagin-Alaska Peninsula region during 1994-1996. Different segments of the Alaska-Aleutian seismic zone behave differently in the decade or two preceding great earthquakes, some showing acceleration of seismic release (type "A" zones), while others show deceleration (type "D" zones). The largest Alaska-Aleutian earthquakes-in 1957, 1964, and 1965-originated in zones that exhibit type D behavior. Type A zones currently showing accelerating release are the Shumagin, Alaska Peninsula, Delarof, and Kommandorski segments. Time-to-failure analysis suggests that the large earthquakes could occur in these latter zones within the next few years. ?? 1994 Birkha??user Verlag.

  12. The 1964 Great Alaska Earthquake and tsunamis: a modern perspective and enduring legacies

    USGS Publications Warehouse

    Brocher, Thomas M.; Filson, John R.; Fuis, Gary S.; Haeussler, Peter J.; Holzer, Thomas L.; Plafker, George; Blair, J. Luke

    2014-01-01

    The magnitude 9.2 Great Alaska Earthquake that struck south-central Alaska at 5:36 p.m. on Friday, March 27, 1964, is the largest recorded earthquake in U.S. history and the second-largest earthquake recorded with modern instruments. The earthquake was felt throughout most of mainland Alaska, as far west as Dutch Harbor in the Aleutian Islands some 480 miles away, and at Seattle, Washington, more than 1,200 miles to the southeast of the fault rupture, where the Space Needle swayed perceptibly. The earthquake caused rivers, lakes, and other waterways to slosh as far away as the coasts of Texas and Louisiana. Water-level recorders in 47 states—the entire Nation except for Connecticut, Delaware, and Rhode Island— registered the earthquake. It was so large that it caused the entire Earth to ring like a bell: vibrations that were among the first of their kind ever recorded by modern instruments. The Great Alaska Earthquake spawned thousands of lesser aftershocks and hundreds of damaging landslides, submarine slumps, and other ground failures. Alaska’s largest city, Anchorage, located west of the fault rupture, sustained heavy property damage. Tsunamis produced by the earthquake resulted in deaths and damage as far away as Oregon and California. Altogether the earthquake and subsequent tsunamis caused 129 fatalities and an estimated $2.3 billion in property losses (in 2013 dollars). Most of the population of Alaska and its major transportation routes, ports, and infrastructure lie near the eastern segment of the Aleutian Trench that ruptured in the 1964 earthquake. Although the Great Alaska Earthquake was tragic because of the loss of life and property, it provided a wealth of data about subductionzone earthquakes and the hazards they pose. The leap in scientific understanding that followed the 1964 earthquake has led to major breakthroughs in earth science research worldwide over the past half century. This fact sheet commemorates Great Alaska Earthquake and

  13. Geomorphic effects of the earthquake of March 27, 1964, in the Martin-Bering Rivers area, Alaska: Chapter B in The Alaska earthquake, March 27, 1964: regional effects

    USGS Publications Warehouse

    Tuthill, Samuel J.; Laird, Wilson M.

    1966-01-01

    The Alaska earthquake of March 27, 1964, caused widespread geomorphic changes in the Martin-Bering Rivers area-900 square miles of uninhabited mountains, alluvial flatlands, and marshes north of the Gulf of Alaska, and east of the Copper River. This area is at lat 60°30’ N. and long 144°22’ W., 32 miles east of Cordova, and approximately 130 miles east-southeast of the epicenter of the earthquake. The geomorphic effects observed were: (1) earthquake-induced ground fractures, (2) mudvent deposits, (3) “earthquake-fountain” craters, (4) subsidence, (5) mudcones, (6) avalanches, (7) subaqueous landslides, (8) turbidity changes in ice-basined lakes on the Martin River glacier, (9) filling of ice-walled sinkholes, (10) gravel-coated snow cones, (11) lake ice fractures, and (12) uplift accompanied the earthquake. In addition to geomorphic effects, the earthquake affected the animal populations of the area. These include migratory fish, terrestrial mollusks, fur-bearing animals, and man. The Alaska earthquake clearly delineated areas of alluvial fill, snow and rock avalanche corridors, and deltas of the deeper lakes as unsuitable for future construction.

  14. Relative Source Time Function Studies of Earthquakes in Southeastern Alaska

    NASA Astrophysics Data System (ADS)

    Escudero, C. R.; Doser, D.

    2008-12-01

    We are using the Relative Source Time Function (RSTF) method to determine the source properties of earthquakes within southeastern Alaska, a region extending from the Queen Charlotte Islands to Yakutat Bay. In our approach we deconvolve the spectral quotient of the P-arrival of a small event from that of a larger event. The arrivals are selected using a tapered cosine window, then we use a water level technique to stabilize the quotient in the frequency domain, and we apply a bandpass or highcut filter before inverse transforming our result. Our first goal is to compare the source processes of earthquakes along the Queen Charlotte-Fairweather fault system to those occurring off these major plate bounding faults to determine if there are differences in stress drop and source duration between these regions. Secondly, we hope to determine if observed differences in source processes of events along the Queen Charlotte-Fairweather fault system may be related to the location of the events relative to known fault asperities and segment boundaries. We have identified about twenty events occurring between 1995 and 2008 distributed throughout the study area. In addition, we have digitized and analyzed seismograms of older events occurring in July 1973 located in the Cross Sound area.

  15. Tectonics of the March 27, 1964, Alaska earthquake: Chapter I in The Alaska earthquake, March 27, 1964: regional effects

    USGS Publications Warehouse

    Plafker, George

    1969-01-01

    The March 27, 1964, earthquake was accomp anied by crustal deformation-including warping, horizontal distortion, and faulting-over probably more than 110,000 square miles of land and sea bottom in south-central Alaska. Regional uplift and subsidence occurred mainly in two nearly parallel elongate zones, together about 600 miles long and as much as 250 miles wide, that lie along the continental margin. From the earthquake epicenter in northern Prince William Sound, the deformation extends eastward 190 miles almost to long 142° and southwestward slightly more than 400 miles to about long 155°. It extends across the two zones from the chain of active volcanoes in the Aleutian Range and Wrangell Mountains probably to the Aleutian Trench axis. Uplift that averages 6 feet over broad areas occurred mainly along the coast of the Gulf of Alaska, on the adjacent Continental Shelf, and probably on the continental slope. This uplift attained a measured maximum on land of 38 feet in a northwest-trending narrow belt less than 10 miles wide that is exposed on Montague Island in southwestern Prince William Sound. Two earthquake faults exposed on Montague Island are subsidiary northwest-dipping reverse faults along which the northwest blocks were relatively displaced a maximum of 26 feet, and both blocks were upthrown relative to sea level. From Montague Island, the faults and related belt of maximum uplift may extend southwestward on the Continental Shelf to the vicinity of the Kodiak group of islands. To the north and northwest of the zone of uplift, subsidence forms a broad asymmetrical downwarp centered over the Kodiak-Kenai-Chugach Mountains that averages 2½ feet and attains a measured maximum of 7½ feet along the southwest coast of the Kenai Peninsula. Maximum indicated uplift in the Alaska and Aleutian Ranges to the north of the zone of subsidence was l½ feet. Retriangulation over roughly 25,000 square miles of the deformed region in and around Prince William Sound

  16. Source and progression of a submarine landslide and tsunami: The 1964 Great Alaska earthquake at Valdez

    NASA Astrophysics Data System (ADS)

    Parsons, Tom; Geist, Eric L.; Ryan, Holly F.; Lee, Homa J.; Haeussler, Peter J.; Lynett, Patrick; Hart, Patrick E.; Sliter, Ray; Roland, Emily

    2014-11-01

    Like many subduction zone earthquakes, the deadliest aspects of the 1964 M = 9.2 Alaska earthquake were the tsunamis it caused. The worst of these were generated by local submarine landslides induced by the earthquake. These caused high runups, engulfing several coastal towns in Prince William Sound. In this paper, we study one of these cases in detail, the Port Valdez submarine landslide and tsunami. We combine eyewitness reports, preserved film, and careful posttsunami surveys with new geophysical data to inform numerical models for landslide tsunami generation. We review the series of events as recorded at Valdez old town and then determine the corresponding subsurface events that led to the tsunami. We build digital elevation models of part of the pretsunami and posttsunami fjord-head delta. Comparing them reveals a ~1500 m long region that receded 150 m to the east, which we interpret as the primary delta landslide source. Multibeam imagery and high-resolution seismic reflection data identify a ~400 m wide chute with hummocky deposits at its terminus, which may define the primary slide path. Using these elements we run hydrodynamic models of the landslide-driven tsunamis that match observations of current direction, maximum inundation, and wave height at Valdez old town. We speculate that failure conditions at the delta front may have been influenced by manmade changes in drainage patterns as well as the fast retreat of Valdez and other glaciers during the past century.

  17. Effects of the March 1964 Alaska earthquake on glaciers: Chapter D in The Alaska earthquake, March 27, 1964: effects on hydrologic regimen

    USGS Publications Warehouse

    Post, Austin

    1967-01-01

    The 1964 Alaska earthquake occurred in a region where there are many hundreds of glaciers, large and small. Aerial photographic investigations indicate that no snow and ice avalanches of large size occurred on glaciers despite the violent shaking. Rockslide avalanches extended onto the glaciers in many localities, seven very large ones occurring in the Copper River region 160 kilometers east of the epicenter. Some of these avalanches traveled several kilometers at low gradients; compressed air may have provided a lubricating layer. If long-term changes in glaciers due to tectonic changes in altitude and slope occur, they will probably be very small. No evidence of large-scale dynamic response of any glacier to earthquake shaking or avalanche loading was found in either the Chugach or Kenai Mountains 16 months after the 1964 earthquake, nor was there any evidence of surges (rapid advances) as postulated by the Earthquake-Advance Theory of Tarr and Martin.

  18. The Alaska earthquake, March 27, 1964: field investigations and reconstruction effort

    USGS Publications Warehouse

    Hansen, Wallace R.; Eckel, Edwin B.; Schaem, William E.; Lyle, Robert E.; George, Warren; Chance, Genie

    1966-01-01

    One of the greatest geotectonic events of our time occurred in southern Alaska late in the afternoon of March 27, 1964. Beneath a leaden sky, the chill of evening was just settling over the Alaskan countryside. Light snow was falling on some communities. It was Good Friday, schools were closed, and the business day was ending. Suddenly without warning half of Alaska was rocked and jarred by the most violent earthquake to occur in North America this century. The descriptive summary that follows is based on the work of many investigators. A large and still-growing scientific literature has accumulated since the earthquake, and this literature has been freely drawn upon here. In particular, the writers have relied upon the findings of their colleagues in the Geological Survey. Some of these findings have been published, but some are still being prepared for publication. Moreover, some field investigations are still in progress. This is the first in a series of six reports that the U.S. Geological Survey published on the results of a comprehensive geologic study that began, as a reconnaissance survey, within 24 hours after the March 27, 1964, Magnitude 9.2 Great Alaska Earthquake and extended, as detailed investigations, through several field seasons. The 1964 Great Alaska earthquake was the largest earthquake in the U.S. since 1700. Professional Paper 541, in 1 part, describes Field Investigations and Reconstruction Effort.

  19. Effects of the earthquake of March 27, 1964, at Whittier, Alaska: Chapter B in The Alaska earthquake, March 27, 1964: effects on communities

    USGS Publications Warehouse

    Kachadoorian, Reuben

    1965-01-01

    Whittier, Alaska, lying at the western end of Passage Canal, is an ocean terminal of The Alaska Railroad. The earthquake that shook south-central Alaska at 5:36 p.m. (Alaska Standard Time) on March 27, 1964, took the lives of 13 persons and caused more than $5 million worth of damage to Government and private property at Whittier. Seismic motion lasted only 2½-3 minutes, but when it stopped the Whittier waterfront was in shambles land the port facilities were inoperable. Damage was caused by (1) a 5.3-foot subsidence of the landmass, sufficient to put some of the developed land under water during high tides, (2) seismic shock, (3) fracturing of fill and unconsolidated sediments, (4) compaction of fill and unconsolidated deposits, (5) submarine landslides which generated waves that destroyed part of The Alaska Railroad roadbed and other property, (6) at least two, but probably three, waves generated by landslides, which completely wrecked the buildings of two lumber companies, the stub pier, the small-boat harbor, the car-barge slip dock, and several homes, and (7) fire that destroyed the fuel-storage tanks at the Whittier waterfront. Many buildings and other facilities were totally wrecked, others were damaged to lesser degrees. For example, the 14-story reinforced concrete Hodge Building, which rests upon at least 44 feet of sandy gravel, was moderately damaged by seismic shock, but the six-story reinforced-concrete Buckner Building, which rests upon bedrock, was only slightly damaged.

  20. Response of a 14-story Anchorage, Alaska, building in 2002 to two close earthquakes and two distant Denali fault earthquakes

    USGS Publications Warehouse

    Celebi, M.

    2004-01-01

    The recorded responses of an Anchorage, Alaska, building during four significant earthquakes that occurred in 2002 are studied. Two earthquakes, including the 3 November 2002 M7.9 Denali fault earthquake, with epicenters approximately 275 km from the building, generated long trains of long-period (>1 s) surface waves. The other two smaller earthquakes occurred at subcrustal depths practically beneath Anchorage and produced higher frequency motions. These two pairs of earthquakes have different impacts on the response of the building. Higher modes are more pronounced in the building response during the smaller nearby events. The building responses indicate that the close-coupling of translational and torsional modes causes a significant beating effect. It is also possible that there is some resonance occurring due to the site frequency being close to the structural frequency. Identification of dynamic characteristics and behavior of buildings can provide important lessons for future earthquake-resistant designs and retrofit of existing buildings. ?? 2004, Earthquake Engineering Research Institute.

  1. Subducting plate geology in three great earthquake ruptures of the western Alaska margin, Kodiak to Unimak

    USGS Publications Warehouse

    von Huene, Roland; Miller, John J.; Weinrebe, Wilhelm

    2012-01-01

    Three destructive earthquakes along the Alaska subduction zone sourced transoceanic tsunamis during the past 70 years. Since it is reasoned that past rupture areas might again source tsunamis in the future, we studied potential asperities and barriers in the subduction zone by examining Quaternary Gulf of Alaska plate history, geophysical data, and morphology. We relate the aftershock areas to subducting lower plate relief and dissimilar materials in the seismogenic zone in the 1964 Kodiak and adjacent 1938 Semidi Islands earthquake segments. In the 1946 Unimak earthquake segment, the exposed lower plate seafloor lacks major relief that might organize great earthquake rupture. However, the upper plate contains a deep transverse-trending basin and basement ridges associated with the Eocene continental Alaska convergent margin transition to the Aleutian island arc. These upper plate features are sufficiently large to have affected rupture propagation. In addition, massive slope failure in the Unimak area may explain the local 42-m-high 1946 tsunami runup. Although Quaternary geologic and tectonic processes included accretion to form a frontal prism, the study of seismic images, samples, and continental slope physiography shows a previous history of tectonic erosion. Implied asperities and barriers in the seismogenic zone could organize future great earthquake rupture.

  2. Mutual Information Between GPS Measurements and Earthquakes

    NASA Astrophysics Data System (ADS)

    Wang, T.; Bebbington, M. S.

    2009-12-01

    Prior to the wide deployment of Continuous GPS stations in the early 1990s, there were a number of well-documented deformation rate changes observed before large earthquakes. GPS measurements provide the opportunity for systematic investigation of pre-, co- and post-seismic deformation anomalies, but contain much noise that needs to be filtered out of the observations. Assuming the existence of an earthquake cycle (for example, mainshock--aftershock--quiescence--precursory seismicity), a hidden Markov model (HMM) provides a natural framework for analyzing the observed GPS data. For two case studies of a) deep earthquakes in the central North Island, New Zealand, and b) shallow earthquakes in Southern California, an HMM fitted to the trend ranges of the GPS measurements can classify the deformation data into different patterns which form proxies for states of the earthquake cycle. Mutual information can be used to examine whether there is any relation between these patterns, in particular the Viterbi path, and subsequent (or previous) earthquakes. One class of GPS movements (identified by the HMM as having the largest range of deformation rate changes) appears to have some precursory character for earthquakes with minimum magnitude 5.1 (central North Island, New Zealand, 26 earthquakes in 1747 days) and 4.5 (Southern California, 50 earthquakes in 3815 days). We define a ``Time of Increased Probability'' (TIP) as being a 10-day interval (central North Island, New Zealand) or a 20-day interval (Southern California) following entry (as identified by the Viterbi algorithm) to the `precursory' hidden state, and examine the performance of this in probabilistically forecasting subsequent earthquakes.

  3. Effects of the March 1964 Alaska earthquake on the hydrology of south-central Alaska: Chapter A in The Alaska earthquake, March 27, 1964: effects on hydrologic regimen

    USGS Publications Warehouse

    Waller, Roger M.

    1966-01-01

    The earthquake of March 27, 1964, greatly affected the hydrology of Alaska and many other parts of the world. Its far-reaching effects were recorded as water-level fluctuations in gages operated on water wells and streams. The close-in effects were even more striking, however; sediment-laden ground water erupted at the surface, and even ice-covered lakes and streams responded by seiching. Lake and river ice was broken for distances of 450 miles from the epicenter by seismic shock and seiche action. The surging action temporarily dewatered some lakes. Fissuring of streambeds and lakeshores, in particular, caused a loss of water, and hydrologic recovery took weeks in some places. Landslides and snow avalanches temporarily blocked streams and diverted some permanently. The only stream or lake structures damaged were a tunnel intake and two earthen dams. The winter conditions-low stages of water and the extensive ice cover on lakes and streams-at the time of the earthquake greatly reduced the damaging potential. Ground water was drastically affected mostly in unconsolidated aquifers for at least 160 miles from the epicenter. Within 100 miles of the epicenter, vast quantities of sediment-laden water were ejected in most of the flood plains of the glaciofluvial valleys. A shallow water table and confinement by frost seemed to be requirements for the ejections, which were commonly associated with cratering and subsidence of the unconsolidated material. Subsidence was also common near the disastrous submarine landslides, and was probably caused by loss of water pressure and by lateral spreading of sediments. Effects on ground water in bedrock were not determinable because of lack of data and accessibility, particularly within 50 miles of the epicenter. Deep aquifers in unconsolidated sediments, which in most areas are under high hydrostatic pressure, were also greatly affected. Postearthquake water levels for a year were compared with long-term prequake levels to show

  4. Paleoseismic Investigations of Subduction Zone Earthquakes on the Southeastern Coast of the Kenai Peninsula, Alaska

    NASA Astrophysics Data System (ADS)

    Kelsey, H. M.; Witter, R. C.; Briggs, R. W.; Engelhart, S. E.; Nelson, A. R.; Haeussler, P. J.

    2013-12-01

    Rupture extents for prehistoric subduction zone earthquakes on the Alaska margin are poorly documented. For example, the 1964 great Alaska earthquake ruptured the subduction zone from Prince William Sound westward to the southwest end of Kodiak Island, but an outstanding question is whether or not earlier subduction earthquakes ruptured a shorter segment in the Kodiak region with the eastern margin located in the Kenai Peninsula. To address the question, we investigated several embayments on the Pacific (southeastern) coast of the Kenai Peninsula to reconstruct the late Holocene paleoseismic history. Constraints to constructing a paleoseismic history on the outer Kenai coast include recent deglaciation of embayments that limits a stratigraphic record to approximately the last 1 to 3 thousand years and the high wave-energy environment that results in frequent closure of embayments by barrier bars. Recognizing these constraints, two approaches have proved productive in investigating paleoseismic history on the outer Kenai coast. One involves understanding how beach ridges can be formed and modified by coseismic subsidence and documenting timing and number of late Holocene prehistoric earthquakes based on beach ridge genesis and evolution. The other approach, which is the more conventional paleoseismic approach for subduction zones, is investigating stratigraphic evidence for coseismic subsidence in peaty and muddy sediment within embayments. We illustrate these two approaches using two coastal sites in Aialik Bay within Kenai Fjords National Park, a strandplain complex at Verdant Cove and a drowned embayment at Quicksand Cove, respectively. Both sites record two prehistoric subduction zone earthquakes prior to the historically known 1964 great Alaska earthquake.

  5. Detection of supershear rupture in 2013 Craig, Alaska, earthquake

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2014-01-01

    Seismic ruptures are akin to opening a zipper—a gap in the crust starts in one location and travels along the fault in a particular direction. When a strained fault ruptures in an earthquake, seismic waves also spread out from the epicenter. In some cases, the waves' passage can trigger the initiation of a new rupture ahead of the initial expanding rupture in locked portions of the fault. If the triggered rupture grows successfully, the overall rupture front can then outpace the passage of the shear waves, secondary seismic waves that travel slowly after the earthquake begins and are responsible for the bulk of violent shaking. These earthquakes display what is known as supershear rupture; only seven such earthquakes have previously been recorded.

  6. Interim report on the St. Elias, Alaska earthquake of 28 February 1979

    USGS Publications Warehouse

    Lahr, John C.; Plafker, George; Stephens, C.D.; Foglean, K.A.; Blackford, M.E.

    1979-01-01

    On 28 February 1979 an earthquake with surface wave magnitude (Ms) of 7.7 (W. Person, personal communication, 1979) occurred beneath the Chugach and St. Elias mountains of southern Alaska (fig. 1). This is a region of complex tectonics resulting from northwestward convergence between the Pacific and North American plates. To the east, the northwest-trending Fairweather fault accommodates the movement with dextral slip of about 5.5 cm/yr (Plafker, Hudson, and others, 1978); to the west, the Pacific plate underthrusts Alaska at the Aleutian trench, which trends southwestward (Plafker 1969). The USGS has operated a telemetered seismic network in southern Alaska since 1971 and it was greatly expanded along the eastern Gulf of Alaska in September 1974. The current configuration of stations is shown in Figure 9. Technical details of the network are available in published earthquake catalogs (Lahr, Page, and others, 1974; Fogleman, Stephens, and others, 1978). Preliminary analysis of the data from this network covering the time period September 1, 1978 through March 10, 1979, as well as worldwide data for the main shock will be discussed in this paper.

  7. Crustal Deformation in Southcentral Alaska: The 1964 Prince William Sound Earthquake Subduction Zone

    NASA Technical Reports Server (NTRS)

    Cohen, Steven C.; Freymueller, Jeffrey T.

    2003-01-01

    This article, for Advances in Geophysics, is a summary of crustal deformation studies in southcentral Alaska. In 1964, southcentral Alaska was struck by the largest earthquake (moment magnitude 9.2) occurring in historical times in North America and the second largest earthquake occurring in the world during the past century. Conventional and space-based geodetic measurements have revealed a complex temporal-spatial pattern of crustal movement. Numerical models suggest that ongoing convergence between the North America and Pacific Plates, viscoelastic rebound, aseismic creep along the tectonic plate interface, and variable plate coupling all play important roles in controlling both the surface and subsurface movements. The geodetic data sets include tide-gauge observations that in some cases provide records back to the decades preceding the earthquake, leveling data that span a few decades around the earthquake, VLBI data from the late 1980s, and GPS data since the mid-1990s. Geologic data provide additional estimates of vertical movements and a chronology of large seismic events. Some of the important features that are revealed by the ensemble of studies that are reviewed in this paper include: (1) Crustal uplift in the region that subsided by up 2 m at the time of the earthquake is as much as 1 m since the earthquake. In the Turnagain Arm and Kenai Peninsula regions of southcentral Alaska, uplift rates in the immediate aftermath of the earthquake reached 150 mm/yr , but this rapid uplift decayed rapidly after the first few years following the earthquake. (2) At some other locales, notably those away the middle of the coseismic rupture zone, postseismic uplift rates were initially slower but the rates decay over a longer time interval. At Kodiak Island, for example, the uplift rates have been decreasing at a rate of about 7mm/yr per decade. At yet other locations, the uplift rates have shown little time dependence so far, but are thought not to be sustainable

  8. Reconnaissance engineering geology of Sitka and vicinity, Alaska, with emphasis on evaluation of earthquake and other geologic hazards

    USGS Publications Warehouse

    Yehle, Lynn A.

    1974-01-01

    A program to study the engineering geology of most of the larger Alaska coastal communities and to evaluate their earthquake and other geologic hazards was started following the 1964 Alaska earthquake; this report about Sitka and vicinity is a product of that program. Field-study methods were of a reconnaissance nature, and thus the interpretations in the report are subject to revision as further information becomes available. This report can provide broad geologic guidelines for planners and engineers during preparation of land-use plans. The use of this information should lead to minimizing future loss of life and property due to geologic hazards, especially during very large earthquakes. Landscape of Sitka and surrounding area is characterized by numerous islands and a narrow strip of gently rolling ground adjacent to rugged mountains; steep valleys and some fiords cut sharply into the mountains. A few valley floors are wide and flat and grade into moderate-sized deltas. Glaciers throughout southeastern Alaska and elsewhere became vastly enlarged during the Pleistocene Epoch. The Sitka area presumably was covered by ice several times; glaciers deeply eroded some valleys and removed fractured bedrock along some faults. The last major deglaciation occurred sometime before 10,000 years ago. Crustal rebound believed to be related to glacial melting caused land emergence at Sitka of at least 35 feet (10.7 m) relative to present sea level. Bedrock at Sitka and vicinity is composed mostly of bedded, hard, dense graywacke and some argillite. Beds strike predominantly northwest and are vertical or steeply dipping. Locally, bedded rocks are cut by dikes of fine-grained igneous rock. Host bedrock is of Jurassic and Cretaceous age. Eight types of surficial deposits of Quaternary age were recognized. Below altitudes of 3S feet (10.7 m), the dominant deposits are those of modern and elevated shores and deltas; at higher altitudes, widespread muskeg overlies a mantle of

  9. Splay faults and tsunamigenic sources across the continental shelf from 1964 great Alaska earthquake

    NASA Astrophysics Data System (ADS)

    Liberty, L. M.; Haeussler, P. J.; Moeller, M.

    2013-12-01

    Using tsunami run up, seismic reflection and bathymetric data, we identify tsunamigenic sea floor ruptures that resulted from the 1964 Great Alaska earthquake. These sea floor lineaments are rooted in megathrust splay faults that appear across the 500-km wide Gulf of Alaska continental shelf. Based on estimated tsunami travel times, we identify two splay faults that produced 5-10 m wave heights in the coastal town of Seward and remote settlements along the Kenai Peninsula. These faults splay from the megathrust along the trailing edge of the subducted Yakutat terrane that is sandwiched between the Pacific and North American plates. Duplexing along the megathrust likely transferred lateral motion along the decollement to vertical splay fault motion that resulted in multi-meter sea floor uplifts. We identify the Cape Cleare fault as the source of the earliest tsunami arrival for Seward, Puget Bay and Whidbey Bay. Sparker seismic data, pre- and post-earthquake bathymetry and crustal seismic data characterize the along-strike Holocene motion on this 70-km long fault that parallels the Patton Bay fault that ruptured on nearby Montague Island. We define a strand of the Middleton Island fault system as the source of the second arrival in Puget and Whidbey Bays and the earliest tsunami source on Middleton Island and other sites in the eastern Gulf of Alaska. Sea floor displacements of more than 20 m suggest both of these faults have repeatedly ruptured during Holocene earthquakes. Additionally, we identify a series of active thrust faults along the length of the Gulf of Alaska to Kodiak Island that likely initiated tsunami waves from smaller sea floor displacements. Sea floor offsets and splay faults that are mapped along the length of the continental shelf suggest Holocene coseismic rupture patterns are not reflected in interseismic GPS measurements along the Kenai Peninsula, but are consistent with seismic, tsunami, and geodetic measurements from the 1964 earthquake

  10. Massive submarine slope failures during the 1964 earthquake in Port Valdez, Alaska

    NASA Astrophysics Data System (ADS)

    Lee, H. J.; Ryan, H. F.; Suleimani, E.; Haeussler, P. A.; Kayen, R. E.; Hampton, M. A.

    2006-12-01

    The M9.2 Alaska earthquake of 1964 caused major damage to the port facilities and town of Valdez, resulting in a total of 32 deaths. Most of the damage and deaths in Valdez were caused by submarine-landslide generated tsunamis that occurred immediately after the earthquake. Some post-earthquake investigations were conducted in the 1960's. Dramatic changes in bathymetry were observed, including several hundred meters of deepening below the head of Port Valdez fjord, and these were attributed to submarine landsliding. Recent multibeam surveys of Port Valdez provide much more information about the morphology of landslide deposits. Also, we collected high-resolution (chirp) surveys over apparent landslide debris to evaluate the chronology and three-dimensional character of the deposits, and we performed quantitative evaluations of pre- and post-earthquake bathymetric data. Landslide morphologies include several forms. In the western part of the fjord, there is a field of large blocks (up to 40-m high) on the fjord floor near the location of the greatest tsunami-wave runup estimated for the 1964 earthquake (~50 m). The runup direction for the waves (northeast) is consistent with the failure of these blocks being the trigger. Surrounding the fields of blocks are lobes from two debris flows that likely occurred at the same time as the block slides. Both debris flows and block slides appear to have resulted from the failure of a large moraine front, formed by Shoup Glacier on the northwest side of Port Valdez. At the fjord head, near the location of the badly damaged old town of Valdez, is an intricate series of gullies, channels, and talus, although these features display little evidence for the large-scale mass movement that occurred. However, near the center of the fjord is the front of a large debris lobe that flowed from the east end of the fjord half-way down the fjord and stopped. This huge deposit represents material that failed at the fjord head, mobilized into a

  11. Massive submarine slope failures during the 1964 earthquake in Port Valdez, Alaska

    USGS Publications Warehouse

    Lee, H.; Ryan, H.F.; Suleimani, E.; Kayen, R.E.; Hampton, M.A.

    2006-01-01

    The M9.2 Alaska earthquake of 1964caused major damage to the port facilities and town of Valdez, resulting in a total of 32 deaths. Most of the damage and deaths in Valdez were caused by submarine-landslide generated tsunamis that occurred immediately after the earthquake. Some post-earthquake investigations were conducted in the 1960's. Dramatic changes in bathymetry were observed, including several hundred meters of deepening below the head of Port Valdezfjord, and these were attributed to submarine landsliding. Recent multibeam surveys of Port Valdez provide much more information about the morphology of landslide deposits. Also, we collected high-resolution (chirp) surveys over apparent landslide debris to evaluate the chronology and three-dimensional character of the deposits, and we performed quantitative evaluations of pre- and post-earthquake bathymetric data. Landslide morphologies include several forms. In the western part of the fjord, there is a field of large blocks (up to 40-m high) on the fjord floor near the location of the greatest tsunami-wave runup estimated for the 1964 earthquake (~50 m). The runup direction for the waves (northeast) is consistent with the failure of these blocks being the trigger. Surrounding the fields of blocks are lobes from two debris flows that likely occurred at the same time as the block slides. Both debris flows and block slides appear to have resulted from the failure of a large moraine front, formed by Shoup Glacier on the northwest side of Port Valdez. At the fjord head, near the location of the badly damaged old town of Valdez, is an intricate series of gullies, channels, and talus, although these features display little evidence for the large-scale mass movement that occurred. However, near the center of the fjord is the front of a large debris lobe that flowed from the east end of the fjord half-way down the fjord and stopped. This huge deposit represents material that failed at the fjord head

  12. Tsunami hazards to U.S. coasts from giant earthquakes in Alaska

    USGS Publications Warehouse

    Ryan, Holly F.; von Huene, Roland; Scholl, Dave; Kirby, Stephen

    2012-01-01

    In the aftermath of Japan's devastating 11 March 2011Mw 9.0 Tohoku earthquake and tsunami, scientists are considering whether and how a similar tsunami could be generated along the Alaskan-Aleutian subduction zone (AASZ). A tsunami triggered by an earthquake along the AASZ would cross the Pacific Ocean and cause extensive damage along highly populated U.S. coasts, with ports being particularly vulnerable. For example, a tsunami in 1946 generated by a Mw 8.6 earthquake near Unimak Pass, Alaska (Figure 1a), caused significant damage along the U.S. West Coast, took 150 lives in Hawaii, and inundated shorelines of South Pacific islands and Antarctica [Fryer et al., 2004; Lopez and Okal, 2006]. The 1946 tsunami occurred before modern broadband seismometers were in place, and the mechanisms that created it remain poorly understood.

  13. Tsunami hazards to U.S. coasts from giant earthquakes in Alaska

    NASA Astrophysics Data System (ADS)

    Ryan, Holly; von Huene, Roland; Scholl, Dave; Kirby, Steve

    2012-05-01

    In the aftermath of Japan's devastating 11 March 2011Mw 9.0 Tohoku earthquake and tsunami, scientists are considering whether and how a similar tsunami could be generated along the Alaskan-Aleutian subduction zone (AASZ). A tsunami triggered by an earthquake along the AASZ would cross the Pacific Ocean and cause extensive damage along highly populated U.S. coasts, with ports being particularly vulnerable. For example, a tsunami in 1946 generated by a Mw 8.6 earthquake near Unimak Pass, Alaska (Figure 1a), caused signifcant damage along the U.S. West Coast, took 150 lives in Hawaii, and inundated shorelines of South Pacific islands and Antarctica [Fryer et al., 2004; Lopez and Okal, 2006]. The 1946 tsunami occurred before modern broadband seismometers were in place, and the mechanisms that created it remain poorly understood.

  14. Rapid Ice Mass Loss: Does It Have an Influence on Earthquake Occurrence in Southern Alaska?

    NASA Technical Reports Server (NTRS)

    Sauber, Jeanne M.

    2008-01-01

    The glaciers of southern Alaska are extensive, and many of them have undergone gigatons of ice wastage on time scales on the order of the seismic cycle. Since the ice loss occurs directly above a shallow main thrust zone associated with subduction of the Pacific-Yakutat plate beneath continental Alaska, the region between the Malaspina and Bering Glaciers is an excellent test site for evaluating the importance of recent ice wastage on earthquake faulting potential. We demonstrate the influence of cumulative glacial mass loss following the 1899 Yakataga earthquake (M=8.1) by using a two dimensional finite element model with a simple representation of ice fluctuations to calculate the incremental stresses and change in the fault stability margin (FSM) along the main thrust zone (MTZ) and on the surface. Along the MTZ, our results indicate a decrease in FSM between 1899 and the 1979 St. Elias earthquake (M=7.4) of 0.2 - 1.2 MPa over an 80 km region between the coast and the 1979 aftershock zone; at the surface, the estimated FSM was larger but more localized to the lower reaches of glacial ablation zones. The ice-induced stresses were large enough, in theory, to promote the occurrence of shallow thrust earthquakes. To empirically test the influence of short-term ice fluctuations on fault stability, we compared the seismic rate from a reference background time period (1988-1992) against other time periods (1993-2006) with variable ice or tectonic change characteristics. We found that the frequency of small tectonic events in the Icy Bay region increased in 2002-2006 relative to the background seismic rate. We hypothesize that this was due to a significant increase in the rate of ice wastage in 2002-2006 instead of the M=7.9, 2002 Denali earthquake, located more than 100km away.

  15. Supershear Rupture of 2013 Jan 05, Mw 7.5, Craig, Alaska earthquake

    NASA Astrophysics Data System (ADS)

    Yue, H.; Lay, T.; Freymueller, J. T.; Ding, K.; Rivera, L. A.; Ruppert, N. A.; Koper, K. D.

    2013-12-01

    Supershear rupture, in which a fracture's crack tip expansion velocity exceeds the elastic shear velocity, has been investigated theoretically and experimentally. Supershear rupture speeds have been inferred for six intraplate strike-slip earthquakes. In this work, we show evidence of supershear rupture expansion of an interplate earthquake, the 5 January 2013, Mw = 7.5, Craig, Alaska earthquake, which is a bilateral strike-slip event on the Queen Charlotte Fault, offshore of southeastern Alaska. We present direct observations of shear shock-waves in regional seismic stations using an empirical Green's function technique, which is most probably produced by a supershear rupture process. Several inversion and modeling techniques were processed to investigate the rupture ve.ocity using regional seismic and geodetic observations. Both theoretical and empirical Green's functions were used in inversion and modeling, with both indicate a consistent supear-shear rupture velocity of 5.5 to 6 km/s, higher than the crustal and upper-mantle S-wave velocity and approaching the P-wave velocity. Supershear rupture occurred along ~100 km of the northern rupture zone, but not along the shorter southern rupture extension. The direction of supershear rupture may be related to the strong material contrast across the continental-oceanic plate boundary, as predicted theoretically and experimentally.

  16. Effects of the earthquake of March 27, 1964, on the Alaska highway system: Chapter C in The Alaska earthquake, March 27, 1964: effects on transportation, communications, and utilities

    USGS Publications Warehouse

    Kachadoorian, Reuben

    1968-01-01

    The great earthquake that struck Alaska about 5:36 p.m., Alaska standard time, Friday, March 27, 1964 (03:36:1.3.0, Greenwich mean time, March 28, 1964), severely crippled the highway system in the south-central part of the State. All the major highways and most secondary roads were impaired. Damage totaled more than $46 million, well over $25 million to bridges and nearly $21 million to roadways. Of the 204 bridges in south-central Alaska, 141 were damaged; 92 were severely damaged or destroyed. The earthquake damaged 186 of the 830 miles of roadway in south-central Alaska, 83 miles so severely that replacement or relocation was required. Earthquake damage to the roadways and bridges was chiefly by (1) seismic shaking, (2) compaction of fills as well as the underlying sediments, (3) lateral displacement of the roadway and bridges, (4) fractures, (5) landslides, (6) avalanches, (7) inundation by seismic sea waves, (8) scouring by seismic sea waves, (9) regional tectonic subsidence, causing inundation and erosion by high tides in subsided areas. The intensity of damage was controlled primarily by the geologic environment (including the depth of the water table) upon which the highway structures rested, and secondarily by the engineering characteristics of the structures. Structures on bedrock were only slightly damaged if at all, whereas those on unconsolidated sediments were slightly to severely damaged, or were completely destroyed by seismic shaking. The low-lying areas underlain by saturated sediments, such as the Snow River Crossing and Turnagain Arm sections of the Seward-Anchorage Highway, were the most severely damaged stretches of the highway system in south-central Alaska. At Snow River and Turnagain Arm, the sediments underlying the roadway are fine grained and the water table is shallow. These factors were responsible for the intense damage along this stretch of the highway. All the bridges on the Copper River Highway except for one on bedrock were

  17. Geologic Traces of a Buried Rupture Earthquake Between the Southern Alaska and Bering Blocks

    NASA Astrophysics Data System (ADS)

    Higman, B. M.; Mattox, A.

    2015-12-01

    The nature and location of the transition between two large crustal blocks that comprise southern and western Alaska is unknown. Oblique subduction of the Pacific Plate beneath Alaska drives counterclockwise rotation of the Southern Alaska Block and clockwise rotation of the Bering Block, indicating crustal strain is occurring in a poorly delineated transition zone in Southcentral Alaska. Previously, no active faults have been identified in this transition zone, south of the Denali Fault and west of Cook Inlet. Near the north shore of Lake Iliamna, over 200 km from the nearest known active fault, we documented an 8 m drop followed by a 2 m rise in a 16,000 year-old abandoned lakeshore, interrupting 10 cm/km isostatic tilting. The deformation is spread over several kilometers. Evidence of dramatic liquefaction exposed in nearby bluffs dates to between 900 and 4200 years ago. These geologic traces tell a story of neotectonic deformation and strong shaking - consistent with a strong earthquake on a blind fault. Nearby geologic mapping and the graben-like depression in paleo-shoreline elevation we documented are consistent with extension accommodated along the Lake Clark Fault. Beyond relevance to regional tectonics, our results show previously undocumented seismic hazard in an area of a potential large-scale mining development (the proposed Pebble Mine), which would require perpetual waste storage.

  18. The January 2006 Volcanic-Tectonic Earthquake Swarm at Mount Martin, Alaska

    USGS Publications Warehouse

    Dixon, James P.; Power, John A.

    2009-01-01

    On January 8, 2006, a swarm of volcanic-tectonic earthquakes began beneath Mount Martin at the southern end of the Katmai volcanic cluster. This was the first recorded swarm at Mount Martin since continuous seismic monitoring began in 1996. The number of located earthquakes increased during the next four days, reaching a peak on January 11. For the next two days, the seismic activity decreased, and on January 14, the number of events increased to twice the previous day's total. Following this increase in activity, seismicity declined, returning to background levels by the end of the month. The Alaska Volcano Observatory located 860 earthquakes near Mount Martin during January 2006. No additional signs of volcanic unrest were noted in association with this earthquake swarm. The earthquakes in the Mount Martin swarm, relocated using the double difference technique, formed an elongated cluster dipping to the southwest. Focal mechanisms beneath Mount Martin show a mix of normal, thrust, and strike-slip solutions, with normal focal mechanisms dominating. For earthquakes more than 1 km from Mount Martin, all focal mechanisms showed normal faulting. The calculated b-value for the Mount Martin swarm is 0.98 and showed no significant change before, during, or after the swarm. The triggering mechanism for the Mount Martin swarm is unknown. The time-history of earthquake occurrence is indicative of a volcanic cause; however, there were no low-frequency events or observations, such as increased steaming associated with the swarm. During the swarm, there was no change in the b-value, and the distribution and type of focal mechanisms were similar to those in the period before the anomalous activity. The short duration of the swarm, the similarity in observed focal mechanisms, and the lack of additional signs of unrest suggest this swarm did not result from a large influx of magma within the shallow crust beneath Mount Martin.

  19. Uplift of the Kenai Peninsula, Alaska, since the 1964 Prince William Sound earthquake

    NASA Technical Reports Server (NTRS)

    Cohen, Steven; Holdahl, Sandford; Caprette, Douglas; Hilla, Stephen; Safford, Robert; Schultz, Donald

    1995-01-01

    Using Global Positioning System (GPS) receivers, we reoccupied several leveling benchmarks on the Kenai Peninsula of Alaska which had been surveyed by conventional leveling immediately following the March 27, 1964, Prince William Sound earthquake (M(sub w) = 9.3). By combining the two sets of measurements with a new, high-resolution model of the geoid in the region, we were able to determine the cumulative 1993-1964 postseismic vertical displacement. We find uplift at all of our benchmarks, relative to Seward, Alaska, a point that is stable according to tide gauge data. The maximum uplift of about 1 m occurs near the middle of the peninsula. The region of maximum uplift appears to be shifted northwest relative to the point of maximum coseismic subsidence. If we use tide gauge data at Nikishka and Seward to constrain the vertical motion, then the observed uplift has a trenchward tilt (down to the southeast) as well as an arching component. To explain the observations, we use creep-at-depth models. Most acceptable models require a fault slip of about 2.75 m, although this result is not unique. If the slip has been continuous since the 1964 earthquake, then the average slip rate is nearly 100 mm/yr, twice the plate convergence rate. Comparing the net uplift achieved in 29 years with that observed over 11 years in an adjacent region southeast of Anchorage, Alaska, we conclude that the rate of uplift is decreasing. A further decrease in the uplift rate is expected as the 29-year averaged displacement rate is about twice the plate convergence rate and therefore cannot be sustained over the entire earthquake cycle.

  20. Effects of the earthquake of March 27, 1964 in the Copper River Basin area, Alaska: Chapter E in The Alaska earthquake, March 27, 1964: regional effects

    USGS Publications Warehouse

    Ferrians, Oscar J.

    1966-01-01

    The Copper River Basin area is in south-central Alaska and covers 17,800 square miles. It includes most of the Copper River Basin and parts of the surrounding Alaska Range and the Talkeetna, Chugach, and Wrangell Mountains. On March 27, 1964, shortly after 5:36 p.m. Alaska standard time, a great earthquake having a Richter magnitude of about 8.5 struck south-central Alaska. Computations by the U.S. Coast and Geodetic Survey place the epicenter of the main shock at lat 61.1° N. and long 147.7° W., and the hypocenter, or actual point of origin, from 20 to 50 kilometers below the surface. The epicenter is near the western shore of Unakwik Inlet in northern Prince William Sound; it is 30 miles from the closest point within the area of study and 180 miles from the farthest point. Releveling data obtained in 1964 after the earthquake indicates that broad areas of south-central Alaska were warped by uplift and subsidence. The configuration of these areas generally parallels the trend of the major tectonic elements of the region. Presumably a large part of this change took place during and immediately after the 1964 earthquake. The water level in several wells in the area lowered appreciably, and the water in many became turbid; generally, however, within a few days after the earthquake the water level returned to normal and the suspended sediment settled out. Newspaper reports that the Copper River was completely dammed and Tazlina Lake drained proved erroneous. The ice on most lakes was cracked, especially around the margins of the lakes where floating ice broke free from the ice frozen to the shore. Ice on Tazlina, Klutina, and Tonsina Lakes was intensely fractured by waves generated by sublacustrine landslides off the fronts of deltas. These waves stranded large blocks of ice above water level along the shores. River ice was generally cracked in the southern half of the area and was locally cracked in the northern half. In the area of study, the majority of the

  1. Supershear rupture of the 5 January 2013 Craig, Alaska (Mw 7.5) earthquake

    NASA Astrophysics Data System (ADS)

    Yue, Han; Lay, Thorne; Freymueller, Jeffrey T.; Ding, Kaihua; Rivera, Luis; Ruppert, Natalia A.; Koper, Keith D.

    2013-11-01

    rupture, in which a fracture's crack tip expansion velocity exceeds the elastic shear wave velocity, has been extensively investigated theoretically and experimentally and previously inferred from seismic wave observations for six continental strike-slip earthquakes. We find extensive evidence of supershear rupture expansion of an oceanic interplate earthquake, the 5 January 2013 Mw = 7.5 Craig, Alaska earthquake. This asymmetric bilateral strike-slip rupture occurred on the Queen Charlotte Fault, offshore of southeastern Alaska. Observations of first-arriving Sn and Sg shear waves originating from positions on the fault closer than the hypocenter for several regional seismic stations, with path calibrations provided by an empirical Green's function approach, indicate a supershear rupture process. Several waveform inversion and modeling techniques were further applied to determine the rupture velocity and space-time distribution of slip using regional seismic and geodetic observations. Both theoretical and empirical Green's functions were used in the analyses, with all results being consistent with a rupture velocity of 5.5 to 6 km/s, exceeding the crustal and upper mantle S wave velocity and approaching the crustal P wave velocity. Supershear rupture occurred along ~100 km of the northern portion of the rupture zone but not along the shorter southern rupture extension. The direction in which supershear rupture developed may be related to the strong material contrast across the continental-oceanic plate boundary, as predicted theoretically and experimentally. The shear and surface wave Mach waves involve strongly enhanced ground motions at azimuths oblique to the rupture direction, emphasizing the enhanced hazard posed by supershear rupture of large strike-slip earthquakes.

  2. Effects of the Alaska earthquake of March 27, 1964, on shore processes and beach morphology: Chapter J in The Alaska earthquake, March 27, 1964: regional effects

    USGS Publications Warehouse

    Stanley, Kirk W.

    1968-01-01

    Some 10,000 miles of shoreline in south-central Alaska was affected by the subsidence or uplift associated with the great Alaska earthquake of March 27, 1964. The changes in shoreline processes and beach morphology that were suddenly initiated by the earthquake were similar to those ordinarily caused by gradual changes in sea level operating over hundreds of years, while other more readily visible changes were similar to some of the effects of great but short-lived storms. Phenomena became available for observation within a few hours which would otherwise not have been available for many years. In the subsided areas—including the shorelines of the Kenai Peninsula, Kodiak Island, and Cook Inlet—beaches tended to flatten in gradient and to recede shoreward. Minor beach features were altered or destroyed on submergence but began to reappear and to stabilize in their normal shapes within a few months after the earthquake. Frontal beach ridges migrated shoreward and grew higher and wider than they were before. Along narrow beaches backed by bluffs, the relatively higher sea level led to vigorous erosion of the bluff toes. Stream mouths were drowned and some were altered by seismic sea waves, but they adjusted within a few months to the new conditions. In the uplifted areas, generally around Prince William Sound, virtually all beaches were stranded out of reach of the sea. New beaches are gradually developing to fit new sea levels, but the processes are slow, in part because the material on the lower parts of the old beaches is predominantly fine grained. Streams were lengthened in the emergent areas, and down cutting and bank erosion have increased. Except at Homer and a few small villages, where groins, bulkheads, and cobble-filled baskets were installed, there has been little attempt to protect the postearthquake shorelines. The few structures that were built have been only partially successful because there was too little time to study the habits of the new shore

  3. Site velocities before and after the Loma Prieta and Gulf of Alaska earthquakes determined from VLBI

    NASA Technical Reports Server (NTRS)

    Argus, Donald F.; Lyzenga, Gregory A.

    1994-01-01

    We use geodetic data from Very Long Baseline Interferometry (VLBI) to determine the pre- and postseismic velocities of two sites. We then place limits on variations in interseismic strain buildup. The 1987 and 1988 Gulf of Alaska earthquakes (each Ms = 7.6) broke the Pacific plate interior. During the earthquakes the Cape Yakataga site moved 78 mm toward southwest. During the 1989 Loma Prieta earthquake (Ms = 7.1) the Fort Ord site moved 48 mm toward north. Baselines (a) from Fairbanks to Cape Yakataga and (b) from Mojave to Fort Ord change at nearly the same rate before and after the earthquakes. Postseismic transients, which we determine from differences between post- and preseismic rates, are minor: at Cape Yakataga the transient is 3 +/- 4 mm in a postseismic interval of 23 months, and at Fort Ord the transient is 6 +/- 5 mm in 21 months. The slip beneath the Loma Prieta rupture needed to generate the Fort Ord transient is 0.22 +/- 0.19 m, one-tenth the coseismic slip (2 m). We analyze elastic lithosphere-viscous asthenosphere models to determine that the characteristic time describing exponential decay in deep fault slip is longer than 6 years. The VLBI measurements are consistent with uniform interseismic strain buildup. They disagree with fast postseismic rates caused by an asthenosphere with very low viscosity.

  4. Submarine slope failures near Seward, Alaska, during the M9.2 1964 earthquake

    USGS Publications Warehouse

    Haeussler, P.J.; Lee, H.J.; Ryan, H.F.; Labay, K.; Kayen, R.E.; Hampton, M.A.; Suleimani, E.

    2007-01-01

    Following the 1964 M9.2 megathrust earthquake in southern Alaska, Seward was the only town hit by tsunamis generated from both submarine landslides and tectonic sources. Within 45 seconds of the start of the earthquake, a 1.2-km-long section of waterfront began sliding seaward, and soon after, ~6-8-m high waves inundated the town. Studies soon after the earthquake concluded that submarine landslides along the Seward waterfront generated the tsunamis that occurred immediately after the earthquake. We analyze pre- and post-earthquake bathymetry data to assess the location and extent of submarine mass failures and sediment transport. New NOAA multibeam bathymetry shows the morphology of the entire fjord at 15 m resolution. We also assembled all older soundings from smooth sheets for comparison to the multibeam dataset. We gridded the sounding data, applied corrections for coseismic subsidence, post-seismic rebound, unrecovered co-seismic subsidence, sea-level rise (vertical datum shift), and measurement errors. The difference grids show changes resulting from the 1964 earthquake. We estimate the total volume of slide material to be about 211 million m3. Most of this material was transported to a deep, flat area, which we refer to as “the bathtub”, about 6 to 13 km south of Seward. Sub-bottom profiling of the bathtub shows an acoustically transparent unit, which we interpret as a sediment flow deposit resulting from the submarine landslides. The scale of the submarine landslides and the distance over which sediment was transported is much larger than previously appreciated.

  5. An information infrastructure for earthquake science

    NASA Astrophysics Data System (ADS)

    Jordan, T. H.; Scec/Itr Collaboration

    2003-04-01

    The Southern California Earthquake Center (SCEC), in collaboration with the San Diego Supercomputer Center, the USC Information Sciences Institute,IRIS, and the USGS, has received a large five-year grant from the NSF's ITR Program and its Geosciences Directorate to build a new information infrastructure for earthquake science. In many respects, the SCEC/ITR Project presents a microcosm of the IT efforts now being organized across the geoscience community, including the EarthScope initiative. The purpose of this presentation is to discuss the experience gained by the project thus far and lay out the challenges that lie ahead; our hope is to encourage cross-discipline collaboration in future IT advancements. Project goals have been formulated in terms of four "computational pathways" related to seismic hazard analysis (SHA). For example, Pathway 1 involves the construction of an open-source, object-oriented, and web-enabled framework for SHA computations that can incorporate a variety of earthquake forecast models, intensity-measure relationships, and site-response models, while Pathway 2 aims to utilize the predictive power of wavefield simulation in modeling time-dependent ground motion for scenario earthquakes and constructing intensity-measure relationships. The overall goal is to create a SCEC "community modeling environment" or collaboratory that will comprise the curated (on-line, documented, maintained) resources needed by researchers to develop and use these four computational pathways. Current activities include (1) the development and verification of the computational modules, (2) the standardization of data structures and interfaces needed for syntactic interoperability, (3) the development of knowledge representation and management tools, (4) the construction SCEC computational and data grid testbeds, and (5) the creation of user interfaces for knowledge-acquisition, code execution, and visualization. I will emphasize the increasing role of standardized

  6. Seismic and Geodetic Investigation of the 1996-1998 Earthquake Swarm at Strandline Lake, Alaska

    NASA Astrophysics Data System (ADS)

    Kilgore, W.; Roman, D. C.; Power, J. A.; Hansen, R. A.; Biggs, J.

    2009-12-01

    Microearthquake (< M3.0) swarms occur frequently in volcanic environments, but do not always culminate in an eruption. Such non-eruptive swarms may be caused by stresses induced by magma intrusion, hydrothermal fluid circulation, or regional tectonic processes, such as slow-slip earthquakes. Strandline Lake, located 30 km northeast of Mount Spurr volcano in south-central Alaska, experienced a strong earthquake swarm between August 1996 and August 1998. The Alaska Volcano Observatory (AVO) catalog indicates that a total of 2,999 earthquakes were detected during the swarm period, with a maximum magnitude of Mw 3.1 and a depth range of 0-30 km below sea level (with the majority of catalog hypocenters located between 5-10 km BSL). The cumulative seismic moment of the swarm was 2.03e15 N m, equivalent to a cumulative magnitude of Mw 4.2. Because of the swarm's distance from the nearest Holocene volcanic vent, seismic monitoring was poor and gas and deformation data for the swarm period do not exist. However, combined waveforms from a dense seismic network on Mount Spurr and from several regional seismic stations allowed us to re-analyze the swarm earthquakes. We first developed a new 1-D velocity model for the Strandline Lake region by re-picking and inverting precise arrival times for 27 large Strandline Lake earthquakes. The new velocity model reduced the average RMS for these earthquakes from 0.16 to 0.11s, and the average horizontal and vertical location errors from 3.3 to 2.5 km and 4.7 to 3.0 km, respectively. Depths of the 27 earthquakes ranged from 10.5 to 22.1 km with an average depth of 16.6 km. A moderately high b-value of 1.33 was determined for the swarm period, possibly indicative of magmatic activity. However, a similarly high b-value of 1.25 was calculated for the background period. 28 well-constrained fault plane solutions for both swarm and background earthquakes indicate a diverse mixture of strike-slip, dip-slip, and reverse faulting beneath

  7. Earthquake locations determined by the Southern Alaska seismograph network for October 1971 through May 1989

    USGS Publications Warehouse

    Fogleman, Kent A.; Lahr, John C.; Stephens, Christopher D.; Page, Robert A.

    1993-01-01

    This report describes the instrumentation and evolution of the U.S. Geological Survey’s regional seismograph network in southern Alaska, provides phase and hypocenter data for seismic events from October 1971 through May 1989, reviews the location methods used, and discusses the completeness of the catalog and the accuracy of the computed hypocenters. Included are arrival time data for explosions detonated under the Trans-Alaska Crustal Transect (TACT) in 1984 and 1985.The U.S. Geological Survey (USGS) operated a regional network of seismographs in southern Alaska from 1971 to the mid 1990s. The principal purpose of this network was to record seismic data to be used to precisely locate earthquakes in the seismic zones of southern Alaska, delineate seismically active faults, assess seismic risks, document potential premonitory earthquake phenomena, investigate current tectonic deformation, and study the structure and physical properties of the crust and upper mantle. A task fundamental to all of these goals was the routine cataloging of parameters for earthquakes located within and adjacent to the seismograph network.The initial network of 10 stations, 7 around Cook Inlet and 3 near Valdez, was installed in 1971. In subsequent summers additions or modifications to the network were made. By the fall of 1973, 26 stations extended from western Cook Inlet to eastern Prince William Sound, and 4 stations were located to the east between Cordova and Yakutat. A year later 20 additional stations were installed. Thirteen of these were placed along the eastern Gulf of Alaska with support from the National Oceanic and Atmospheric Administration (NOAA) under the Outer Continental Shelf Environmental Assessment Program to investigate the seismicity of the outer continental shelf, a region of interest for oil exploration. Since then the region covered by the network remained relatively fixed while efforts were made to make the stations more reliable through improved electronic

  8. Offshore observations of aftershocks following the January 5th 2013 Mw 7.5 Queen Charlotte-Fairweather fault earthquake, southeast Alaska

    NASA Astrophysics Data System (ADS)

    Roland, E. C.; Gulick, S. P.; Levoir, M. A.; Haeussler, P. J.

    2013-12-01

    We present initial results from a rapid-response ocean bottom seismometer (OBS) deployment that recorded aftershock activity on the Queen Charlotte-Fairweather (QC-F) fault following the Mw 7.5 earthquake on January 5th 2013 near Craig, Alaska. This earthquake was the second of two Mw > 7 events on this fault system in a 3 month time period; the Craig earthquake followed a Mw 7.8 thrust event that occurred in October 2012, west of Haida Gwaii, British Columbia. Although the QC-F is a major plate boundary fault, little is known about the regional fault structure, interseismic coupling, and rheological controls on the depth distribution of seismic slip along the continent-ocean transform. The majority of the QC-F fault system extends offshore western British Columbia and southeast Alaska, making it difficult to characterize earthquakes and fault deformation with land-based seismic and geodetic instruments. This experiment is the first ever offshore seismometer deployment to record earthquake activity along this northern segment of the QC-F system, and was set in motion with help from the US Coast Guard, who provided a vessel and crew to deploy and recover the OBS array on short notice. The seismic array utilized 6 GeoPro short period OBS from the University of Texas Institute for Geophysics, which recorded approximately 3 weeks of aftershock activity in April-May of 2013. Combining high-quality local OBS recordings with land-based seismic observations from Alaska Earthquake Information Center (AEIC) stations to the east, we present more precise aftershock locations and depths that help to better characterize fault zone architecture along the northern section of the QC-F. Although moment tensor solutions indicate that the January 5th mainshock sustained slip consistent with Pacific-North America plate motions, aftershock focal mechanisms indicate some interaction with neighboring faults, such as the Chatham Straight fault. This new OBS dataset will also help to

  9. Catalog of earthquake hypocenters at Redoubt Volcano and Mt. Spurr, Alaska: October 12, 1989 - December 31, 1990

    USGS Publications Warehouse

    Power, John A.; March, Gail D.; Lahr, John C.; Jolly, Arthur D.; Cruse, Gina R.

    1993-01-01

    Following a 23 year period of quiescence, Redoubt Volcano erupted between December 14,1989 and April 21,1990. The eruption was accompanied by thousands of earthquakes (Alaska Volcano Observatory Staff, 1990). Throughout the eruption sequence, data from the PC/AT system provided the primary means of determining earthquake hypocenters. This report catalogs the earthquake hypocenters and magnitudes calculated from data collected between October 12, 1989 and December 31, 1990 on the PC/AT acquisition system, provides station locations, statistics, and calibrations, and outlines which stations were recorded and used in triggering the PC/AT system.

  10. Combining Dynamic Earthquake and Tsunami Models With Case Studies Offshore Alaska and Southern California

    NASA Astrophysics Data System (ADS)

    Ryan, Kenny

    Earthquakes and their corresponding tsunamis pose significant hazard to popu- lated regions around the world. Therefore, it is critically important that we seek to more fully understand the physics of the combined earthquake-tsunami system. One way to address this goal is through numerical modeling. The work discussed herein focuses on combining dynamic earthquake and tsunami models through the use of the Finite Element Method (FEM) and the Finite Difference Method (FDM). Dynamic earthquake models ac- count for the force that the entire fault system exerts on each individual element of the model for each time step, so that earthquake rupture takes a path based on the physics of the model; dynamic tsunami models can incorporate water height variations to produce water wave formation, propagation, and inundation. Chapter 1 provides an introduction to some important concepts and equations of elastodynamics and fluid dynamics as well as a brief example of the FEM. In Chapter 2, we investigate the 3-D effects of realistic fault dynamics on slip, free surface deformation, and resulting tsunami formation from an Mw 9 megathrust earthquake offshore Southern Alaska. Corresponding tsunami models, which use a FDM to solve linear long-wave equations, match sea floor deformation, in time, to the free surface deformation from the rupture simulations. Tsunamis generated in this region could have large adverse effects on Pacific coasts. In Chapter 3, we construct a 3-D dynamic rupture model of an earthquake on a reverse fault structure offshore Southern California to model the resulting tsunami, with a goal of elucidating the seismic and tsunami hazard in this area. The corresponding tsunami model uses final seafloor displacements from the rupture model as initial conditions to compute local propagation and inundation, resulting in large peak tsunami amplitudes northward and eastward due to site and path effects. In Chapter 4, we begin to evaluate 2-D earthquake source parameters

  11. Effects of the earthquake of March 27, 1964, at Seward, Alaska: Chapter E in The Alaska earthquake, March 27, 1964: effects on communities

    USGS Publications Warehouse

    Lemke, Richard W.

    1967-01-01

    Seward, in south-central Alaska, was one of the towns most devastated by the Alaska earthquake of March 27, 1964. The greater part of Seward is built on an alluvial fan-delta near the head of Resurrection Bay on the southeast coast of the Kenai Peninsula. It is one of the few ports in south-central Alaska that is ice free all year, and the town’s economy is almost entirely dependent upon its port facilities. The Alaska earthquake of March 27, 1964, magnitude approximately 8.3–8.4, began at 6:36 p.m. Its epicenter was in the northern part of the Prince William Sound area; focal depth was 20–50 km. Strong ground motion at Seward lasted 3–4 minutes. During the shaking, a strip of land 50–400 feet wide along the Seward waterfront, together with docks and other harbor facilities, slid into Resurrection Bay as a result of large-scale submarine landsliding. Fractures ruptured the ground for'severa1 hundred feet back from the landslide scarps. Additional ground was fractured in the Forest Acres subdivision and on the alluvial floor of the Resurrection River valley; fountaining and sand boils accompanied the ground fracturing. Slide-generated wares, possibly seiche waves, and seismic sea waves crashed onto shore; ware runup was as much as 30 feet above mean lower low water and caused tremendous damage; fire from burning oil tanks added to the destruction. Damage from strong ground motion itself was comparatively minor. Tectonic subsidence of about 3.6 feet resulted in low areas being inundated at high tide. Thirteen people were killed and five were injured as a result of the earthquake. Eighty-six houses were totally destroyed and 260 were heavily damaged. The harbor facilities were almost completely destroyed, and the entire economic base of the town was wiped out. The total cost to replace the destroyed public and private facilities was estimated at $22 million. Seward lies on the axis of the Chugach Mountains geosyncline. The main structural trend in the mapped

  12. Providing Seismotectonic Information to the Public Through Continuously Updated National Earthquake Information Center Products

    NASA Astrophysics Data System (ADS)

    Bernardino, M. J.; Hayes, G. P.; Dannemann, F.; Benz, H.

    2012-12-01

    summaries provide the public with immediate background information useful for teaching and media related purposes and are an essential component to many NEIC products. As part of the NEIC's earthquake response, rapid earthquake summary posters are created in the hours following a significant global earthquake. These regional tectonic summaries are included in each earthquake summary poster along with a discussion of the event, written by research scientists at the NEIC, often with help from regional experts. Now, through the efforts of this and related studies, event webpages will automatically contain a regional tectonic summary immediately after an event has been posted. These new summaries include information about plate boundary interactions and other associated tectonic elements, trends in seismicity and brief descriptions of significant earthquakes that have occurred in a region. The tectonic summaries for the following regions have been updated as part of this work: South America, the Caribbean, Alaska and the Aleutians, Kuril-Kamchatka, Japan and vicinity, and Central America, with newly created summaries for Sumatra and Java, the Mediterranean, Middle East, and the Himalayas. The NEIC is currently planning to integrate concise stylized maps with each tectonic summary for display on the USGS website.

  13. Three-dimensional P-wave velocity structure and precise earthquake relocation at Great Sitkin Volcano, Alaska

    USGS Publications Warehouse

    Pesicek, Jeremy; Thurber, Clifford H.; DeShon, Heather R.; Prejean, Stephanie G.; Zhang, Haijiang

    2008-01-01

    Waveform cross-correlation with bispectrum verification is combined with double-difference tomography to increase the precision of earthquake locations and constrain regional 3D P-wave velocity heterogeneity at Great Sitkin volcano, Alaska. From 1999 through 2005, the Alaska Volcano Observatory (AVO) recorded ∼1700 earthquakes in the vicinity of Great Sitkin, including two ML 4.3 earthquakes that are among the largest events in the AVO catalog. The majority of earthquakes occurred during 2002 and formed two temporally and spatially separate event sequences. The first sequence began on 17 March 2002 and was centered ∼20 km west of the volcano. The second sequence occurred on the southeast flank of Great Sitkin and began 28 May 2002. It was preceded by two episodes of volcanic tremor. Earthquake relocations of this activity on the southeast flank define a vertical planar feature oriented radially from the summit and in the direction of the assumed regional maximum compressive stress due to convergence along the Alaska subduction zone. This swarm may have been caused or accompanied by the emplacement of a dike. Relocations of the mainshock–aftershock sequence occurring west of Great Sitkin are consistent with rupture on a strike-slip fault. Tomographic images support the presence of a vertically dipping fault striking parallel to the direction of convergence in this region. The remaining catalog hypocenters relocate along discrete features beneath the volcano summit; here, low P-wave velocities possibly indicate the presence of magma beneath the volcano.

  14. Effects of the earthquake of March 27, 1964, at Anchorage, Alaska: Chapter A in The Alaska earthquake, March 27, 1964: effects on communities

    USGS Publications Warehouse

    Hansen, Wallace R.

    1965-01-01

    Anchorage, Alaska’s largest city, is about 80 miles west-northwest of the epicenter of the March 27 earthquake. Because of its size, Anchorage bore the brunt of property damage from the quake; it sustained greater losses than all the rest of Alaska combined. Damage was caused by direct seismic vibration, by ground cracks, and by landslides. Direct seismic vibration affected chiefly multistory buildings and buildings having large floor areas, probably because of the long period and large amplitude of the seismic waves reaching Anchorage. Most small buildings were spared. Ground cracks caused capricious damage throughout the Anchorage Lowland. Cracking was mast prevalent near the heads or within landslides but was also widespread elsewhere. Landslides themselves caused the most devastating damage. Triggering of landslides by the earthquake was related to the physical-engineering properties of the Bootlegger Cove Clay, a glacial estuarine-marine deposit that underlies much of the Anchorage area. The Bootlegger Cove Clay contains zones of low shear strength, high water content, and high sensitivity that failed under the vibratory stress of the earthquake. Shear strength in sensitive zones ranged from less than 0.2 tsf to about 0.5 tsf; sensitivity ranged from about 10 to more than 40. Sensitive zones generally are centered about 10 to 20 feet above sea level, between zones of stiff insensitive clay. Many physical tests by the U.S. Army Corps of Engineers were directed toward analyzing the causes of failure in the Bootlegger Cove Clay and finding possible remedies. Strengths and sensitivities were measured directly in the field by means of vane shear apparatus. A4tterberg limits, natural water contents, triaxial shear, sensitivity, dynamic modulus, consolidation strength, and other properties were measured in the laboratory. Pulsating-load tests simulated earthquake loading. Most of the destructive landslides in the Anchorage area moved primarily by translation rather

  15. Anisotropy, repeating earthquakes, and seismicity associated with the 2008 eruption of Okmok Volcano, Alaska

    USGS Publications Warehouse

    Johnson, Jessica H.; Prejean, Stephanie; Savage, Martha K.; Townend, John

    2010-01-01

    We use shear wave splitting (SWS) analysis and double-difference relocation to examine temporal variations in seismic properties prior to and accompanying magmatic activity associated with the 2008 eruption of Okmok volcano, Alaska. Using bispectrum cross-correlation, a multiplet of 25 earthquakes is identified spanning five years leading up to the eruption, each event having first motions compatible with a normal fault striking NE–SW. Cross-correlation differential times are used to relocate earthquakes occurring between January 2003 and February 2009. The bulk of the seismicity prior to the onset of the eruption on 12 July 2008 occurred southwest of the caldera beneath a geothermal field. Earthquakes associated with the onset of the eruption occurred beneath the northern portion of the caldera and started as deep as 13 km. Subsequent earthquakes occurred predominantly at 3 km depth, coinciding with the depth at which the magma body has been modeled using geodetic data. Automated SWS analysis of the Okmok catalog reveals radial polarization outside the caldera and a northwest-southeast polarization within. We interpret these polarizations in terms of a magma reservoir near the center of the caldera, which we model with a Mogi point source. SWS analysis using the same input processing parameters for each event in the multiplet reveals no temporal changes in anisotropy over the duration of the multiplet, suggesting either a short-term or small increase in stress just before the eruption that was not detected by GPS, or eruption triggering by a mechanism other than a change of stress in the system.

  16. Recorded earthquake responses from the integrated seismic monitoring network of the Atwood Building, Anchorage, Alaska

    USGS Publications Warehouse

    Celebi, M.

    2006-01-01

    An integrated seismic monitoring system with a total of 53 channels of accelerometers is now operating in and at the nearby free-field site of the 20-story steel-framed Atwood Building in highly seismic Anchorage, Alaska. The building has a single-story basement and a reinforced concrete foundation without piles. The monitoring system comprises a 32-channel structural array and a 21-channel site array. Accelerometers are deployed on 10 levels of the building to assess translational, torsional, and rocking motions, interstory drift (displacement) between selected pairs of adjacent floors, and average drift between floors. The site array, located approximately a city block from the building, comprises seven triaxial accelerometers, one at the surface and six in boreholes ranging in depths from 15 to 200 feet (???5-60 meters). The arrays have already recorded low-amplitude shaking responses of the building and the site caused by numerous earthquakes at distances ranging from tens to a couple of hundred kilometers. Data from an earthquake that occurred 186 km away traces the propagation of waves from the deepest borehole to the roof of the building in approximately 0.5 seconds. Fundamental structural frequencies [0.58 Hz (NS) and 0.47 Hz (EW)], low damping percentages (2-4%), mode coupling, and beating effects are identified. The fundamental site frequency at approximately 1.5 Hz is close to the second modal frequencies (1.83 Hz NS and 1.43 EW) of the building, which may cause resonance of the building. Additional earthquakes prove repeatability of these characteristics; however, stronger shaking may alter these conclusions. ?? 2006, Earthquake Engineering Research Institute.

  17. Hydrologic effects of the earthquake of March 27, 1964, outside Alaska, with sections on Hydroseismograms from the Nunn-Bush Shoe Co. well, Wisconsin, and Alaska earthquake effects on ground water in Iowa: Chapter C in The Alaska earthquakes, March 27, 1964: effects on hydrologic regimen

    USGS Publications Warehouse

    Vorhis, Robert C.; Rexin, Elmer E.; Coble, R.W.

    1967-01-01

    The Alaska earthquake of March 27, 1964, had widespread hydrologic effects throughout practically all of the United States. More than 1,450 water-level recorders, scattered throughout all the 50 States except Connecticut, Delaware, and Rhode Island, registered the earthquake. Half of the water-level records were obtained from ground-water observation wells and half at surface-water gaging stations. The earthquake is also known to have registered on water-level recorders on wells in Canada, England, Denmark, Belgium, Egypt, Israel, Libya, Philippine Islands, South-West Africa, South Africa, and Northern Territory of Australia. The Alaska earthquake is the first for which widespread surface-water effects are known. The effects were recorded at stations on flowing streams, rivers, reservoirs, lakes, and ponds. The 755 surface-water stations recording effects are spread through 38 States, but are most numerous in the south-central and southeastern States, especially in Florida and Louisiana. Most of the fluctuations recorded can be referred to more precisely as seismic seiches; however, a few stations recorded the quake as a minor change in stage. The largest recorded seiche outside Alaska was 1.83 feet on a reservoir in Michigan. The next largest was 1.45 feet on Lake Ouachita in Arkansas. The largest fluctuation in a well was 23 feet registered by a pressure recorder near Belle Fourche, S. Dak. Fluctuations of more than 10 feet were reported from wells in Alabama, Florida, Georgia, Illinois, Missouri, and Pennsylvania. A 3.40-foot fluctuation was recorded in a well in Puerto Rico. The Alaska earthquake was registered by about seven times as many water-level recorders as recorded the Hebgen Lake, Mont., earthquake of August 19, 1959.

  18. Seismic response of the katmai volcanoes to the 6 December 1999 magnitude 7.0 Karluk Lake earthquake, Alaska

    USGS Publications Warehouse

    Power, J.A.; Moran, S.C.; McNutt, S.R.; Stihler, S.D.; Sanchez, J.J.

    2001-01-01

    A sudden increase in earthquake activity was observed beneath volcanoes in the Katmai area on the Alaska Peninsula immediately following the 6 December 1999 magnitude (Mw) 7.0 Karluk Lake earthquake beneath southern Kodiak Island, Alaska. The observed increase in earthquake activity consisted of small (ML < 1.3), shallow (Z < 5.0 km) events. These earthquakes were located beneath Mount Martin, Mount Mageik, Trident Volcano, and the Katmai caldera and began within the coda of the Karluk Lake mainshock. All of these earthquakes occurred in areas and magnitude ranges that are typical for the background seismicity observed in the Katmai area. Seismicity rates returned to background levels 8 to 13 hours after the Karluk Lake mainshock. The close temporal relationship with the Karluk Lake mainshock, the onset of activity within the mainshock coda, and the simultaneous increase beneath four separate volcanic centers all suggest these earthquakes were remotely triggered. Modeling of the Coulomb stress changes from the mainshock for optimally oriented faults suggests negligible change in static stress beneath the Katmai volcanoes. This result favors models that involve dynamic stresses as the mechanism for triggered seismicity at Katmai.

  19. Harnessing the Collective Power of Eyewitnesses for Improved Earthquake Information

    NASA Astrophysics Data System (ADS)

    Bossu, R.; Lefebvre, S.; Mazet-Roux, G.; Steed, R.

    2013-12-01

    The Euro-Med Seismological Centre (EMSC) operates the second global earthquake information website (www.emsc-csem.org) which attracts 2 million visits a month from about 200 different countries. We collect information about earthquakes' effects from eyewitnesses such as online questionnaires, geolocated pics to rapidly constrain impact scenario. At the beginning, the collection was purely intended to address a scientific issue: the rapid evaluation of earthquake's impact. However, it rapidly appears that the understanding of eyewitnesses' expectations and motivations in the immediate aftermath of an earthquake was essential to optimise this data collection. Crowdsourcing information on earthquake's effects does not apply to a pre-existing community. By definition, eyewitnesses only exist once the earthquake has struck. We developed a strategy on social networks (Facebook, Google+, Twitter...) to interface with spontaneously emerging online communities of eyewitnesses. The basic idea is to create a positive feedback loop: attract eyewitnesses and engage with them by providing expected earthquake information and services, collect their observations, collate them for improved earthquake information services to attract more witnesses. We will present recent examples to illustrate how important the use of social networks is to engage with eyewitnesses especially in regions of low seismic activity where people are unaware of existing Internet resources dealing with earthquakes. A second type of information collated in our information services is derived from the real time analysis of the traffic on our website in the first minutes following an earthquake occurrence, an approach named flashsourcing. We show, using the example of the Mineral, Virginia earthquake that the arrival times of eyewitnesses of our website follows the propagation of the generated seismic waves and then, that eyewitnesses can be considered as ground motion sensors. Flashsourcing discriminates felt

  20. Alaska earthquake source for the SAFRR tsunami scenario: Chapter B in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

    USGS Publications Warehouse

    Kirby, Stephen; Scholl, David; von Huene, Roland; Wells, Ray

    2013-01-01

    Tsunami modeling has shown that tsunami sources located along the Alaska Peninsula segment of the Aleutian-Alaska subduction zone have the greatest impacts on southern California shorelines by raising the highest tsunami waves for a given source seismic moment. The most probable sector for a Mw ~ 9 source within this subduction segment is between Kodiak Island and the Shumagin Islands in what we call the Semidi subduction sector; these bounds represent the southwestern limit of the 1964 Mw 9.2 Alaska earthquake rupture and the northeastern edge of the Shumagin sector that recent Global Positioning System (GPS) observations indicate is currently creeping. Geological and geophysical features in the Semidi sector that are thought to be relevant to the potential for large magnitude, long-rupture-runout interplate thrust earthquakes are remarkably similar to those in northeastern Japan, where the destructive Mw 9.1 tsunamigenic earthquake of 11 March 2011 occurred. In this report we propose and justify the selection of a tsunami source seaward of the Alaska Peninsula for use in the Tsunami Scenario that is part of the U.S. Geological Survey (USGS) Science Application for Risk Reduction (SAFRR) Project. This tsunami source should have the potential to raise damaging tsunami waves on the California coast, especially at the ports of Los Angeles and Long Beach. Accordingly, we have summarized and abstracted slip distribution from the source literature on the 2011 event, the best characterized for any subduction earthquake, and applied this synoptic slip distribution to the similar megathrust geometry of the Semidi sector. The resulting slip model has an average slip of 18.6 m and a moment magnitude of Mw = 9.1. The 2011 Tohoku earthquake was not anticipated, despite Japan having the best seismic and geodetic networks in the world and the best historical record in the world over the past 1,500 years. What was lacking was adequate paleogeologic data on prehistoric earthquakes

  1. RELATIVE SOURCE TIME FUNCTION STUDIES OF EARTHQUAKES IN SOUTHEASTERN ALASKA-NORTHWESTERN CANADA

    NASA Astrophysics Data System (ADS)

    Escudero, C. R.; Doser, D. I.

    2009-12-01

    We are using the Relative Source Time Function (RSTF) method to determine the source properties of sixteen earthquakes within southeastern Alaska-northwestern Canada, a region extending from south of the Queen Charlotte Islands to Icy Bay, and north to the Totschunda fault. In our approach we deconvolve the spectral quotient of the P-arrival of a small event from that of a larger event. The arrivals are selected using a tapered cosine window, then we use a water level technique to stabilize the quotient in the frequency domain, and we apply a bandpass or highcut filter before inverse transforming our result. We compare the source processes of earthquakes along the Queen Charlotte-Fairweather fault system to those occurring off these major plate bounding faults to determine the differences in the relation of moment and stress drop, as well as source duration between these regions. Secondly, we determine the relation between the observed differences in source processes of events along the Queen Charlotte-Fairweather fault system and the location of the events relative to known fault asperities and segment boundaries. Finally, we perform a directivity analysis of the obtained relative source time functions.

  2. NEIC; the National Earthquake Information Center

    USGS Publications Warehouse

    Masse, R.P.; Needham, R.E.

    1989-01-01

    At least 9,500 people were killed, 30,000 were injured and 100,000 were left homeless by this earthquake. According to some unconfirmed reports, the death toll from this earthquake may have been as high as 35,000. this earthquake is estimated to have seriously affected an area of 825,000 square kilometers, caused between 3 and 4 billion dollars in damage, and been felt by 20 million people. 

  3. Reconnaissance engineering geology of the Metlakatla area, Annette Island, Alaska, with emphasis on evaluation of earthquakes and other geologic hazards

    USGS Publications Warehouse

    Yehle, Lynn A.

    1977-01-01

    A program to study the engineering geology of most larger Alaska coastal communities and to evaluate their earthquake and other geologic hazards was started following the 1964 Alaska earthquake; this report about the Metlakatla area, Annette Island, is a product of that program. Field-study methods were of a reconnaissance nature, and thus the interpretations in the report are tentative. Landscape of the Metlakatla Peninsula, on which the city of Metlakatla is located, is characterized by a muskeg-covered terrane of very low relief. In contrast, most of the rest of Annette Island is composed of mountainous terrane with steep valleys and numerous lakes. During the Pleistocene Epoch the Metlakatla area was presumably covered by ice several times; glaciers smoothed the present Metlakatla Peninsula and deeply eroded valleys on the rest. of Annette Island. The last major deglaciation was completed probably before 10,000 years ago. Rebound of the earth's crust, believed to be related to glacial melting, has caused land emergence at Metlakatla of at least 50 ft (15 m) and probably more than 200 ft (61 m) relative to present sea level. Bedrock in the Metlakatla area is composed chiefly of hard metamorphic rocks: greenschist and greenstone with minor hornfels and schist. Strike and dip of beds are generally variable and minor offsets are common. Bedrock is of late Paleozoic to early Mesozoic age. Six types of surficial geologic materials of Quaternary age were recognized: firm diamicton, emerged shore, modern shore and delta, and alluvial deposits, very soft muskeg and other organic deposits, and firm to soft artificial fill. A combination map unit is composed of bedrock or diamicton. Geologic structure in southeastern Alaska is complex because, since at least early Paleozoic time, there have been several cycles of tectonic deformation that affected different parts of the region. Southeastern Alaska is transected by numerous faults and possible faults that attest to major

  4. Three-dimensional seismic velocity structure and earthquake relocations at Katmai, Alaska

    USGS Publications Warehouse

    Murphy, Rachel; Thurber, Clifford; Prejean, Stephanie G.; Bennington, Ninfa

    2014-01-01

    We invert arrival time data from local earthquakes occurring between September 2004 and May 2009 to determine the three-dimensional (3D) upper crustal seismic structure in the Katmai volcanic region. Waveforms for the study come from the Alaska Volcano Observatory's permanent network of 20 seismic stations in the area (predominantly single-component, short period instruments) plus a densely spaced temporary array of 11 broadband, 3-component stations. The absolute and relative arrival times are used in a double-difference seismic tomography inversion to solve for 3D P- and S-wave velocity models for an area encompassing the main volcanic centers. The relocated hypocenters provide insight into the geometry of seismogenic structures in the area, revealing clustering of events into four distinct zones associated with Martin, Mageik, Trident-Novarupta, and Mount Katmai. The seismic activity extends from about sea level to 2 km depth (all depths referenced to mean sea level) beneath Martin, is concentrated near 2 km depth beneath Mageik, and lies mainly between 2 and 4 km depth below Katmai and Trident-Novarupta. Many new features are apparent within these earthquake clusters. In particular, linear features are visible within all clusters, some associated with swarm activity, including an observation of earthquake migration near Trident in 2008. The final velocity model reveals a possible zone of magma storage beneath Mageik, but there is no clear evidence for magma beneath the Katmai-Novarupta area where the 1912 eruptive activity occurred, suggesting that the storage zone for that eruption may have largely been evacuated, or remnant magma has solidified.

  5. Effects of the March 1964 Alaska earthquake on the hydrology of the Anchorage area, Alaska: Chapter B in The Alaska earthquake, March 27, 1964: effects hydrologic regimen

    USGS Publications Warehouse

    Waller, Roger M.

    1966-01-01

    The Anchorage hydrologic system was greatly affected by the seismic shock. Immediate but temporary effects included increased stream discharge, seiche action on lakes, and fluctuations in ground-water levels. Generally, ground-water levels were residually lowered after the initial period of fluctuation. This lowering is attributed either to changes in the discharge zones offshore or to a change in the permeability of the aquifers by seismically induced strain. Water supplies were disrupted temporarily by snowslides on streams and by sanding or turbidity in wells. Salt-water encroachment to wells on Fire Island seems to have increased. The approximate 3.7-foot lowering of land level and the diminished artesian head may permit further salt-water encroachment. Increased pore pressure in the Pleistocene Bootlegger Cove Clay led to liquefaction in silt and sand lenses that contributed to the disastrous bluff landslides. Measurements after the earthquake indicate that most pore pressures are declining, whereas some remain high or are increasing. Subsidence in the area was caused principally by tectonic readjustment, but differential compaction within the Bootlegger Cove Clay contributed to subsidences estimated to be as much as 0.6 foot beneath Anchorage.

  6. Unraveling the Earthquake History of the Denali Fault System, Alaska: Filling a Blank Canvas With Paleoearthquakes

    NASA Astrophysics Data System (ADS)

    Schwartz, D. P.; Haeussler, P. J.; Seitz, G. G.; Dawson, T. E.; Stenner, H. D.; Matmon, A.; Crone, A. J.; Personius, S.; Burns, P. B.; Cadena, A.; Thoms, E.

    2005-12-01

    Developing accurate rupture histories of long, high-slip-rate strike-slip faults is is especially challenging where recurrence is relatively short (hundreds of years), adjacent segments may fail within decades of each other, and uncertainties in dating can be as large as, or larger than, the time between events. The Denali Fault system (DFS) is the major active structure of interior Alaska, but received little study since pioneering fault investigations in the early 1970s. Until the summer of 2003 essentially no data existed on the timing or spatial distribution of past ruptures on the DFS. This changed with the occurrence of the M7.9 2002 Denali fault earthquake, which has been a catalyst for present paleoseismic investigations. It provided a well-constrained rupture length and slip distribution. Strike-slip faulting occurred along 290 km of the Denali and Totschunda faults, leaving unruptured ?140km of the eastern Denali fault, ?180 km of the western Denali fault, and ?70 km of the eastern Totschunda fault. The DFS presents us with a blank canvas on which to fill a chronology of past earthquakes using modern paleoseismic techniques. Aware of correlation issues with potentially closely-timed earthquakes we have a) investigated 11 paleoseismic sites that allow a variety of dating techniques, b) measured paleo offsets, which provide insight into magnitude and rupture length of past events, at 18 locations, and c) developed late Pleistocene and Holocene slip rates using exposure age dating to constrain long-term fault behavior models. We are in the process of: 1) radiocarbon-dating peats involved in faulting and liquefaction, and especially short-lived forest floor vegetation that includes outer rings of trees, spruce needles, and blueberry leaves killed and buried during paleoearthquakes; 2) supporting development of a 700-900 year tree-ring time-series for precise dating of trees used in event timing; 3) employing Pb 210 for constraining the youngest ruptures in

  7. Erosion and deposition on a beach raised by the 1964 earthquake, Montague Island, Alaska: Chapter H in The Alaska earthquake, March 27, 1964: regional effects

    USGS Publications Warehouse

    Kirkby, M.J.; Kirkby, Anne V.

    1969-01-01

    During the 1964 Alaska earthquake, tectonic deformation uplifted the southern end of Montague Island as much as 33 feet or more. The uplifted shoreline is rapidly being modified by subaerial and marine processes. The new raised beach is formed in bedrock, sand, gravel, and deltaic bay-head deposits, and the effect of each erosional process was measured in each material. Fieldwork was concentrated in two areas—MacLeod Harbor on the northwest side and Patton Bay on the southeast side of Montague Island. In the unconsolidated deltaic deposits of MacLeod Harbor, 97 percent of the erosion up to June 1965, 15 months after the earthquake, was fluvial, 2.2 percent was by rainwash, and only 0.8 percent was marine; 52 percent of the total available raised beach material had already been removed. The volume removed by stream erosion was proportional to low-flow discharge raised to the power of 0.75 to 0.95, and this volume increased as the bed material became finer. Stream response to the relative fall in base level was very rapid, most of the downcutting in unconsolidated materials occurring within 48 hours of the uplift for streams with low flows greater than 10 cubic feet per second. Since then, erosion by these streams has been predominantly lateral. Streams with lower discharges, in unconsolidated materials, still had knickpoints after 15 months. No response to uplift could be detected in stream courses above the former preearthquake sea level. Where the raised beach is in bedrock, it is being destroyed principally by marine action but at such a low rate that no appreciable erosion of bedrock was found 15 months after the earthquake. A dated rock platform raised earlier has eroded at a mean rate of 0.49 foot per year. In this area the factor limiting the rate of erosion was rock resistance rather than the transporting capacity of the waves. The break in slope between the top of the raised beach and the former seacliff is being obliterated by debris which is

  8. Surface rupture of the 2002 Denali fault, Alaska, earthquake and comparison with other strike-slip ruptures

    USGS Publications Warehouse

    Haeussler, P.J.; Schwartz, D.P.; Dawson, T.E.; Stenner, Heidi D.; Lienkaemper, J.J.; Cinti, F.; Montone, Paola; Sherrod, B.; Craw, P.

    2004-01-01

    On 3 November 2002, an M7.9 earthquake produced 340 km of surface rupture on the Denali and two related faults in Alaska. The rupture proceeded from west to east and began with a 40-km-long break on a previously unknown thrust fault. Estimates of surface slip on this thrust are 3-6 m. Next came the principal surface break along ???218 km of the Denali fault. Right-lateral offsets averaged around 5 m and increased eastward to a maximum of nearly 9 m. The fault also ruptured beneath the trans-Alaska oil pipeline, which withstood almost 6 m of lateral offset. Finally, slip turned southeastward onto the Totschunda fault. Right-lateral offsets are up to 3 m, and the surface rupture is about 76 km long. This three-part rupture ranks among the longest strike-slip events of the past two centuries. The earthquake is typical when compared to other large earthquakes on major intracontinental strike-slip faults. ?? 2004, Earthquake Engineering Research Institute.

  9. Revisiting the 1899 Earthquakes of Yakutat Bay, Alaska Using New and Existing Geophysical Data

    NASA Astrophysics Data System (ADS)

    Walton, M. A. L.; Gulick, S. P. S.; Haeussler, P. J.

    2015-12-01

    North of Yakutat Bay in southeastern Alaska, the subducting Yakutat Block intersects with the Fairweather transform fault system. A series of large earthquakes occurred in the region in September of 1899, including a Mw 8.2 event on 10 September that resulted in >14 m of coseismic uplift and a 6 m tsunami in Yakutat Bay. Despite recurrence risk of the 1899 or similar events in the region, the fault(s) that ruptured in 1899 remain unidentified. Previous efforts to map active Yakutat Bay faults carried out by Plafker and Thatcher (2008) used post-1899 bedrock uplift measurements to infer the location of potentially important structures, including the Esker Creek and Bancas Point thrusts. As measurement error was not assessed in their study, we revisit the uplift measurements by quantifying uncertainty due to glacial isostatic adjustment, tidal range, and specific benchmark methods. We also combine new seismic reflection data with existing topography, bathymetry, GPS, and satellite photo data to update the original fault map. Our reevaluation of uplift measurements suggests that primary slip and uplift during the 10 September earthquake was limited to northwest of Yakutat Bay. Additionally, a high-resolution seismic reflection survey we conducted in Yakutat Bay during August 2012 constrains faulting to on- or near-shore based on the absence of bay-crossing faults. Collectively, our results imply that predominantly strike-slip and transpressive horsetail-type faults are southeast of Yakutat Bay, with compressional structures related to Yakutat Block subduction/collision to the northwest. We interpret the 10 September 1899 event to be the result of complex rupture somewhere within the Yakutat subduction/collision system. Based on our updated map of coseismic uplift and fault structure, we favor a rupture model where primary slip occurred along the Esker Creek system locally with possible induced coseismic slip along the neighboring Boundary transpressive fault system.

  10. Swarms of repeating long-period earthquakes at Shishaldin Volcano, Alaska, 2001-2004

    USGS Publications Warehouse

    Petersen, Tanja

    2007-01-01

    During 2001–2004, a series of four periods of elevated long-period seismic activity, each lasting about 1–2 months, occurred at Shishaldin Volcano, Aleutian Islands, Alaska. The time periods are termed swarms of repeating events, reflecting an abundance of earthquakes with highly similar waveforms that indicate stable, non-destructive sources. These swarms are characterized by increased earthquake amplitudes, although the seismicity rate of one event every 0.5–5 min has remained more or less constant since Shishaldin last erupted in 1999. A method based on waveform cross-correlation is used to identify highly repetitive events, suggestive of spatially distinct source locations. The waveform analysis shows that several different families of similar events co-exist during a given swarm day, but generally only one large family dominates. A network of hydrothermal fractures may explain the events that do not belong to a dominant repeating event group, i.e. multiple sources at different locations exist next to a dominant source. The dominant waveforms exhibit systematic changes throughout each swarm, but some of these waveforms do reappear over the course of 4 years indicating repeatedly activated source locations. The choked flow model provides a plausible trigger mechanism for the repeating events observed at Shishaldin, explaining the gradual changes in waveforms over time by changes in pressure gradient across a constriction within the uppermost part of the conduit. The sustained generation of Shishaldin's long-period events may be attributed to complex dynamics of a multi-fractured hydrothermal system: the pressure gradient within the main conduit may be regulated by temporarily sealing and reopening of parallel flow pathways, by the amount of debris within the main conduit and/or by changing gas influx into the hydrothermal system. The observations suggest that Shishaldin's swarms of repeating events represent time periods during which a dominant source

  11. Intermediate-Term Declines in Seismicity at Two Volcanoes in Alaska Following the Mw7.9 Denali Fault Earthquake

    NASA Astrophysics Data System (ADS)

    McNutt, S. R.; Sanchez, J. J.; Moran, S. C.; Power, J. A.

    2002-12-01

    The Mw7.9 Denali Fault earthquake provided an opportunity to look for intermediate-term (days to weeks) responses of Alaskan volcanoes to shaking from a large regional earthquake. The Alaska Volcano Observatory monitors 24 volcanoes with seismic networks. We examined one station for each volcano, generally the closest (typically 5 km from the vent) unless noise, site response, or other factors made the data unusable. Data were digitally bandpass filtered between 0.8 and 5 Hz to reduce noise from microseisms and wind. Data for the period three days before to three days after the Mw7.9 earthquake were then plotted at a standard scale used for AVO routine monitoring. Shishaldin volcano, which has a background rate of several hundred seismic events per day on station SSLS, showed no change from before to after the earthquake. Veniaminof volcano, which has had recent mild eruptions and a rate of several dozen seismic events per day on station VNNF, suffered a drop in seismicity at the time of the earthquake by a factor of 2.5; this lasted for 15 days. We tested this result using a different station, VNSS, and a different method of counting (non-filtered data on helicorder records) and found the same result. We infer that Veniaminof's activity was modified by the Mw7.9 earthquake. Wrangell, the closest volcano, had a background rate of about 10 events per day. Data from station WANC could not be measured for 8 days after the Mw7.9 earthquake because the large number of aftershocks precluded identification of local seismicity. For the following eight days, however, its seismicity rate was 30 percent lower than before. While subtle, we infer that this may be related to the earthquake. It is known that Wrangell increased its heat output after the Mw9.2 Alaska earthquake of 1964 and again after the Ms7.1 St. Elias earthquake of 1979. The other 21 volcanoes showed no changes in seismicity from 3 days before to 3 days after the Mw7.9 event. We conclude that intermediate

  12. Geophysical data reveal the crustal structure of the Alaska Range orogen within the aftershock zone of the Mw 7.9 Denali fault earthquake

    USGS Publications Warehouse

    Fisher, M.A.; Ratchkovski, N.A.; Nokleberg, W.J.; Pellerin, L.; Glen, J.M.G.

    2004-01-01

    Geophysical information, including deep-crustal seismic reflection, magnetotelluric (MT), gravity, and magnetic data, cross the aftershock zone of the 3 November 2002 Mw 7.9 Denali fault earthquake. These data and aftershock seismicity, jointly interpreted, reveal the crustal structure of the right-lateral-slip Denali fault and the eastern Alaska Range orogen, as well as the relationship between this structure and seismicity. North of the Denali fault, strong seismic reflections from within the Alaska Range orogen show features that dip as steeply as 25?? north and extend downward to depths between 20 and 25 km. These reflections reveal crustal structures, probably ductile shear zones, that most likely formed during the Late Cretaceous, but these structures appear to be inactive, having produced little seismicity during the past 20 years. Furthermore, seismic reflections mainly dip north, whereas alignments in aftershock hypocenters dip south. The Denali fault is nonreflective, but modeling of MT, gravity, and magnetic data suggests that the Denali fault dips steeply to vertically. However, in an alternative structural model, the Denali fault is defined by one of the reflection bands that dips to the north and flattens into the middle crust of the Alaska Range orogen. Modeling of MT data indicates a rock body, having low electrical resistivity (>10 ??-m), that lies mainly at depths greater than 10 km, directly beneath aftershocks of the Denali fault earthquake. The maximum depth of aftershocks along the Denali fault is 10 km. This shallow depth may arise from a higher-than-normal geothermal gradient. Alternatively, the low electrical resistivity of deep rocks along the Denali fault may be associated with fluids that have weakened the lower crust and helped determine the depth extent of the after-shock zone.

  13. Seismology Outreach in Alaska

    NASA Astrophysics Data System (ADS)

    Gardine, L.; Tape, C.; West, M. E.

    2014-12-01

    Despite residing in a state with 75% of North American earthquakes and three of the top 15 ever recorded, most Alaskans have limited knowledge about the science of earthquakes. To many, earthquakes are just part of everyday life, and to others, they are barely noticed until a large event happens, and often ignored even then. Alaskans are rugged, resilient people with both strong independence and tight community bonds. Rural villages in Alaska, most of which are inaccessible by road, are underrepresented in outreach efforts. Their remote locations and difficulty of access make outreach fiscally challenging. Teacher retention and small student bodies limit exposure to science and hinder student success in college. The arrival of EarthScope's Transportable Array, the 50th anniversary of the Great Alaska Earthquake, targeted projects with large outreach components, and increased community interest in earthquake knowledge have provided opportunities to spread information across Alaska. We have found that performing hands-on demonstrations, identifying seismological relevance toward career opportunities in Alaska (such as natural resource exploration), and engaging residents through place-based experience have increased the public's interest and awareness of our active home.

  14. Effects of the earthquake of March 27, 1964, on air and water transport, communications, and utilities systems in south-central Alaska: Chapter B in The Alaska earthquake, March 27, 1964: effects on transportation, communications, and utilities

    USGS Publications Warehouse

    Eckel, Edwin B.

    1967-01-01

    The earthquake of March 27, 1964, wrecked or severely hampered all forms of transportation, all utilities, and all communications systems over a very large part of south-central Alaska. Effects on air transportation were minor as compared to those on the water, highway, and railroad transport systems. A few planes were damaged or wrecked by seismic vibration or by flooding. Numerous airport facilities were damaged by vibration or by secondary effects of the earthquake, notably seismic sea and landslide-generated waves, tectonic subsidence, and compaction. Nearly all air facilities were partly or wholly operational within a few hours after the earthquake. The earthquake inflicted enormous damage on the shipping industry, which is indispensable to a State that imports fully 90 percent of its requirements—mostly by water—and whose largest single industry is fishing. Except for those of Anchorage, all port facilities in the earthquake-affected area were destroyed or made inoperable by submarine slides, waves, tectonic uplift, and fire. No large vessels were lost, but more than 200 smaller ones (mostly crab or salmon boats) were lost or severely damaged. Navigation aids were destroyed, and hitherto well-known waterways were greatly altered by uplift or subsidence. All these effects wrought far-reaching changes in the shipping economy of Alaska, many of them to its betterment. Virtually all utilities and communications in south-central Alaska were damaged or wrecked by the earthquake, but temporary repairs were effected in remarkably short times. Communications systems were silenced almost everywhere by loss of power or by downed lines; their place was quickly taken by a patchwork of self-powered radio transmitters. A complex power-generating system that served much of the stricken area from steam, diesel, and hydrogenerating plants was disrupted in many places by vibration damage to equipment and by broken transmission lines. Landslides in Anchorage broke gas

  15. ­Dynamic interactions between the October 28th 2012 Haida Gwaii and January 5th 2013 Craig earthquakes and other faults in Southeast Alaska

    NASA Astrophysics Data System (ADS)

    Walter, J. I.; Kao, H.; Meng, X.; Peng, Z.; Hobbs, T. E.; Dotray, P.; Newman, A. V.; Mulder, T.

    2015-12-01

    The Mw 7.8 (28 October 2012) Haida Gwaii earthquake and the Mw 7.5 (5 January 2013) Craig, Alaska earthquake occurred just 400 km and 68 days apart from each other. The short duration and distance between the events poses the question of whether these two events are related. We combine existing seismic data from permanent networks in Alaska and Canada, including temporary aftershock deployments (both on land and ocean-bottom sensors) installed in the Haida Gwaii islands, to search for precursory activity prior to each of the events. In order to improve the catalog completeness, we utilize a matched-filter technique to identify potential missing earthquakes before and after each mainshock. This technique utilizes existing cataloged waveforms as templates to identify repeating or nearby earthquakes with high cross-correlations. We examine the seismic activity prior to and following each event and determine whether any dynamic or delayed triggering of earthquakes or tremor occurs regionally due to these earthquakes. We find small earthquakes on the Fairweather Fault, near Glacier Bay, directly triggered in the minutes after the Haida Gwaii event. In addition, preliminary evidence suggests the Haida Gwaii earthquake triggered some seismicity in the rupture region of the Craig earthquake over the ~2 month period of time between the mainshocks. We plan to assess whether the later-occurring Craig earthquake triggered any increase in aftershock activity within the Haida Gwaii rupture region. The static and dynamic transmission of stresses from large earthquakes has important implications for transient fault zone loading in areas adjacent to those initial rupture zones. This study should shed some light on large earthquake interactions at various distance scales and future seismic risks across Alaska and western Canada.

  16. Earthquakes

    EPA Pesticide Factsheets

    Information on this page will help you understand environmental dangers related to earthquakes, what you can do to prepare and recover. It will also help you recognize possible environmental hazards and learn what you can do to protect you and your family

  17. Effects of the earthquake of March 27, 1964, on the Alaska Railroad: Chapter D in The Alaska earthquake, March 27, 1964: effects on transportation, communications, and utilities

    USGS Publications Warehouse

    McCulloch, David S.; Bonilla, Manuel G.

    1970-01-01

    In the 1964 Alaska earthquake, the federally owned Alaska Railroad sustained damage of more than $35 million: 54 percent of the cost for port facilities; 25 percent, roadbed and track; 9 percent, buildings and utilities; 7 percent, bridges and culverts; and 5 percent, landslide removal. Principal causes of damage were: (1) landslides, landslide-generated waves, and seismic sea waves that destroyed costly port facilities built on deltas; (2) regional tectonic subsidence that necessitated raising and armoring 22 miles of roadbed made susceptible to marine erosion; and (3), of greatest importance in terms of potential damage in seismically active areas, a general loss of strength experienced by wet waterlaid unconsolidated granular sediments (silt to coarse gravel) that allowed embankments to settle and enabled sediments to undergo fiowlike displacement toward topographic depressions, even in fiat-lying areas. The term “landspreading” is proposed for the lateral displacement and distension of mobilized sediments; landspreading appears to have resulted largely from liquefaction. Because mobilization is time dependent and its effects cumulative, the long duration of strong ground motion (timed as 3 to 4 minutes) along the southern 150 miles of the rail line made landspreading an important cause of damage. Sediments moved toward natural and manmade topographic depressions (stream valleys, gullies, drainage ditches, borrow pits, and lakes). Stream widths decreased, often about 20 inches but at some places by as much as 6.5 feet, and sediments moved upward beneath stream channels. Landspreading toward streams and even small drainage ditches crushed concrete and metal culverts. Bridge superstructures were compressed and failed by lateral buckling, or more commonly were driven into, through, or over bulkheads. Piles and piers were torn free of superstructures by moving sediments, crowded toward stream channels, and lifted in the center. The lifted piles arched the

  18. A teleseismic study of the 2002 Denali fault, Alaska, earthquake and implications for rapid strong-motion estimation

    USGS Publications Warehouse

    Ji, C.; Helmberger, D.V.; Wald, D.J.

    2004-01-01

    Slip histories for the 2002 M7.9 Denali fault, Alaska, earthquake are derived rapidly from global teleseismic waveform data. In phases, three models improve matching waveform data and recovery of rupture details. In the first model (Phase I), analogous to an automated solution, a simple fault plane is fixed based on the preliminary Harvard Centroid Moment Tensor mechanism and the epicenter provided by the Preliminary Determination of Epicenters. This model is then updated (Phase II) by implementing a more realistic fault geometry inferred from Digital Elevation Model topography and further (Phase III) by using the calibrated P-wave and SH-wave arrival times derived from modeling of the nearby 2002 M6.7 Nenana Mountain earthquake. These models are used to predict the peak ground velocity and the shaking intensity field in the fault vicinity. The procedure to estimate local strong motion could be automated and used for global real-time earthquake shaking and damage assessment. ?? 2004, Earthquake Engineering Research Institute.

  19. Near-field ground motion of the 2002 Denali fault, Alaska, earthquake recorded at pump station 10

    USGS Publications Warehouse

    Ellsworth, W.L.; Celebi, M.; Evans, J.R.; Jensen, E.G.; Kayen, R.; Metz, M.C.; Nyman, D.J.; Roddick, J.W.; Spudich, P.; Stephens, C.D.

    2004-01-01

    A free-field recording of the Denali fault earthquake was obtained by the Alyeska Pipeline Service Company 3 km from the surface rupture of the Denali fault. The instrument, part of the monitoring and control system for the trans-Alaska pipeline, was located at Pump Station 10, approximately 85 km east of the epicenter. After correction for the measured instrument response, we recover a seismogram that includes a permanent displacement of 3.0 m. The recorded ground motion has relatively low peak acceleration (0.36 g) and very high peak velocity (180 cm/s). Nonlinear soil response may have reduced the peak acceleration to this 0.36 g value. Accelerations in excess of 0.1 g lasted for 10 s, with the most intense motion occurring during a 1.5-s interval when the rupture passed the site. The low acceleration and high velocity observed near the fault in this earthquake agree with observations from other recent large-magnitude earthquakes. ?? 2004, Earthquake Engineering Research Institute.

  20. USGS SAFRR Tsunami Scenario: Potential Impacts to the U.S. West Coast from a Plausible M9 Earthquake near the Alaska Peninsula

    NASA Astrophysics Data System (ADS)

    Ross, S.; Jones, L. M.; Wilson, R. I.; Bahng, B.; Barberopoulou, A.; Borrero, J. C.; Brosnan, D.; Bwarie, J. T.; Geist, E. L.; Johnson, L. A.; Hansen, R. A.; Kirby, S. H.; Knight, E.; Knight, W. R.; Long, K.; Lynett, P. J.; Miller, K. M.; Mortensen, C. E.; Nicolsky, D.; Oglesby, D. D.; Perry, S. C.; Porter, K. A.; Real, C. R.; Ryan, K. J.; Suleimani, E. N.; Thio, H. K.; Titov, V. V.; Wein, A. M.; Whitmore, P.; Wood, N. J.

    2012-12-01

    inform decision makers. The SAFRR Tsunami Scenario is organized by a coordinating committee with several working groups, including Earthquake Source, Paleotsunami/Geology Field Work, Tsunami Modeling, Engineering and Physical Impacts, Ecological Impacts, Emergency Management and Education, Social Vulnerability, Economic and Business Impacts, and Policy. In addition, the tsunami scenario process is being assessed and evaluated by researchers from the Natural Hazards Center at the University of Colorado at Boulder. The source event, defined by the USGS' Tsunami Source Working Group, is an earthquake similar to the 2011 Tohoku event, but set in the Semidi subduction sector, between Kodiak Island and the Shumagin Islands off the Pacific coast of the Alaska Peninsula. The Semidi sector is probably late in its earthquake cycle and comparisons of the geology and tectonic settings between Tohoku and the Semidi sector suggest that this location is appropriate. Tsunami modeling and inundation results have been generated for many areas along the California coast and elsewhere, including current velocity modeling for the ports of Los Angeles, Long Beach, and San Diego, and Ventura Harbor. Work on impacts to Alaska and Hawaii will follow. Note: Costas Synolakis (USC) is also an author of this abstract.

  1. Intraplate Splay Faults and Near-field Tsunami Generation during Giant Megathrust Earthquakes in Chile, Alaska, and Sumatra

    NASA Astrophysics Data System (ADS)

    Plafker, G.; Savage, J. C.; Lee, W. H.

    2010-12-01

    The Mw 9.5 Chile earthquake sequence (21-22/05/1960), the largest instrumentally-recorded seismic event in history, was generated by a megathrust rupture of the southern end of the Peru-Chile Arc about 850 km long and 60-150 km wide down dip. Within Chile, the accompanying tsunami reached 15 m high and took an estimated 1,000 of the more than 2,000 lives lost. The trans-Pacific tsunami killed 230 people in Japan, Hawaii and the Philippine Islands. The tsunami source was primarily due to regional offshore upwarp, with possible superimposed larger local uplift due to displacement on splay faults. The Mw 9.2 Alaska earthquake (27/03/1964) ruptured major segments of the eastern Aleutian Arc 800 km long by 250-350 km wide down dip. Coseismic uplift along splay faults offshore generated a major near-field tsunami reaching 13 m high in Alaska that took at least 21 lives. Local earthquake-triggered submarine landslides in fiords along the rugged Kenai and Chugach mountains generated local (non-tsunami) waves with run up to 52 m high that took about 77 lives and caused major damage to coastal communities. Tectonically-generated tsunami waves were also generated over the continental shelf and slope due to regional uplift that averaged about 2 m; these waves added to the damage in coastal Alaska and caused 15 deaths and local property damage as far away as Oregon and California. The Mw 9.15 Sumatra earthquake (26/12/2004) ruptured segments of the Sunda Arc more than 1200 km long by 150-200 km wide down dip. The accompanying near-field tsunami was as high as 36 m in northern Sumatra where it caused 169,000 casualties along 200 km of shoreline while the far-field tsunami took an additional 63,000 lives throughout the Indian Ocean region. This made it the deadliest tsunami in recorded history. In addition to a few meters of regional uplift caused by slip on the megathrust, large-slip splay fault sources are inferred from intraplate seismicity, and from early tsunami arrival

  2. Alaska

    SciTech Connect

    Jones, B.C.; Sears, D.W.

    1981-10-01

    Twenty-five exploratory wells were drilled in Alaska in 1980. Five oil or gas discovery wells were drilled on the North Slope. One hundred and seventeen development and service wells were drilled and completed, primarily in the Prudhoe Bay and Kuparuk River fields on the North Slope. Geologic-geophysical field activity consisted of 115.74 crew months, an increase of almost 50% compared to 1979. These increases affected most of the major basins of the state as industry stepped up preparations for future lease sales. Federal acreage under lease increased slightly, while state lease acreage showed a slight decline. The year's oil production showed a increase of 16%, while gas production was down slightly. The federal land freeze in Alaska showed signs of thawing, as the US Department of Interior asked industry to identify areas of interest onshore for possible future leasing. National Petroleum Reserve in Alaska was opened to private exploration, and petroleum potential of the Arctic Wildlife Refuge will be studied. One outer continental shelf lease sale was held in the eastern Gulf of Alaska, and a series of state and federal lease sales were announced for the next 5 years. 5 figures, 5 tables.

  3. Geologic effects of the March 1964 earthquake and associated seismic sea waves on Kodiak and nearby islands, Alaska: Chapter D in The Alaska earthquake, March 27, 1964: regional effects

    USGS Publications Warehouse

    Plafker, George; Kachadoorian, Reuben

    1966-01-01

    Kodiak Island and the nearby islands constitute a mountainous landmass with an aggregate area of 4,900 square miles that lies at the western border of the Gulf of Alaska and from 20 to 40 miles off the Alaskan mainland. Igneous and metamorphic rocks underlie most of the area except for a narrow belt of moderately to poorly indurated rocks bordering the Gulf of Alaska coast and local accumulations of unconsolidated alluvial and marine deposits along the streams and coast. The area is relatively undeveloped and is sparsely inhabited. About 4,800 of the 5,700 permanent residents in the area live in the city of Kodiak or at the Kodiak Naval Station. The great earthquake, which occurred on March 27, 1964, at 5:36 p.m. Alaska standard time (March 28,1964, 0336 Greenwich mean time), and had a Richter magnitude of 8.4-8.5, was the most severe earthquake felt on Kodiak Island and its nearby islands in modern times. Although the epicenter lies in Prince William Sound 250 miles northeast of Kodiak—the principal city of the area—the areal distribution of the thousands of aftershocks that followed it, the local tectonic deformation, and the estimated source area of the subsequent seismic sea wave, all suggest that the Kodiak group of islands lay immediately adjacent to, and northwest of, the focal region from which the elastic seismic energy was radiated. The duration of strong ground motion in the area was estimated at 2½ minutes. Locally, the tremors were preceded by sounds audible to the human ear and were reportedly accompanied in several places by visible ground waves. Intensity and felt duration of the shocks during the main earthquake and aftershock sequence varied markedly within the area and were strongly influenced by the local geologic environment. Estimated Mercalli intensities in most areas underlain by unconsolidated Quaternary deposits ranged from VIII to as high as IX. In contrast, intensities in areas of upper Tertiary rock ranged from VII to VIII, and in

  4. Earthquakes

    MedlinePlus

    An earthquake happens when two blocks of the earth suddenly slip past one another. Earthquakes strike suddenly, violently, and without warning at any time of the day or night. If an earthquake occurs in a populated area, it may cause ...

  5. Earthquakes

    MedlinePlus

    ... Thunderstorms & Lightning Tornadoes Tsunamis Volcanoes Wildfires Main Content Earthquakes Earthquakes are sudden rolling or shaking events caused ... at any time of the year. Before An Earthquake Look around places where you spend time. Identify ...

  6. Stress transfer to the Denali and other regional faults from the M 9.2 Alaska earthquake of 1964

    USGS Publications Warehouse

    Bufe, C.G.

    2004-01-01

    Stress transfer from the great 1964 Prince William Sound earthquake is modeled on the Denali fault, including the Denali-Totschunda fault segments that ruptured in 2002, and on other regional fault systems where M 7.5 and larger earthquakes have occurred since 1900. The results indicate that analysis of Coulomb stress transfer from the dominant earthquake in a region is a potentially powerful tool in assessing time-varying earthquake hazard. Modeled Coulomb stress increases on the northern Denali and Totschunda faults from the great 1964 earthquake coincide with zones that ruptured in the 2002 Denali fault earthquake, although stress on the Susitna Glacier thrust plane, where the 2002 event initiated, was decreased. A southeasterlytrending Coulomb stress transect along the right-lateral Totschunda-Fairweather-Queen Charlotte trend shows stress transfer from the 1964 event advancing slip on the Totschunda, Fairweather, and Queen Charlotte segments, including the southern Fairweather segment that ruptured in 1972. Stress transfer retarding right-lateral strike slip was observed from the southern part of the Totschunda fault to the northern end of the Fairweather fault (1958 rupture). This region encompasses a gap with shallow thrust faulting but with little evidence of strike-slip faulting connecting the segments to the northwest and southeast. Stress transfer toward failure was computed on the north-south trending right-lateral strike-slip faults in the Gulf of Alaska that ruptured in 1987 and 1988, with inhibitory stress changes at the northern end of the northernmost (1987) rupture. The northern Denali and Totschunda faults, including the zones that ruptured in the 2002 earthquakes, follow very closely (within 3%), for about 90??, an arc of a circle of radius 375 km. The center of this circle is within a few kilometers of the intersection at depth of the Patton Bay fault with the Alaskan megathrust. This inferred asperity edge may be the pole of counterclockwise

  7. 76 FR 71600 - Renewal of Agency Information Collection for Reindeer in Alaska; Request for Comments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-18

    ... Reindeer in Alaska. The information collection is currently authorized by OMB Control Number 1076-0047... identifiable information, we cannot guarantee that we will be able to do so. III. Data OMB Control Number:...

  8. The M=7.9 Alaska Earthquake of 3 November 2002: Felt Reports and Unusual Effects Across Western Canada

    NASA Astrophysics Data System (ADS)

    Cassidy, J. F.; Rogers, G. C.; Bird, A. L.; Mulder, T. L.

    2002-12-01

    The 3 November 2002 M=7.9 Alaska earthquake was one of the largest earthquakes recorded in North America during the past 100 years. This earthquake occurred at 2:12 p.m. PST (on a Sunday) and was located 330 km to the west of the Yukon-Alaska border. Surface rupture and aftershocks extended to within about 100 km of the Canadian border. More than 250 "felt" reports were submitted to the Geological Survey of Canada website (http://www.pgc.nrcan.gc.ca/seismo/table.htm) within a few days of the earthquake. Here, we summarize those reports which include typical high-frequency shaking effects to distances of about 1500 km, as well as numerous long-period effects, such as human effects (nausea), swaying highrises, telephone poles and chandeliers, seiches in lakes and inlets, water sloshing from swimming pools, and instances of dirty well-water to distances of nearly 3500 km across Western Canada. Felt intensities (MMI)of about IV were observed across the Yukon Territory at distances of 350 km to 750 km. There were a few reports of minor damage in this region, as well as numerous reports of items knocked from shelves and parked vehicles rocking noticeably. The most distant felt reports in western Canada were from southern Alberta (2400 km distance) where people in highrises felt the swaying. More than 30 reports of human effects were received. These ranged from people feeling dizzy, seasick or nauseated (to distances of 2400 km), to difficulty standing and maintaining balance (to distances of 1000 km). Long-period effects of houses "swaying", large signs flexing, and telephone poles and tall trees swaying were reported to distances of more than 1000 km. Swinging of chandeliers, hanging plants and lights were reported to distances of 2400 km. There were more than 30 reports of seiches. Most reports came from southern British Columbia (2200-2400 km) where, although no ground shaking was noticed, water surges up to 1 m were observed. In one case a cabin held by cables near

  9. A Synthesis of Characteristics of Submarine Landslides Generated by the 1964 Great Alaska Earthquake in Six Fjords

    NASA Astrophysics Data System (ADS)

    Haeussler, P. J.; Parsons, T.; Lee, H. J.; Ryan, H. F.; Brothers, D. S.; Liberty, L. M.; Hart, P. E.; Geist, E. L.; Roland, E. C.; Witter, R. C.; Kayen, R. E.

    2015-12-01

    Submarine landslide-generated tsunamis were the single largest cause of fatalities in the Mw9.2 1964 Great Alaska earthquake. In the last decade, we studied the submarine slope failures in six fjords: Resurrection Bay, Port Valdez, Passage Canal, southern Dangerous Passage, Aialik Bay, and Harris Bay. The six fjords lie 20 to 30 km above the Alaska-Aleutian megathrust, which provides an ideal landslide trigger mechanism. To characterize the landslides, we used multibeam bathymetry data, pre- and post-event bathymetry differencing, sparker and chirp seismic data, wave runup directions and heights, shear wave velocity profiles, the onland sedimentary record of the tsunamis, observations during the earthquake, and tsunami models. All slides originated at the margins of the fjords, mostly in unconsolidated sediment of the fjord-head deltas(?), and transported sediment to the deepest part of the fjords. The slides transported material up to ~15 km, resulting in slide deposits up to 20 m thick, and a subsequent megaturbidite deposit up to 15 m thick. These slides resurfaced the entire fjord bottom and the resultant flow of sediment and water brought numerous deep dwelling fish to the surface, killed by the sudden pressure changes. Typical fjord sedimentation resulted in conditions primed for slope failures. Fjord-head deltas deposited unconsolidated sediment at the upper margins of the fjords, which composed the majority of sediment that failed during the earthquake. We find that the highest tsunami runups were correlated with blocky landslides that required unique depositional conditions. The Little Ice Age (LIA) occurred between the penultimate megathrust earthquake ~900 yr ago and 1964, with the most recent maximum extent around 1875AD. The LIA glacial expansion led to significant sedimentation at the margins of the fjords. Near Shoup Bay in Port Valdez, in Passage Canal, and probably in southern Dangerous Passage, ice overrode till and sediment deposited in front of

  10. Three-dimensional velocity structure and high-precision earthquake relocations at Augustine, Akutan, and Makushin Volcanoes, Alaska

    NASA Astrophysics Data System (ADS)

    Syracuse, E. M.; Thurber, C. H.; Power, J. A.; Prejean, S. G.

    2010-12-01

    Alaska contains over 100 volcanoes, 21 of which have been active within the past 20 years, including Augustine in Cook Inlet, and Akutan and Makushin in the central Aleutian arc. We incorporate 14-15 years of earthquake data from the Alaska Volcano Observatory (AVO) to obtain P-wave velocity structure and high-precision earthquake locations at each volcano. At Augustine, most relocated seismicity is beneath the summit at an average depth of 0.6 km. In the weeks leading to the 2006 eruption, seismicity shallowed and focused on a NW-SE line, suggestive of an inflating dike. Through August 2006, intermittent seismicity was observed at 1 to 4.5 km depth, pointing to an association with the transport of magma. Active-source data are also incorporated into the tomographic inversion, illuminating a high-velocity column beneath the summit, and elevated velocities on the south flank. The high-velocity column surrounds the observed deeper seismicity and is likely due to intruded volcanic material. The elevated velocities on the south flank are associated with uplifted zeolitzed sandstones. Akutan most recently erupted in 1992, before the seismic network was installed. Most seismicity is above 9 km depth, with 10% occurring between 14 to30 km depth. Seismicity is separated into two main groups that dip away from the caldera—one to the east and one to the west. The eastern group contains earthquakes from a swarm in early 1996 and the western group contains earthquakes from mid-1996 through the present that form rough lines radiating from the summit. Ongoing seismicity also occurs in a broader region beneath the caldera. Makushin most recently erupted in 1995, also prior to seismic monitoring by AVO. Relocations here show that most seismicity is at 3 to 13 km depth and either beneath the caldera or within one of two dipping clusters 20 km to the northeast. Additional seismicity occurs at up to 25 km depth beneath the summit, as well as scattered throughout the island at

  11. 77 FR 47371 - Proposed Information Collection; Comment Request; Alaska Interagency Electronic Reporting System...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-08

    ... current information collection. eLandings and seaLandings are data entry components of the Alaska... and production data for Fishery Management Plan species in the Exclusive Economic Zone (EEZ). ADF&G collects harvest data for groundfish species taken in the State of Alaska waters, and has...

  12. Wetlands & Wildlife: Alaska Wildlife Curriculum Teacher Information Manual, Parts I-II.

    ERIC Educational Resources Information Center

    Sigman, Marilyn; And Others

    This document consists of a teacher manual and a set of information cards. The teacher manual is designed to educate Alaskan students about the important functions of Alaska's wetlands and about the fish and wildlife that live there. Part I of the manual explores Alaska's wetland habitats, the plants and animals that live there, and the…

  13. Transient rheology of the upper mantle beneath central Alaska inferred from the crustal velocity field following the 2002 Denali earthquake

    USGS Publications Warehouse

    Pollitz, F.F.

    2005-01-01

    The M7.9 2002 Denali earthquake, Alaska, is one of the largest strike-slip earthquakes ever recorded. The postseismic GPS velocity field around the 300-km-long rupture is characterized by very rapid horizontal velocity up to ???300 mm/yr for the first 0.1 years and slower but still elevated horizontal velocity up to ???100 mm/yr for the succeeding 1.5 years. I find that the spatial and temporal pattern of the displacement field may be explained by a transient mantle rheology. Representing the regional upper mantle as a Burghers body, I infer steady state and transient viscosities of ??1 = 2.8 ?? 1018 Pa s and ??2 = 1.0 ?? 1017 Pa s, respectively, corresponding to material relaxation times of 1.3 and 0.05 years. The lower crustal viscosity is poorly constrained by the considered horizontal velocity field, and the quoted mantle viscosities assume a steady state lower crust viscosity that is 7??1. Systematic bias in predicted versus observed velocity vectors with respect to a fixed North America during the first 3-6 months following the earthquake is reduced when all velocity vectors are referred to a fixed site. This suggests that the post-Denali GPS time series for the first 1.63 years are shaped by a combination of a common mode noise source during the first 3-6 months plus viscoelastic relaxation controlled by a transient mantle rheology.

  14. Large rock avalanches triggered by the M 7.9 Denali Fault, Alaska, earthquake of 3 November 2002

    USGS Publications Warehouse

    Jibson, R.W.; Harp, E.L.; Schulz, W.; Keefer, D.K.

    2006-01-01

    The moment magnitude (M) 7.9 Denali Fault, Alaska, earthquake of 3 November 2002 triggered thousands of landslides, primarily rock falls and rock slides, that ranged in volume from rock falls of a few cubic meters to rock avalanches having volumes as great as 20 ?? 106 m3. The pattern of landsliding was unusual: the number and concentration of triggered slides was much less than expected for an earthquake of this magnitude, and the landslides were concentrated in a narrow zone about 30-km wide that straddled the fault-rupture zone over its entire 300-km length. Despite the overall sparse landslide concentration, the earthquake triggered several large rock avalanches that clustered along the western third of the rupture zone where acceleration levels and ground-shaking frequencies are thought to have been the highest. Inferences about near-field strong-shaking characteristics drawn from interpretation of the landslide distribution are strikingly consistent with results of recent inversion modeling that indicate that high-frequency energy generation was greatest in the western part of the fault-rupture zone and decreased markedly to the east. ?? 2005 Elsevier B.V. All rights reserved.

  15. Landslides triggered by the 2002 Denali fault, Alaska, earthquake and the inferred nature of the strong shaking

    USGS Publications Warehouse

    Jibson, R.W.; Harp, E.L.; Schulz, W.; Keefer, D.K.

    2004-01-01

    The 2002 M7.9 Denali fault, Alaska, earthquake triggered thousands of landslides, primarily rock falls and rock slides, that ranged in volume from rock falls of a few cubic meters to rock avalanches having volumes as great as 15 ?? 106 m3. The pattern of landsliding was unusual; the number of slides was less than expected for an earthquake of this magnitude, and the landslides were concentrated in a narrow zone 30-km wide that straddled the fault rupture over its entire 300-km length. The large rock avalanches all clustered along the western third of the rupture zone where acceleration levels and ground-shaking frequencies are thought to have been the highest. Inferences about near-field strong shaking characteristics drawn from the interpretation of the landslide distribution are consistent with results of recent inversion modeling that indicate high-frequency energy generation was greatest in the western part of the fault rupture zone and decreased markedly to the east. ?? 2004, Earthquake Engineering Research Institute.

  16. Holocene slip rate and revised characteristic earthquake parameters for the western segment of the Castle Mountain fault, Alaska

    USGS Publications Warehouse

    Willis, Julie B.; Haeussler, Peter J.; Bruhn, Ronald L.; Willis, Grant C.

    2007-01-01

    The western segment of the Castle Mountain fault poses a significant seismic hazard to the most populated region of south-central Alaska. We identify a previously unrecognized margin of a postglacial outwash channel that is offset right laterally 36 ± 4 m across the western segment of the Castle Mountain fault. This offset occurred after glaciers withdrew from the lowland 11,300–15,380 cal yr b.p. and after outwash channel margins were cut and stabilized 11,210–13,470 cal yr b.p. Using these ages and the measured separation, we obtain a maximum slip rate of 3.0 ± 0.6 mm yr−1 and a minimum slip rate of 2.8 ± 0.7 mm yr−1. These are the first lateral slip rates for the Castle Mountain fault established by a field measurement. Based on timing of the most recent earthquake, 670 ± 60 yr b.p., the Castle Mountain fault could have accumulated an average single-event slip of about 1.9 m (extremes range from 1.3 to 2.6 m). The fault consists of two segments; a surface-rupturing earthquake likely will be limited to the 62-km-long western segment. Area-magnitude regression calculations suggest that such an earthquake on the western Castle Mountain fault would have a moment magnitude of 6.9 to 7.3.

  17. Rupture processes of the 28 October 2012 (Mw 7.7) and 5 January 2013 (Mw 7.6) earthquakes along the Queen Charlotte Fault system (South Alaska)

    NASA Astrophysics Data System (ADS)

    Atakan, Kuvvet; Raeesi, Mohammad

    2013-04-01

    The plate boundary linking the Alaska and Cascadia subduction zones is known as an oceanic transform fault system, called Queen Charlotte. However, the bathymetry along the system shows a trench-like structure. Two major earthquakes with different mechanisms ruptured two segments of the system about 200 km apart. The 28 October 2012 (Mw 7.7) event has a high-angle thrust mechanism, while the 5 January 2013 (Mw 7.6) earthquake has a pure strike-slip mechanism. We analyze these two earthquakes through body-waveform inversion and a gravity-derived anomaly, "Trench Parallel Bouguer Anomaly" (TPBA). TPBA can be used for detecting asperities of earthquakes along forearc settings independent of the earthquake. A likely scenario for these two events will be presented.

  18. Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Though it's not quite spring, waters in the Gulf of Alaska (right) appear to be blooming with plant life in this true-color MODIS image from March 4, 2002. East of the Alaska Peninsula (bottom center), blue-green swirls surround Kodiak Island. These colors are the result of light reflecting off chlorophyll and other pigments in tiny marine plants called phytoplankton. The bloom extends southward and clear dividing line can be seen west to east, where the bloom disappears over the deeper waters of the Aleutian Trench. North in Cook Inlet, large amounts of red clay sediment are turning the water brown. To the east, more colorful swirls stretch out from Prince William Sound, and may be a mixture of clay sediment from the Copper River and phytoplankton. Arcing across the top left of the image, the snow-covered Brooks Range towers over Alaska's North Slope. Frozen rivers trace white ribbons across the winter landscape. The mighty Yukon River traverses the entire state, beginning at the right edge of the image (a little way down from the top) running all the way over to the Bering Sea, still locked in ice. In the high-resolution image, the circular, snow-filled calderas of two volcanoes are apparent along the Alaska Peninsula. In Bristol Bay (to the west of the Peninsula) and in a couple of the semi-clear areas in the Bering Sea, it appears that there may be an ice algae bloom along the sharp ice edge (see high resolution image for better details). Ground-based observations from the area have revealed that an under-ice bloom often starts as early as February in this region and then seeds the more typical spring bloom later in the season.

  19. Surface faults on Montague Island associated with the 1964 Alaska earthquake: Chapter G in The Alaska earthquake, March 27, 1964: regional effects

    USGS Publications Warehouse

    Plafter, George

    1967-01-01

    Two reverse faults on southwestern Montague Island in Prince William Sound were reactivated during the earthquake of March 27, 1964. New fault scarps, fissures, cracks, and flexures appeared in bedrock and unconsolidated surficial deposits along or near the fault traces. Average strike of the faults is between N. 37° E. and N. 47° E.; they dip northwest at angles ranging from 50° to 85°. The dominant motion was dip slip; the blocks northwest of the reactivated faults were relatively upthrown, and both blocks were upthrown relative to sea level. No other earthquake faults have been found on land. The Patton Bay fault on land is a complex system of en echelon strands marked by a series of spectacular landslides along the scarp and (or) by a zone of fissures and flexures on the upthrown block that locally is as much as 3,000 feet wide. The fault can be traced on land for 22 miles, and it has been mapped on the sea floor to the southwest of Montague Island an additional 17 miles. The maximum measured vertical component of slip is 20 to 23 feet and the maximum indicated dip slip is about 26 feet. A left-lateral strike-slip component of less than 2 feet occurs near the southern end of the fault on land where its strike changes from northeast to north. Indirect evidence from the seismic sea waves and aftershocks associated with the earthquake, and from the distribution of submarine scarps, suggests that the faulting on and near Montague Island occurred at the northeastern end of a reactivated submarine fault system that may extend discontinuously for more than 300 miles from Montague Island to the area offshore of the southeast coast of Kodiak Island. The Hanning Bay fault is a minor rupture only 4 miles long that is marked by an exceptionally well defined almost continuous scarp. The maximum measured vertical component of slip is 16⅓ feet near the midpoint, and the indicated dip slip is about 20 feet. There is a maximum left-lateral strike-slip component of one

  20. Seismic swarm associated with the 2008 eruption of Kasatochi Volcano, Alaska: Earthquake locations and source parameters

    USGS Publications Warehouse

    Ruppert, N.A.; Prejean, S.; Hansen, R.A.

    2011-01-01

    An energetic seismic swarm accompanied an eruption of Kasatochi Volcano in the central Aleutian volcanic arc in August of 2008. In retrospect, the first earthquakes in the swarm were detected about 1 month prior to the eruption onset. Activity in the swarm quickly intensified less than 48 h prior to the first large explosion and subsequently subsided with decline of eruptive activity. The largest earthquake measured as moment magnitude 5.8, and a dozen additional earthquakes were larger than magnitude 4. The swarm exhibited both tectonic and volcanic characteristics. Its shear failure earthquake features were b value = 0.9, most earthquakes with impulsive P and S arrivals and higher-frequency content, and earthquake faulting parameters consistent with regional tectonic stresses. Its volcanic or fluid-influenced seismicity features were volcanic tremor, large CLVD components in moment tensor solutions, and increasing magnitudes with time. Earthquake location tests suggest that the earthquakes occurred in a distributed volume elongated in the NS direction either directly under the volcano or within 5-10 km south of it. Following the MW 5.8 event, earthquakes occurred in a new crustal volume slightly east and north of the previous earthquakes. The central Aleutian Arc is a tectonically active region with seismicity occurring in the crusts of the Pacific and North American plates in addition to interplate events. We postulate that the Kasatochi seismic swarm was a manifestation of the complex interaction of tectonic and magmatic processes in the Earth's crust. Although magmatic intrusion triggered the earthquakes in the swarm, the earthquakes failed in context of the regional stress field. Copyright ?? 2011 by the American Geophysical Union.

  1. Seismic swarm associated with the 2008 eruption of Kasatochi Volcano, Alaska: earthquake locations and source parameters

    USGS Publications Warehouse

    Ruppert, Natalia G.; Prejean, Stephanie G.; Hansen, Roger A.

    2011-01-01

    An energetic seismic swarm accompanied an eruption of Kasatochi Volcano in the central Aleutian volcanic arc in August of 2008. In retrospect, the first earthquakes in the swarm were detected about 1 month prior to the eruption onset. Activity in the swarm quickly intensified less than 48 h prior to the first large explosion and subsequently subsided with decline of eruptive activity. The largest earthquake measured as moment magnitude 5.8, and a dozen additional earthquakes were larger than magnitude 4. The swarm exhibited both tectonic and volcanic characteristics. Its shear failure earthquake features were b value = 0.9, most earthquakes with impulsive P and S arrivals and higher-frequency content, and earthquake faulting parameters consistent with regional tectonic stresses. Its volcanic or fluid-influenced seismicity features were volcanic tremor, large CLVD components in moment tensor solutions, and increasing magnitudes with time. Earthquake location tests suggest that the earthquakes occurred in a distributed volume elongated in the NS direction either directly under the volcano or within 5-10 km south of it. Following the MW 5.8 event, earthquakes occurred in a new crustal volume slightly east and north of the previous earthquakes. The central Aleutian Arc is a tectonically active region with seismicity occurring in the crusts of the Pacific and North American plates in addition to interplate events. We postulate that the Kasatochi seismic swarm was a manifestation of the complex interaction of tectonic and magmatic processes in the Earth's crust. Although magmatic intrusion triggered the earthquakes in the swarm, the earthquakes failed in context of the regional stress field.

  2. Earthquakes.

    ERIC Educational Resources Information Center

    Walter, Edward J.

    1977-01-01

    Presents an analysis of the causes of earthquakes. Topics discussed include (1) geological and seismological factors that determine the effect of a particular earthquake on a given structure; (2) description of some large earthquakes such as the San Francisco quake; and (3) prediction of earthquakes. (HM)

  3. Earthquakes.

    ERIC Educational Resources Information Center

    Pakiser, Louis C.

    One of a series of general interest publications on science topics, the booklet provides those interested in earthquakes with an introduction to the subject. Following a section presenting an historical look at the world's major earthquakes, the booklet discusses earthquake-prone geographic areas, the nature and workings of earthquakes, earthquake…

  4. Effects of the earthquake of March 27, 1964, on various communities: Chapter G in The Alaska earthquake, March 27, 1964: effects on communities

    USGS Publications Warehouse

    Plafker, George; Kachadoorian, Reuben; Eckel, Edwin B.; Mayo, Lawrence R.

    1969-01-01

    The 1964 earthquake caused wide-spread damage to inhabited places throughout more than 60,000 square miles of south-central Alaska. This report describes damage to all communities in the area except Anchorage, Whittier, Homer, Valdez, Seward, the communities of the Kodiak group of islands, and communities in the Copper River Basin; these were discussed in previous chapters of the Geological Survey's series of reports on the earthquake. At the communities discussed herein, damage resulted primarily from sea waves of diverse origins, displacements of the land relative to sea level, and seismic shaking. Waves took all of the 31 lives lost at those communities; physical damage was primarily from the waves and vertical displacements of the land relative to sea level. Destructive waves of local origin struck during or immediately after the earthquake throughout much of Prince William Sound, the southern Kenai Peninsula, and the shores of Kenai Lake. In Prince William Sound, waves demolished all but one home at the native village of Chenega, destroyed homesites at Point Nowell and Anderson Bay, and caused varying amounts of damage to waterfront facilities at Sawmill Bay, Latouche, Port Oceanic, Port Nellie Juan, Perry Island, and western Port Valdez. The local waves, which ran up as high as 70 feet above tide level at Chenega and more than 170 feet in several uninhabited parts of the Sound, took nearly all of the lives lost by drowning at these communities. Destructive local waves that devastated shores of Anderson Bay and adjacent parts of western Port Valdez probably were generated primarily by massive submarine slides of glacial and fluvioglacial deposits ; the origin of the waves that caused damage at most of the other communities and at extensive uninhabited segments of shoreline is not known. At these places the most probable generative mechanisms are: unidentified submarine slides of unconsolidated deposits, and (or) the horizontal tectonic displacements, of 20 to

  5. The 2002 Denali fault earthquake, Alaska: A large magnitude, slip-partitioned event

    USGS Publications Warehouse

    Eberhart-Phillips, D.; Haeussler, P.J.; Freymueller, J.T.; Frankel, A.D.; Rubin, C.M.; Craw, P.; Ratchkovski, N.A.; Anderson, G.; Carver, G.A.; Crone, A.J.; Dawson, T.E.; Fletcher, H.; Hansen, R.; Harp, E.L.; Harris, R.A.; Hill, D.P.; Hreinsdottir, S.; Jibson, R.W.; Jones, L.M.; Kayen, R.; Keefer, D.K.; Larsen, C.F.; Moran, S.C.; Personius, S.F.; Plafker, G.; Sherrod, B.; Sieh, K.; Sitar, N.; Wallace, W.K.

    2003-01-01

    The MW (moment magnitude) 7.9 Denali fault earthquake on 3 November 2002 was associated with 340 kilometers of surface rupture and was the largest strike-slip earthquake in North America in almost 150 years. It illuminates earthquake mechanics and hazards of large strike-slip faults. It began with thrusting on the previously unrecognized Susitna Glacier fault, continued with right-slip on the Denali fault, then took a right step and continued with right-slip on the Totschunda fault. There is good correlation between geologically observed and geophysically inferred moment release. The earthquake produced unusually strong distal effects in the rupture propagation direction, including triggered seismicity.

  6. An Advanced Real-Time Earthquake Information System in Japan

    NASA Astrophysics Data System (ADS)

    Takahashi, I.; Nakamura, H.; Suzuki, W.; Kunugi, T.; Aoi, S.; Fujiwara, H.

    2015-12-01

    J-RISQ (Japan Real-time Information System for earthquake) has been developing in NIED for appropriate first-actions to big earthquakes. When an earthquake occurs, seismic intensities (SI) are calculated first at each observation station and sent to the Data Management Center in different timing. The system begins the first estimation when the number of the stations observing the SI of 2.5 or larger exceeds the threshold amount. It estimates SI distribution, exposed population and earthquake damage on buildings by using basic data for estimation, such as subsurface amplification factors, population, and building information. It has been accumulated in J-SHIS (Japan Seismic Information Station) developed by NIED, a public portal for seismic hazard information across Japan. The series of the estimation is performed for each 250m square mesh and finally the estimated data is converted into information for each municipality. Since October 2013, we have opened estimated SI, exposed population etc. to the public through the website by making full use of maps and tables.In the previous system, we sometimes could not inspect the information of the surrounding areas out of the range suffered from strong motions, or the details of the focusing areas, and could not confirm whether the present information was the latest or not without accessing the website. J-RISQ has been advanced by introducing the following functions to settle those problems and promote utilization in local areas or in personal levels. In addition, the website in English has been released.・It has become possible to focus on the specific areas and inspect enlarged information.・The estimated information can be downloaded in the form of KML.・The estimated information can be updated automatically and be provided as the latest one.・The newest information can be inspected by using RSS readers or browsers corresponding to RSS.・Exclusive pages for smartphones have been prepared.The information estimated

  7. An Earthquake Information Service with Free and Open Source Tools

    NASA Astrophysics Data System (ADS)

    Jüngling, Sebastian; Schroeder, Matthias; Lühr, Birger-Gottfried; Woith, Heiko; Wächter, Joachim

    2016-04-01

    At the GFZ German Research Centre for Geosciences in Potsdam, the working group Earthquakes and Volcano Physics examines the spatiotemporal behavior of earthquakes. In this context also the hazards of volcanic eruptions and tsunamis are explored. The aim is to collect related event parameters after the occurrence of extreme events and make them available for science and public as quick as possible. However, the overall objective of this research is to reduce geological risks that emanate from such natural hazards. In order to meet the stated objectives and to get a quick overview about the seismicity of a particular region and to compare the situation to historical and current events, a comprehensive visualization is necessary. Based on the web-accessible data from the famous GFZ GEOFON network a user-friendly interactive web mapping application could be realized. Further, this web service tool integrates historical and current earthquake information from the USGS earthquake database NEIC, and more historical events from various other catalogues like Pacheco, International Seismological Centre (ISC) and others. This compilation of data sources is unique in Earth sciences. Additionally, information about historical and current occurrences of volcanic eruptions and tsunamis are retrievable too. Another special feature in the application is the limitation of time spans via a time shifting tool. Users can interactively vary the visualization by moving the time slider. In addition, the events can be narrowed down based on the magnitude, the wave height of tsunamis or the volcanic explosion index. Furthermore, the use of the latest JavaScript libraries makes it possible to display the application on all screen sizes and devices. With this application, information on current and historical earthquakes and other extreme events can be obtained based on the spatio-temporal context, such as the concomitant visualization of seismicity of a particular region.

  8. Effects of the earthquake of March 27, 1964, on the communities of Kodiak and nearby islands: Chapter F in The Alaska earthquake, March 27, 1964: effects on communities

    USGS Publications Warehouse

    Kachadoorian, Reuben; Plafker, George

    1967-01-01

    The great earthquake (Richter magnitude of 8.4–8.5) that struck south-central Alaska at 5:36 p.m., Alaska standard time, on March 27, 1964 (03:36, March 28, Greenwich mean time), was felt in every community on Kodiak Island and the nearby islands. It was the most severe earthquake to strike this part of Alaska in modern time, and took the lives of 18 persons in the area by drowning; this includes two in Kodiak and three at Kaguyak. Property damage and loss of income to the communities is estimated at more than $45 million. The largest community, Kodiak, had the greatest loss from the earthquake. Damage was caused chiefly by 5.6 feet of tectonic subsidence and a train of 10 seismic sea waves that inundated the low-lying areas of the town. The seismic sea waves destroyed all but one of the docking facilities and more than 215 structures; many other structures were severely damaged. The waves struck the town during the evening hours of March 27 and early morning hours of March 28. They moved from the southwest and northeast: and reached their maximum height of 20–30 feet above mean lower low water at Shahafka Cove between 11:00 and 11:45 p.m., March 27. The violently destructive seismic sea waves not only severely damaged homes, shops, and naval-station structures but also temporarily crippled the fishing industry in Kodiak by destroying the processing plants and most of the fishing vessels. The waves scoured out 10 feet of sediments in the channel between Kodiak Island and Near Island and exposed bedrock. This bedrock presented a major post-earthquake construction problem because no sediments remained into which piles could be driven for foundations of waterfront facilities. Because of tectonic subsidence, high tides now flood Mission and Potatopatch Lakes which, before the earthquake, had not been subject to tidal action. The subsidence also accelerated erosion of the unconsolidated sediments along the shoreline in the city of Kodiak. Seismic shaking lasted 4

  9. Intermediate-Term Declines in Seismicity at Mt. Wrangell and Mt. Veniaminof Volcanoes, Alaska, Following the November 3, 2002 Mw 7.9 Denali Fault Earthquake

    NASA Astrophysics Data System (ADS)

    Sanchez, J. J.; McNutt, S. R.

    2003-12-01

    On November 3, 2002 a Mw 7.9 earthquake ruptured segments of the Denali Fault and adjacent faults in interior Alaska providing a unique opportunity to look for intermediate-term (days to weeks) responses of Alaskan volcanoes to shaking from a large regional earthquake. The Alaska Volcano Observatory (AVO) monitors 24 volcanoes with seismograph networks. We examined one station per volcano, generally the closest to the vent (typically within 5 km) unless noise, or other factors made the data unusable. Data were digitally filtered between 0.8 and 5 Hz to enhance the signal-to-noise ratio. Data for the period four weeks before to four weeks after the Mw 7.9 earthquake were then plotted at a standard scale used for AVO routine monitoring. Mt. Veniaminof volcano, which has had recent mild eruptions and a rate of ten earthquakes per day on station VNNF, suffered a drop in seismicity by a factor of two after the earthquake; this lasted for 15 days. Wrangell, the closest volcano to the epicenter, had a background rate of about 16 earthquakes per day. Data from station WANC could not be measured for 3 days after the Mw 7.9 earthquake because the large number and size of aftershocks impeded identification of local earthquakes. For the following 30 days, however, its seismicity rate dropped by a factor of two. Seismicity then remained low for an additional 4 months at Wrangell, whereas that at Veniaminof returned to normal within weeks. The seismicity at both Mt. Veniaminof and Mt. Wrangell is dominated by low-frequency volcanic events. The detection thresholds for both seismograph networks are low and stations VNNF and WANC operated normally during the time of our study, thus we infer that the changes in seismicity may be related to the earthquake. It is known that Wrangell increased its heat output after the Mw 9.2 Alaska earthquake of 1964 and again after the Ms 7.1 St.Elias earthquake of 1979. The other volcanoes showed no changes in seismicity that can be attributable to

  10. Sharing Ideas. Southeast Alaska Cultures: Teaching Ideas and Resource Information.

    ERIC Educational Resources Information Center

    Hinckley, Kay, Comp.; Kleinert, Jean, Comp.

    The product of two 1975 workshops held in Southeastern Alaska (Fairbanks and Sitka), this publication presents the following: (1) papers (written by the educators in attendance at the workshops) which address education methods and concepts relevant to the culture of Southeastern Alaska ("Tlingit Sea Lion Parable"; "Using Local…

  11. Scientific Information Platform for the 2008 Great Wenchuan Earthquake

    NASA Astrophysics Data System (ADS)

    Liang, C.

    2012-12-01

    The 2008 MS 8.0 Wenchuan earthquake is one of the deadliest in recent human history. This earthquake has not just united the whole world to help local people to lead their life through the difficult time, it has also fostered significant global cooperation to study this event from various aspects: including pre-seismic events (such as the seismicity, gravity, electro-magnetic fields, well water level, radon level in water etc), co-seismic events (fault slipping, landslides, man-made structure damages etc) and post-seismic events (such as aftershocks, well water level changing etc) as well as the disaster relief efforts. In the last four years, more than 300 scientific articles have been published on peer-reviewed journals, among them about 50% are published in Chinese, 30% in English, and about 20% in both languages. These researches have advanced our understanding of earthquake science in general. It has also sparked open debates in many aspects. Notably, the role of the Zipingpu reservoir (built not long ago before the earthquake) in the triggering of this monstrous earthquake is still one of many continuing debates. Given that all these articles are ssporadically spread out on different journals and numerous issues and in different languages, it can be very inefficient, sometimes impossible, to dig out the information that are in need. The Earthquake Research Group in the Chengdu University of Technology (ERGCDUT) has initiated an effort to develop an information platform to collect and analyze scientific research on or related to this earthquake, the hosting faults and the surrounding tectonic regions. A preliminary website has been setup for this purpose: http://www.wenchuaneqresearch.org. Up to this point (July 2012), articles published in 6 Chinese journals and 7 international journals have been collected. Articles are listed journal by journal, and also grouped by contents into four major categories, including pre-seismic events, co-seismic events, post

  12. EarthScope's Transportable Array in Alaska and Western Canada

    NASA Astrophysics Data System (ADS)

    Enders, M.; Miner, J.; Bierma, R. M.; Busby, R.

    2015-12-01

    EarthScope's Transportable Array (TA) in Alaska and Canada is an ongoing deployment of 261 high quality broadband seismographs. The Alaska TA is the continuation of the rolling TA/USArray deployment of 400 broadband seismographs in the lower 48 contiguous states and builds on the success of the TA project there. The TA in Alaska and Canada is operated by the IRIS Consortium on behalf of the National Science Foundation as part of the EarthScope program. By Sept 2015, it is anticipated that the TA network in Alaska and Canada will be operating 105 stations. During the summer 2015, TA field crews comprised of IRIS and HTSI station specialists, as well as representatives from our partner agencies the Alaska Earthquake Center and the Alaska Volcano Observatory and engineers from the UNAVCO Plate Boundary Observatory will have completed a total of 36 new station installations. Additionally, we will have completed upgrades at 9 existing Alaska Earthquake Center stations with borehole seismometers and the adoption of an additional 35 existing stations. As the array doubles in Alaska, IRIS continues to collaborate closely with other network operators, universities and research consortia in Alaska and Canada including the Alaska Earthquake Center (AEC), the Alaska Volcano Observatory (AVO), the UNAVCO Plate Boundary Observatory (PBO), the National Tsunami Warning Center (NTWC), Natural Resources Canada (NRCAN), Canadian Hazard Information Service (CHIS), the Yukon Geologic Survey (YGS), the Pacific Geoscience Center of the Geologic Survey, Yukon College and others. During FY14 and FY15 the TA has completed upgrade work at 20 Alaska Earthquake Center stations and 2 AVO stations, TA has co-located borehole seismometers at 5 existing PBO GPS stations to augment the EarthScope observatory. We present an overview of deployment plan and the status through 2015. The performance of new Alaska TA stations including improvements to existing stations is described.

  13. Beach ridges as paleoseismic indicators of abrupt coastal subsidence during subduction zone earthquakes, and implications for Alaska-Aleutian subduction zone paleoseismology, southeast coast of the Kenai Peninsula, Alaska

    USGS Publications Warehouse

    Kelsey, Harvey M.; Witter, Robert C.; Engelhart, Simon E.; Briggs, Richard; Nelson, Alan R.; Haeussler, Peter J.; Corbett, D. Reide

    2015-01-01

    The Kenai section of the eastern Alaska-Aleutian subduction zone straddles two areas of high slip in the 1964 great Alaska earthquake and is the least studied of the three megathrust segments (Kodiak, Kenai, Prince William Sound) that ruptured in 1964. Investigation of two coastal sites in the eastern part of the Kenai segment, on the southeast coast of the Kenai Peninsula, identified evidence for two subduction zone earthquakes that predate the 1964 earthquake. Both coastal sites provide paleoseismic data through inferred coseismic subsidence of wetlands and associated subsidence-induced erosion of beach ridges. At Verdant Cove, paleo-beach ridges record the paleoseismic history; whereas at Quicksand Cove, buried soils in drowned coastal wetlands are the primary indicators of paleoearthquake occurrence and age. The timing of submergence and death of trees mark the oldest earthquake at Verdant Cove that is consistent with the age of a well documented ∼900-year-ago subduction zone earthquake that ruptured the Prince William Sound segment of the megathrust to the east and the Kodiak segment to the west. Soils buried within the last 400–450 years mark the penultimate earthquake on the southeast coast of the Kenai Peninsula. The penultimate earthquake probably occurred before AD 1840 from its absence in Russian historical accounts. The penultimate subduction zone earthquake on the Kenai segment did not rupture in conjunction with the Prince William Sound to the northeast. Therefore the Kenai segment, which is presently creeping, can rupture independently of the adjacent Prince William Sound segment that is presently locked.

  14. Activity remotely triggered in volcanic and geothermal centers in California and Washington by the 3 November 2002 Mw=7.9 Alaska earthquake

    NASA Astrophysics Data System (ADS)

    Hill, D. P.; Prejean, S.; Oppenheimer, D.; Pitt, A. M.; S. D. Malone; Richards-Dinger, K.

    2002-12-01

    The M=7.9 Alaska earthquake of 3 November 2002 was followed by bursts of remotely triggered earthquakes at several volcanic and geothermal areas across the western United States at epicentral distances of 2,500 to 3,660 km. Husen et al. (this session) describe the triggered response for Yellowstone caldera, Wyoming. Here we highlight the triggered response for the Geysers geothermal field in northern California, Mammoth Mountain and Long Valley caldera in eastern California, the Coso geothermal field in southeastern California, and Mount Rainier in central Washington. The onset of triggered seismicity at each of these areas began 15 to 17 minutes after the Alaska earthquake during the S-wave coda and the early phases of the Love and Raleigh waves with periods of 5 to 40 seconds and dynamic strains of a few microstrain. In each case, the seismicity was characterized by spasmodic bursts of small (M<2 ), brittle-failure earthquakes. The activity persisted for just a few minutes at Mount Rainier and Mammoth Mountain and roughly 30 minutes at the Geysers and Coso geothermal fields. Many of the triggered earthquakes at all three sites were too small for reliable locations (magnitudes M<1), although their small S-P times indicate hypocentral locations within a few km of the nearest seismic station. Borehole dilatometers in vicinity of Mammoth Mountain recorded strain offsets on the order of 0.1 microstrain coincident in time with the triggered seismicity (Johnston et al. this session), and water level in the 3-km-deep LVEW well in the center of Long Valley caldera dropped by ~13 cm during passage of the seismic wave train from the Alaska earthquake followed by a gradual recovery. The Geysers, Coso, and Mount Rainier have no continuous, high-resolution strain instrumentation. A larger earthquake swarm that began 23.5 hours later (21:38 UT on the 4th) in the south moat of Long Valley caldera and included nine M>2 and one M=3.0 earthquake may represent a delayed response to

  15. 75 FR 5760 - Proposed Information Collection; Comment Request; Western Alaska Community Development Quota Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-04

    ... Alaska Community Development Quota Program AGENCY: National Oceanic and Atmospheric Administration (NOAA... patsy.bearden@noaa.gov . SUPPLEMENTARY INFORMATION: I. Abstract The Community Development Quota (CDQ... communities the opportunity to participate and invest in Bering Sea and Aleutian Islands Management...

  16. 77 FR 19315 - Renewal of Agency Information Collection for Reindeer in Alaska

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-30

    .... The information collection is currently authorized by OMB Control Number 1076-0047, which expires... that we will be able to do so. III. Data OMB Control Number: 1076-0047. Title: Reindeer in Alaska,...

  17. Earthquakes

    ERIC Educational Resources Information Center

    Roper, Paul J.; Roper, Jere Gerard

    1974-01-01

    Describes the causes and effects of earthquakes, defines the meaning of magnitude (measured on the Richter Magnitude Scale) and intensity (measured on a modified Mercalli Intensity Scale) and discusses earthquake prediction and control. (JR)

  18. Earthquakes

    MedlinePlus

    ... and Cleanup Workers Hurricanes PSAs ASL Videos: Hurricanes Landslides & Mudslides Lightning Lightning Safety Tips First Aid Recommendations ... Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis Volcanoes Wildfires Winter Weather Earthquakes Language: ...

  19. Duration-amplitude relationships of volcanic tremor and earthquake swarms preceding and during the 2009 eruption of Redoubt Volcano, Alaska

    NASA Astrophysics Data System (ADS)

    DeRoin, Nicole; McNutt, Stephen R.; Thompson, Glenn

    2015-02-01

    Duration-amplitude relationships were studied for tremor episodes and earthquake swarms occurring during the 2009 eruption of Redoubt Volcano, Alaska. Duration-amplitude distribution plots were generated daily from January 1 to May 31 and fit with both an exponential law and power law. Comparing R2 values of the fit for both laws showed that the exponential law fit better for days in which volcanic tremor and earthquake swarms occurred, while the power law fit better for other days. Fitting segments of seismic data with both an exponential and a power law leads to a metric that has potential for volcano monitoring: R2exp/R2pow, the ratio of the R2 fits using the exponential law and the power law. The ratio R2exp/R2pow tended to be greater than 1 when volcanic activity or precursory seismic activity was occurring, and less than 1 when no volcano-seismic activity was occurring. Duration-amplitude plots were generated for episodes of volcanic tremor that were identified by the R2exp/R2pow ≥ 1 method and compared in an attempt to identify changes that may have occurred during the eruption. Stronger episodes of volcanic tremor showed higher characteristic amplitudes. Maximum heights of the plumes generated by the explosions showed a positive correlation with the characteristic amplitude of the concurrent tremor.

  20. Mechanism of the 1996-97 non-eruptive volcano-tectonic earthquake swarm at Iliamna Volcano, Alaska

    USGS Publications Warehouse

    Roman, D.C.; Power, J.A.

    2011-01-01

    A significant number of volcano-tectonic(VT) earthquake swarms, some of which are accompanied by ground deformation and/or volcanic gas emissions, do not culminate in an eruption.These swarms are often thought to represent stalled intrusions of magma into the mid- or shallow-level crust.Real-time assessment of the likelihood that a VTswarm will culminate in an eruption is one of the key challenges of volcano monitoring, and retrospective analysis of non-eruptive swarms provides an important framework for future assessments. Here we explore models for a non-eruptive VT earthquake swarm located beneath Iliamna Volcano, Alaska, in May 1996-June 1997 through calculation and inversion of fault-plane solutions for swarm and background periods, and through Coulomb stress modeling of faulting types and hypocenter locations observed during the swarm. Through a comparison of models of deep and shallow intrusions to swarm observations,we aim to test the hypothesis that the 1996-97 swarm represented a shallow intrusion, or "failed" eruption.Observations of the 1996-97 swarm are found to be consistent with several scenarios including both shallow and deep intrusion, most likely involving a relatively small volume of intruded magma and/or a low degree of magma pressurization corresponding to a relatively low likelihood of eruption. ?? 2011 Springer-Verlag.

  1. An Earthquake Information Service with Free and Open Source Tools

    NASA Astrophysics Data System (ADS)

    Schroeder, M.; Stender, V.; Jüngling, S.

    2015-12-01

    At the GFZ German Research Centre for Geosciences in Potsdam, the working group Earthquakes and Volcano Physics examines the spatiotemporal behavior of earthquakes. In this context also the hazards of volcanic eruptions and tsunamis are explored. The aim is to collect related information after the occurrence of such extreme event and make them available for science and partly to the public as quickly as possible. However, the overall objective of this research is to reduce the geological risks that emanate from such natural hazards. In order to meet the stated objectives and to get a quick overview about the seismicity of a particular region and to compare the situation to historical events, a comprehensive visualization was desired. Based on the web-accessible data from the famous GFZ GEOFON network a user-friendly web mapping application was realized. Further, this web service integrates historical and current earthquake information from the USGS earthquake database, and more historical events from various other catalogues like Pacheco, International Seismological Centre (ISC) and more. This compilation of sources is unique in Earth sciences. Additionally, information about historical and current occurrences of volcanic eruptions and tsunamis are also retrievable. Another special feature in the application is the containment of times via a time shifting tool. Users can interactively vary the visualization by moving the time slider. Furthermore, the application was realized by using the newest JavaScript libraries which enables the application to run in all sizes of displays and devices. Our contribution will present the making of, the architecture behind, and few examples of the look and feel of this application.

  2. Effects of the earthquake of March 27, 1964, at Valdez, Alaska: Chapter C in The Alaska earthquake, March 27, 1964: effects on communities

    USGS Publications Warehouse

    Coulter, Henry Welty; Migliaccio, Ralph R.

    1966-01-01

    Valdez is situated on the seaward edge of a large outwash delta composed of a thick section of saturated silty sand and gravel. The earthquake of March 27, 1964, triggered a massive submarine slide, involving approximately 98 million cubic yards of material that destroyed the harbor facilities and nearshore installations. Waves generated by the slide and subsequent strong seiches did additional damage in the downtown area. Stresses generated by the seismic shocks and the slide developed an extensive system of fissures throughout the unconsolidated deposits at the head of the fiord. These fissures plus the shocks caused structural damage to many of the buildings in Valdez and destroyed the sewer and water systems. Removal of support from the face of the delta by submarine sliding allowed some of the material to move seaward and caused parts of the shore area to subside below high-tide level. A site for relocating the town of Valdez has been designated. It is situated on the Mineral Creek fan--an area underlain by coarse alluvial gravel. This relocation site is protected from sea waves by a series of bedrock ridges and islands that also provide a resistant buttress retaining and protecting the toe of the fan from danger of sliding or slumping. The absence of evidence of ground breakage on the Mineral Creek fan indicates that the coarse subsoils at the relocation site react favorably under seismic conditions.

  3. History of earthquakes and tsunamis along the eastern Aleutian-Alaska megathrust, with implications for tsunami hazards in the California Continental Borderland

    USGS Publications Warehouse

    Ryan, Holly F.; von Huene, Roland; Wells, Ray E.; Scholl, David W.; Kirby, Stephen; Draut, Amy E.; Dumoulin, J.A.; Dusel-Bacon, C.

    2012-01-01

    During the past several years, devastating tsunamis were generated along subduction zones in Indonesia, Chile, and most recently Japan. Both the Chile and Japan tsunamis traveled across the Pacific Ocean and caused localized damage at several coastal areas in California. The question remains as to whether coastal California, in particular the California Continental Borderland, is vulnerable to more extensive damage from a far-field tsunami sourced along a Pacific subduction zone. Assuming that the coast of California is at risk from a far-field tsunami, its coastline is most exposed to a trans-Pacific tsunami generated along the eastern Aleutian-Alaska subduction zone. We present the background geologic constraints that could control a possible giant (Mw ~9) earthquake sourced along the eastern Aleutian-Alaska megathrust. Previous great earthquakes (Mw ~8) in 1788, 1938, and 1946 ruptured single segments of the eastern Aleutian-Alaska megathrust. However, in order to generate a giant earthquake, it is necessary to rupture through multiple segments of the megathrust. Potential barriers to a throughgoing rupture, such as high-relief fracture zones or ridges, are absent on the subducting Pacific Plate between the Fox and Semidi Islands. Possible asperities (areas on the megathrust that are locked and therefore subject to infrequent but large slip) are identified by patches of high moment release observed in the historical earthquake record, geodetic studies, and the location of forearc basin gravity lows. Global Positioning System (GPS) data indicate that some areas of the eastern Aleutian-Alaska megathrust, such as that beneath Sanak Island, are weakly coupled. We suggest that although these areas will have reduced slip during a giant earthquake, they are not really large enough to form a barrier to rupture. A key aspect in defining an earthquake source for tsunami generation is determining the possibility of significant slip on the updip end of the megathrust near

  4. Calibration of PS09, PS10, and PS11 trans-Alaska pipeline system strong-motion instruments, with acceleration, velocity, and displacement records of the Denali fault earthquake, 03 November 2002

    USGS Publications Warehouse

    Evans, John R.; Jensen, E. Gray; Sell, Russell; Stephens, Christopher D.; Nyman, Douglas J.; Hamilton, Robert C.; Hager, William C.

    2006-01-01

    In September, 2003, the Alyeska Pipeline Service Company (APSC) and the U.S. Geological Survey (USGS) embarked on a joint effort to extract, test, and calibrate the accelerometers, amplifiers, and bandpass filters from the earthquake monitoring systems (EMS) at Pump Stations 09, 10, and 11 of the Trans-Alaska Pipeline System (TAPS). These were the three closest strong-motion seismographs to the Denali fault when it ruptured in the MW 7.9 earthquake of 03 November 2002 (22:12:41 UTC). The surface rupture is only 3.0 km from PS10 and 55.5 km from PS09 but PS11 is 124.2 km away from a small rupture splay and 126.9 km from the main trace. Here we briefly describe precision calibration results for all three instruments. Included with this report is a link to the seismograms reprocessed using these new calibrations: http://nsmp.wr.usgs.gov/data_sets/20021103_2212_taps.html Calibration information in this paper applies at the time of the Denali fault earthquake (03 November 2002), but not necessarily at other times because equipment at these stations is changed by APSC personnel at irregular intervals. In particular, the equipment at PS09, PS10, and PS11 was changed by our joint crew in September, 2003, so that we could perform these calibrations. The equipment stayed the same from at least the time of the earthquake until that retrieval, and these calibrations apply for that interval.

  5. Insight into the Earthquake Risk Information Seeking Behavior of the Victims: Evidence from Songyuan, China

    PubMed Central

    Li, Shasha; Zhai, Guofang; Zhou, Shutian; Fan, Chenjing; Wu, Yunqing; Ren, Chongqiang

    2017-01-01

    Efficient risk communication is a vital way to reduce the vulnerability of individuals when facing emergency risks, especially regarding earthquakes. Efficient risk communication aims at improving the supply of risk information and fulfilling the need for risk information by individuals. Therefore, an investigation into individual-level information seeking behavior within earthquake risk contexts is very important for improved earthquake risk communication. However, at present there are very few studies that have explored the behavior of individuals seeking earthquake risk information. Under the guidance of the Risk Information Seeking and Processing model as well as relevant practical findings using the structural equation model, this study attempts to explore the main determinants of an individual’s earthquake risk information seeking behavior, and to validate the mediator effect of information need during the seeking process. A questionnaire-based survey of 918 valid respondents in Songyuan, China, who had been hit by a small earthquake swarm, was used to provide practical evidence for this study. Results indicated that information need played a noteworthy role in the earthquake risk information seeking process, and was detected both as an immediate predictor and as a mediator. Informational subjective norms drive the seeking behavior on earthquake risk information through both direct and indirect approaches. Perceived information gathering capacity, negative affective responses and risk perception have an indirect effect on earthquake risk information seeking behavior via information need. The implications for theory and practice regarding risk communication are discussed and concluded. PMID:28272359

  6. Late Holocene coastal stratigraphy of Sitkinak Island reveals Aleutian-Alaska megathrust earthquakes and tsunamis southwest of Kodiak Island

    NASA Astrophysics Data System (ADS)

    Nelson, A. R.; Briggs, R. W.; Kemp, A.; Haeussler, P. J.; Engelhart, S. E.; Dura, T.; Angster, S. J.; Bradley, L.

    2012-12-01

    Uncertainty in earthquake and tsunami prehistory of the Aleutian-Alaska megathrust westward of central Kodiak Island limit assessments of southern Alaska's earthquake hazard and forecasts of potentially damaging tsunamis along much of North America's west coast. Sitkinak Island, one of the Trinity Islands off the southwest tip of Kodiak Island, lies at the western end of the rupture zone of the 1964 Mw9.2 earthquake. Plafker reports that a rancher on the north coast of Sitkinak Island observed ~0.6 m of shoreline uplift immediately following the 1964 earthquake, and the island is now subsiding at about 3 mm/yr (PBO GPS). Although a high tsunami in 1788 caused the relocation of the first Russian settlement on southwestern Kodiak Island, the eastern extent of the megathrust rupture accompanying the tsunami is uncertain. Interpretation of GPS observations from the Shumagin Islands, 380 km southwest of Kodiak Island, suggests an entirely to partially creeping megathrust in that region. Here we report the first stratigraphic evidence of tsunami inundation and land-level change during prehistoric earthquakes west of central Kodiak Island. Beneath tidal and freshwater marshes around a lagoon on the south coast of Sitkinak Island, 27 cores and tidal outcrops reveal the deposits of four to six tsunamis in 2200 years and two to four abrupt changes in lithology that may correspond with coseismic uplift and subsidence over the past millennia. A 2- to 45-mm-thick bed of clean to peaty sand in sequences of tidal sediment and freshwater peat, identified in more than one-half the cores as far inland as 1.5 km, was probably deposited by the 1788 tsunami. A 14C age on Scirpus seeds, double 137Cs peaks at 2 cm and 7 cm depths (Chernobyl and 1963?), a consistent decline in 210Pb values, and our assumption of an exponential compaction rate for freshwater peat, point to a late 18th century age for the sand bed. Initial 14C ages suggest that two similar extensive sandy beds, identified

  7. Gravity survey and regional geology of the Prince William Sound epicentral region, Alaska: Chapter C in The Alaska earthquake, March 27, 1964: regional effects

    USGS Publications Warehouse

    Case, J.E.; Barnes, D.F.; Plafker, George; Robbins, S.L.

    1966-01-01

    Sedimentary and volcanic rocks of Mesozoic and early Tertiary age form a roughly arcuate pattern in and around Prince William Sound, the epicentral region of the Alaska earthquake of 1964. These rocks include the Valdez Group, a predominantly slate and graywacke sequence of Jurassic and Cretaceous age, and the Orca Group, a younger sequence of early Tertiary age. The Orca consists of a lower unit of dense-average 2.87 g per cm3 (grams per cubic centimeter) pillow basalt and greenstone intercalated with sedimentary rocks and an upper unit of lithologically variable sandstone interbedded with siltstone or argillite. Densities of the clastic rocks in both the Valdez and Orca Groups average about 2.69 g per cm3. Granitic rocks of relatively low density (2.62 g per cm3) cut the Valdez and Orca Groups at several localities. Both the Valdez and the Orca Groups were complexly folded and extensively faulted during at least three major episodes of deformation: an early period of Cretaceous or early Tertiary orogeny, a second orogeny that probably culminated in late Eocene or early Oligocene time and was accompanied or closely followed by emplacement of granitic batholiths, and a third episode of deformation that began in late Cenozoic time and continued intermittently to the present. About 500 gravity stations were established in the Prince William Sound region in conjunction with postearthquake geologic investigations. Simple Bouguer anomaly contours trend approximately parallel to the arcuate geologic structure around the sound. Bouguer anomalies decrease northward from +40 mgal (milligals) at the southwestern end of Montague Island to -70 mgal at College and Harriman Fiords. Most of this change may be interpreted as a regional gradient caused by thickening of the continental crust. Superimposed on the gradient is a prominent gravity high of as much as 65 mgal that extends from Elrington Island on the southwest, across Knight and Glacier Islands to the Ellamar Peninsula

  8. Fault Segmentation and Earthquake Generation in the Transition from Strike-slip to Subduction Plate Motion, Saint Elias Orogen, Alaska and Yukon (Invited)

    NASA Astrophysics Data System (ADS)

    Bruhn, R. L.; Shennan, I.; Pavlis, T. L.

    2010-12-01

    The structural transition from strike-slip motion along the Fairweather transform fault to subduction on the Aleutian megathrust occurs within the collision zone between the Yakutat microplate and southern Alaska. The collision is marked by belts of thrust and strike-slip faulting both within the microplate and along its margins, forming a complex fault network that mechanically interacts with rupturing of the Aleutian megathrust on one hand, and the Fairweather transform fault on the other. For example, stress released by M8+ earthquakes within the central and eastern parts of the Yakutat microplate in 1899 may have constrained the 1964 rupture on the Aleutian megathrust to the western part of the microplate. However, megathrust earthquakes circa 900 BP and 1500 BP may have ruptured farther east than in 1964, generating earthquakes of significantly greater magnitude and tsunami potential. Structurally, the thrust-faulting earthquake of Sept. 10, 1899 occurred on faults that are loaded primarily by the Fairweather transform, but the earlier event of Sept. 4 is more closely linked to the Aleutian megathrust. Large reverse faults that rise off of the megathrust are superimposed on older structures within the microplate; creating complex duplex and wedge fault geometries beneath the mountains onshore that link to simpler fault propagation folds offshore. These lateral variations in fault network style correlate with 1) permanent uplift of the coast at ≈ 1 cm/yr in the Yakataga region of the microplate, 2) an abrupt change in structural style and orientation across the Kayak Island - Bering Glacier deformation zone, and 3) the seaward limit of ruptures in the 1899 earthquakes which occurred beneath the mountains onshore. Future goals include refining locations of earthquake source faults and determining the recurrence history of earthquakes within the Yakutat microplate. The history of rupturing within the microplate offshore is of particular interest given the

  9. National clearinghouse for Loma Prieta earthquake information catalog, April 1992

    SciTech Connect

    Not Available

    1992-01-01

    This catalog lists 142 new citations on the Loma Prieta earthquake. Section titles are: General topics and conference proceedings; Selected topics in seismology; Engineering seismology; Strong-motion seismometry; Dynamics of soils, rocks, and foundations; Dynamics of structures; Earthquake-resistant design and construction; Earthquake damage; and Earthquakes as natural disasters. Included are indexes by author, title, subject, and format.

  10. Assessing Lay Understanding of Common Presentations of Earthquake Hazard Information

    NASA Astrophysics Data System (ADS)

    Thompson, K. J.; Krantz, D. H.

    2010-12-01

    The Working Group on California Earthquake Probabilities (WGCEP) includes, in its introduction to earthquake rupture forecast maps, the assertion that "In daily living, people are used to making decisions based on probabilities -- from the flip of a coin (50% probability of heads) to weather forecasts (such as a 30% chance of rain) to the annual chance of being killed by lightning (about 0.0003%)." [3] However, psychology research identifies a large gap between lay and expert perception of risk for various hazards [2], and cognitive psychologists have shown in numerous studies [1,4-6] that people neglect, distort, misjudge, or misuse probabilities, even when given strong guidelines about the meaning of numerical or verbally stated probabilities [7]. The gap between lay and expert use of probability needs to be recognized more clearly by scientific organizations such as WGCEP. This study undertakes to determine how the lay public interprets earthquake hazard information, as presented in graphical map form by the Uniform California Earthquake Rupture Forecast (UCERF), compiled by the WGCEP and other bodies including the USGS and CGS. It also explores alternate ways of presenting hazard data, to determine which presentation format most effectively translates information from scientists to public. Participants both from California and from elsewhere in the United States are included, to determine whether familiarity -- either with the experience of an earthquake, or with the geography of the forecast area -- affects people's ability to interpret an earthquake hazards map. We hope that the comparisons between the interpretations by scientific experts and by different groups of laypeople will both enhance theoretical understanding of factors that affect information transmission and assist bodies such as the WGCEP in their laudable attempts to help people prepare themselves and their communities for possible natural hazards. [1] Kahneman, D & Tversky, A (1979). Prospect

  11. EarthScope Transportable Array Siting Outreach Activities in Alaska and Western Canada

    NASA Astrophysics Data System (ADS)

    Dorr, P. M.; Gardine, L.; Tape, C.; McQuillan, P.; Cubley, J. F.; Samolczyk, M. A.; Taber, J.; West, M. E.; Busby, R.

    2015-12-01

    The EarthScope Transportable Array is deploying about 260 stations in Alaska and western Canada. IRIS and EarthScope are partnering with the Alaska Earthquake Center, part of the University of Alaska's Geophysical Institute, and Yukon College to spread awareness of earthquakes in Alaska and western Canada and the benefits of the Transportable Array for people living in these regions. We provide an update of ongoing education and outreach activities in Alaska and Canada as well as continued efforts to publicize the Transportable Array in the Lower 48. Nearly all parts of Alaska and portions of western Canada are tectonically active. The tectonic and seismic variability of Alaska, in particular, requires focused attention at the regional level, and the remoteness and inaccessibility of most Alaskan and western Canadian villages and towns often makes frequent visits difficult. When a community is accessible, every opportunity to engage the residents is made. Booths at state fairs and large cultural gatherings, such as the annual convention of the Alaska Federation of Natives, are excellent venues to distribute earthquake information and to demonstrate a wide variety of educational products and web-based applications related to seismology and the Transportable Array that residents can use in their own communities. Meetings and interviews with Alaska Native Elders and tribal councils discussing past earthquakes has led to a better understanding of how Alaskans view and understand earthquakes. Region-specific publications have been developed to tie in a sense of place for residents of Alaska and the Yukon. The Alaska content for IRIS's Active Earth Monitor emphasizes the widespread tectonic and seismic features and offers not just Alaska residents, but anyone interested in Alaska, a glimpse into what is going on beneath their feet. The concerted efforts of the outreach team will have lasting effects on Alaskan and Canadian understanding of the seismic hazard and

  12. Geophysical investigation of the Denali fault and Alaska Range orogen within the aftershock zone of the October-November 2002, M = 7.9 Denali fault earthquake

    USGS Publications Warehouse

    Fisher, M.A.; Nokleberg, W.J.; Ratchkovski, N.A.; Pellerin, L.; Glen, J.M.; Brocher, T.M.; Booker, J.

    2004-01-01

    The aftershock zone of the 3 November 2002, M = 7.9 earthquake that ruptured along the right-slip Denali fault in south-central Alaska has been investigated by using gravity and magnetic, magnetotelluric, and deep-crustal, seismic reflection data as well as outcrop geology and earthquake seismology. Strong seismic reflections from within the Alaska Range orogen north of the Denali fault dip as steeply as 25°N and extend to depths as great as 20 km. These reflections outline a relict crustal architecture that in the past 20 yr has produced little seismicity. The Denali fault is nonreflective, probably because this fault dips steeply to vertical. The most intriguing finding from geophysical data is that earthquake aftershocks occurred above a rock body, with low electrical resistivity (>10 Ω·m), that is at depths below ∼10 km. Aftershocks of the Denali fault earthquake have mainly occurred shallower than 10 km. A high geothermal gradient may cause the shallow seismicity. Another possibility is that the low resistivity results from fluids, which could have played a role in locating the aftershock zone by reducing rock friction within the middle and lower crust.

  13. Reconnaissance engineering geology of the Haines area, Alaska, with emphasis on evaluation of earthquake and other geologic hazards

    USGS Publications Warehouse

    Lemke, Richard Walter; Yehle, Lynn A.

    1972-01-01

    The Alaska earthquake of March 27, 1964, brought into sharp focus the need for engineering geologic studies in urban areas. Study of the Haines area constitutes an integral part of an overall program to evaluate earthquake and other geologic hazards in most of the larger Alaska coastal communities. The evaluations of geologic hazards that follow, although based only upon reconnaissance studies and, therefore, subject to revision, will provide broad guidelines useful in city and land-use planning. It is hoped that the knowledge gained will result in new facilities being built in the best possible geologic environments and being designed so as to minimize future loss of life and property damage. Haines, which is in the northern part of southeastern Alaska approximately 75 miles northwest of Juneau, had a population, of about 700 people in 1970. It is built at the northern end of the Chilkat Peninsula and lies within the Coast Mountains of the Pacific Mountain system. The climate is predominantly marine and is characterized by mild winters and cool summers. The mapped area described in this report comprises about 17 square miles of land; deep fiords constitute most of the remaining mapped area that is evaluated in this study. The Haines area was covered by glacier ice at least once and probably several times during the Pleistocene Epoch. The presence of emergent marine deposits, several hundred feet above sea level, demonstrates that the land has been uplifted relative to sea level since the last major deglaciation of the region about 10,000 years ago. The rate of relative uplift of the land at Haines during the past 39 years is 2.26 cm per year. Most or all of this uplift appears to be due to rebound as a result of deglaciation. Both bedrock and surficial deposits are present in the area. Metamorphic and igneous rocks constitute the exposed bedrock. The metamorphic rocks consist of metabasalt of Mesozoic age and pyroxenite of probable early middle Cretaceous age. The

  14. Imaging the transition from Aleutian subduction to Yakutat collision in central Alaska, with local earthquakes and active source data

    USGS Publications Warehouse

    Eberhart-Phillips, D.; Christensen, D.H.; Brocher, T.M.; Hansen, R.; Ruppert, N.A.; Haeussler, P.J.; Abers, G.A.

    2006-01-01

    In southern and central Alaska the subduction and active volcanism of the Aleutian subduction zone give way to a broad plate boundary zone with mountain building and strike-slip faulting, where the Yakutat terrane joins the subducting Pacific plate. The interplay of these tectonic elements can be best understood by considering the entire region in three dimensions. We image three-dimensional seismic velocity using abundant local earthquakes, supplemented by active source data. Crustal low-velocity correlates with basins. The Denali fault zone is a dominant feature with a change in crustal thickness across the fault. A relatively high-velocity subducted slab and a low-velocity mantle wedge are observed, and high Vp/Vs beneath the active volcanic systems, which indicates focusing of partial melt. North of Cook Inlet, the subducted Yakutat slab is characterized by a thick low-velocity, high-Vp/Vs, crust. High-velocity material above the Yakutat slab may represent a residual older slab, which inhibits vertical flow of Yakutat subduction fluids. Alternate lateral flow allows Yakutat subduction fluids to contribute to Cook Inlet volcanism and the Wrangell volcanic field. The apparent northeast edge of the subducted Yakutat slab is southwest of the Wrangell volcanics, which have adakitic composition consistent with melting of this Yakutat slab edge. In the mantle, the Yakutat slab is subducting with the Pacific plate, while at shallower depths the Yakutat slab overthrusts the shallow Pacific plate along the Transition fault. This region of crustal doubling within the shallow slab is associated with extremely strong plate coupling and the primary asperity of the Mw 9.2 great 1964 earthquake. Copyright 2006 by the American Geophysical Union.

  15. Kinematic and dynamic rupture models of the November 3, 2002 Mw7.9 Denali, Alaska, earthquake

    USGS Publications Warehouse

    Dreger, Douglas S.; Oglesby, D.D.; Harris, R.; Ratchkovski, N.; Hansen, R.

    2004-01-01

    Regional seismic waveforms, continuous and campaign-mode GPS data, and surface slip measurements were used to obtain a kinematic model of the rupture process of the November 3, 2002 Mw 7.9 Denali, Alaska, earthquake. The event initiated as a Mw 7.0 reverse slip event on the north-dipping Susitna Glacier fault with subsequent right-lateral slip distributed over approximately 300 km of the Denali fault system. Near-shear rupture velocity is inferred from the kinematic modeling. The average and maximum slips were found to be 2.14 in and 10.3 m. Static stress drop varies from 1.3 to 5.0 MPa over the 5-segment fault model. Dynamic modeling shows the rupture propagated along the Susitna Glacier and Denali faults, then transferred to the Totschunda fault before stopping, largely due to the Totschunda's more favorable orientation with respect to the regional stress field. Copyright 2004 by the American Geophysical Union.

  16. Changes in population evacuation potential for tsunami hazards in Seward, Alaska, since the 1964 Good Friday earthquake

    USGS Publications Warehouse

    Wood, Nathan J.; Schmidtlein, Mathew C.; Peters, Jeff

    2014-01-01

    Pedestrian evacuation modeling for tsunami hazards typically focuses on current land-cover conditions and population distributions. To examine how post-disaster redevelopment may influence the evacuation potential of at-risk populations to future threats, we modeled pedestrian travel times to safety in Seward, Alaska, based on conditions before the 1964 Good Friday earthquake and tsunami disaster and on modern conditions. Anisotropic, path distance modeling is conducted to estimate travel times to safety during the 1964 event and in modern Seward, and results are merged with various population data, including the location and number of residents, employees, public venues, and dependent care facilities. Results suggest that modeled travel time estimates conform well to the fatality patterns of the 1964 event and that evacuation travel times have increased in modern Seward due to the relocation and expansion of port and harbor facilities after the disaster. The majority of individuals threatened by tsunamis today in Seward are employee, customer, and tourist populations, rather than residents in their homes. Modern evacuation travel times to safety for the majority of the region are less than wave arrival times for future tectonic tsunamis but greater than arrival times for landslide-related tsunamis. Evacuation travel times will likely be higher in the winter time, when the presence of snow may constrain evacuations to roads.

  17. Effects of the earthquake of March 27, 1964, on the Eklutna Hydroelectric Project, Anchorage, Alaska, with a section on television examination of earthquake damage to underground communication and electrical systems in Anchorage: Chapter A in The Alaska earthquake, March 27, 1964: effects on transportation, communications, and utilities

    USGS Publications Warehouse

    Logan, Malcolm H.; with a section on Television Examination of Earthquake Damage to Underground Communication and Electrical Systems in Anchorage by Burton, Lynn R.

    1967-01-01

    The March 27, 1964, Alaska earthquake and its associated aftershocks caused damage requiring several million dollars worth of repair to the Eklwtna Hydroelectric Project, 34 miles northeast of Anchorage. Electric service from the Eklutna powerplant was interrupted during the early phase of the March 27 earthquake, built was restored (intermittently) until May 9,1964, when the plant was closed for inspection and repair. Water for Eklutna project is transported from Eklutna Lake to the powerplant at tidewater on Knik Arm of Cook Inlet by an underwater intake connected to a 4.46-mile tunnel penstock. The primary damage caused by the earthquake was 1at the intake structure in Eklutna Lake. No damage to the power tunnel was observed. The piles-supported powerplant and appurtenant structures, Anchorage and Palmer substations, and the transmission lines suffered minor dammage. Most damage occurred to facilities constructed on un-consolidated sediments and overburden which densified and subsided during the earthquake. Structures built on bedrock experienced little or no damage. Underground communication and electrical systems in Anchorage were examined with a small-diameter television camera to locate damaged areas requiring repair. Most of the damage was concentrated at or near valley slopes. Those parts of the systems within the major slide areas of the city were destroyed.

  18. Source model for the 2002 Denali Fault (Alaska) Earthquakes from InSAR andcontinuous GPS measurements.

    NASA Astrophysics Data System (ADS)

    Wright, T.; Lu, Z.; Wicks, C.; Thatcher, W.

    2003-04-01

    The November 3 2002, M7.9 Great Denali Fault earthquake was the largest earthquake to occur in the world in 2002, and is the largest continentalal strike-slip earthquake to have occurred since the development of InSAR. It was preceded by a M6.7 "preshock" on 23 October. Almost all previous InSAR studies of earthquakes have used data from the ERS satellites, but we have so far been unable to process recently-acquired data from ERS-2 because of large Doppler centroid values. Instead, we have processed eight coseismic interferograms using satellite radar data acquired by the Canadian Radarsat satellite, and a 60 m DEM from the USGS. The interferograms were acquired on a mixture of ascending and descending passes, mostly covering intervals of just 24 days. They are largely coherent except for some glaciated areas with high relief within 5-10 kilometres of the fault rupture. Three interferograms span the 23 October preshock only, two the 3 November mainshock only, and three cover both events. Our spatial coverage is poor for the eastern half of the mainshock rupture, where we only have one interferogram with relatively poor coherence, but good for the western half. Where possible, we have concatenated multiple SAR frames together to form interferograms 500-600 km long, centred on the Denali fault. Some care was required because, unlike the ERS satellites when fully operational, Radarsat nominally operates with a broadside imaging geometry and the Doppler centroid therefore varies significantly with latitude. In cases where there were large along-track variations in centroid values, we processed the data in separate patches. Unfortunately, five of the interferograms only contain data south of the Denali fault because of a sudden change in the Radarsat beam mode at this location, which results in a data gap. In addition to the InSAR data, horizontal and vertical displacements from 11 continuous GPS sites within 500 km of the earthquake rupture were available. After sub

  19. 78 FR 70956 - 30-Day Notice of Proposed Information Collection: Assessment of Native American, Alaska Native...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-27

    ..., Alaska Native and Native Hawaiian Housing Needs AGENCY: Office of the Chief Information Officer, HUD... Housing Needs. OMB Approval Number: 2528-0288. Type of Request: Revision of a currently approved collection. Form Number: None. Description of the need for the information and proposed use: The...

  20. 77 FR 65201 - Proposed Information Collection; Alaska Migratory Bird Subsistence Harvest Household Survey

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-25

    ... Fish and Wildlife Service Proposed Information Collection; Alaska Migratory Bird Subsistence Harvest... 703-358- 2482 (telephone). SUPPLEMENTARY INFORMATION: I. Abstract The Migratory Bird Treaty Act of... Department of the Interior as the key agency responsible for managing migratory bird populations...

  1. EDIM - Earthquake Disaster Information System for the Marmara Region, Turkey

    NASA Astrophysics Data System (ADS)

    Wenzel, Friedemann; Erdik, Mustafa; Zschau, Jochen; Fischer, Joachim; Christ, Ingrid; Kiehle, Christian

    2010-05-01

    The main objectives of EDIM (www.cedim.de/EDIM.php) are to enhance the Istanbul earthquake early warning (EEW) system with a number of scientific and technological developments that - in the end - provide a tool set for EEW with wide applicability. Innovations focus on three areas. (1) Analysis and options for improvement of the current system; (2) development of a new type of self-organising sensor system and its application to early warning; (3) development of a geoinformation infrastructure and geoinformation system tuned to early warning purposes. Development in the frame of the Istanbul system, set up and operated by KOERI, allows testing our novel methods and techniques in an operational system environment and working in a partnership with a long-standing traditon of success. EDIM is a consortium of Karlsruhe University (TH), GeoForschungsZentrum (GFZ) Potsdam, Humboldt University (HU) Berlin, lat/lon GmbH Bonn, DELPHI Informations Muster Management GmbH Potsdam, and Kandilli Observatory and Earthquake Research Institute (KOERI) of the Bogazici University in Istanbul. The integration of strong motion seismology, sensor system hard- and software development, and geoinformation real-time management tools prove a successful concept in making seismic early warning a novel technology with high potential for scientific and technological innovation, disaster mitigation, and many spin-offs for other fields. EDIM can serve as a model for further developments in the field of early warning on a global scale.

  2. Earthquake!

    ERIC Educational Resources Information Center

    Hernandez, Hildo

    2000-01-01

    Examines the types of damage experienced by California State University at Northridge during the 1994 earthquake and what lessons were learned in handling this emergency are discussed. The problem of loose asbestos is addressed. (GR)

  3. Earthquakes

    USGS Publications Warehouse

    Shedlock, Kaye M.; Pakiser, Louis Charles

    1998-01-01

    One of the most frightening and destructive phenomena of nature is a severe earthquake and its terrible aftereffects. An earthquake is a sudden movement of the Earth, caused by the abrupt release of strain that has accumulated over a long time. For hundreds of millions of years, the forces of plate tectonics have shaped the Earth as the huge plates that form the Earth's surface slowly move over, under, and past each other. Sometimes the movement is gradual. At other times, the plates are locked together, unable to release the accumulating energy. When the accumulated energy grows strong enough, the plates break free. If the earthquake occurs in a populated area, it may cause many deaths and injuries and extensive property damage. Today we are challenging the assumption that earthquakes must present an uncontrollable and unpredictable hazard to life and property. Scientists have begun to estimate the locations and likelihoods of future damaging earthquakes. Sites of greatest hazard are being identified, and definite progress is being made in designing structures that will withstand the effects of earthquakes.

  4. Numerical study of tsunami generated by multiple submarine slope failures in Resurrection Bay, Alaska, during the MW 9.2 1964 earthquake

    USGS Publications Warehouse

    Suleimani, E.; Hansen, R.; Haeussler, P.J.

    2009-01-01

    We use a viscous slide model of Jiang and LeBlond (1994) coupled with nonlinear shallow water equations to study tsunami waves in Resurrection Bay, in south-central Alaska. The town of Seward, located at the head of Resurrection Bay, was hit hard by both tectonic and local landslide-generated tsunami waves during the MW 9.2 1964 earthquake with an epicenter located about 150 km northeast of Seward. Recent studies have estimated the total volume of underwater slide material that moved in Resurrection Bay during the earthquake to be about 211 million m3. Resurrection Bay is a glacial fjord with large tidal ranges and sediments accumulating on steep underwater slopes at a high rate. Also, it is located in a seismically active region above the Aleutian megathrust. All these factors make the town vulnerable to locally generated waves produced by underwater slope failures. Therefore it is crucial to assess the tsunami hazard related to local landslide-generated tsunamis in Resurrection Bay in order to conduct comprehensive tsunami inundation mapping at Seward. We use numerical modeling to recreate the landslides and tsunami waves of the 1964 earthquake to test the hypothesis that the local tsunami in Resurrection Bay has been produced by a number of different slope failures. We find that numerical results are in good agreement with the observational data, and the model could be employed to evaluate landslide tsunami hazard in Alaska fjords for the purposes of tsunami hazard mitigation. ?? Birkh??user Verlag, Basel 2009.

  5. Surface Rupture Map of the 2002 M7.9 Denali Fault Earthquake, Alaska: Digital Data

    USGS Publications Warehouse

    Haeussler, Peter J.

    2009-01-01

    The November 3, 2002, Mw7.9 Denali Fault earthquake produced about 340 km of surface rupture along the Susitna Glacier Thrust Fault and the right-lateral, strike-slip Denali and Totschunda Faults. Digital photogrammetric methods were primarily used to create a 1:500-scale, three-dimensional surface rupture map, and 1:6,000-scale aerial photographs were used for three-dimensional digitization in ESRI's ArcMap GIS software, using Leica's StereoAnalyst plug in. Points were digitized 4.3 m apart, on average, for the entire surface rupture. Earthquake-induced landslides, sackungen, and unruptured Holocene fault scarps on the eastern Denali Fault were also digitized where they lay within the limits of air photo coverage. This digital three-dimensional fault-trace map is superior to traditional maps in terms of relative and absolute accuracy, completeness, and detail and is used as a basis for three-dimensional visualization. Field work complements the air photo observations in locations of dense vegetation, on bedrock, or in areas where the surface trace is weakly developed. Seventeen km of the fault trace, which broke through glacier ice, were not digitized in detail due to time constraints, and air photos missed another 10 km of fault rupture through the upper Black Rapids Glacier, so that was not mapped in detail either.

  6. A distal earthquake cluster concurrent with the 2006 explosive eruption of Augustine Volcano, Alaska

    USGS Publications Warehouse

    Fisher, M.A.; Ruppert, N.A.; White, R.A.; Wilson, F.H.; Comer, D.; Sliter, R.W.; Wong, F.L.

    2009-01-01

    Clustered earthquakes located 25??km northeast of Augustine Volcano began about 6??months before and ceased soon after the volcano's 2006 explosive eruption. This distal seismicity formed a dense cluster less than 5??km across, in map view, and located in depth between 11??km and 16??km. This seismicity was contemporaneous with sharply increased shallow earthquake activity directly below the volcano's vent. Focal mechanisms for five events within the distal cluster show strike-slip fault movement. Cluster seismicity best defines a plane when it is projected onto a northeast-southwest cross section, suggesting that the seismogenic fault strikes northwest. However, two major structural trends intersect near Augustine Volcano, making it difficult to put the seismogenic fault into a regional-geologic context. Specifically, interpretation of marine multichannel seismic-reflection (MCS) data shows reverse faults, directly above the seismicity cluster, that trend northeast, parallel to the regional geologic strike but perpendicular to the fault suggested by the clustered seismicity. The seismogenic fault could be a reactivated basement structure.

  7. Slide-induced waves, seiching and ground fracturing caused by the earthquake of March 27, 1964 at Kenai Lake, Alaska: Chapter A in The Alaska earthquake, March 27, 1964: regional effects

    USGS Publications Warehouse

    McCulloch, David S.

    1966-01-01

    The March 27, 1964, earthquake dislodged slides from nine deltas in Kenai Lake, south-central Alaska. Sliding removed protruding parts of deltas-often the youngest parts-and steepened delta fronts, increasing the chances of further sliding. Fathograms show that debris from large slides spread widely over the lake floor, some reaching the toe of the opposite shore; at one place debris traveled 5,000 feet over the horizontal lake floor. Slides generated two kinds of local waves: a backfill and far-shore wave. Backfill waves were formed by water that rushed toward the delta to fill the void left by the sinking slide mass, overtopped the slide scrap, and came ashore over the delta. Some backfill waves had runup heights of 30 feet and ran inland more than 300 feet, uprooting and breaking off large trees. Far-shore waves hit the shore opposite the slides. They were formed by slide debris that crossed the lake floor and forced water ahead of it, which then ran up the opposite slope, burst above the lake surface, and struck the shore. One far-shore wave had a runup height of 72 feet. Kenai Lake was tilted and seiched; a power spectrum analysis of a limnogram shows a wave having the period of the calculated uninodal seiche (36 minutes) and several shorter period waves. In constricted and shallow reaches, waves caused by seiching had 20- and 30-foot runup heights. Deep lateral spreading of sediments toward delta margins displaced deeply driven railroad-bridge piles, and set up stress fields in the surface sediments which resulted in the formation of many shear and some tension fractures on the surface of two deltas.

  8. Resource-Constrained Information Management: Providing Governments with Information for Earthquake Preparedness.

    PubMed

    Vatenmacher, Michael; Isaac, Shabtai; Svoray, Tal

    2017-02-07

    This study seeks to attain a better understanding of the information that is required by governments to prepare for earthquakes, and of the constraints they face in obtaining this information. The contributions of the study are two-fold. A survey that was conducted among those responsible for earthquake preparedness actions in different governmental agencies and at different levels revealed on the one hand a desire for information on a broad range of topics, but on the other hand that no resources were allocated in practice to gather this information. A Geographic Information System-based process that was developed following the survey, allowed the required information on seismic hazards and loss and damage risks to be rapidly collected, mapped and integrated. This supported the identification of high-priority areas, for which a more detailed analysis could be initiated. An implementation of the process showed promise, and confirmed its feasibility. Its relative simplicity may ensure that an earthquake preparedness process is initiated by governments that are otherwise reluctant to allocate resources for this purpose.

  9. A digital social network for rapid collection of earthquake disaster information

    NASA Astrophysics Data System (ADS)

    Xu, J. H.; Nie, G. Z.; Xu, X.

    2013-02-01

    Acquiring disaster information quickly after an earthquake is crucial for disaster and emergency rescue management. This study examines a digital social network - an earthquake disaster information reporting network - for rapid collection of earthquake disaster information. Based on the network, the disaster information rapid collection method is expounded in this paper. The structure and components of the reporting network are introduced. Then the work principles of the reporting network are discussed, in which the rapid collection of disaster information is realised by using Global System for Mobile Communications (GSM) messages to report the disaster information and Geographic information system (GIS) to analyse and extract useful disaster information. This study introduces some key technologies for the work principles, including the methods of mass sending and receiving of SMS for disaster management, the reporting network grouping management method, brief disaster information codes, and the GIS modelling of the reporting network. Finally, a city earthquake disaster information quick reporting system is developed and with the support of this system the reporting network obtained good results in a real earthquake and earthquake drills. This method is a semi-real time disaster information collection method which extends current SMS based method and meets the need of small and some moderate earthquakes.

  10. New Near-Source Tsunami Field Data for the April 1, 1946 Aleutian Earthquake, Alaska

    NASA Astrophysics Data System (ADS)

    Plafker, G.; Synolakis, C. E.; Okal, E. A.

    2001-12-01

    The April 1, 1946 Aleutian earthquake (Ms 7.4; Mw 8.2) stands out among tsunamigenic events because it generated both very high run-up near the earthquake source region and a destructive trans-Pacific tsunami. For this puzzling event, maximum near-field run-up (42 m) is more than 6 times the computed average dip slip on the source fault (Johnson and Satake, 1997). Attempts to model the near-field tsunami have been hampered by an almost total absence of reliable data on wave run-up, direction, and arrival time because the ocean coast in the region was virtually uninhabited, the earthquake and tsunami occurred at night, and there were no nearby recording tide gauges. The lone exception is the Scotch Cap Coast Guard station on the southwestern end of Unimak Island where a reinforced concrete lighthouse and its crew of 5 Coast Guardsmen were obliterated by the tsunami. Survivors at the station, who were in a communications facility on the sea cliff above the lighthouse, report that the wave arrived shortly before low tide at 2:18 A.M., some 48 minutes after the main shock was felt. Previous surveys by Coast Guard personnel indicated a maximum wave run-up elevation of 30-35 m at the station above an unspecified datum. We obtained new data on tsunami distribution along south-facing coasts between Unimak Pass on the west and Sanak Island on the east by measuring the height of driftwood and beach materials that were deposited by the tsunami above the extreme storm tide level. Our data indicate that: 1. The highest measured run-up, which is at the Scotch Cap lighthouse, was 42 m above tide level or about 37 m above present storm tide elevation; 2. Run-up along the rugged coast from Scotch Cap for 12 km NW to Sennett Point is 12.6-18 m and for 30 km east of Scotch Cap to Cape Lutke it is 24-40.6 m; 3. Run-up along the broad lowlands bordering Unimak Bight is 10-15 m and inundation is locally more than 1,000 m; 5. Run-up diminishes to 8 m or less at the SE corner of Unimak

  11. National clearinghouse for Loma Prieta earthquake information catalog, November 1991

    SciTech Connect

    Not Available

    1991-01-01

    This catalog lists 440 new citations including recently completed work, abstracts of National Science Foundation research projects in progress, and contributions to the clearinghouse received after April, 1991. Section titles are: General topics and conference proceedings; Selected topics in seismology; Engineering seismology; Strong-motion seismometry; Dynamics of soils, rocks, and foundations; Dynamics of structures; Earthquake-resistant design and construction; Earthquake damage; and Earthquakes as natural disasters. Included are indexes by author, title, subject, and format.

  12. National clearinghouse for Loma Prieta earthquake information catalog, April 1991

    SciTech Connect

    Not Available

    1991-01-01

    This catalog provides a descriptive list of 570 newspaper and periodical articles, papers in conference proceedings, maps, slides, videos, technical reports, and strong-motion data generated as a result of the October 17, 1989 Loma Prieta earthquake. Section titles are: General topics and conference proceedings; Selected topics in seismology; Engineering seismology; Strong-motion seismometry; Dynamics of soils, rocks, and foundations; Dynamics of structures; Earthquake-resistant design and construction; Earthquake damage; and Earthquakes as natural disasters. Included are indexes by author, title, subject, and format.

  13. Information Processing Patterns of Postsecondary American Indian/Alaska Native Students

    ERIC Educational Resources Information Center

    Aragon, Steven R.

    2004-01-01

    In the last of a three-part series, this study examined the information processing patterns of postsecondary American Indian/Alaska Native students attending community and tribal colleges in the Southwest. Using a survey design, students completed the Kolb Learning Style Inventory, the Briggs and Myers Myers-Briggs Type Indicator, and the Oltman,…

  14. 76 FR 53412 - Proposed Information Collection; Comment Request; Alaska Commercial Operator's Annual Report (COAR)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-26

    ... wholesale values for statewide fish and shellfish products. Containing information from shoreside processors, stationary floating processors, motherships, and catcher/processors, this data collection yields equivalent.../processor or mothership with a Federal permit operating in the EEZ off Alaska is required to annually...

  15. EarthScope Transportable Array Siting Outreach Activities in Alaska and Western Canada

    NASA Astrophysics Data System (ADS)

    Gardine, L.; Dorr, P. M.; Tape, C.; McQuillan, P.; Taber, J.; West, M. E.; Busby, R. W.

    2014-12-01

    The EarthScopeTransportable Array is working to locate over 260 stations in Alaska and western Canada. In this region, new tactics and partnerships are needed to increase outreach exposure. IRIS and EarthScope are partnering with the Alaska Earthquake Center, part of University of Alaska Geophysical Institute, to spread awareness of Alaska earthquakes and the benefits of the Transportable Array for Alaskans. Nearly all parts of Alaska are tectonically active. The tectonic and seismic variability of Alaska requires focused attention at the regional level, and the remoteness and inaccessibility of most Alaska villages and towns often makes frequent visits difficult. For this reason, Alaska outreach most often occurs at community events. When a community is accessible, every opportunity to engage the residents is made. Booths at state fairs and large cultural gatherings, such as the annual convention of the Alaska Federation of Natives, are excellent venues to distribute earthquake information and to demonstrate a wide variety of educational products and web-based applications related to seismology and the Transportable Array that residents can use in their own communities. Region-specific publications have been developed to tie in a sense of place for residents of Alaska. The Alaska content for IRIS's Active Earth Monitor will emphasize the widespread tectonic and seismic features and offer not just Alaska residents, but anyone interested in Alaska, a glimpse into what is going on beneath their feet. The concerted efforts of the outreach team will have lasting effects on Alaskan understanding of the seismic hazard and tectonics of the region. Efforts to publicize the presence of the Transportable Array in Alaska, western Canada, and the Lower 48 also continue. There have been recent articles published in university, local and regional newspapers; stories appearing in national and international print and broadcast media; and documentaries produced by some of the world

  16. Preparing for an Earthquake: Information for Schools and Families

    ERIC Educational Resources Information Center

    Heath, Melissa Allen; Dean, Brenda

    2008-01-01

    Over the past decade, catastrophic earthquakes have garnered international attention regarding the need for improving immediate and ongoing support services for disrupted communities. Following the December 26, 2004 Indonesian earthquake, the Indian Ocean tsunami was responsible for displacing millions and taking the lives of an estimated 320,000…

  17. Curriculum, Instruction, and Assessment in Alaska School Districts, 1990-91. A Status Report. With Supplementary Information about Interdisciplinary Education in Alaska School Districts.

    ERIC Educational Resources Information Center

    Silverman, Bob, Ed.; Gorsuch, Marjorie

    This document reports responses from Alaska's 54 school districts to a Department of Education survey on curriculum, instruction, and assessment. The first section provides general information about the school districts' responses in those three areas, including information on curriculum guides, graduation requirements, student assessment…

  18. Information Theoric Framework for the Earthquake Recurrence Models : Methodica Firma Per Terra Non-Firma

    SciTech Connect

    Esmer, Oezcan

    2006-11-29

    This paper first evaluates the earthquake prediction method (1999 ) used by US Geological Survey as the lead example and reviews also the recent models. Secondly, points out the ongoing debate on the predictability of earthquake recurrences and lists the main claims of both sides. The traditional methods and the 'frequentist' approach used in determining the earthquake probabilities cannot end the complaints that the earthquakes are unpredictable. It is argued that the prevailing 'crisis' in seismic research corresponds to the Pre-Maxent Age of the current situation. The period of Kuhnian 'Crisis' should give rise to a new paradigm based on the Information-Theoric framework including the inverse problem, Maxent and Bayesian methods. Paper aims to show that the information- theoric methods shall provide the required 'Methodica Firma' for the earthquake prediction models.

  19. The SAFRR Tsunami Scenario: Improving Resilience for California from a Plausible M9 Earthquake near the Alaska Peninsula

    NASA Astrophysics Data System (ADS)

    Ross, S.; Jones, L.; Wilson, R. I.; Bahng, B.; Barberopoulou, A.; Borrero, J. C.; Brosnan, D.; Bwarie, J.; Geist, E. L.; Johnson, L.; Kirby, S. H.; Knight, W.; Long, K.; Lynett, P. J.; Miller, K.; Mortensen, C. E.; Nicolsky, D.; Oglesby, D. D.; Perry, S. C.; Plumlee, G. S.; Porter, K. A.; Real, C. R.; Ryan, K. J.; Suleimani, E.; Thio, H. K.; Titov, V.; Wein, A. M.; Whitmore, P.; Wood, N. J.

    2013-12-01

    The SAFRR Tsunami Scenario models a hypothetical but plausible tsunami, created by an Mw9.1 earthquake occurring offshore from the Alaskan peninsula, and its impacts on the California coast. We present the likely inundation areas, current velocities in key ports and harbors, physical damage and repair costs, economic consequences, environmental impacts, social vulnerability, emergency management, and policy implications for California associated with the tsunami scenario. The intended users are those who must make mitigation decisions before and rapid decisions during future tsunamis. Around a half million people would be present in the scenario's inundation area in residences, businesses, public venues, parks and beaches. Evacuation would likely be ordered for the State of California's maximum mapped tsunami inundation zone, evacuating an additional quarter million people from residences and businesses. Some island and peninsula communities would face particular evacuation challenges because of limited access options and short warning time, caused by the distance between Alaska and California. Evacuations may also be a challenge for certain dependent-care populations. One third of the boats in California's marinas could be damaged or sunk, costing at least 700 million in repairs to boats and docks, and potentially much more to address serious issues due to sediment transport and environmental contamination. Fires would likely start at many sites where fuel and petrochemicals are stored in ports and marinas. Tsunami surges and bores may travel several miles inland up coastal rivers. Debris clean-up and recovery of inundated and damaged areas will take days, months, or years depending on the severity of impacts and the available resources for recovery. The Ports of Los Angeles and Long Beach (POLA/LB) would be shut down for a miniμm of two days due to strong currents. Inundation of dry land in the ports would result in 100 million damages to cargo and additional

  20. Slip Transfer from the Denali to Totschunda Faults During the 3 November 2002 Mw 7.9 Denali, Alaska, Earthquake

    NASA Astrophysics Data System (ADS)

    Bhat, H. S.; Dmowska, R.; Rice, J. R.; Kame, N.

    2003-12-01

    We analyze dynamic slip transfer from the Denali to the Totschunda faults. This adopts methodology from earlier studies (Poliakov et al., 2002; Kame et al., 2003) in which it was shown that the propensity of the rupture path to follow a fault branch is determined by the preexisting stress state, branch angle and incoming rupture velocity at the branch location. Even though the studies rely on 2D numerical simulations, we think that they describe correctly the first order of phenomena associated with dynamic branching along geological fault systems. Here we check that theory on the Denali-Totschunda rupture process. This is a more complete analysis than Bhat et al. (2002). The Mw 7.9 Denali earthquake, which was mainly a right lateral strike-slip event, occurred on 3 November 2002 and ruptured for about 340 km, with the last 76 km being on the Totschunda Fault which branches off from the Denali Fault at an angle of about 15° to the extensional side. The rupture path chose Totschunda, exclusively, beyond the Denali-Totschunda branching point. We have no evidence on prestress directions very near the branch, but Ratchkovski and Hansen (2002, 2003) have recently evaluated stress directions for interior Alaska including near the Denali fault. The principal stress closest to the branch is almost fault-normal with the local direction of the Denali fault (Ratchkovski, 2003). Earlier works on the stress field in central Alaska suggest that the prestress inclination with Denali was around 70° in the area of branching. Thus we use the values of 70° and 80° in our numerical simulations. The average rupture velocity seems to be about 0.8 cs (Kikuchi and Yamanaka, 2002), although the velocity as the branch was approached is not yet constrained. As it is not yet clear what was the rupture velocity at the branching point, other than that it was rather high (Eberhart-Phillips et. al., 2003), we use 0.6 cs, 0.8 cs, 0.9 cs and even 1.4 cs as parameters in our simulations. We

  1. Hydrologic information for land-use planning; Fairbanks vicinity, Alaska

    USGS Publications Warehouse

    Nelson, Gordon L.

    1978-01-01

    The flood plain on the Chena and Tanana Rivers near Fairbanks, Alaska, has abundant water in rivers and in an unconfined alluvial aquifer. The principal source of ground water is the Tanana River, from which ground water flows northwesterly to the Chena River. Transmissivity of the aquifer commonly exceed 100 ,000 sq ft. The shallow water table (less than 15 ft below land surface), high hydraulic conductivity of the sediments and cold soil give the flood plain a high susceptibility to pollution by onsite sewerage systems. The Environmental Protection Agency recommended maximum concentrations for drinking water may be exceeded in surface water for manganese and bacteria and in ground water for iron, manganese, and bacteria. Residents of the uplands obtain water principally from a widely-distributed fractured schist aquifer. The aquifer is recharged by local infiltration of precipitation and is drained by springs on the lower slopes and by ground-water flow to alluvial aquifers of the valleys. The annual base flow from basins in the uplands ranged from 3,000 to 100,000 gallons per acre; the smallest base flows occur in basins nearest the city of Fairbanks. The thick silt cover and great depth to the water table give much of the uplands a low susceptibility to pollution by onsite sewage disposal. Ground water is locally high in nitrate, arsenic, iron , and manganese. (Woodard-USGS)

  2. New imaging of submarine landslides from the 1964 earthquake near Whittier, Alaska, and a comparison to failures in other Alaskan fjords

    USGS Publications Warehouse

    Haeussler, Peter J.; Parsons, Thomas E.; Finlayson, David P.; Hart, Patrick J.; Chaytor, Jason D.; Ryan, Holly F; Lee, Homa J.; Labay, Keith; Peterson, Andrew; Liberty, Lee

    2014-01-01

    The 1964 Alaska M w 9.2 earthquake triggered numerous submarine slope failures in fjords of southern Alaska. These failures generated local tsunamis, such as at Whittier, where they inundated the town within 4 min of the beginning of shaking. Run-up was up to 32 m, with 13 casualties. We collected new multibeam bathymetry and high-resolution sparker seismic data in Passage Canal, and we examined bathymetry changes before and after the earthquake. The data reveal the debris flow deposit from the 1964 landslides, which covers the western 5 km of the fjord bottom. Individual blocks in the flow are up to 145-m wide and 25-m tall. Bathymetry changes show the mass transfer deposits originated from the fjord head and Whittier Creek deltas and had a volume of about 42 million m3. The 1964 deposit has an average thickness of ∼5.4 m. Beyond the debris flow, the failures likely deposited a ∼4.6-m thick megaturbidite in a distal basin. We have studied the 1964 submarine landslides in three fjords. All involved failure of the fjord-head delta. All failures eroded basin-floor sediments and incorporated them as they travelled. All the failures deposited blocks, but their size and travel distances varied greatly. We find a correlation between maximum block size and maximum tsunami run-up regardless of the volume of the slides. Lastly, the fjord’s margins were influenced by increased supply of glacial sediments during the little ice age, which along with a long interseismic interval (∼900 years) may have caused the 1964 earthquake to produce particularly numerous and large submarine landslides.

  3. An overview of the National Earthquake Information Center acquisition software system, Edge/Continuous Waveform Buffer

    USGS Publications Warehouse

    Patton, John M.; Ketchum, David C.; Guy, Michelle R.

    2015-11-02

    This document provides an overview of the capabilities, design, and use cases of the data acquisition and archiving subsystem at the U.S. Geological Survey National Earthquake Information Center. The Edge and Continuous Waveform Buffer software supports the National Earthquake Information Center’s worldwide earthquake monitoring mission in direct station data acquisition, data import, short- and long-term data archiving, data distribution, query services, and playback, among other capabilities. The software design and architecture can be configured to support acquisition and (or) archiving use cases. The software continues to be developed in order to expand the acquisition, storage, and distribution capabilities.

  4. Meeting Nontraditional Medical Information Needs for the Unique Populations and Geographically Remote Locations of Alaska.

    PubMed

    Lema, Dana V

    2016-01-01

    The types of information required by hospital and clinical staff can be greatly influenced by the geography and culture of the area in which they operate. In some situations, information must be acquired from sources that fall outside the traditional provisions of a medical or reference library. This article provides examples of the unique information needs of clinical staff serving a primarily Native Alaskan and Native American clientele in Alaska. It also presents sources and personnel utilized to meet those information needs outside of traditional reference sources.

  5. Earthquake watch

    USGS Publications Warehouse

    Hill, M.

    1976-01-01

     When the time comes that earthquakes can be predicted accurately, what shall we do with the knowledge? This was the theme of a November 1975 conference on earthquake warning and response held in San Francisco called by Assistant Secretary of the Interior Jack W. Carlson. Invited were officials of State and local governments from Alaska, California, Hawaii, Idaho, Montana, Nevada, utah, Washington, and Wyoming and representatives of the news media. 

  6. Rupture process of the M 7.9 Denali fault, Alaska, earthquake: Subevents, directivity, and scaling of high-frequency ground motions

    USGS Publications Warehouse

    Frankel, A.

    2004-01-01

    Displacement waveforms and high-frequency acceleration envelopes from stations at distances of 3-300 km were inverted to determine the source process of the M 7.9 Denali fault earthquake. Fitting the initial portion of the displacement waveforms indicates that the earthquake started with an oblique thrust subevent (subevent # 1) with an east-west-striking, north-dipping nodal plane consistent with the observed surface rupture on the Susitna Glacier fault. Inversion of the remainder of the waveforms (0.02-0.5 Hz) for moment release along the Denali and Totschunda faults shows that rupture proceeded eastward on the Denali fault, with two strike-slip subevents (numbers 2 and 3) centered about 90 and 210 km east of the hypocenter. Subevent 2 was located across from the station at PS 10 (Trans-Alaska Pipeline Pump Station #10) and was very localized in space and time. Subevent 3 extended from 160 to 230 km east of the hypocenter and had the largest moment of the subevents. Based on the timing between subevent 2 and the east end of subevent 3, an average rupture velocity of 3.5 km/sec, close to the shear wave velocity at the average rupture depth, was found. However, the portion of the rupture 130-220 km east of the epicenter appears to have an effective rupture velocity of about 5.0 km/ sec, which is supershear. These two subevents correspond approximately to areas of large surface offsets observed after the earthquake. Using waveforms of the M 6.7 Nenana Mountain earthquake as empirical Green's functions, the high-frequency (1-10 Hz) envelopes of the M 7.9 earthquake were inverted to determine the location of high-frequency energy release along the faults. The initial thrust subevent produced the largest high-frequency energy release per unit fault length. The high-frequency envelopes and acceleration spectra (>0.5 Hz) of the M 7.9 earthquake can be simulated by chaining together rupture zones of the M 6.7 earthquake over distances from 30 to 180 km east of the

  7. The Operational Use of Suomi National Polar-Orbiting Partnership (S-NPP) Satellite Information in Alaska

    NASA Astrophysics Data System (ADS)

    Scott, C. A.; Goldberg, M.

    2014-12-01

    The National Weather Service (NWS), Alaska Region (AR) provides warnings, forecasts and information for an area greater than 20% of the size of the continental United States. This region experiences an incredible diversity of weather phenomena, yet ironically is one of the more data-sparse areas in the world. Polar orbiting satellite-borne sensors offer one of the most cost effective means of gaining repetitive information over this data-sparse region to provide insight on Alaskan weather and the environment on scales ranging from synoptic to mesoscale in a systematic manner. Because of Alaska's high latitude location, polar orbiting satellites can provide coverage about every two hours at high resolution. The Suomi National Polar-orbiting Partnership (S-NPP) Satellite, equipped with a new generation of satellite sensors to better monitor, detect, and track weather and the environment was launched October 2011. Through partnership through the with NESDIS JPSS, the University of Alaska - Geographical Information Network of Alaska (GINA), the NWS Alaska Region was able to gain timely access to the Visible Infrared Imaging Radiometer Suite (VIIRS) imagery from S-NPP. The imagery was quickly integrated into forecast operations across the spectrum of NWS Alaska areas of responsibility. The VIIRS has provided a number of new or improved capabilities for detecting low cloud/fog, snow cover, volcanic ash, fire hotspots/smoke, flooding due to river ice break up, and sea ice and ice-free passages. In addition the Alaska Region has successfully exploited the 750 m spatial resolution of the VIIRS/Near Constant Contrast (NCC) low-light visible measurements. Forecasters have also begun the integration of NOAA Unique Cross-track Infrared Sounder (CrIS)/Advanced Technology Microwave Sounder (ATMS) Processing System (NUCAPS) Soundings in AWIPS-II operations at WFO Fairbanks and Anchorage, the Alaska Aviation Weather Unit (AAWU) and the Alaska Region, Regional Operations Center (ROC

  8. 88 hours: the U.S. Geological Survey National Earthquake Information Center response to the March 11, 2011 Mw 9.0 Tohoku earthquake

    USGS Publications Warehouse

    Wald, David J.; Hayes, Gavin P.; Benz, Harley M.; Earle, Paul S.; Briggs, Richard W.

    2011-01-01

    The M 9.0 11 March 2011 Tohoku, Japan, earthquake and associated tsunami near the east coast of the island of Honshu caused tens of thousands of deaths and potentially over one trillion dollars in damage, resulting in one of the worst natural disasters ever recorded. The U.S. Geological Survey National Earthquake Information Center (USGS NEIC), through its responsibility to respond to all significant global earthquakes as part of the National Earthquake Hazards Reduction Program, quickly produced and distributed a suite of earthquake information products to inform emergency responders, the public, the media, and the academic community of the earthquake's potential impact and to provide scientific background for the interpretation of the event's tectonic context and potential for future hazard. Here we present a timeline of the NEIC response to this devastating earthquake in the context of rapidly evolving information emanating from the global earthquake-response community. The timeline includes both internal and publicly distributed products, the relative timing of which highlights the inherent tradeoffs between the requirement to provide timely alerts and the necessity for accurate, authoritative information. The timeline also documents the iterative and evolutionary nature of the standard products produced by the NEIC and includes a behind-the-scenes look at the decisions, data, and analysis tools that drive our rapid product distribution.

  9. Turning the rumor of May 11, 2011 earthquake prediction In Rome, Italy, into an information day on earthquake hazard

    NASA Astrophysics Data System (ADS)

    Amato, A.; Cultrera, G.; Margheriti, L.; Nostro, C.; Selvaggi, G.; INGVterremoti Team

    2011-12-01

    A devastating earthquake had been predicted for May 11, 2011 in Rome. This prediction was never released officially by anyone, but it grew up in the Internet and was amplified by media. It was erroneously ascribed to Raffaele Bendandi, an Italian self-taught natural scientist who studied planetary motions. Indeed, around May 11, 2011, a planetary alignment was really expected and this contributed to give credibility to the earthquake prediction among people. During the previous months, INGV was overwhelmed with requests for information about this supposed prediction by Roman inhabitants and tourists. Given the considerable mediatic impact of this expected earthquake, INGV decided to organize an Open Day in its headquarter in Rome for people who wanted to learn more about the Italian seismicity and the earthquake as natural phenomenon. The Open Day was preceded by a press conference two days before, in which we talked about this prediction, we presented the Open Day, and we had a scientific discussion with journalists about the earthquake prediction and more in general on the real problem of seismic risk in Italy. About 40 journalists from newspapers, local and national tv's, press agencies and web news attended the Press Conference and hundreds of articles appeared in the following days, advertising the 11 May Open Day. The INGV opened to the public all day long (9am - 9pm) with the following program: i) meetings with INGV researchers to discuss scientific issues; ii) visits to the seismic monitoring room, open 24h/7 all year; iii) guided tours through interactive exhibitions on earthquakes and Earth's deep structure; iv) lectures on general topics from the social impact of rumors to seismic risk reduction; v) 13 new videos on channel YouTube.com/INGVterremoti to explain the earthquake process and give updates on various aspects of seismic monitoring in Italy; vi) distribution of books and brochures. Surprisingly, more than 3000 visitors came to visit INGV

  10. The Southern California Earthquake Center/Undergraduate Studies in Earthquake Information Technology (SCEC/UseIT) Internship Program

    NASA Astrophysics Data System (ADS)

    Perry, S.; Jordan, T.

    2006-12-01

    Our undergraduate research program, SCEC/UseIT, an NSF Research Experience for Undergraduates site, provides software for earthquake researchers and educators, movies for outreach, and ways to strengthen the technical career pipeline. SCEC/UseIT motivates diverse undergraduates towards science and engineering careers through team-based research in the exciting field of earthquake information technology. UseIT provides the cross-training in computer science/information technology (CS/IT) and geoscience needed to make fundamental progress in earthquake system science. Our high and increasing participation of women and minority students is crucial given the nation"s precipitous enrollment declines in CS/IT undergraduate degree programs, especially among women. UseIT also casts a "wider, farther" recruitment net that targets scholars interested in creative work but not traditionally attracted to summer science internships. Since 2002, SCEC/UseIT has challenged 79 students in three dozen majors from as many schools with difficult, real-world problems that require collaborative, interdisciplinary solutions. Interns design and engineer open-source software, creating increasingly sophisticated visualization tools (see "SCEC-VDO," session IN11), which are employed by SCEC researchers, in new curricula at the University of Southern California, and by outreach specialists who make animated movies for the public and the media. SCEC-VDO would be a valuable tool for research-oriented professional development programs.

  11. Haiti Earthquake Underscores Need for Better Use of Seismic Information

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2010-01-01

    When Eric Calais, professor of geophysics in Purdue University's Department of Earth and Atmospheric Sciences, first learned about the 12 January strikeslip earthquake along a portion of the Enriquillo-Plantain Garden fault zone (EPGFZ) in Haiti, he knew right away that it would be a shallow event and a large event, very close to the capital city of Port-au-Prince. Having worked in Haiti, he also was aware that the poor nation lacks seismic and building construction codes. “My immediate reaction was, ‘This is going to be a total nightmare and a huge disaster for Haiti,’” Calais, who also is a researcher at the French National Center for Scientific Research, told Eos. The main earthquake, currently estimated at magnitude 7.0, occurred at 2153:10 UTC at a depth of 13 kilometers, just 25 kilometers outside of Port-au-Prince, the U.S. Geological Survey (USGS) reports. Since then, there have been dozens of aftershocks, many of them above magnitude 5.0; these aftershocks could continue for weeks or even months, according to USGS (see Figure 1). In recent decades, there had not been a major earthquake along the approximately 600-kilometer-long EPGFZ (named after the end points in Jamaica and the Dominican Republic), although seismologists indicate that large earthquakes in 1860, 1770, and earlier likely originated along that system.

  12. Testing the use of bulk organic δ13C, δ15N, and Corg:Ntot ratios to estimate subsidence during the 1964 great Alaska earthquake

    USGS Publications Warehouse

    Bender, Adrian M; Witter, Robert C.; Rogers, Matthew

    2015-01-01

    During the Mw 9.2 1964 great Alaska earthquake, Turnagain Arm near Girdwood, Alaska subsided 1.7 ± 0.1 m based on pre- and postearthquake leveling. The coseismic subsidence in 1964 caused equivalent sudden relative sea-level (RSL) rise that is stratigraphically preserved as mud-over-peat contacts where intertidal silt buried peaty marsh surfaces. Changes in intertidal microfossil assemblages across these contacts have been used to estimate subsidence in 1964 by applying quantitative microfossil transfer functions to reconstruct corresponding RSL rise. Here, we review the use of organic stable C and N isotope values and Corg:Ntot ratios as alternative proxies for reconstructing coseismic RSL changes, and report independent estimates of subsidence in 1964 by using δ13C values from intertidal sediment to assess RSL change caused by the earthquake. We observe that surface sediment δ13C values systematically decrease by ∼4‰ over the ∼2.5 m increase in elevation along three 60- to 100-m-long transects extending from intertidal mud flat to upland environments. We use a straightforward linear regression to quantify the relationship between modern sediment δ13C values and elevation (n = 84, R2 = 0.56). The linear regression provides a slope–intercept equation used to reconstruct the paleoelevation of the site before and after the earthquake based on δ13C values in sandy silt above and herbaceous peat below the 1964 contact. The regression standard error (average = ±0.59‰) reflects the modern isotopic variability at sites of similar surface elevation, and is equivalent to an uncertainty of ±0.4 m elevation with respect to Mean Higher High Water. To reduce potential errors in paleoelevation and subsidence estimates, we analyzed multiple sediment δ13C values in nine cores on a shore-perpendicular transect at Bird Point. Our method estimates 1.3 ± 0.4 m of coseismic RSL rise across the 1964 contact by taking the arithmetic mean of the

  13. How citizen seismology is transforming rapid public earthquake information and interactions between seismologists and society

    NASA Astrophysics Data System (ADS)

    Bossu, Rémy; Steed, Robert; Mazet-Roux, Gilles; Roussel, Fréderic; Caroline, Etivant

    2015-04-01

    Historical earthquakes are only known to us through written recollections and so seismologists have a long experience of interpreting the reports of eyewitnesses, explaining probably why seismology has been a pioneer in crowdsourcing and citizen science. Today, Internet has been transforming this situation; It can be considered as the digital nervous system comprising of digital veins and intertwined sensors that capture the pulse of our planet in near real-time. How can both seismology and public could benefit from this new monitoring system? This paper will present the strategy implemented at Euro-Mediterranean Seismological Centre (EMSC) to leverage this new nervous system to detect and diagnose the impact of earthquakes within minutes rather than hours and how it transformed information systems and interactions with the public. We will show how social network monitoring and flashcrowds (massive website traffic increases on EMSC website) are used to automatically detect felt earthquakes before seismic detections, how damaged areas can me mapped through concomitant loss of Internet sessions (visitors being disconnected) and the benefit of collecting felt reports and geolocated pictures to further constrain rapid impact assessment of global earthquakes. We will also describe how public expectations within tens of seconds of ground shaking are at the basis of improved diversified information tools which integrate this user generated contents. A special attention will be given to LastQuake, the most complex and sophisticated Twitter QuakeBot, smartphone application and browser add-on, which deals with the only earthquakes that matter for the public: the felt and damaging earthquakes. In conclusion we will demonstrate that eyewitnesses are today real time earthquake sensors and active actors of rapid earthquake information.

  14. AN ANALYSIS OF THE POLICY TO PROVIDE THE TRAFFIC INFORMATION IN THE CASE OF EARTHQUAKES AN EXAMPLE ON THE NOTO PENINSULA EARTHQUAKE, ISHIKAWA PREFECTURE

    NASA Astrophysics Data System (ADS)

    Takahashi, Masanori; Takayama, Jun-Ichi; Nakayama, Shoichiro

    Noto Peninsula earthquake occurred in Ishikawa Pref., in March, 2007, and the Noto Yuryo, and many arterial roads were damaged. This led to the conosiderable confusion of the road traffic in Noto Peninsula area and gave the influence on all kinds of social/economic activities. Therefore, an method of providing the traffic information for drivers is important in the case of disasters such as earthquakes. We carried out a questionnaire survey for local inhabitants and investigated the road use situation at the time of the Noto Peninsula earthquake and the information acquisition situation about it. We also analyzed whether or not the method of providing the traffic information was appropriate. In addition, we examined the best traffic information in the case of earthquakes.

  15. Geodetic mass balance of surge-type Black Rapids Glacier, Alaska, 1980-2001-2010, including role of rockslide deposition and earthquake displacement

    NASA Astrophysics Data System (ADS)

    Kienholz, C.; Hock, R.; Truffer, M.; Arendt, A. A.; Arko, S.

    2016-12-01

    We determine the geodetic mass balance of surge-type Black Rapids Glacier, Alaska, for the time periods 1980-2001 and 2001-2010 by combining modern interferometric synthetic aperture radar (InSAR)-derived digital elevation models (DEMs), DEMs derived from archival aerial imagery, laser altimetry data, and in situ surface elevation measurements. Our analysis accounts for both the large rockslides and terrain displacements caused by the 2002 M7.9 earthquake on the Denali fault, which runs through Black Rapids Glacier. To estimate uncertainties, we apply Monte Carlo simulations. For the earthquake-triggered rockslides we find a volume of 56.62 ± 2.86 × 106 m3, equivalent to an average debris thickness of 4.44 ± 0.24 m across the 11.7 km2 deposit area on the glacier. Terrain displacement due to the earthquake corresponds to an apparent glacier volume change of -53.1 × 106 m3, which would cause an apparent specific mass balance of -0.19 meter water equivalent (mwe) if not taken into account. The geodetic mass balance of Black Rapids Glacier is -0.48 ± 0.07 mwe a-1 for the entire 30 year period, but more negative for the period 2001-2010 (-0.64 ± 0.11 mwe a-1) than the period 1980-2001 (-0.42 ± 0.11 mwe a-1), in agreement with trends indicated by in situ mass balance measurements. Elevation data indicate no net thickening of the surge reservoir between 1980 and 2010, in contrast to what is expected during the quiescent phase. A surge of Black Rapids Glacier in the near future is thus considered unlikely.

  16. Earthquake ethics through scientific knowledge, historical memory and societal awareness: the experience of direct internet information.

    NASA Astrophysics Data System (ADS)

    de Rubeis, Valerio; Sbarra, Paola; Sebaste, Beppe; Tosi, Patrizia

    2013-04-01

    The experience of collection of data on earthquake effects and diffusion of information to people, carried on through the site "haisentitoilterremoto.it" (didyoufeelit) managed by the Istituto Nazionale di Geofisica e Vulcanologia (INGV), has evidenced a constantly growing interest by Italian citizens. Started in 2007, the site has collected more than 520,000 compiled intensity questionnaires, producing intensity maps of almost 6,000 earthquakes. One of the most peculiar feature of this experience is constituted by a bi-directional information exchange. Every person can record observed effects of the earthquake and, at the same time, look at the generated maps. Seismologists, on the other side, can find each earthquake described in real time through its effects on the whole territory. In this way people, giving punctual information, receive global information from the community, mediated and interpreted by seismological knowledge. The relationship amongst seismologists, mass media and civil society is, thus, deep and rich. The presence of almost 20,000 permanent subscribers distributed on the whole Italian territory, alerted in case of earthquake, has reinforced the participation: the subscriber is constantly informed by the seismologists, through e-mail, about events occurred in his-her area, even if with very small magnitude. The "alert" service provides the possibility to remember that earthquakes are a phenomenon continuously present, on the other hand it shows that high magnitude events are very rare. This kind of information is helpful as it is fully complementary to that one given by media. We analyze the effects of our activity on society and mass media. The knowledge of seismic phenomena is present in each person, having roots on fear, idea of death and destruction, often with the deep belief of very rare occurrence. This position feeds refusal and repression. When a strong earthquake occurs, surprise immediately changes into shock and desperation. A

  17. The Canterbury Tales: Lessons from the Canterbury Earthquake Sequence to Inform Better Public Communication Models

    NASA Astrophysics Data System (ADS)

    McBride, S.; Tilley, E. N.; Johnston, D. M.; Becker, J.; Orchiston, C.

    2015-12-01

    This research evaluates the public education earthquake information prior to the Canterbury Earthquake sequence (2010-present), and examines communication learnings to create recommendations for improvement in implementation for these types of campaigns in future. The research comes from a practitioner perspective of someone who worked on these campaigns in Canterbury prior to the Earthquake Sequence and who also was the Public Information Manager Second in Command during the earthquake response in February 2011. Documents, specifically those addressing seismic risk, that were created prior to the earthquake sequence, were analyzed, using a "best practice matrix" created by the researcher, for how closely these aligned to best practice academic research. Readability tests and word counts are also employed to assist with triangulation of the data as was practitioner involvement. This research also outlines the lessons learned by practitioners and explores their experiences in regards to creating these materials and how they perceive these now, given all that has happened since the inception of the booklets. The findings from the research showed these documents lacked many of the attributes of best practice. The overly long, jargon filled text had little positive outcome expectancy messages. This probably would have failed to persuade anyone that earthquakes were a real threat in Canterbury. Paradoxically, it is likely these booklets may have created fatalism in publics who read the booklets. While the overall intention was positive, for scientists to explain earthquakes, tsunami, landslides and other risks to encourage the public to prepare for these events, the implementation could be greatly improved. This final component of the research highlights points of improvement for implementation for more successful campaigns in future. The importance of preparedness and science information campaigns can be not only in preparing the population but also into development of

  18. The Alaska Mineral Resource Assessment Program; background information to accompany folio of geologic and resource maps of the Ugashik, Bristol Bay, and western part of Karluk quadrangles, Alaska

    USGS Publications Warehouse

    Detterman, Robert L.; Case, J.E.; Church, S.E.; Frisken, J.G.; Wilson, F.H.; Yount, M.E.

    1990-01-01

    The Ugashik, Bristol Bay, and western part of Karluk quadrangles (1:250,000) are a part of the Alaska Peninsula in southwestern Alaska. This circular, in conjunction with a companion folio of MF-series maps, two I-series geologic maps, and three bulletins, represents the results of integrated field and laboratory studies on the geology, geophysics, geochemistry, paleontology, geochronology, and mineral resources of the quadrangles. These studies were undertaken to provide a modern assessment of the mineral and energy resources of the quadrangles. Each map contains descriptive text, explanatory material, tables, diagrams, and pertinent references. This circular provides background information for the mineral resource assessment map (MF-1539-1) and integrates the component M F- and I-series maps. A comprehensive bibliography cites both specific and general references relevant to the geology and resources of the quadrangles.

  19. Estimating and Presenting Individualized Earthquake Risk Using Web-Based Information Services

    NASA Astrophysics Data System (ADS)

    Holliday, J. R.; Rundle, J. B.; Donnellan, A.

    2009-12-01

    Great natural disasters have occurred many times throughout human history. Events such as the San Francisco earthquake of 1906, the 2004 Sumatra earthquake and tsunami, and the 2005 Hurricane Katrina have caused massive destruction and suffering. With the modern tools of risk analysis, forecasting, and the world wide web available, human societies should no longer tolerate the human and economic losses these disasters produce. Thanks to new technologies and web-based applications, it will soon be possible to enable a more sustainable human society in the face of severe, recurring natural disasters in the complex earth system. Web-based information services make it easy to specify geographical locations and describe specific building structures. Couple this with publicly available earthquake forecasts and web-based mapping tools and the public can make more informed choices about how to manage their personal exposure to risk from natural catastrophes.

  20. Formal and informal material aid following the 2010 Haiti earthquake as reported by camp dwellers.

    PubMed

    Versluis, Anna

    2014-04-01

    Following the 2010 Haiti earthquake, more than two million people moved to temporary camps, most of which arose spontaneously in the days after the earthquake. This study focuses on the material assistance people in five Port-au-Prince camps reported receiving, noting the differences between assistance from formal aid agencies and from 'informal' sources such as family. Seven weeks after the earthquake, 32% of camp dwellers reported receiving no assistance whatsoever; 55% had received formal aid, typically a tent or tarpaulins; and 40% had received informal aid, usually in the form of cash transfers from family living abroad. While people were grateful for any material aid, cash was more frequently considered timely and more effective than aid-in-kind. Should this study be indicative of the greater displaced population, aid agencies should consider how they might make better use of cash transfers as an aid modality.

  1. Estimating soil erosion changes in the Wenchuan earthquake disaster area using geo-spatial information technology

    NASA Astrophysics Data System (ADS)

    Zhang, Bing; Jiao, Quanjun; Wu, Yanhong; Zhang, Wenjuan

    2009-05-01

    The secondary disasters induced by the Wenchuan earthquake of May 12, 2008, such as landslides, collapsing rocks, debris flows, floods, etc., have changed the local natural landscape tremendously and caused heavy soil erosion in the earthquake-hit areas. Using thematic mapper images taken before the earthquake and airborne images taken after the earthquake, we extracted information about the destroyed landscape by utilizing remote sensing and geographical information system techniques. Then, taking into account multi-year precipitation, vegetation cover, soil type, land use, and elevation data, we evaluated the soil erosion area and intensity using the revised universal soil loss equation. Results indicate that the soil erosion in earthquake-hit areas was exacerbated, with the severe erosion area increasing by 279.2 km2, or 1.9% of the total statistical area. Large amounts of soil and debris blocked streams and formed many barrier lakes over an area of more than 3.9 km2. It was evident from the spatial distribution of soil erosion areas that the intensity of soil erosion accelerated in the stream valley areas, especially in the valleys of the Min River and the Jian River.

  2. Catalog of earthquake hypocenters for Augustine, Redoubt, Iliamna, and Mount Spurr volcanoes, Alaska: January 1, 1991 - December 31, 1993

    USGS Publications Warehouse

    Jolly, Arthur D.; Power, John A.; Stihler, Scott D.; Rao, Lalitha N.; Davidson, Gail; Paskievitch, John F.; Estes, Steve; Lahr, John C.

    1996-01-01

    The 1992 eruptions at Mount Spurr's Crater Peak vent provided the highlight of the catalog period. The crisis included three sub-plinian eruptions, which occurred on June 27, August 18, and September 16-17, 1992. The three eruptions punctuated a complex seismic sequence which included volcano-tectonic (VT) earthquakes, tremor, and both deep and shallow long period (LP) earthquakes. The seismic sequence began on August 18, 1991, with a small swarm of volcano-tectonic events beneath Crater Peak, and spread throughout the volcanic complex by November of the same year. Elevated levels of seismicity persisted at Mount Spurr beyond the catalog time period.

  3. Seeking Information after the 2010 Haiti Earthquake: A Case Study in Mass-Fatality Management

    ERIC Educational Resources Information Center

    Gupta, Kailash

    2013-01-01

    The 2010 earthquake in Haiti, which killed an estimated 316,000 people, offered many lessons in mass-fatality management (MFM). The dissertation defined MFM in seeking information and in recovery, preservation, identification, and disposition of human remains. Specifically, it examined how mass fatalities were managed in Haiti, how affected…

  4. Combined effects of tectonic and landslide-generated Tsunami Runup at Seward, Alaska during the Mw 9.2 1964 earthquake

    USGS Publications Warehouse

    Suleimani, E.; Nicolsky, D.J.; Haeussler, P.J.; Hansen, R.

    2011-01-01

    We apply a recently developed and validated numerical model of tsunami propagation and runup to study the inundation of Resurrection Bay and the town of Seward by the 1964 Alaska tsunami. Seward was hit by both tectonic and landslide-generated tsunami waves during the Mw 9.2 1964 mega thrust earthquake. The earthquake triggered a series of submarine mass failures around the fjord, which resulted in land sliding of part of the coastline into the water, along with the loss of the port facilities. These submarine mass failures generated local waves in the bay within 5 min of the beginning of strong ground motion. Recent studies estimate the total volume of underwater slide material that moved in Resurrection Bay to be about 211 million m3 (Haeussler et al. in Submarine mass movements and their consequences, pp 269-278, 2007). The first tectonic tsunami wave arrived in Resurrection Bay about 30 min after the main shock and was about the same height as the local landslide-generated waves. Our previous numerical study, which focused only on the local land slide generated waves in Resurrection Bay, demonstrated that they were produced by a number of different slope failures, and estimated relative contributions of different submarine slide complexes into tsunami amplitudes (Suleimani et al. in Pure Appl Geophys 166:131-152, 2009). This work extends the previous study by calculating tsunami inundation in Resurrection Bay caused by the combined impact of landslide-generated waves and the tectonic tsunami, and comparing the composite inundation area with observations. To simulate landslide tsunami runup in Seward, we use a viscous slide model of Jiang and LeBlond (J Phys Oceanogr 24(3):559-572, 1994) coupled with nonlinear shallow water equations. The input data set includes a high resolution multibeam bathymetry and LIDAR topography grid of Resurrection Bay, and an initial thickness of slide material based on pre- and post-earthquake bathymetry difference maps. For

  5. K12 Education Program Lessons Learned at the Center for Earthquake Research and Information

    NASA Astrophysics Data System (ADS)

    Patterson, G. L.; Dry, M.

    2003-12-01

    The Center for Earthquake Research and Information at the University of Memphis has been committed to increasing awareness for Seismic Hazard, Earthquake Engineering, and Earth Science among Mid-America's policy-makers, engineers, emergency managers, the general public, and K-12 teachers and students for nearly three decades. During that time we have learned many lessons related to providing effective education and outreach programs, especially for K-12 students. The lessons learned from these activities may be particularly appropriate for other regions where large earthquakes occur infrequently but have disproportionately high consequence areas due to low attenuation of seismic waves. Effective education programs in these settings must provide a consistent message across many states to a wide variety of socio-economic groups and professional communities through the leveraged resources of various groups and agencies. It is also beneficial to hire and train staff with K-12 teaching experience to work directly K-12 education organizations, and science curriculum coordinators.

  6. Alaska's Children, 1997.

    ERIC Educational Resources Information Center

    Douglas, Dorothy, Ed.

    1997-01-01

    These four issues of the "Alaska's Children" provide information on the activities of the Alaska Head Start State Collaboration Project and other Head Start activities. Legal and policy changes affecting the education of young children in Alaska are also discussed. The Spring 1997 issue includes articles on brain development and the…

  7. Alaska Natives & the Land.

    ERIC Educational Resources Information Center

    Arnold, Robert D.; And Others

    Pursuant to the Native land claims within Alaska, this compilation of background data and interpretive materials relevant to a fair resolution of the Alaska Native problem seeks to record data and information on the Native peoples; the land and resources of Alaska and their uses by the people in the past and present; land ownership; and future…

  8. Earthquakes, May-June 1991

    USGS Publications Warehouse

    Person, W.J.

    1992-01-01

    In the United States, a magnitude 5.8 earthquake in southern California on June 28 killed two people and caused considerable damage. Strong earthquakes hit Alaska on May 1 and May 30; the May 1 earthquake caused some minor damage. 

  9. 25 CFR 124.2 - Who should an agency or the State of Alaska contact for information?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Interior, Office of the Special Trustee for American Indians. For further information including depositing instructions, contact: Office of the Special Trustee for American Indians, Attention: Division of Trust Funds... 25 Indians 1 2010-04-01 2010-04-01 false Who should an agency or the State of Alaska contact...

  10. 25 CFR 124.2 - Who should an agency or the State of Alaska contact for information?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Interior, Office of the Special Trustee for American Indians. For further information including depositing instructions, contact: Office of the Special Trustee for American Indians, Attention: Division of Trust Funds... 25 Indians 1 2011-04-01 2011-04-01 false Who should an agency or the State of Alaska contact...

  11. Surface deformation associated with the March 1996 earthquake swarm at Akutan Island, Alaska, revealed by C-band ERS and L-band JERS radar interferometry

    USGS Publications Warehouse

    Lu, Zhiming; Wicks, C.; Kwoun, O.; Power, J.A.; Dzurisin, D.

    2005-01-01

    In March 1996, an intense earthquake swarm beneath Akutan Island, Alaska, was accompanied by extensive ground cracking but no eruption of Akutan volcano. Radar interferograms produced from L-band JERS-1 and C-band ERS-1/2 images show uplift associated with the swarm by as much as 60 cm on the western part of the island. The JERS-1 interferogram has greater coherence, especially in areas with loose surface material or thick vegetation. It also shows subsidence of similar magnitude on the eastern part of the island and displacements along faults reactivated during the swarm. The axis of uplift and subsidence strikes about N70??W, which is roughly parallel to a zone of fresh cracks on the northwest flank of the volcano, to normal faults that cut the island and to the inferred maximum compressive stress direction. A common feature of models that fit the deformation is the emplacement of a shallow dike along this trend beneath the northwest flank of the volcano. Both before and after the swarm, the northwest flank was uplifted 5-20 mm/year relative to the southwest flank, probably by magma intrusion. The zone of fresh cracks subsided about 20 mm during 1996-1997 and at lesser rates thereafter, possibly because of cooling and degassing of the intrusion. ?? 2005 CASI.

  12. The method of earthquake landslide information extraction with high-resolution remote sensing

    NASA Astrophysics Data System (ADS)

    Wu, Jian; Chen, Peng; Liu, Yaolin; Wang, Jing

    2014-05-01

    As a kind of secondary geological disaster caused by strong earthquake, the earthquake-induced landslide has drawn much attention in the world due to the severe hazard. The high-resolution remote sensing, as a new technology for investigation and monitoring, has been widely applied in landslide susceptibility and hazard mapping. The Ms 8.0 Wenchuan earthquake, occurred on 12 May 2008, caused many buildings collapse and half million people be injured. Meanwhile, damage caused by earthquake-induced landslides, collapse and debris flow became the major part of total losses. By analyzing the property of the Zipingpu landslide occurred in the Wenchuan earthquake, the present study advanced a quick-and-effective way for landslide extraction based on NDVI and slope information, and the results were validated with pixel-oriented and object-oriented methods. The main advantage of the idea lies in the fact that it doesn't need much professional knowledge and data such as crustal movement, geological structure, fractured zone, etc. and the researchers can provide the landslide monitoring information for earthquake relief as soon as possible. In pixel-oriented way, the NDVI-differential image as well as slope image was analyzed and segmented to extract the landslide information. When it comes to object-oriented method, the multi-scale segmentation algorithm was applied in order to build up three-layer hierarchy. The spectral, textural, shape, location and contextual information of individual object classes, and GLCM (Grey Level Concurrence Matrix homogeneity, shape index etc. were extracted and used to establish the fuzzy decision rule system of each layer for earthquake landslide extraction. Comparison of the results generated from the two methods, showed that the object-oriented method could successfully avoid the phenomenon of NDVI-differential bright noise caused by the spectral diversity of high-resolution remote sensing data and achieved better result with an overall

  13. Climate science informs participatory scenario development and applications to decision making in Alaska

    NASA Astrophysics Data System (ADS)

    Welling, L. A.; Winfree, R.; Mow, J.

    2012-12-01

    Climate change presents unprecedented challenges for managing natural and cultural resources into the future. Impacts are expected to be highly consequential but specific effects are difficult to predict, requiring a flexible process for adaptation planning that is tightly coupled to climate science delivery systems. Scenario planning offers a tool for making science-based decisions under uncertainty. The National Park Service (NPS) is working with the Department of the Interior Climate Science Centers (CSCs), the NOAA Regional Integrated Science and Assessment teams (RISAs), and other academic, government, non-profit, and private partners to develop and apply scenarios to long-range planning and decision frameworks. In April 2012, Alaska became the first region of the NPS to complete climate change scenario planning for every national park, preserve, and monument. These areas, which collectively make up two-thirds of the total area of the NPS, are experiencing visible and measurable effects attributable to climate change. For example, thawing sea ice, glaciers and permafrost have resulted in coastal erosion, loss of irreplaceable cultural sites, slope failures, flooding of visitor access routes, and infrastructure damage. With higher temperatures and changed weather patterns, woody vegetation has expanded into northern tundra, spruce and cedar diebacks have occurred in southern Alaska, and wildland fire severity has increased. Working with partners at the Alaska Climate Science Center and the Scenario Network for Alaska Planning the NPS integrates quantitative, model-driven data with qualitative, participatory techniques to scenario creation. The approach enables managers to access and understand current climate change science in a form that is relevant for their decision making. Collaborative workshops conducted over the past two years grouped parks from Alaska's southwest, northwest, southeast, interior and central areas. The emphasis was to identify and connect

  14. Combining Real-time Seismic and Geodetic Data to Improve Rapid Earthquake Information

    NASA Astrophysics Data System (ADS)

    Murray, M. H.; Neuhauser, D. S.; Gee, L. S.; Dreger, D. S.; Basset, A.; Romanowicz, B.

    2002-12-01

    The Berkeley Seismological Laboratory operates seismic and geodetic stations in the San Francisco Bay area and northern California for earthquake and deformation monitoring. The seismic systems, part of the Berkeley Digital Seismic Network (BDSN), include strong motion and broadband sensors, and 24-bit dataloggers. The data from 20 GPS stations, part of the Bay Area Regional Deformation (BARD) network of more than 70 stations in northern California, are acquired in real-time. We have developed methods to acquire GPS data at 12 stations that are collocated with the seismic systems using the seismic dataloggers, which have large on-site data buffer and storage capabilities, merge it with the seismic data stream in MiniSeed format, and continuously stream both data types using reliable frame relay and/or radio modem telemetry. Currently, the seismic data are incorporated into the Rapid Earthquake Data Integration (REDI) project to provide notification of earthquake magnitude, location, moment tensor, and strong motion information for hazard mitigation and emergency response activities. The geodetic measurements can provide complementary constraints on earthquake faulting, including the location and extent of the rupture plane, unambiguous resolution of the nodal plane, and distribution of slip on the fault plane, which can be used, for example, to refine strong motion shake maps. We are developing methods to rapidly process the geodetic data to monitor transient deformation, such as coseismic station displacements, and for combining this information with the seismic observations to improve finite-fault characterization of large earthquakes. The GPS data are currently processed at hourly intervals with 2-cm precision in horizontal position, and we are beginning a pilot project in the Bay Area in collaboration with the California Spatial Reference Center to do epoch-by-epoch processing with greater precision.

  15. End-User Applications of Real-Time Earthquake Information in Europe

    NASA Astrophysics Data System (ADS)

    Cua, G. B.; Gasparini, P.; Giardini, D.; Zschau, J.; Filangieri, A. R.; Reakt Wp7 Team

    2011-12-01

    The primary objective of European FP7 project REAKT (Strategies and Tools for Real-Time Earthquake Risk Reduction) is to improve the efficiency of real-time earthquake risk mitigation methods and their capability of protecting structures, infrastructures, and populations. REAKT aims to address the issues of real-time earthquake hazard and response from end-to-end, with efforts directed along the full spectrum of methodology development in earthquake forecasting, earthquake early warning, and real-time vulnerability systems, through optimal decision-making, and engagement and cooperation of scientists and end users for the establishment of best practices for use of real-time information. Twelve strategic test cases/end users throughout Europe have been selected. This diverse group of applications/end users includes civil protection authorities, railway systems, hospitals, schools, industrial complexes, nuclear plants, lifeline systems, national seismic networks, and critical structures. The scale of target applications covers a wide range, from two school complexes in Naples, to individual critical structures, such as the Rion Antirion bridge in Patras, and the Fatih Sultan Mehmet bridge in Istanbul, to large complexes, such as the SINES industrial complex in Portugal and the Thessaloniki port area, to distributed lifeline and transportation networks and nuclear plants. Some end-users are interested in in-depth feasibility studies for use of real-time information and development of rapid response plans, while others intend to install real-time instrumentation and develop customized automated control systems. From the onset, REAKT scientists and end-users will work together on concept development and initial implementation efforts using the data products and decision-making methodologies developed with the goal of improving end-user risk mitigation. The aim of this scientific/end-user partnership is to ensure that scientific efforts are applicable to operational

  16. National Earthquake Information Center systems overview and integration

    USGS Publications Warehouse

    Guy, Michelle R.; Patton, John M.; Fee, Jeremy; Hearne, Mike; Martinez, Eric; Ketchum, D.; Worden, Charles; Quitoriano, Vince; Hunter, Edward; Smoczyk, Gregory; Schwarz, Stan

    2015-08-18

    It is important to note that this document provides a brief introduction to the work of dozens of software developers and IT specialists, spanning in many cases more than a decade. References to significant amounts of supporting documentation, code, and information are supplied within.

  17. Using JavaScript and the FDSN web service to create an interactive earthquake information system

    NASA Astrophysics Data System (ADS)

    Fischer, Kasper D.

    2015-04-01

    The FDSN web service provides a web interface to access earthquake meta-data (e. g. event or station information) and waveform date over the internet. Requests are send to a server as URLs and the output is either XML or miniSEED. This makes it hard to read by humans but easy to process with different software. Different data centers are already supporting the FDSN web service, e. g. USGS, IRIS, ORFEUS. The FDSN web service is also part of the Seiscomp3 (http://www.seiscomp3.org) software. The Seismological Observatory of the Ruhr-University switched to Seiscomp3 as the standard software for the analysis of mining induced earthquakes at the beginning of 2014. This made it necessary to create a new web-based earthquake information service for the publication of results to the general public. This has be done by processing the output of a FDSN web service query by javascript running in a standard browser. The result is an interactive map presenting the observed events and further information of events and stations on a single web page as a table and on a map. In addition the user can download event information, waveform data and station data in different formats like miniSEED, quakeML or FDSNxml. The developed code and all used libraries are open source and freely available.

  18. Volunteered Geographic Information for Disaster Management with Application to Earthquake Disaster Databank & Sharing Platform

    NASA Astrophysics Data System (ADS)

    Chen, H.; Zhang, W. C.; Deng, C.; Nie, N.; Yi, L.

    2017-02-01

    All phases of disaster management require up-to-date and accurate information. Different in-situ and remote sensor systems help to monitor dynamic properties such as air quality, water level or inundated areas. The rapid emergence of web-based services has facilitated the collection, dissemination, and cartographic representation of spatial information from the public, giving rise to the idea of using Volunteered Geographic Information (VGI) to aid disaster management. In this study, with a brief review on the concept and the development of disaster management, opportunities and challenges for applying VGI in disaster management were explored. The challenges, including Data availability, Data quality, Data management and Legal issues of using VGI for disaster management, were discussed in detail with particular emphasis on the actual needs of disaster management practice in China. Three different approaches to assure VGI data quality, namely the classification and authority design of volunteers, a government-led VGI data acquisition framework for disaster management and a quality assessment system for VGI, respectively, were presented and discussed. As a case study, a prototype of VGI oriented earthquake disaster databank & sharing platform, an open WebGIS system for volunteers and other interested individuals collaboratively create and manage the earthquake disaster related information, was proposed, to provide references for improving the level of earthquake emergency response and disaster mitigation in China.

  19. The use of geologic and seismologic information to reduce earthquake Hazards in California

    USGS Publications Warehouse

    Kockelman, W.J.; Campbell, C.C.

    1984-01-01

    Five examples illustrate how geologic and seismologic information can be used to reduce the effects of earthquakes Included are procedures for anticipating damage to critical facilities, preparing, adopting, or implementing seismic safety studies, plans, and programs, retrofitting highway bridges, regulating development in areas subject to fault-rupture, and strengthening or removing unreinforced masonry buildings. The collective effect of these procedures is to improve the public safety, health, and welfare of individuals and their communities. ?? 1984 Springer-Verlag New York Inc.

  20. Comparison of magmatic structures beneath Redoubt (Alaska) and Toba (Northern Sumatra) volcanoes derived from local earthquake tomography studies

    NASA Astrophysics Data System (ADS)

    Kasatkina, Ekaterina; Koulakov, Ivan; West, Michael

    2014-05-01

    We present the results of seismic tomography studies of two different volcanoes - Mt. Redoubt and Toba caldera. These two subduction related volcanoes have different ages and scales of eruption activity. Velocity model beneath the Redoubt volcano is based on tomographic inversion of P- and S- arrival time data from over 4000 local earthquakes recorded by 19 stations since 1989 to 2012 provided by the Alaskan Volcano Observatory (University of Fairbanks). Just below the volcano edifice we observe an anomaly of high Vp/Vs ratio reaching 2.2 which is seen down to 2- 3 km depth. This indicates a presence of partially molten substance or fluid filled rocks. We can suggest that anomaly area matches with volcano magma chamber. One of the previous velocity models of Toba caldera was obtained by Koulakov et al. (2009) and was based on data recorded by temporary network from January to May 1995. In this study this "old" dataset was supplemented with "new" data recorded by a temporary network deployed in approximately same area by GFZ-Potsdam from May to November 2008. We have manually picked the arrival times from the local events recorded by the later experiment and then performed the tomography inversion for the combined dataset using the LOTOS code (Koulakov, 2009). In the uppermost layers we observe strong low-velocity P- and S- anomalies within the Caldera which can be interpreted by the presence of think sediments filling the caldera. In the lower crust and uppermost mantle we observe a vertical anomaly of low P- and S-velocities which probably represent the path of conduits which link the caldera area with the slab. Similar to Redoubt volcano, resulting velocity model of Toba has an increased value of Vp/Vs ratio that indicates a presence of magma reservoir. Comparison of the tomographic results obtained for the completely different volcanic systems helps in understanding some basic principles of feeding the volcanoes. This study was partly supported by the Project #7

  1. Effects of the earthquake of March 27, 1964, in the Homer area, Alaska, with a section on beach changes on Homer Spit: Chapter D in The Alaska earthquake, March 27, 1964: effects on communities

    USGS Publications Warehouse

    Waller, Roger M.; Stanley, Kirk W.

    1966-01-01

    The March 27, 1964, earthquake shook the Homer area for about 3 minutes. Land effects consisted of a 2- to 6-foot subsidence of the mainland and Homer Spit, one earthflow at the mouth of a canyon, several landslides on the Homer escarpment and along the sea bluffs, and minor fissuring of the ground, principally at the edges of bluffs and on Homer Spit. Hydrologic effects consisted of at least one and possibly two submarine landslides at the end of the spit, seiche waves in Kachemak Bay, ice breakage on Beluga Lake, sanding of wells, and a temporary loss of water in some wells. Seismic damage to the community was light in comparison with that of other communities closer to the epicenter. One submarine landslide, however, took out most of the harbor breakwater. The greatest damage was due to the subsidence of the spit, both tectonically (2–3 ft) and by differential compaction or lateral spreading (an additional 1–4 ft). Higher tides now flood much of the spit. The harbor and dock had to be replaced, and buildings on the end of the spit had to be elevated. Protection works for other buildings and the highway were needed. These works included application of fill to raise the highway and parts of the spit above high tides. Reconstruction costs and disaster loans totaled about $2½ million, but this amount includes added improvement costs over preexisting values. Homer Spit in particular and the Homer area in general rank as areas where precautions must be taken in selecting building sites. The hazards of landslides, earthflows, compaction and submarine slumping—all of which might be triggered by an earthquake—should be considered in site selection. In plan, Homer Spit resembles a scimitar with its curving blade pointed seaward. It is about 4 miles long and as much as 1,500 feet wide. The spit is composed largely of gravel intermixed with some sand. After the earthquake and the resulting tectonic subsidence and compaction, much of the spit was below high

  2. Earthquakes; January-February, 1979

    USGS Publications Warehouse

    Person, W.J.

    1979-01-01

    The first major earthquake (magnitude 7.0 to 7.9) of the year struck in southeastern Alaska in a sparsely populated area on February 28. On January 16, Iran experienced the first destructive earthquake of the year causing a number of casualties and considerable damage. Peru was hit by a destructive earthquake on February 16 that left casualties and damage. A number of earthquakes were experienced in parts of the Untied States, but only minor damage was reported. 

  3. Earthquake Education and Public Information Centers: A Collaboration Between the Earthquake Country Alliance and Free-Choice Learning Institutions in California

    NASA Astrophysics Data System (ADS)

    Degroot, R. M.; Springer, K.; Brooks, C. J.; Schuman, L.; Dalton, D.; Benthien, M. L.

    2009-12-01

    In 1999 the Southern California Earthquake Center initiated an effort to expand its reach to multiple target audiences through the development of an interpretive trail on the San Andreas fault at Wallace Creek and an earthquake exhibit at Fingerprints Youth Museum in Hemet. These projects and involvement with the San Bernardino County Museum in Redlands beginning in 2007 led to the creation of Earthquake Education and Public Information Centers (EPIcenters) in 2008. The impetus for the development of the network was to broaden participation in The Great Southern California ShakeOut. In 2009 it has grown to be more comprehensive in its scope including its evolution into a statewide network. EPIcenters constitute a variety of free-choice learning institutions, representing museums, science centers, libraries, universities, parks, and other places visited by a variety of audiences including families, seniors, and school groups. They share a commitment to demonstrating and encouraging earthquake preparedness. EPIcenters coordinate Earthquake Country Alliance activities in their county or region, lead presentations or organize events in their communities, or in other ways demonstrate leadership in earthquake education and risk reduction. The San Bernardino County Museum (Southern California) and The Tech Museum of Innovation (Northern California) serve as EPIcenter regional coordinating institutions. They interact with over thirty institutional partners who have implemented a variety of activities from displays and talks to earthquake exhibitions. While many activities are focused on the time leading up to and just after the ShakeOut, most EPIcenter members conduct activities year round. Network members at Kidspace Museum in Pasadena and San Diego Natural History Museum have formed EPIcenter focus groups on early childhood education and safety and security. This presentation highlights the development of the EPIcenter network, synergistic activities resulting from this

  4. Earthquakes & Volcanoes, Volume 21, Number 1, 1989: Featuring the U.S. Geological Survey's National Earthquake Information Center in Golden, Colorado, USA

    USGS Publications Warehouse

    ,; Spall, Henry; Schnabel, Diane C.

    1989-01-01

    Earthquakes and Volcanoes is published bimonthly by the U.S. Geological Survey to provide current information on earthquakes and seismology, volcanoes, and related natural hazards of interest to both generalized and specialized readers. The Secretary of the Interior has determined that the publication of this periodical is necessary in the transaction of the public business required by law of this Department. Use of funds for printing this periodical has been approved by the Office of Management and Budget through June 30, 1989. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

  5. Twitter as Information Source for Rapid Damage Estimation after Major Earthquakes

    NASA Astrophysics Data System (ADS)

    Eggert, Silke; Fohringer, Joachim

    2014-05-01

    Natural disasters like earthquakes require a fast response from local authorities. Well trained rescue teams have to be available, equipment and technology has to be ready set up, information have to be directed to the right positions so the head quarter can manage the operation precisely. The main goal is to reach the most affected areas in a minimum of time. But even with the best preparation for these cases, there will always be the uncertainty of what really happened in the affected area. Modern geophysical sensor networks provide high quality data. These measurements, however, are only mapping disjoint values from their respective locations for a limited amount of parameters. Using observations of witnesses represents one approach to enhance measured values from sensors ("humans as sensors"). These observations are increasingly disseminated via social media platforms. These "social sensors" offer several advantages over common sensors, e.g. high mobility, high versatility of captured parameters as well as rapid distribution of information. Moreover, the amount of data offered by social media platforms is quite extensive. We analyze messages distributed via Twitter after major earthquakes to get rapid information on what eye-witnesses report from the epicentral area. We use this information to (a) quickly learn about damage and losses to support fast disaster response and to (b) densify geophysical networks in areas where there is sparse information to gain a more detailed insight on felt intensities. We present a case study from the Mw 7.1 Philippines (Bohol) earthquake that happened on Oct. 15 2013. We extract Twitter messages, so called tweets containing one or more specified keywords from the semantic field of "earthquake" and use them for further analysis. For the time frame of Oct. 15 to Oct 18 we get a data base of in total 50.000 tweets whereof 2900 tweets are geo-localized and 470 have a photo attached. Analyses for both national level and locally for

  6. Surface rupture and slip distribution of the Denali and Totschunda faults in the 3 November 2002 M 7.9 earthquake, Alaska

    USGS Publications Warehouse

    Haeussler, Peter J.; Schwartz, David P.; Dawson, Timothy E.; Stenner, Heidi D.; Lienkaemper, James J.; Sherrod, Brian; Cinti, Francesca R.; Montone, Paola; Craw, Patricia; Crone, Anthony J.; Personius, Stephen F.

    2004-01-01

    The 3 November 2002 Denali fault, Alaska, earthquake resulted in 341 km of surface rupture on the Susitna Glacier, Denali, and Totschunda faults. The rupture proceeded from west to east and began with a 48-km-long break on the previously unknown Susitna Glacier thrust fault. Slip on this thrust averaged about 4 m (Crone et al., 2004). Next came the principal surface break, along 226 km of the Denali fault, with average right-lateral offsets of 4.5–5.1 m and a maximum offset of 8.8 m near its eastern end. The Denali fault trace is commonly left stepping and north side up. About 99 km of the fault ruptured through glacier ice, where the trace orientation was commonly influenced by local ice fabric. Finally, slip transferred southeastward onto the Totschunda fault and continued for another 66 km where dextral offsets average 1.6–1.8 m. The transition from the Denali fault to the Totschunda fault occurs over a complex 25-km-long transfer zone of right-slip and normal fault traces. Three methods of calculating average surface slip all yield a moment magnitude of Mw 7.8, in very good agreement with the seismologically determined magnitude of M 7.9. A comparison of strong-motion inversions for moment release with our slip distribution shows they have a similar pattern. The locations of the two largest pulses of moment release correlate with the locations of increasing steps in the average values of observed slip. This suggests that slip-distribution data can be used to infer moment release along other active fault traces.

  7. Earthquakes; March-April, 1979

    USGS Publications Warehouse

    Person, W.J.

    1979-01-01

    In the United States, a number of earthquakes were experienced, the most damaging one in southern California on March 15. The aftershocks continued in southeastern Alaska but caused no additional damage. 

  8. Probabilistic Tsunami Hazard Assessment along Nankai Trough (1) An assessment based on the information of the forthcoming earthquake that Earthquake Research Committee(2013) evaluated

    NASA Astrophysics Data System (ADS)

    Hirata, K.; Fujiwara, H.; Nakamura, H.; Osada, M.; Morikawa, N.; Kawai, S.; Ohsumi, T.; Aoi, S.; Yamamoto, N.; Matsuyama, H.; Toyama, N.; Kito, T.; Murashima, Y.; Murata, Y.; Inoue, T.; Saito, R.; Takayama, J.; Akiyama, S.; Korenaga, M.; Abe, Y.; Hashimoto, N.

    2015-12-01

    The Earthquake Research Committee(ERC)/HERP, Government of Japan (2013) revised their long-term evaluation of the forthcoming large earthquake along the Nankai Trough; the next earthquake is estimated M8 to 9 class, and the probability (P30) that the next earthquake will occur within the next 30 years (from Jan. 1, 2013) is 60% to 70%. In this study, we assess tsunami hazards (maximum coastal tsunami heights) in the near future, in terms of a probabilistic approach, from the next earthquake along Nankai Trough, on the basis of ERC(2013)'s report. The probabilistic tsunami hazard assessment that we applied is as follows; (1) Characterized earthquake fault models (CEFMs) are constructed on each of the 15 hypothetical source areas (HSA) that ERC(2013) showed. The characterization rule follows Toyama et al.(2015, JpGU). As results, we obtained total of 1441 CEFMs. (2) We calculate tsunamis due to CEFMs by solving nonlinear, finite-amplitude, long-wave equations with advection and bottom friction terms by finite-difference method. Run-up computation on land is included. (3) A time predictable model predicts the recurrent interval of the present seismic cycle is T=88.2 years (ERC,2013). We fix P30 = 67% by applying the renewal process based on BPT distribution with T and alpha=0.24 as its aperiodicity. (4) We divide the probability P30 into P30(i) for i-th subgroup consisting of the earthquakes occurring in each of 15 HSA by following a probability re-distribution concept (ERC,2014). Then each earthquake (CEFM) in i-th subgroup is assigned a probability P30(i)/N where N is the number of CEFMs in each sub-group. Note that such re-distribution concept of the probability is nothing but tentative because the present seismology cannot give deep knowledge enough to do it. Epistemic logic-tree approach may be required in future. (5) We synthesize a number of tsunami hazard curves at every evaluation points on coasts by integrating the information about 30 years occurrence

  9. Evidence for Deep Tectonic Tremor in the Alaska-Aleutian Subduction Zone

    NASA Astrophysics Data System (ADS)

    Brown, J. R.; Prejean, S. G.; Beroza, G. C.; Gomberg, J. S.; Haeussler, P. J.

    2010-12-01

    We search for, characterize, and locate tremor not associated with volcanoes along the Alaska-Aleutian subduction zone using continuous seismic data recorded by the Alaska Volcano Observatory and Alaska Earthquake Information Center from 2005 to the present. Visual inspection of waveform spectra and time series reveal dozens of 10 to 20-minute bursts of tremor throughout the Alaska-Aleutian subduction zone (Peterson, 2009). Using autocorrelation methods, we show that these tremor signals are composed of hundreds of repeating low-frequency earthquakes (LFEs) as has been found in other circum-Pacific subduction zones. We infer deep sources based on phase arrival move-out times of less than 4 seconds across multiple monitoring networks (max. inter-station distances of 50 km), which are designed to monitor individual volcanoes. We find tremor activity is localized in 7 segments: Cook Inlet, Shelikof Strait, Alaska Peninsula, King Cove, Unalaska-Dutch Harbor, Andreanof Islands, and the Rat Islands. Locations along the Cook Inlet, Shelikof Straight and Alaska Peninsula are well constrained due to adequate station coverage. LFE hypocenters in these regions are located on the plate interface and form a sharp edge near the down-dip limit of the 1964 M 9.2 rupture area. Although the geometry, age, thermal structure, frictional and other relevant properties of the Alaska-Aleutian subduction are poorly known, it is likely these characteristics differ along its entire length, and also differ from other subduction zones where tremor has been found. LFE hypocenters in the remaining areas are also located down-dip of the most recent M 8+ megathrust earthquakes, between 60-75 km depth and almost directly under the volcanic arc. Although these locations are less well constrained, our preliminary results suggest LFE/tremor activity marks the down-dip rupture limit for megathrust earthquakes in this subduction zone. Also, we cannot rule out the possibility that our observations could

  10. Literature and information related to the natural resources of the North Aleutian Basin of Alaska.

    SciTech Connect

    Stull, E.A.; Hlohowskyj, I.; LaGory, K. E.; Environmental Science Division

    2008-01-31

    The North Aleutian Basin Planning Area of the Minerals Management Service (MMS) is a large geographic area with significant natural resources. The Basin includes most of the southeastern part of the Bering Sea Outer Continental Shelf, including all of Bristol Bay. The area supports important habitat for a wide variety of species and globally significant habitat for birds and marine mammals, including several federally listed species. Villages and communities of the Alaska Peninsula and other areas bordering or near the Basin rely on its natural resources (especially commercial and subsistence fishing) for much of their sustenance and livelihood. The offshore area of the North Aleutian Basin is considered to have important hydrocarbon reserves, especially natural gas. In 2006, the MMS released a draft proposed program, 'Outer Continental Shelf Oil and Gas Leasing Program, 2007-2012' and an accompanying draft programmatic environmental impact statement (EIS). The draft proposed program identified two lease sales proposed in the North Aleutian Basin in 2010 and 2012, subject to restrictions. The area proposed for leasing in the Basin was restricted to the Sale 92 Area in the southwestern portion. Additional EISs will be needed to evaluate the potential effects of specific lease actions, exploration activities, and development and production plans in the Basin. A full range of updated multidisciplinary scientific information will be needed to address oceanography, fate and effects of oil spills, marine ecosystems, fish, fisheries, birds, marine mammals, socioeconomics, and subsistence in the Basin. Scientific staff at Argonne National Laboratory were contracted to assist MMS with identifying and prioritizing information needs related to potential future oil and gas leasing and development activities in the North Aleutian Basin. Argonne focused on three related tasks: (1) identify and gather relevant literature published since 1996, (2) synthesize and summarize the

  11. Earthquake Hazard Analysis using Geological Characteristics and Geographic Information System (GIS) in the Southeastern Part of Korea

    NASA Astrophysics Data System (ADS)

    Song, Kyo-Young

    2010-05-01

    Earthquake Hazard Analysis using Geological Characteristics and GIS in the Southeastern Part of Korea The purpose of this study is to investigate earthquake hazards using geologic characteristics and geographic information system (GIS) for assessment and mitigation of earthquake hazards. The southeastern part of Korean peninsula, especially Ulsan and Pohang cities, was chosen for construction of GIS database and analysis of earthquake hazards such as liquefaction, landslide. Two municipal areas are represented as ones of the most populous industrial cities in Korea. However, several large-scale faults such as the Yangsan fault occurred in the vicinity of those areas. In this study, important factors closely related to earthquake hazards such as seismicity, geology, soil distribution, groundwater depth and ground slope data were compiled for spatial database using GIS, and ranked by relative susceptibility of earthquake hazards. To classify vulnerable areas and analyze probability for susceptibility of earthquake hazards, each factor was computed and applied to established dataset for liquefaction and landslide induced from earthquake. To present, the probability of liquefaction in the study area is calculated to about 0.012~0.133 when g value is 0.13~0.14 g. But if the moment magnitude increases to 7.0, the probability of liquefaction increases up to 0.802. The probability of landslide is almost null at present, but it increases rapidly when the moment magnitude reaches 5.0. The landslide is expected in all unstable slopes when the moment magnitude exceeds 6.0. The acquired results from the study area indicate that the liquefaction and landslide induced from earthquake is closely related to the geology. Therefore, general geology such as kind of rocks and age of rocks is very important factor in analyzing earthquake hazards.

  12. Three-dimensional P-wave velocity structure derived from local earthquakes at the Katmai group of volcanoes, Alaska

    USGS Publications Warehouse

    Jolly, A.D.; Moran, S.C.; McNutt, S.R.; Stone, D.B.

    2007-01-01

    The three-dimensional P-wave velocity structure beneath the Katmai group of volcanoes is determined by inversion of more than 10,000 rays from over 1000 earthquakes recorded on a local 18 station short-period network between September 1996 and May 2001. The inversion is well constrained from sea level to about 6??km below sea level and encompasses all of the Katmai volcanoes; Martin, Mageik, Trident, Griggs, Novarupta, Snowy, and Katmai caldera. The inversion reduced the average RMS travel-time error from 0.22??s for locations from the standard one-dimensional model to 0.13??s for the best three-dimensional model. The final model, from the 6th inversion step, reveals a prominent low velocity zone (3.6-5.0??km/s) centered at Katmai Pass and extending from Mageik to Trident volcanoes. The anomaly has values about 20-25% slower than velocities outboard of the region (5.0-6.5??km/s). Moderately low velocities (4.5-6.0??km/s) are observed along the volcanic axis between Martin and Katmai Caldera. Griggs volcano, located about 10??km behind (northwest of) the volcanic axis, has unremarkable velocities (5.0-5.7??km/s) compared to non-volcanic regions. The highest velocities are observed between Snowy and Griggs volcanoes (5.5-6.5??km/s). Relocated hypocenters for the best 3-D model are shifted significantly relative to the standard model with clusters of seismicity at Martin volcano shifting systematically deeper by about 1??km to depths of 0 to 4??km below sea level. Hypocenters for the Katmai Caldera are more tightly clustered, relocating beneath the 1912 scarp walls. The relocated hypocenters allow us to compare spatial frequency-size distributions (b-values) using one-dimensional and three-dimensional models. We find that the distribution of b is significantly changed for Martin volcano, which was characterized by variable values (0.8 < b < 2.0) with standard locations and more uniform values (0.8 < b < 1.2) after relocation. Other seismic clusters at Mageik (1.2 < b

  13. Extraction of spatio-temporal information of earthquake event based on semantic technology

    NASA Astrophysics Data System (ADS)

    Fan, Hong; Guo, Dan; Li, Huaiyuan

    2015-12-01

    In this paper a web information extraction method is presented which identifies a variety of thematic events utilizing the event knowledge framework derived from text training, and then further uses the syntactic analysis to extract the event key information. The method which combines the text semantic information and domain knowledge of the event makes the extraction of information people interested more accurate. In this paper, web based earthquake news extraction is taken as an example. The paper firstly briefs the overall approaches, and then details the key algorithm and experiments of seismic events extraction. Finally, this paper conducts accuracy analysis and evaluation experiments which demonstrate that the proposed method is a promising way of hot events mining.

  14. 88 hours: The U.S. Geological Survey National Earthquake Information Center response to the 11 March 2011 Mw 9.0 Tohoku earthquake

    USGS Publications Warehouse

    Hayes, G.P.; Earle, P.S.; Benz, H.M.; Wald, D.J.; Briggs, R.W.

    2011-01-01

    This article presents a timeline of NEIC response to a major global earthquake for the first time in a formal journal publication. We outline the key observations of the earthquake made by the NEIC and its partner agencies, discuss how these analyses evolved, and outline when and how this information was released to the public and to other internal and external parties. Our goal in the presentation of this material is to provide a detailed explanation of the issues faced in the response to a rare, giant earthquake. We envisage that the timeline format of this presentation can highlight technical and procedural successes and shortcomings, which may in turn help prompt research by our academic partners and further improvements to our future response efforts. We have shown how NEIC response efforts have significantly improved over the past six years since the great 2004 Sumatra-Andaman earthquake. We are optimistic that the research spawned from this disaster, and the unparalleled dense and diverse data sets that have been recorded, can lead to similar-and necessary-improvements in the future.

  15. Evaluation of the streamflow-gaging network of Alaska in providing regional streamflow information

    USGS Publications Warehouse

    Brabets, Timothy P.

    1996-01-01

    In 1906, the U.S. Geological Survey (USGS) began operating a network of streamflow-gaging stations in Alaska. The primary purpose of the streamflow- gaging network has been to provide peak flow, average flow, and low-flow characteristics to a variety of users. In 1993, the USGS began a study to evaluate the current network of 78 stations. The objectives of this study were to determine the adequacy of the existing network in predicting selected regional flow characteristics and to determine if providing additional streamflow-gaging stations could improve the network's ability to predict these characteristics. Alaska was divided into six distinct hydrologic regions: Arctic, Northwest, Southcentral, Southeast, Southwest, and Yukon. For each region, historical and current streamflow data were compiled. In Arctic, Northwest, and Southwest Alaska, insufficient data were available to develop regional regression equations. In these areas, proposed locations of streamflow-gaging stations were selected by using clustering techniques to define similar areas within a region and by spatial visual analysis using the precipitation, physiographic, and hydrologic unit maps of Alaska. Sufficient data existed in Southcentral and Southeast Alaska to use generalized least squares (GLS) procedures to develop regional regression equations to estimate the 50-year peak flow, annual average flow, and a low-flow statistic. GLS procedures were also used for Yukon Alaska but the results should be used with caution because the data do not have an adequate spatial distribution. Network analysis procedures were used for the Southcentral, Southeast, and Yukon regions. Network analysis indicates the reduction in the sampling error of the regional regression equation that can be obtained given different scenarios. For Alaska, a 10-year planning period was used. One scenario showed the results of continuing the current network with no additional gaging stations and another scenario showed the results

  16. Southern California Earthquake Center/Undergraduate Studies in Earthquake Information Technology (SCEC/UseIT): Towards the Next Generation of Internship

    NASA Astrophysics Data System (ADS)

    Perry, S.; Benthien, M.; Jordan, T. H.

    2005-12-01

    The SCEC/UseIT internship program is training the next generation of earthquake scientist, with methods that can be adapted to other disciplines. UseIT interns work collaboratively, in multi-disciplinary teams, conducting computer science research that is needed by earthquake scientists. Since 2002, the UseIT program has welcomed 64 students, in some two dozen majors, at all class levels, from schools around the nation. Each summer''s work is posed as a ``Grand Challenge.'' The students then organize themselves into project teams, decide how to proceed, and pool their diverse talents and backgrounds. They have traditional mentors, who provide advice and encouragement, but they also mentor one another, and this has proved to be a powerful relationship. Most begin with fear that their Grand Challenge is impossible, and end with excitement and pride about what they have accomplished. The 22 UseIT interns in summer, 2005, were primarily computer science and engineering majors, with others in geology, mathematics, English, digital media design, physics, history, and cinema. The 2005 Grand Challenge was to "build an earthquake monitoring system" to aid scientists who must visualize rapidly evolving earthquake sequences and convey information to emergency personnel and the public. Most UseIT interns were engaged in software engineering, bringing new datasets and functionality to SCEC-VDO (Virtual Display of Objects), a 3D visualization software that was prototyped by interns last year, using Java3D and an extensible, plug-in architecture based on the Eclipse Integrated Development Environment. Other UseIT interns used SCEC-VDO to make animated movies, and experimented with imagery in order to communicate concepts and events in earthquake science. One movie-making project included the creation of an assessment to test the effectiveness of the movie''s educational message. Finally, one intern created an interactive, multimedia presentation of the UseIT program.

  17. How citizen seismology is transforming rapid public earthquake information: the example of LastQuake smartphone application and Twitter QuakeBot

    NASA Astrophysics Data System (ADS)

    Bossu, R.; Etivant, C.; Roussel, F.; Mazet-Roux, G.; Steed, R.

    2014-12-01

    Smartphone applications have swiftly become one of the most popular tools for rapid reception of earthquake information for the public. Wherever someone's own location is, they can be automatically informed when an earthquake has struck just by setting a magnitude threshold and an area of interest. No need to browse the internet: the information reaches you automatically and instantaneously! One question remains: are the provided earthquake notifications always relevant for the public? A while after damaging earthquakes many eyewitnesses scrap the application they installed just after the mainshock. Why? Because either the magnitude threshold is set too high and many felt earthquakes are missed, or it is set too low and the majority of the notifications are related to unfelt earthquakes thereby only increasing anxiety among the population at each new update. Felt and damaging earthquakes are the ones of societal importance even when of small magnitude. LastQuake app and Twitter feed (QuakeBot) focuses on these earthquakes that matter for the public by collating different information threads covering tsunamigenic, damaging and felt earthquakes. Non-seismic detections and macroseismic questionnaires collected online are combined to identify felt earthquakes regardless their magnitude. Non seismic detections include Twitter earthquake detections, developed by the USGS, where the number of tweets containing the keyword "earthquake" is monitored in real time and flashsourcing, developed by the EMSC, which detect traffic surges on its rapid earthquake information website caused by the natural convergence of eyewitnesses who rush to the Internet to investigate the cause of the shaking that they have just felt. We will present the identification process of the felt earthquakes, the smartphone application and the 27 automatically generated tweets and how, by providing better public services, we collect more data from citizens.

  18. Tremor and the Depth Extent of Slip in Large Earthquakes

    NASA Astrophysics Data System (ADS)

    BEroza, G. C.; Brown, J. R.; Ide, S.

    2013-05-01

    We survey the evidence for the distribution of tremor and mainshock slip. In Southwest Japan, where tremor is well located, it outlines the down-dip edge of slip in the 1944 and 1946 Nankai earthquakes. In Alaska and the Aleutians, tremor location and slip distributions in slip are subject to greater uncertainty, but within that uncertainty they are consistent with the notion that tremor outlines the down-dip limit of mainshock slip. In Mexico, tremor locations and the extent of rupture in large (M > 7) earthquakes are also uncertain, but show a similar relationship. Taken together, these observations suggest that tremor may provide important information on the depth extent of rupture in large earthquakes where there have been no large earthquakes to test that hypothesis. If applied to the Cascadia subduction zone, it suggests slip will extend farther inland than previously assumed. If applied to the San Andreas Fault, it suggests slip will extend deeper than has previously been assumed.

  19. Alaska's renewable energy potential.

    SciTech Connect

    Not Available

    2009-02-01

    This paper delivers a brief survey of renewable energy technologies applicable to Alaska's climate, latitude, geography, and geology. We first identify Alaska's natural renewable energy resources and which renewable energy technologies would be most productive. e survey the current state of renewable energy technologies and research efforts within the U.S. and, where appropriate, internationally. We also present information on the current state of Alaska's renewable energy assets, incentives, and commercial enterprises. Finally, we escribe places where research efforts at Sandia National Laboratories could assist the state of Alaska with its renewable energy technology investment efforts.

  20. Earthquake Drill for Effective Emergency Response and Quick Collection of Damage Information by Collaboration between Local Government and Residents

    NASA Astrophysics Data System (ADS)

    Hisada, Yoshiaki; Murakami, Masahiro; Zama, Shinsaku; Endo, Makoto; Shibayama, Akihiro; Ichii, Tsuguyuki; Sekizawa, Ai; Suematsu, Takashi; Yamada, Takeshi; Noda, Itsuki; Matsui, Hiroki; Kubo, Tomohiro; Ohgai, Akira

    An earthquake drill for collecting quickly earthquake damage information and conducting effective emergency response was developed and carried out by collaboration between a local government and residents. The methodology for the drill consists of two stages; at the first stage, workshops by local communities' associations and government officers are held to make disaster prevention maps, which indicate strong and weak points of the local area, such as the locations of fire distinguishers, fire hydrants, storages of rescue equipments, weak walls and buildings, open spaces, and so on. During the workshop, the participants also discuss about what happens during a large earthquake, and how to cope with the disaster. At second stage, an emergency drill is carried out by collaboration between the local government and the community residents, as follows. First, the panels are suspended at electric poles just before the drill, which show the information about earthquake damage, such as a fire breaking, a collapsed building, and a blocked road, starts. Second, when the drill starts under the assumption of the occurrence of a large earthquake, the local residents check the area to collect the damage information, and to conduct emergency response. For example, when a resident finds a panel of fire breaking, he/she is expected to gather people, fire distinguishers, and buckets with water as many as possible within 10 minutes. Third, the residents get together at the local evacuation center, and make a map indicating the locations of the damage and their information. Local government officials at the evacuation center collect those damage maps, and immediately sent them to the emergency operation center of the government. Fourth, the operation center gathers and analyzes all the data, and informs the residents about important information, such as the evacuation order from the local center to other safe areas due to a possible massive fire. The proposed methodology was applied

  1. Incorporating Real-time Earthquake Information into Large Enrollment Natural Disaster Course Learning

    NASA Astrophysics Data System (ADS)

    Furlong, K. P.; Benz, H.; Hayes, G. P.; Villasenor, A.

    2010-12-01

    Although most would agree that the occurrence of natural disaster events such as earthquakes, volcanic eruptions, and floods can provide effective learning opportunities for natural hazards-based courses, implementing compelling materials into the large-enrollment classroom environment can be difficult. These natural hazard events derive much of their learning potential from their real-time nature, and in the modern 24/7 news-cycle where all but the most devastating events are quickly out of the public eye, the shelf life for an event is quite limited. To maximize the learning potential of these events requires that both authoritative information be available and course materials be generated as the event unfolds. Although many events such as hurricanes, flooding, and volcanic eruptions provide some precursory warnings, and thus one can prepare background materials to place the main event into context, earthquakes present a particularly confounding situation of providing no warning, but where context is critical to student learning. Attempting to implement real-time materials into large enrollment classes faces the additional hindrance of limited internet access (for students) in most lecture classrooms. In Earth 101 Natural Disasters: Hollywood vs Reality, taught as a large enrollment (150+ students) general education course at Penn State, we are collaborating with the USGS’s National Earthquake Information Center (NEIC) to develop efficient means to incorporate their real-time products into learning activities in the lecture hall environment. Over time (and numerous events) we have developed a template for presenting USGS-produced real-time information in lecture mode. The event-specific materials can be quickly incorporated and updated, along with key contextual materials, to provide students with up-to-the-minute current information. In addition, we have also developed in-class activities, such as student determination of population exposure to severe ground

  2. 76 FR 32142 - Proposed Information Collection; Comment Request; Alaska Saltwater Sportfishing Economic Survey

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-03

    ... Saltwater Sportfishing Economic Survey AGENCY: National Oceanic and Atmospheric Administration (NOAA... economic analyses of marine sport fishing in Alaska. This survey is necessary to understand the factors that affect the economic value of marine recreational fishing trips and improve estimates of...

  3. 76 FR 62374 - Proposed Information Collection; Comment Request; Alaska Recreational Charter Vessel Guide and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-07

    ... effect of regulatory restrictions (currently in place or potential) on charter operator and owner..., such as charter vessel logbooks administered by Alaska Department of Fish and Game (ADF&G). However... improved analysis and of the effects of fisheries regulations on the charter fishing industry,...

  4. Reporting Child Abuse & Neglect in Alaska. Information for Medical and Health Personnel.

    ERIC Educational Resources Information Center

    Alaska State Library, Juneau.

    Alaska law requires that medical and health personnel report known and suspected child abuse and neglect. No one is more likely to see indicators of abuse and neglect than medical and other health-related personnel. Such indicators can include broken bones, bruises, malnutrition and other effects of neglect, infections, and other signs of sexual…

  5. Earthquakes: Natural Science Museum and Civil Protection of Trento to inform citizens

    NASA Astrophysics Data System (ADS)

    Lauro, Claudia; Avanzini, Marco

    2010-05-01

    During 2009 the Natural Science Museum of Trento organized the exhibition "Attraction Earth: Earthquakes and Terrestrial Magnetism" in collaboration with the INGV (Italian National Institute of Geophysic and Volcanology). In this exhibition a particular sector has been devoted to the seismic activity and its monitoring in the Province of Trento. The purpose was to inform local people on the geological features of their territory, the monitoring activity carried out by the Civil Protection and the potential earthquake hazards, also in order to adopt a correct behaviour in case of seismic event. This sector, "The seismometric Trentino network", was organized by the Geological Service of the Trento Civil Protection and it is open till May 2010, both for general public and school students. For the latter, a particular education pack, realized by the Educational Department of the Museum and consisting of a guided tour coupled with the laboratory activity "Waves upside-down: seismology", is proposed. The whole exhibition has been also coupled with a cycle conferences targeted to adults, in which these topics have been explained by researchers and technicians of INGV and of Trento Geological Service. "The seismometric Trentino network" sector presents the daily monitoring activity of the Geological Service, that has been monitoring the seismic activity for the last 30 years, and describes the deep earth processes of the local territory, such as presence of tectonic discontinuities and their activity. It consists of display panels, a seismometer with rotating drums and a multimedia that reports the monitoring activity of the seismometric network, with real time connection to the various monitoring stations. This allows visitors to observe instantly the local seismic events recorded by each station. The seismometric network was established by the institutions of Trento Province after the earthquakes occurred in Friuli Venezia-Giulia and at Riva del Garda (1976). It started

  6. Using a geographic information system (GIS) to assess pediatric surge potential after an earthquake.

    PubMed

    Curtis, Jacqueline W; Curtis, Andrew; Upperman, Jeffrey S

    2012-06-01

    Geographic information systems (GIS) and geospatial technology (GT) can help hospitals improve plans for postdisaster surge by assessing numbers of potential patients in a catchment area and providing estimates of special needs populations, such as pediatrics. In this study, census-derived variables are computed for blockgroups within a 3-mile radius from Children's Hospital Los Angeles (CHLA) and from Los Angeles County-University of Southern California (LAC-USC) Medical Center. Landslide and liquefaction zones are overlaid on US Census Bureau blockgroups. Units that intersect with the hazard zones are selected for computation of pediatric surge potential in case of an earthquake. In addition, cartographic visualization and cluster analysis are performed on the entire 3-mile study area to identify hot spots of socially vulnerable populations. The results suggest the need for locally specified vulnerability models for pediatric populations. GIS and GT have untapped potential to contribute local specificity to planning for surge potential after a disaster. Although this case focuses on an earthquake hazard, the methodology is appropriate for an all-hazards approach. With the advent of Google Earth, GIS output can now be easily shared with medical personnel for broader application and improvement in planning.

  7. Tsunami Source Specification for Southeast Alaska with Focus on Inundation Mapping and Hazard Risk Assessment in Sitka

    NASA Astrophysics Data System (ADS)

    Suleimani, E. N.; Nicolsky, D. J.; Hansen, R. A.

    2012-12-01

    The Alaska Earthquake Information Center (AEIC) conducts tsunami inundation mapping for coastal communities in Alaska. This activity provides local emergency officials with tsunami hazard assessment and mitigation tools. At-risk communities are spread along several segments of the Alaska-Aleutian Subduction Zone, with each segment having a unique seismic history and potential tsunami hazard. As a result, almost every community has a distinct set of potential tsunami sources that need to be considered in order to make a tsunami inundation map. Therefore, an important component of the inundation mapping effort is identification and specification of potential tsunami sources. We are creating tsunami inundation maps for Sitka, Alaska, in the scope of the National Tsunami Hazard Mitigation Program. Tsunami potential from tectonic and submarine landslide sources must be evaluated in this case for comprehensive mapping of areas at risk for inundation. The community of Sitka, the former capital of Russian Alaska, is located in Southeast Alaska, on the west coast of Baranof Island, facing the Pacific Ocean. In this area of southern Alaska, the subduction of the Pacific plate beneath the North America plate becomes a transform boundary that continues down the coast as the Fairweather - Queen Charlotte (FW-QC) transform fault system. The Sitka segment of the FW-QC fault system ruptured in large strike-slip earthquakes in 1927 (Ms7.1) and in 1972 (Ms7.6). We numerically model the extent of inundation in Sitka due to tsunami waves generated from earthquake and landslide sources. Tsunami scenarios include a repeat of the tsunami triggered by the 1964 Great Alaska earthquake, repeat of the tsunami triggered by the 2011 Tohoku earthquake, tsunami waves generated by a hypothetically extended 1964 rupture, a hypothetical Cascadia megathrust earthquake, and hypothetical earthquakes in the FW-QC fault system. Underwater landslide events off the continental shelf along the FW-QC fault

  8. The Alaska Mineral Resource Assessment Program; guide to information about the geology and mineral resources of the Ketchikan and Prince Rupert quadrangles, southeastern Alaska

    USGS Publications Warehouse

    Berg, Henry C.

    1982-01-01

    The Ketchikan and Prince Rupert 1-degree by 2-degree quadrangles, which encompass about 16,000 km2 at the south tip of southeastern Alaska, have been investigated by integrated field and laboratory studies in the disciplines of geology, geochemistry, geophysics, and Landsat data interpretation to determine their mineral-resource potential. Mineral deposits in the study area have been mined or prospected intermittently since about 1900, and production of small tonnages of ores containing gold, silver, copper, lead, zinc, and tungsten has been recorded. Extensive exploration and development currently (1981) is underway at a molybdenum prospect about 65 km east of Ketchikan. Our mineral-resource assessment indicates that the area contains potentially significant amounts of those metallic commodities, as well as of molybdenum, iron, antimony, and barite. The results of these studies have been published in a folio of maps accompanied by descriptive texts, diagrams, tables, and pertinent references. The present report serves as a guide to these investigations, provides relevant background information, and integrates the component maps and reports. It also describes revisions to the geology based on studies completed since the folio was published and includes a list of specific and general references on the geology and mineral deposits of the study area.

  9. Connecting slow earthquakes to huge earthquakes.

    PubMed

    Obara, Kazushige; Kato, Aitaro

    2016-07-15

    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of their high sensitivity to stress changes in the seismogenic zone. Episodic stress transfer to megathrust source faults leads to an increased probability of triggering huge earthquakes if the adjacent locked region is critically loaded. Careful and precise monitoring of slow earthquakes may provide new information on the likelihood of impending huge earthquakes.

  10. Alaska marine ice atlas

    SciTech Connect

    LaBelle, J.C.; Wise, J.L.; Voelker, R.P.; Schulze, R.H.; Wohl, G.M.

    1982-01-01

    A comprehensive Atlas of Alaska marine ice is presented. It includes information on pack and landfast sea ice and calving tidewater glacier ice. It also gives information on ice and related environmental conditions collected over several years time and indicates the normal and extreme conditions that might be expected in Alaska coastal waters. Much of the information on ice conditions in Alaska coastal waters has emanated from research activities in outer continental shelf regions under assessment for oil and gas exploration and development potential. (DMC)

  11. Data and Visualizations in the Southern California Earthquake Center's Fault Information System

    NASA Astrophysics Data System (ADS)

    Perry, S.

    2003-12-01

    The Southern California Earthquake Center's Fault Information System (FIS) provides a single point of access to fault-related data and models from multiple databases and datasets. The FIS is built of computer code, metadata and Web interfaces based on Web services technology, which enables queries and data interchange irrespective of computer software or platform. Currently we have working prototypes of programmatic and browser-based access. The first generation FIS may be searched and downloaded live, by automated processes, as well as interactively, by humans using a browser. Users get ascii data in plain text or encoded in XML. Via the Earthquake Information Technology (EIT) Interns (Juve and others, this meeting), we are also testing the effectiveness of querying multiple databases using a fault database ontology. For more than a decade, the California Geological Survey (CGS), SCEC, and the U. S. Geological Survey (USGS) have put considerable, shared resources into compiling and assessing published fault data, then providing the data on the Web. Several databases now exist, with different formats, datasets, purposes, and users, in various stages of completion. When fault databases were first envisioned, the full power of today's internet was not yet recognized, and the databases became the Web equivalents of review papers, where one could read an overview summation of a fault, then copy and paste pertinent data. Today, numerous researchers also require rapid queries and downloads of data. Consequently, the first components of the FIS are MySQL databases that deliver numeric values from earlier, text-based databases. Another essential service provided by the FIS is visualizations of fault representations such as those in SCEC's Community Fault Model. The long term goal is to provide a standardized, open-source, platform-independent visualization technique. Currently, the FIS makes available fault model viewing software for users with access to Matlab or Java3D

  12. Application of information technology within a field hospital deployment following the January 2010 Haiti earthquake disaster.

    PubMed

    Levy, Gad; Blumberg, Nehemia; Kreiss, Yitshak; Ash, Nachman; Merin, Ofer

    2010-01-01

    Following the January 2010 earthquake in Haiti, the Israel Defense Force Medical Corps dispatched a field hospital unit. A specially tailored information technology solution was deployed within the hospital. The solution included a hospital administration system as well as a complete electronic medical record. A light-weight picture archiving and communication system was also deployed. During 10 days of operation, the system registered 1111 patients. The network and system up times were more than 99.9%. Patient movements within the hospital were noted, and an online command dashboard screen was generated. Patient care was delivered using the electronic medical record. Digital radiographs were acquired and transmitted to stations throughout the hospital. The system helped to introduce order in an otherwise chaotic situation and enabled adequate utilization of scarce medical resources by continually gathering information, analyzing it, and presenting it to the decision-making command level. The establishment of electronic medical records promoted the adequacy of medical treatment and facilitated continuity of care. This experience in Haiti supports the feasibility of deploying information technologies within a field hospital operation. Disaster response teams and agencies are encouraged to consider the use of information technology as part of their contingency plans.

  13. Application of information technology within a field hospital deployment following the January 2010 Haiti earthquake disaster

    PubMed Central

    Blumberg, Nehemia; Kreiss, Yitshak; Ash, Nachman; Merin, Ofer

    2010-01-01

    Following the January 2010 earthquake in Haiti, the Israel Defense Force Medical Corps dispatched a field hospital unit. A specially tailored information technology solution was deployed within the hospital. The solution included a hospital administration system as well as a complete electronic medical record. A light-weight picture archiving and communication system was also deployed. During 10 days of operation, the system registered 1111 patients. The network and system up times were more than 99.9%. Patient movements within the hospital were noted, and an online command dashboard screen was generated. Patient care was delivered using the electronic medical record. Digital radiographs were acquired and transmitted to stations throughout the hospital. The system helped to introduce order in an otherwise chaotic situation and enabled adequate utilization of scarce medical resources by continually gathering information, analyzing it, and presenting it to the decision-making command level. The establishment of electronic medical records promoted the adequacy of medical treatment and facilitated continuity of care. This experience in Haiti supports the feasibility of deploying information technologies within a field hospital operation. Disaster response teams and agencies are encouraged to consider the use of information technology as part of their contingency plans. PMID:20962123

  14. Application of 3D WebGIS and real-time technique in earthquake information publishing and visualization

    NASA Astrophysics Data System (ADS)

    Li, Boren; Wu, Jianping; Pan, Mao; Huang, Jing

    2015-06-01

    In hazard management, earthquake researchers have utilized GIS to ease the process of managing disasters. Researchers use WebGIS to assess hazards and seismic risk. Although they can provide a visual analysis platform based on GIS technology, they lack a general description in the extensibility of WebGIS for processing dynamic data, especially real-time data. In this paper, we propose a novel approach for real-time 3D visual earthquake information publishing model based on WebGIS and digital globe to improve the ability of processing real-time data in systems based on WebGIS. On the basis of the model, we implement a real-time 3D earthquake information publishing system—EqMap3D. The system can not only publish real-time earthquake information but also display these data and their background geoscience information in a 3D scene. It provides a powerful tool for display, analysis, and decision-making for researchers and administrators. It also facilitates better communication between researchers engaged in geosciences and the interested public.

  15. Minority Women's Health: American Indians/Alaska Natives

    MedlinePlus

    ... Minority Women's Health > American Indians/Alaska Natives Minority Women's Health American Indians/Alaska Natives Related information How ... conditions common in American Indian and Alaska Native women Accidents Alcoholism and drug abuse Breast cancer Cancer ...

  16. Alaska's Children, 1998. Alaska Head Start State Collaboration Project, Quarterly Report.

    ERIC Educational Resources Information Center

    Douglas, Dorothy, Ed.

    1998-01-01

    This document consists of four issues of the quarterly report "Alaska's Children," which provides information on the Alaska Head Start State Collaboration Project and updates on Head Start activities in Alaska. Regular features in the issues include a calendar of conferences and meetings, a status report on Alaska's children, reports…

  17. The Alaska Mineral Resource Assessment Program; background information to accompany geologic and mineral-resource maps of the Cordova and Middleton Island quadrangles, southern Alaska

    USGS Publications Warehouse

    Winkler, Gary R.; Plafker, George; Goldfarb, R.J.; Case, J.E.

    1992-01-01

    report summarizes recent results of integrated geological, geochemical, and geophysical field and laboratory studies conducted by the U.S. Geological Survey in the Cordova and Middleton Island 1?x3 ? quadrangles of coastal southern Alaska. Published open-file reports and maps accompanied by descriptive and interpretative texts, tables, diagrams, and pertinent references provide background information for a mineral-resource assessment of the two quadrangles. Mines in the Cordova and Middleton Island quadrangles produced copper and byproduct gold and silver in the first three decades of the 20th century. The quadrangles may contain potentially significant undiscovered resources of precious and base metals (gold, silver, copper, zinc, and lead) in veins and massive sulfide deposits hosted by Cretaceous and Paleogene sedimentary and volcanic rocks. Resources of manganese also may be present in the Paleogene rocks; uranium resources may be present in Eocene granitic rocks; and placer gold may be present in beach sands near the mouth of the Copper River, in alluvial sands within the canyons of the Copper River, and in smaller alluvial deposits underlain by rocks of the Valdez Group. Significant coal resources are present in the Bering River area, but difficult access and structural complexities have discouraged development. Investigation of numerous oil and gas seeps near Katalla in the eastern part of the area led to the discovery of a small, shallow field from which oil was produced between 1902 and 1933. The field has been inactive since, and subsequent exploration and drilling onshore near Katalla in the 1960's and offshore near Middleton Island on the outer continental shelf in the 1970's and 1980's was not successful.

  18. Speeding earthquake disaster relief

    USGS Publications Warehouse

    Mortensen, Carl; Donlin, Carolyn; Page, Robert A.; Ward, Peter

    1995-01-01

    In coping with recent multibillion-dollar earthquake disasters, scientists and emergency managers have found new ways to speed and improve relief efforts. This progress is founded on the rapid availability of earthquake information from seismograph networks.

  19. Earthquake information products and tools from the Advanced National Seismic System (ANSS)

    USGS Publications Warehouse

    Wald, Lisa

    2006-01-01

    This Fact Sheet provides a brief description of postearthquake tools and products provided by the Advanced National Seismic System (ANSS) through the U.S. Geological Survey Earthquake Hazards Program. The focus is on products specifically aimed at providing situational awareness in the period immediately following significant earthquake events.

  20. GeoFORCE Alaska, A Successful Summer Exploring Alaska's Geology

    NASA Astrophysics Data System (ADS)

    Wartes, D.

    2012-12-01

    Thirty years old this summer, RAHI, the Rural Alaska Honors Institute is a statewide, six-week, summer college-preparatory bridge program at the University of Alaska Fairbanks for Alaska Native and rural high school juniors and seniors. This summer, in collaboration with the University of Texas Austin, the Rural Alaska Honors Institute launched a new program, GeoFORCE Alaska. This outreach initiative is designed to increase the number and diversity of students pursuing STEM degree programs and entering the future high-tech workforce. It uses Earth science to entice kids to get excited about dinosaurs, volcanoes and earthquakes, and includes physics, chemistry, math, biology and other sciences. Students were recruited from the Alaska's Arctic North Slope schools, in 8th grade to begin the annual program of approximately 8 days, the summer before their 9th grade year and then remain in the program for all four years of high school. They must maintain a B or better grade average and participate in all GeoFORCE events. The culmination is an exciting field event each summer. Over the four-year period, events will include trips to Fairbanks and Anchorage, Arizona, Oregon and the Appalachians. All trips focus on Earth science and include a 100+ page guidebook, with tests every night culminating with a final exam. GeoFORCE Alaska was begun by the University of Alaska Fairbanks in partnership with the University of Texas at Austin, which has had tremendous success with GeoFORCE Texas. GeoFORCE Alaska is managed by UAF's long-standing Rural Alaska Honors Institute, that has been successfully providing intense STEM educational opportunities for Alaskan high school students for over 30 years. The program will add a new cohort of 9th graders each year for the next four years. By the summer of 2015, GeoFORCE Alaska is targeting a capacity of 160 students in grades 9th through 12th. Join us to find out more about this exciting new initiative, which is enticing young Alaska Native

  1. The 7.9 Denali Fault Earthquake: Damage to Structures and Lifelines

    NASA Astrophysics Data System (ADS)

    Cox, T.; Hreinsdöttir, S.; Larsen, C.; Estes, S.

    2002-12-01

    In the early afternoon of Sunday, November 3rd, the residents of many interior Alaska towns were shaken up by a magnitude 7.9 earthquake. The shaking lasted an average of three minutes and when it stopped, nearly 300 km of the Denali Fault had ruptured. In the hours that followed, the Alaska Earthquake Information Center (AEIC) fielded reports of structural damage from Cantwell to Tok and other earthquake effects as far away as Louisiana. Upon investigation, the most severe effects were found in the village of Mentasta where basic utilities were interrupted and the school and several houses suffered major damage. Almost 3000 reports submitted to a community internet intensity map show a maximum Mercalli intensity VIII along the eastern end of the rupture area. The Richardson and Parks Highways, two main north-south thoroughfares in Alaska, both buckled and split as a result of the fault rupture. Traffic was stopped for a few hours while repairs were made. Between the Richardson Highway the Tok Cutoff, a section of the Glenn Highway that connects Tok and Glennallen, the maximum offsets on the Denali Fault were observed. Designed to withstand a magnitude 8.5 earthquake at the Denali Fault crossing, the 800-mile long Trans-Alaska Pipeline suffered relatively minor damage. According to Alyeska Pipeline Service Company press releases, the pipeline was shut down shortly after the earthquake occurred. Repairs to pipeline supports and engineering evaluations began immediately thereafter, and oil began flowing through the pipeline Thursday, November 7th . Through it all, the AEIC has collected and archived many photographs, emails, and eyewitness accounts of those who experienced the destruction firsthand. We will detail the effects that the M7.9 Denali Fault earthquake had from near and far.

  2. Digital Dead Ends along Alaska's Information Highway: Broadband Access for Students and Teachers in Alaska's High School One-to-One Laptop Programs

    ERIC Educational Resources Information Center

    Lloyd, Pamela Jo

    2012-01-01

    This dissertation analyzes the potential impact community broadband availability has on personal and classroom levels of technology adoption for high school students and teachers in Alaska. Community broadband availability was defined as, (a) terrestrial broadband availability; (b) satellite broadband availability; and (c) no broadband available.…

  3. U.S. Tsunami Information technology (TIM) Modernization:Developing a Maintainable and Extensible Open Source Earthquake and Tsunami Warning System

    NASA Astrophysics Data System (ADS)

    Hellman, S. B.; Lisowski, S.; Baker, B.; Hagerty, M.; Lomax, A.; Leifer, J. M.; Thies, D. A.; Schnackenberg, A.; Barrows, J.

    2015-12-01

    Tsunami Information technology Modernization (TIM) is a National Oceanic and Atmospheric Administration (NOAA) project to update and standardize the earthquake and tsunami monitoring systems currently employed at the U.S. Tsunami Warning Centers in Ewa Beach, Hawaii (PTWC) and Palmer, Alaska (NTWC). While this project was funded by NOAA to solve a specific problem, the requirements that the delivered system be both open source and easily maintainable have resulted in the creation of a variety of open source (OS) software packages. The open source software is now complete and this is a presentation of the OS Software that has been funded by NOAA for benefit of the entire seismic community. The design architecture comprises three distinct components: (1) The user interface, (2) The real-time data acquisition and processing system and (3) The scientific algorithm library. The system follows a modular design with loose coupling between components. We now identify the major project constituents. The user interface, CAVE, is written in Java and is compatible with the existing National Weather Service (NWS) open source graphical system AWIPS. The selected real-time seismic acquisition and processing system is open source SeisComp3 (sc3). The seismic library (libseismic) contains numerous custom written and wrapped open source seismic algorithms (e.g., ML/mb/Ms/Mwp, mantle magnitude (Mm), w-phase moment tensor, bodywave moment tensor, finite-fault inversion, array processing). The seismic library is organized in a way (function naming and usage) that will be familiar to users of Matlab. The seismic library extends sc3 so that it can be called by the real-time system, but it can also be driven and tested outside of sc3, for example, by ObsPy or Earthworm. To unify the three principal components we have developed a flexible and lightweight communication layer called SeismoEdex.

  4. UAFSmoke Modeling in Alaska

    NASA Astrophysics Data System (ADS)

    Stuefer, M.; Grell, G.; Freitas, S.; Newby, G.

    2008-12-01

    Alaska wildfires have strong impact on air pollution on regional Arctic, Sub-Arctic and even hemispheric scales. In response to a high number of wildfires in Alaska, emphasis has been placed on developing a forecast system for wildfire smoke dispersion in Alaska. We have developed a University of Alaska Fairbanks WRF/Chem smoke (UAFSmoke) dispersion system, which has been adapted and initialized with source data suitable for Alaska. UAFSmoke system modules include detection of wildfire location and area using Alaska Fire Service information and satellite remote sensing data from the MODIS instrument. The fire emissions are derived from above ground biomass fuel load data in one-kilometer resolution. WRF/Chem Version 3 with online chemistry and online plume dynamics represents the core of the UAFSmoke system. Besides wildfire emissions and NOAA's Global Forecast System meteorology, WRF/Chem initial and boundary conditions are updated with anthropogenic and sea salt emission data from the Georgia Institute of Technology-Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) Model. System runs are performed at the Arctic Region Supercomputing Center's Sun Opteron cluster "Midnight". During the 2008 fire season once daily UAFSmoke runs were presented at a dedicated webpage at http://smoke.arsc.edu. We present examples from these routine runs and from the extreme 2004 Alaska wildfire season.

  5. Can We Predict Earthquakes?

    SciTech Connect

    Johnson, Paul

    2016-08-31

    The only thing we know for sure about earthquakes is that one will happen again very soon. Earthquakes pose a vital yet puzzling set of research questions that have confounded scientists for decades, but new ways of looking at seismic information and innovative laboratory experiments are offering tantalizing clues to what triggers earthquakes — and when.

  6. Can We Predict Earthquakes?

    ScienceCinema

    Johnson, Paul

    2016-09-09

    The only thing we know for sure about earthquakes is that one will happen again very soon. Earthquakes pose a vital yet puzzling set of research questions that have confounded scientists for decades, but new ways of looking at seismic information and innovative laboratory experiments are offering tantalizing clues to what triggers earthquakes — and when.

  7. Multiple seismogenic processes for high-frequency earthquakes at Katmai National Park, Alaska: Evidence from stress tensor inversions of fault-plane solutions

    USGS Publications Warehouse

    Moran, S.C.

    2003-01-01

    The volcanological significance of seismicity within Katmai National Park has been debated since the first seismograph was installed in 1963, in part because Katmai seismicity consists almost entirely of high-frequency earthquakes that can be caused by a wide range of processes. I investigate this issue by determining 140 well-constrained first-motion fault-plane solutions for shallow (depth < 9 km) earthquakes occuring between 1995 and 2001 and inverting these solutions for the stress tensor in different regions within the park. Earthquakes removed by several kilometers from the volcanic axis occur in a stress field characterized by horizontally oriented ??1 and ??3 axes, with ??1 rotated slightly (12??) relative to the NUVELIA subduction vector, indicating that these earthquakes are occurring in response to regional tectonic forces. On the other hand, stress tensors for earthquake clusters beneath several Katmai cluster volcanoes have vertically oriented ??1 axes, indicating that these events are occuring in response to local, not regional, processes. At Martin-Mageik, vertically oriented ??1 is most consistent with failure under edifice loading conditions in conjunction with localized pore pressure increases associated with hydrothermal circulation cells. At Trident-Novarupta, it is consistent with a number of possible models, including occurence along fractures formed during the 1912 eruption that now serve as horizontal conduits for migrating fluids and/or volatiles from nearby degassing and cooling magma bodies. At Mount Katmai, it is most consistent with continued seismicity along ring-fracture systems created in the 1912 eruption, perhaps enhanced by circulating hydrothermal fluids and/or seepage from the caldera-filling lake.

  8. Tracking Earthquake Cascades

    NASA Astrophysics Data System (ADS)

    Jordan, T. H.

    2011-12-01

    In assessing their risk to society, earthquakes are best characterized as cascades that can propagate from the natural environment into the socio-economic (built) environment. Strong earthquakes rarely occur as isolated events; they usually cluster in foreshock-mainshock-aftershock sequences, seismic swarms, and extended sequences of large earthquakes that propagate along major fault systems. These cascades are regulated by stress-mediated interactions among faults driven by tectonic loading. Within these cascades, each large event can itself cause a chain reaction in which the primary effects of faulting and ground shaking induce secondary effects, including tsunami, landslides, liquefaction, and set off destructive processes within the built environment, such as fires and radiation leakage from nuclear plants. Recent earthquakes have demonstrated how the socio-economic effects of large earthquakes can reverberate for many years. To reduce earthquake risk and improve the resiliency of communities to earthquake damage, society depends on five geotechnologies for tracking earthquake cascades: long-term probabilistic seismic hazard analysis (PSHA), short-term (operational) earthquake forecasting, earthquake early warning, tsunami warning, and the rapid production of post-event information for response and recovery (see figure). In this presentation, I describe how recent advances in earthquake system science are leading to improvements in this geotechnology pipeline. In particular, I will highlight the role of earthquake simulations in predicting strong ground motions and their secondary effects before and during earthquake cascades

  9. Trends in Alaska's People and Economy.

    ERIC Educational Resources Information Center

    Leask, Linda; Killorin, Mary; Martin, Stephanie

    This booklet provides data on Alaska's population, economy, health, education, government, and natural resources, including specific information on Alaska Natives. Since 1960, Alaska's population has tripled and become more diverse, more stable, older, less likely to be male or married, and more concentrated. About 69 percent of the population…

  10. The Alaska Mineral Resource Assessment Program; guide to information contained in the folio of geologic and mineral-resource maps of the Medfra Quadrangle, Alaska

    USGS Publications Warehouse

    Patton, William Wallace; Moll, E.J.; King, Harley D.

    1984-01-01

    The Medfra quadrangle in west-central Alaska was investigated by a multidisciplinary team of geoscientists to assess its mineral resources. This Circular is intended to serve as a guide to a folio of 13 separate Open-File Reports covering various aspects of these investigations, including geology, bedrock and stream-sediment geochemistry, potassium-argon dating, Landsat imagery, mineral occurrences, aeromagnetic interpretation, and mineral-resource assessment. This Circular presents a complete reference list of these reports and a summary of the important results of each of the investigations.

  11. 76 FR 35462 - Proposed Renewal of Information Collection; Source Directory of American Indian and Alaska Native...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-17

    ... 1085-0001. FOR FURTHER INFORMATION CONTACT: Requests for additional information or copies of the Source... Crafts Board uses this information collected in information collection 1085-0001 to determine whether an... Number: 1085-0001. ] Type of Review: Renewal of an existing collection. Affected Entities: Business...

  12. Alaska Resource Data File, Nabesna quadrangle, Alaska

    USGS Publications Warehouse

    Hudson, Travis L.

    2003-01-01

    Descriptions of the mineral occurrences shown on the accompanying figure follow. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

  13. Alaska Resource Data File, Wiseman quadrangle, Alaska

    USGS Publications Warehouse

    Britton, Joe M.

    2003-01-01

    Descriptions of the mineral occurrences shown on the accompanying figure follow. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

  14. Alaska Resource Data File, Juneau quadrangle, Alaska

    USGS Publications Warehouse

    Barnett, John C.; Miller, Lance D.

    2003-01-01

    Descriptions of the mineral occurrences shown on the accompanying figure follow. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

  15. IMPROVING SCIENCE EDUCATION AND CAREER OPPORTUNITIES IN RURAL ALASKA:The Synergistic Connection between Educational Outreach Efforts in the Copper Valley, Alaska.

    NASA Astrophysics Data System (ADS)

    Solie, D. J.; McCarthy, S.

    2004-12-01

    four times a year. Even though the in-class time per year is not large, our experience suggests that a long term, multi-year connection enhances learning by the students. We coordinate with HAARP research campaigns so as to utilize the availability of top scientists for public lectures. We do not limit our scope to only ionospheric physics, but try to meet the demands and needs of the region as they arise. Less than two weeks after the November, 2002 Denali Fault Earthquake, we traveled to the villages most strongly effected by the quake and presented basic preliminary information about the quake (Sources: Alaska Earthquake Information Center, Alaska State Geological Survey & USGS). As a teachable moment it was unparalleled, but it was also an example of where even preliminary information on an event can truly help to calm people.

  16. 77 FR 65903 - Agency Information Collection Activities: Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-31

    ... earthquake hazard assessments and earthquake occurrence under the Earthquake Hazards Reduction Act of 1977..., Earthquake Hazards Program, (703) 648-6716. SUPPLEMENTARY INFORMATION: Title: Earthquake Hazards Program... under the Earthquake Hazards Reduction Act to develop earthquake hazard assessments and recording...

  17. Investigating the Tsunamigenic Potential of Earthquakes from Analysis of the Informational and Multifractal Properties of Seismograms

    NASA Astrophysics Data System (ADS)

    Telesca, Luciano; Chamoli, Ashutosh; Lovallo, Michele; Stabile, Tony Alfredo

    2015-07-01

    Revealing the tsunamigenic potential of an earthquake is very challenging in regards to minimizing the casualties a tsunami can provoke. Thus, development of methodologies that can reliably furnish a early warnings of a tsunami is crucial. In order to accomplish this aim it is important to preliminarily identify the characteristics of seismograms that can be used to distinguish tsunamigenic (TS) earthquakes from non-tsunamigenic (NTS) earthquakes. In this paper P-wave time dynamic of 17 seismograms of TS earthquakes and 26 NTS seismograms are analysed by means of two advanced statistical tools: the Fisher-Shannon method and the multifractal detrended fluctuation analysis (MFDFA). Both methods are well suited to disclosing the inner time properties of complex signals, as seismograms appear to be. Using these two methods jointly, we defined a classifier, the performance of which was tested by means of the receiver-operating characteristic curve that plots true positive rate versus false positive rate. This classifier shows a discrimination power that can be considered acceptable in comparison with the devastating effects caused by a non-alarmed tsunami. Our findings indicate that proper choice of the classifier's threshold allows correctly identification of approximately 69 % of the NTS seismograms and approximately 76 % of the TS seismograms. The presented results presented may be helpful in addressing the complex problem of early tsunami warning.

  18. The Earthquake Information Test: Validating an Instrument for Determining Student Misconceptions.

    ERIC Educational Resources Information Center

    Ross, Katharyn E. K.; Shuell, Thomas J.

    Some pre-instructional misconceptions held by children can persist through scientific instruction and resist changes. Identifying these misconceptions would be beneficial for science instruction. In this preliminary study, scores on a 60-item true-false test of knowledge and misconceptions about earthquakes were compared with previous interview…

  19. Using ShakeMap to Improve Awareness of Seismic Hazard and Risk in Alaska

    NASA Astrophysics Data System (ADS)

    Gardine, M.; West, M. E.; Ruppert, N.

    2014-12-01

    As part of the Alaska Earthquake Center's effort to create customized and relevant products to diverse Alaskan communities, we have embarked on a process to take results from ShakeMap and tailor them to state needs. We have created customized ShakeMaps, produced shaking estimates for small communities that may not be obvious on large-scale maps, and greatly expanded a suite of earthquake scenarios throughout the state for use in hazard assessment and disaster preparation. These efforts have the combined goal helping Alaskans better prepare for the possibility of a damaging earthquake in their community. ShakeMap is a well-regarded system created by the U.S. Geological Survey (USGS) to produce maps of measured and predicted ground-motions for real and scenario earthquakes; many seismic networks throughout the world use it operationally. The Earthquake Center routinely uses ShakeMap to provide general information about recent earthquakes to stakeholders and the public. Customized ShakeMaps are produced for notable earthquakes near the Trans-Alaska Pipeline and made available to Alyeska, the pipeline operator. These ShakeMaps are part of a larger system to alert Alyeska of any strong motions that could cause damage to the pipeline infrastructure to help minimize economic and environmental issues. However, despite being the most seismically active state in the United States, limited work has been done to assess possible earthquake scenarios in much of the state and even fewer of the end products are known to residents, many of whom live in small towns and villages, isolated both in distance and in infrastructure from the rest of the population. ShakeMap scenarios are visual representations of earthquake data that have tremendous outreach value as a stand-alone product. For many of the scenarios, we have used earthquake parameters pulled from the numerous notable earthquakes in the history of the state, from the well-known (2004 M7.9 Denali Fault, 1964 M9.2 Good Friday

  20. Shrinking Sea Ice, Thawing Permafrost, Bigger Storms, and Extremely Limited Data - Addressing Information Needs of Stakeholders in Western Alaska Through Participatory Decisions and Collaborative Science.

    NASA Astrophysics Data System (ADS)

    Murphy, K. A.; Reynolds, J.

    2015-12-01

    Communities, Tribes, and decision makers in coastal western Alaska are being impacted by declining sea ice, sea level rise, changing storm patterns and intensities, and increased rates of coastal erosion. Relative to their counterparts in the contiguous USA, their ability to plan for and respond to these changes is constrained by the region's generally meager or non-existent information base. Further, the information needs and logistic challenges are of a scale that perhaps can be addressed only through strong, strategic collaboration. Landscape Conservation Cooperatives (LCCs) are fundamentally about applied science and collaboration, especially collaborative decision making. The Western Alaska LCC has established a process of participatory decision making that brings together researchers, agency managers, local experts from Tribes and field specialists to identify and prioritize shared information needs; develop a course of action to address them by using the LCC's limited resources to catalyze engagement, overcome barriers to progress, and build momentum; then ensure products are delivered in a manner that meets decision makers' needs. We briefly review the LCC's activities & outcomes from the stages of (i) collaborative needs assessment (joint with the Alaska Climate Science Center and the Alaska Ocean Observing System), (ii) strategic science activities, and (iii) product refinement and delivery. We discuss lessons learned, in the context of our recent program focused on 'Changes in Coastal Storms and Their Impacts' and current collaborative efforts focused on delivery of Coastal Resiliency planning tools and results from applied science projects. Emphasis is given to the various key interactions between scientists and decision makers / managers that have been promoted by this process to ensure alignment of final products to decision maker needs.

  1. Comprehensive Seismic Monitoring for Emergency Response and Hazards Assessment: Recent Developments at the USGS National Earthquake Information Center

    NASA Astrophysics Data System (ADS)

    Buland, R. P.; Guy, M.; Kragness, D.; Patton, J.; Erickson, B.; Morrison, M.; Bryon, C.; Ketchum, D.; Benz, H.

    2009-12-01

    The USGS National Earthquake Information Center (NEIC) has put into operation a new generation of seismic acquisition, processing and distribution subsystems that seamlessly integrate regional, national and global seismic network data for routine monitoring of earthquake activity and response to large, damaging earthquakes. The system, Bulletin Hydra, was designed to meet Advanced National Seismic System (ANSS) design goals to handle thousands of channels of real-time seismic data, compute and distribute time-critical seismic information for emergency response applications, and manage the integration of contributed earthquake products and information, arriving from near-real-time up to six weeks after an event. Bulletin Hydra is able meet these goals due to a modular, scalable, and flexible architecture that supports on-the-fly consumption of new data, readily allows for the addition of new scientific processing modules, and provides distributed client workflow management displays. Through the Edge subsystem, Bulletin Hydra accepts waveforms in half a dozen formats. In addition, Bulletin Hydra accepts contributed seismic information including hypocenters, magnitudes, moment tensors, unassociated and associated picks, and amplitudes in a variety of formats including earthworm import/export pairs and EIDS. Bulletin Hydra has state-driven algorithms for computing all IASPEI standard magnitudes (e.g. mb, mb_BB, ML, mb_LG, Ms_20, and Ms_BB) as well as Md, Ms(VMAX), moment tensor algorithms for modeling different portions of the wave-field at different distances (e.g. teleseismic body-wave, centroid, and regional moment tensors), and broadband depth. All contributed and derived data are centrally managed in an Oracle database. To improve on single station observations, Bulletin Hydra also does continuous real-time beam forming of high-frequency arrays. Finally, workflow management displays are used to assist NEIC analysts in their day-to-day duties. All combined

  2. 78 FR 40435 - Proposed Information Collection; Comment Request; Gulf of Alaska Trawl Fishery, Rationalization...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-05

    ... achieve the stated objectives. II. Method of Collection Literature reviews, secondary sources including... information as possible. III. Data OMB Control Number: None. Form Number: None. Type of Review:...

  3. Conducting a desk review to inform the mental health and psychosocial support response to the 2016 Ecuador earthquake

    PubMed Central

    Troya, M. Isabela; Greene, M. Claire; Santos, Clara Gesteira; Shultz, James M.

    2016-01-01

    ABSTRACT Following the 7.8 magnitude earthquake that struck Ecuador on 16 April 2016, multiple salient public health concerns were raised, including the need to provide mental health and psychosocial support for individual survivors and their communities. The World Health Organization and the United Nations High Commissioner for Refugees recommend conducting a desk review to summarize existing information, specific to the affected communities, that will support timely, culturally-attuned assessment and delivery of mental health and psychosocial support shortly after the onset of a disaster or humanitarian emergency. The desk review is one component of a comprehensive toolkit designed to inform and support humanitarian actors and their responders in the field. This commentary provides a case example of the development of a desk review that was used to inform personnel responding to the 2016 earthquake in Ecuador. The desk review process is described in addition to several innovations that were introduced to the process during this iteration. Strengths and limitations are discussed, as well as lessons learned and recommendations for future applications. PMID:28265485

  4. Conducting a desk review to inform the mental health and psychosocial support response to the 2016 Ecuador earthquake.

    PubMed

    Troya, M Isabela; Greene, M Claire; Santos, Clara Gesteira; Shultz, James M

    2016-01-01

    Following the 7.8 magnitude earthquake that struck Ecuador on 16 April 2016, multiple salient public health concerns were raised, including the need to provide mental health and psychosocial support for individual survivors and their communities. The World Health Organization and the United Nations High Commissioner for Refugees recommend conducting a desk review to summarize existing information, specific to the affected communities, that will support timely, culturally-attuned assessment and delivery of mental health and psychosocial support shortly after the onset of a disaster or humanitarian emergency. The desk review is one component of a comprehensive toolkit designed to inform and support humanitarian actors and their responders in the field. This commentary provides a case example of the development of a desk review that was used to inform personnel responding to the 2016 earthquake in Ecuador. The desk review process is described in addition to several innovations that were introduced to the process during this iteration. Strengths and limitations are discussed, as well as lessons learned and recommendations for future applications.

  5. 77 FR 50712 - Information Collection: Southern Alaska Sharing Network and Subsistence Study; Proposed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-22

    ... responsibilities of research. This study will facilitate the meeting of DOI/BOEM information needs on subsistence... will use the information collected to gain knowledge about local social systems that will help shape... collection will be obtained through personal interviews that are voluntary. Interview Methods: The...

  6. A lake-centric geospatial database to guide research and inform management decisions in an Arctic watershed in northern Alaska experiencing climate and land-use changes.

    PubMed

    Jones, Benjamin M; Arp, Christopher D; Whitman, Matthew S; Nigro, Debora; Nitze, Ingmar; Beaver, John; Gädeke, Anne; Zuck, Callie; Liljedahl, Anna; Daanen, Ronald; Torvinen, Eric; Fritz, Stacey; Grosse, Guido

    2017-03-25

    Lakes are dominant and diverse landscape features in the Arctic, but conventional land cover classification schemes typically map them as a single uniform class. Here, we present a detailed lake-centric geospatial database for an Arctic watershed in northern Alaska. We developed a GIS dataset consisting of 4362 lakes that provides information on lake morphometry, hydrologic connectivity, surface area dynamics, surrounding terrestrial ecotypes, and other important conditions describing Arctic lakes. Analyzing the geospatial database relative to fish and bird survey data shows relations to lake depth and hydrologic connectivity, which are being used to guide research and aid in the management of aquatic resources in the National Petroleum Reserve in Alaska. Further development of similar geospatial databases is needed to better understand and plan for the impacts of ongoing climate and land-use changes occurring across lake-rich landscapes in the Arctic.

  7. UNIT, ALASKA.

    ERIC Educational Resources Information Center

    Louisiana Arts and Science Center, Baton Rouge.

    THE UNIT DESCRIBED IN THIS BOOKLET DEALS WITH THE GEOGRAPHY OF ALASKA. THE UNIT IS PRESENTED IN OUTLINE FORM. THE FIRST SECTION DEALS PRINCIPALLY WITH THE PHYSICAL GEOGRAPHY OF ALASKA. DISCUSSED ARE (1) THE SIZE, (2) THE MAJOR LAND REGIONS, (3) THE MOUNTAINS, VOLCANOES, GLACIERS, AND RIVERS, (4) THE NATURAL RESOURCES, AND (5) THE CLIMATE. THE…

  8. Reviewing information support during the Great East Japan Earthquake disaster : From the perspective of a hospital library that received support

    NASA Astrophysics Data System (ADS)

    Terasawa, Motoko

    The Great East Japan Earthquake of March 11, 2011 caused extensive damage over a widespread area. Our hospital library, which is located in the affected area, was no exception. A large collection of books was lost, and some web content was inaccessible due to damage to the network environment. This greatly hindered our efforts to continue providing post-disaster medical information services. Information support, such as free access to databases, journals, and other online content related to the disaster areas, helped us immensely during this time. We were fortunate to have the cooperation of various medical employees and library members via social networks, such as twitter, during the process of attaining this information support.

  9. The Apparent Periodicity of Felt Reports in the Alaskan Earthquake Record

    NASA Astrophysics Data System (ADS)

    Hafner, L. A.; McNutt, S. R.

    2004-12-01

    Felt reports for Alaskan earthquakes were found to be non-uniformly distributed throughout the year. With a predominantly tourist economy, the Alaskan population nearly triples in the summer months, possibly affecting the reporting of earthquakes in the historical record. Using published felt reports from the National Earthquake Information Center and the Alaska Earthquake Information Center, the percentage of events felt each month in central mainland Alaska were tabulated and compared between the summer and winter seasons. Earthquakes were selected from January 1, 1990 to October 31, 2002, from latitudes 58 to 70 degrees N and longitudes 140 to 160 degrees W, and depths 0 to 200 km. 408 events were felt out of a total of 695 that occurred. A number of parameters, including time of day, latitude, longitude, and magnitude, were additionally compared to specify possible limiting factors within each season. While a strong seasonal effect was not found in magnitude 4.0 ML events and greater, the months of May and June were consistently found to have the highest percentage of felt events with a steep drop occurring in the month of July. We ascribe this effect to the summer melting of the top layer of frozen ground to a depth of about 1.5 meters. Additionally, smaller events from magnitude 1.0 to 4.0 ML were also examined. 396 events were felt out of a total of 7,451 that occurred. We found that small earthquakes were felt, with a significant difference, more readily during summer months than in winter. This is likely an effect of the higher summer population of tourists and greater distribution of open businesses. Together these observations suggest that the historical Alaskan earthquake record is likely biased in favor of more frequent reporting of events occurring in summer months as opposed to winter.

  10. Selected 1970 Census Data for Alaska Communities. Part 2 - Northwest Alaska.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Community and Regional Affairs, Juneau. Div. of Community Planning.

    As 1 of 6 regional reports supplying statistical information on Alaska's incorporated and unincorporated communities (those of 25 or more people), this report on Northwest Alaska presents data derived from the 1970 U.S. Census first-count microfilm. Organized via the 3 Northwest Alaska census division, data are presented for the 32 communities of…

  11. Evidence for shallow megathrust slip across the Unalaska seismic gap during the great 1957 Andreanof Islands earthquake, eastern Aleutian Islands, Alaska

    USGS Publications Warehouse

    Nicolsky, D. J.; Freymueller, J.T.; Witter, R.C.; Suleimani, E. N.; Koehler, R.D.

    2016-01-01

    We reassess the slip distribution of the 1957 Andreanof Islands earthquake in the eastern part of the aftershock zone where published slip models infer little or no slip. Eyewitness reports, tide gauge data, and geological evidence for 9–23 m tsunami runups imply seafloor deformation offshore Unalaska Island in 1957, in contrast with previous studies that labeled the area a seismic gap. Here, we simulate tsunami dynamics for a suite of deformation models that vary in depth and amount of megathrust slip. Tsunami simulations show that a shallow (5–15 km deep) rupture with ~20 m of slip most closely reproduces the 1957 Dutch Harbor marigram and nearby >18 m runup at Sedanka Island marked by stranded drift logs. Models that place slip >20 km predict waves that arrive too soon. Our results imply that shallow slip on the megathrust in 1957 extended east into an area that presently creeps.

  12. Evidence for shallow megathrust slip across the Unalaska seismic gap during the great 1957 Andreanof Islands earthquake, eastern Aleutian Islands, Alaska

    NASA Astrophysics Data System (ADS)

    Nicolsky, D. J.; Freymueller, J. T.; Witter, R. C.; Suleimani, E. N.; Koehler, R. D.

    2016-10-01

    We reassess the slip distribution of the 1957 Andreanof Islands earthquake in the eastern part of the aftershock zone where published slip models infer little or no slip. Eyewitness reports, tide gauge data, and geological evidence for 9-23 m tsunami runups imply seafloor deformation offshore Unalaska Island in 1957, in contrast with previous studies that labeled the area a seismic gap. Here we simulate tsunami dynamics for a suite of deformation models that vary in depth and amount of megathrust slip. Tsunami simulations show that a shallow (5-15 km deep) rupture with 20 m of slip most closely reproduces the 1957 Dutch Harbor marigram and nearby >18 m runup at Sedanka Island marked by stranded drift logs. Slip models >20 km deep predict waves that arrive too soon. Our results imply that shallow slip on the megathrust in 1957 extended east into an area that presently creeps.

  13. Operational earthquake forecasting can enhance earthquake preparedness

    USGS Publications Warehouse

    Jordan, T.H.; Marzocchi, W.; Michael, A.J.; Gerstenberger, M.C.

    2014-01-01

    We cannot yet predict large earthquakes in the short term with much reliability and skill, but the strong clustering exhibited in seismic sequences tells us that earthquake probabilities are not constant in time; they generally rise and fall over periods of days to years in correlation with nearby seismic activity. Operational earthquake forecasting (OEF) is the dissemination of authoritative information about these time‐dependent probabilities to help communities prepare for potentially destructive earthquakes. The goal of OEF is to inform the decisions that people and organizations must continually make to mitigate seismic risk and prepare for potentially destructive earthquakes on time scales from days to decades. To fulfill this role, OEF must provide a complete description of the seismic hazard—ground‐motion exceedance probabilities as well as short‐term rupture probabilities—in concert with the long‐term forecasts of probabilistic seismic‐hazard analysis (PSHA).

  14. Alaska Seismic Network Upgrade and Expansion

    NASA Astrophysics Data System (ADS)

    Sandru, J. M.; Hansen, R. A.; Estes, S. A.; Fowler, M.

    2009-12-01

    AEIC (Alaska Earthquake Information Center) has begun the task of upgrading the older regional seismic monitoring sites that have been in place for a number of years. Many of the original sites (some dating to the 1960's) are still single component analog technology. This was a very reasonable and ultra low power reliable system for its day. However with the advanced needs of today's research community, AEIC has begun upgrading to Broadband and Strong Motion Seismometers, 24 bit digitizers and high-speed two-way communications, while still trying to maintain the utmost reliability and maintaining low power consumption. Many sites have been upgraded or will be upgraded from single component to triaxial broad bands and triaxial accerometers. This provided much greater dynamic range over the older antiquated technology. The challenge is compounded by rapidly changing digital technology. Digitizersand data communications based on analog phone lines utilizing 9600 baud modems and RS232 are becoming increasingly difficult to maintain and increasingly expensive compared to current methods that use Ethernet, TCP/IP and UDP connections. Gaining a reliable Internet connection can be as easy as calling up an ISP and having a DSL connection installed or may require installing our own satellite uplink, where other options don't exist. LANs are accomplished with a variety of communications devices such as spread spectrum 900 MHz radios or VHF radios for long troublesome shots. WANs are accomplished with a much wider variety of equipment. Traditional analog phone lines are being used in some instances, however 56K lines are much more desirable. Cellular data links have become a convenient option in semiurban environments where digital cellular coverage is available. Alaska is slightly behind the curve on cellular technology due to its low population density and vast unpopulated areas but has emerged into this new technology in the last few years. Partnerships with organizations

  15. 78 FR 3447 - Information Collection: Southern Alaska Sharing Network and Subsistence Study; Submitted for OMB...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-16

    ... structure contemporary subsistence-cash economies using research methods that involve the residents of these... manages the responsibilities of research. This study will facilitate the meeting of DOI/BOEM information... interim baseline for impact monitoring to compare against future research in these areas. Without...

  16. 78 FR 40103 - Proposed Information Collection; Comment Request; Alaska Region Gear Identification Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-03

    ... Region Gear Identification Requirements AGENCY: National Oceanic and Atmospheric Administration (NOAA... markings. The marking of gear aids law enforcement and enables other fishermen to report on misplaced gear. II. Method of Collection No information is submitted; this is a gear-marking requirement. ] III....

  17. 75 FR 31761 - Proposed Information Collection; Comment Request; Alaska Region Gear Identification Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-04

    ... Region Gear Identification Requirements AGENCY: National Oceanic and Atmospheric Administration (NOAA... also specify the size and color of markings. The marking of gear aids law enforcement and enables other fishermen to report on misplaced gear. II. Method of Collection No information is submitted; this is a...

  18. 78 FR 75365 - 30-Day Notice of Proposed Information Collection: Assessment of Native American, Alaska Native...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-11

    ... URBAN DEVELOPMENT 30-Day Notice of Proposed Information Collection: Assessment of Native American..., Department of Housing and Urban Development, 451 7th Street SW., Washington, DC 20410; email Colette Pollard... Number: 2528-0288. Type of Request: Revision of a currently approved collection. Form Number:...

  19. Real time earthquake information and tsunami estimation system for Indonesia, Philippines and Central-South American regions

    NASA Astrophysics Data System (ADS)

    Pulido Hernandez, N. E.; Inazu, D.; Saito, T.; Senda, J.; Fukuyama, E.; Kumagai, H.

    2015-12-01

    Southeast Asia as well as Central-South American regions are within the most active seismic regions in the world. To contribute to the understanding of source process of earthquakes the National Research Institute for Earth Science and Disaster Prevention NIED maintains the international seismic Network (ISN) since 2007. Continuous seismic waveforms from 294 broadband seismic stations in Indonesia, Philippines, and Central-South America regions are received in real time at NIED, and used for automatic location of seismic events. Using these data we perform automatic and manual estimation of moment tensor of seismic events (Mw>4.5) by using the SWIFT program developed at NIED. We simulate the propagation of local tsunamis in these regions using a tsunami simulation code and visualization system developed at NIED, combined with CMT parameters estimated by SWIFT. The goals of the system are to provide a rapid and reliable earthquake and tsunami information in particular for large seismic, and produce an appropriate database of earthquake source parameters and tsunami simulations for research. The system uses the hypocenter location and magnitude of earthquakes automatically determined at NIED by the SeisComP3 system (GFZ) from the continuous seismic waveforms in the region, to perform the automated calculation of moment tensors by SWIFT, and then carry out the automatic simulation and visualization of tsunami. The system generates maps of maximum tsunami heights within the target regions and along the coasts and display them with the fault model parameters used for tsunami simulations. Tsunami calculations are performed for all events with available automatic SWIFT/CMT solutions. Tsunami calculations are re-computed using SWIFT manual solutions for events with Mw>5.5 and centroid depths shallower than 100 km. Revised maximum tsunami heights as well as animation of tsunami propagation are also calculated and displayed for the two double couple solutions by SWIFT

  20. Alaska Mathematics Standards

    ERIC Educational Resources Information Center

    Alaska Department of Education & Early Development, 2012

    2012-01-01

    High academic standards are an important first step in ensuring that all Alaska's students have the tools they need for success. These standards reflect the collaborative work of Alaskan educators and national experts from the nonprofit National Center for the Improvement of Educational Assessment. Further, they are informed by public comments.…

  1. Alaska Resource Data File: Chignik quadrangle, Alaska

    USGS Publications Warehouse

    Pilcher, Steven H.

    2000-01-01

    Descriptions of the mineral occurrences can be found in the report. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska. There is a website from which you can obtain the data for this report in text and Filemaker Pro formats

  2. Missing great earthquakes

    USGS Publications Warehouse

    Hough, Susan E.

    2013-01-01

    The occurrence of three earthquakes with moment magnitude (Mw) greater than 8.8 and six earthquakes larger than Mw 8.5, since 2004, has raised interest in the long-term global rate of great earthquakes. Past studies have focused on the analysis of earthquakes since 1900, which roughly marks the start of the instrumental era in seismology. Before this time, the catalog is less complete and magnitude estimates are more uncertain. Yet substantial information is available for earthquakes before 1900, and the catalog of historical events is being used increasingly to improve hazard assessment. Here I consider the catalog of historical earthquakes and show that approximately half of all Mw ≥ 8.5 earthquakes are likely missing or underestimated in the 19th century. I further present a reconsideration of the felt effects of the 8 February 1843, Lesser Antilles earthquake, including a first thorough assessment of felt reports from the United States, and show it is an example of a known historical earthquake that was significantly larger than initially estimated. The results suggest that incorporation of best available catalogs of historical earthquakes will likely lead to a significant underestimation of seismic hazard and/or the maximum possible magnitude in many regions, including parts of the Caribbean.

  3. Earthquake classification, location, and error analysis in a volcanic environment: implications for the magmatic system of the 1989-1990 eruptions at redoubt volcano, Alaska

    USGS Publications Warehouse

    Lahr, J.C.; Chouet, B.A.; Stephens, C.D.; Power, J.A.; Page, R.A.

    1994-01-01

    Determination of the precise locations of seismic events associated with the 1989-1990 eruptions of Redoubt Volcano posed a number of problems, including poorly known crustal velocities, a sparse station distribution, and an abundance of events with emergent phase onsets. In addition, the high relief of the volcano could not be incorporated into the hypoellipse earthquake location algorithm. This algorithm was modified to allow hypocenters to be located above the elevation of the seismic stations. The velocity model was calibrated on the basis of a posteruptive seismic survey, in which four chemical explosions were recorded by eight stations of the permanent network supplemented with 20 temporary seismographs deployed on and around the volcanic edifice. The model consists of a stack of homogeneous horizontal layers; setting the top of the model at the summit allows events to be located anywhere within the volcanic edifice. Detailed analysis of hypocentral errors shows that the long-period (LP) events constituting the vigorous 23-hour swarm that preceded the initial eruption on December 14 could have originated from a point 1.4 km below the crater floor. A similar analysis of LP events in the swarm preceding the major eruption on January 2 shows they also could have originated from a point, the location of which is shifted 0.8 km northwest and 0.7 km deeper than the source of the initial swarm. We suggest this shift in LP activity reflects a northward jump in the pathway for magmatic gases caused by the sealing of the initial pathway by magma extrusion during the last half of December. Volcano-tectonic (VT) earthquakes did not occur until after the initial 23-hour-long swarm. They began slowly just below the LP source and their rate of occurrence increased after the eruption of 01:52 AST on December 15, when they shifted to depths of 6 to 10 km. After January 2 the VT activity migrated gradually northward; this migration suggests northward propagating withdrawal of

  4. The Alaskan mineral resource assessment program; background information to accompany folio of geologic and mineral resource maps of the Ambler River Quadrangle, Alaska

    USGS Publications Warehouse

    Mayfield, Charles F.; Tailleur, I.L.; Albert, N.R.; Ellersieck, Inyo; Grybeck, Donald; Hackett, S.W.

    1983-01-01

    The Ambler River quadrangle, consisting of 14,290 km2 (5,520 mi2) in northwest Alaska, was investigated by an interdisciplinary research team for the purpose of assessing the mineral resource potential of the quadrangle. This report provides background information for a folio of maps on the geology, reconnaissance geochemistry, aeromagnetics, Landsat imagery, and mineral resource evaluation of the quadrangle. A summary of the geologic history, radiometric dates, and fossil localities and a comprehensive bibliography are also included. The quadrangle contains jade reserves, now being mined, and potentially significant resources of copper, zinc, lead, and silver.

  5. Earthquakes of the Holocene.

    USGS Publications Warehouse

    Schwartz, D.P.

    1987-01-01

    Areas in which significant new data and insights have been obtained are: 1) fault slip rates; 2) earthquake recurrence models; 3) fault segmentation; 4) dating past earthquakes; 5) paleoseismicity in the E and central US; 6) folds and earthquakes, and 7) future earthquake behavior. Summarizes important trends in each of these research areas based on information published between June 1982 and June 1986 and preprints of papers in press. The bibliography for this period contains mainly referred publications in journals and books.-from Author

  6. Mineral-resource assessments in Alaska; background information to accompany maps and reports about the geology and undiscovered-mineral-resource potential of the Mount Katmai Quadrangle and adjacent parts of the Naknek and Afognak quadrangles, Alaska Peninsula

    USGS Publications Warehouse

    Riehle, J.R.; Church, S.E.; Detterman, R.L.; Miller, J.W.

    1994-01-01

    Geologic and geochemical field studies were carded out from 1983 to 1987 in the Mount Katmai l?x2 ? quadrangle and adjoining region, at the northeast end of the Alaska Peninsula. The region is nearly entirely within Katmai National Park and Preserve and has had almost no mineral production, so prior to this study there were few data by which to assess the mineral potential of the region. This report describes the folio of publications that have resulted from the study: geologic maps, geochemical results, fossil identifications, radiometric rock ages, and an assessment of the undiscovered-mineral-resource potential of the region. The Katmai region is inferred to potentially have three types of undiscovered mineral deposits: porphyry copper (molybdenum), precious-metal vein, and hot-springs gold. These deposit types occur elsewhere on the Alaska Peninsula in similar geologic units. Evidence suggesting their occurrence in the Katmai region is the presence of trace amounts of metals typically associated with these kinds of deposits in bedrock of certain tracts and in sediments of streams draining those tracts. Magma to provide heat, fractures to provide pathways for mineralizing fluids, and altered rock are required by genetic models of these deposit types. Such features do occur in the Katmai tracts. Confirmation of any mineral deposit in the Katmai region requires detailed follow-up sampling and acquisition of subsurface information, which is beyond the scope of this study. However, producing porphyry deposits are unknown elsewhere on the Alaska Peninsula in similar rocks, so if any such deposits occur in the Katmai region, they are likely to be few in number. Conversely, vein deposits are typically small in size so there may be several of such deposits. The properties and thermal history of the sedimentary rocks that could serve as reservoirs for oil or gas are unfavorable in adjacent regions. Thus the potential of the Katmai region for producible quantities of

  7. Alaska GeoFORCE, A New Geologic Adventure in Alaska

    NASA Astrophysics Data System (ADS)

    Wartes, D.

    2011-12-01

    RAHI, the Rural Alaska Honors Institute is a statewide, six-week, summer college-preparatory bridge program at the University of Alaska Fairbanks for Alaska Native and rural high school juniors and seniors. A program of rigorous academic activity combines with social, cultural, and recreational activities. Students are purposely stretched beyond their comfort levels academically and socially to prepare for the big step from home or village to a large culturally western urban campus. This summer RAHI is launching a new program, GeoFORCE Alaska. This outreach initiative is designed to increase the number and diversity of students pursuing STEM degree programs and entering the future high-tech workforce. It uses Earth science as the hook because most kids get excited about dinosaurs, volcanoes and earthquakes, but it includes physics, chemistry, math, biology and other sciences. Students will be recruited, initially from the Arctic North Slope schools, in the 8th grade to begin the annual program of approximately 8 days, the summer before their 9th grade year and then remain in the program for all four years of high school. They must maintain a B or better grade average and participate in all GeoFORCE events. The carrot on the end of the stick is an exciting field event each summer. Over the four-year period, events will include trips to Fairbanks, Arizona, Oregon and the Appalachians. All trips are focused on Earth science and include a 100+ page guidebook, with tests every night culminating with a final exam. GeoFORCE Alaska is being launched by UAF in partnership with the University of Texas at Austin, which has had tremendous success with GeoFORCE Texas. GeoFORCE Alaska will be managed by UAF's long-standing Rural Alaska Honors Insitute (RAHI) that has been successfully providing intense STEM educational opportunities for Alaskan high school students for almost 30 years. The Texas program, with adjustments for differences in culture and environment, will be

  8. Women's Legal Rights in Alaska. Reprint.

    ERIC Educational Resources Information Center

    Tatter, Sue Ellen; Saville, Sandra K.

    This publication is intended to help women in Alaska learn about their legal rights. Some of the information is of a general nature and will be of interest to women in other states. Some of the laws and resources are relevant to Alaska only. The publication can serve as a model to other states wanting to develop a resource to inform women about…

  9. Earthquake damage to schools

    USGS Publications Warehouse

    McCullough, Heather

    1994-01-01

    These unusual slides show earthquake damage to school and university buildings around the world. They graphically illustrate the potential danger to our schools, and to the welfare of our children, that results from major earthquakes. The slides range from Algeria, where a collapsed school roof is held up only by students' desks; to Anchorage, Alaska, where an elementary school structure has split in half; to California and other areas, where school buildings have sustained damage to walls, roofs, and chimneys. Interestingly, all the United States earthquakes depicted in this set of slides occurred either on a holiday or before or after school hours, except the 1935 tremor in Helena, Montana, which occurred at 11:35 am. It undoubtedly would have caused casualties had the schools not been closed days earlier by Helena city officials because of a damaging foreshock. Students in Algeria, the People's Republic of China, Armenia, and other stricken countries were not so fortunate. This set of slides represents 17 destructive earthquakes that occurred in 9 countries, and covers more than a century--from 1886 to 1988. Two of the tremors, both of which occurred in the United States, were magnitude 8+ on the Richter Scale, and four were magnitude 7-7.9. The events represented by the slides (see table below) claimed more than a quarter of a million lives.

  10. The Earthscope Plate Boundary Observatory Alaska Region an Overview of Network Operation, Maintenance and Improvement

    NASA Astrophysics Data System (ADS)

    Enders, M.; Boyce, E. S.; Bierma, R.; Walker, K.; Feaux, K.

    2011-12-01

    UNAVCO has now completed its third year of operation of the 138 continuous GPS stations, 12 tiltmeters and 31 communications relays that comprise the Alaska Region of the Earthscope Plate Boundary Observatory. Working in Alaska has been challenging due to the extreme environmental conditions encountered and logistics difficulties. Despite these challenges we have been able to complete each summer field season with network operation at 95% or better. Throughout the last three years we have analyzed both our successes and failures to improve the quality of our network and better serve the scientific community. Additionally, we continue to evaluate and deploy new technologies to improve station reliability and add to the data set available from our stations. 2011 was a busy year for the Alaska engineering team and some highlights from last year's maintenance season include the following. This spring we completed testing and deployment of the first Inmarsat BGAN satellite terminal for data telemetry at AC60 Shemya Island. Shemya Island is at the far western end of the Aleutian Islands and is one of the most remote and difficult to access stations in the PBO AK network. Until the installation of the BGAN, this station was offline with no data telemetry for almost one year. Since the installation of the BGAN in early April 2011 dataflow has been uninterrupted. This year we also completed the first deployments of Stardot NetCamSC webcams in the PBO Network. Currently, these are installed and operational at six GPS stations in Alaska, with plans to install several more next season in Alaska. Images from these cameras can be found at the station homepages linked to from the UNAVCO website. In addition to the hard work put in by PBO engineers this year, it is important that we recognize the contributions of our partners. In particular the Alaska Volcano Observatory, the Alaska Earthquake Information Center and others who have provided us with valuable engineering assistance

  11. Recruiting first generation college students into the Geosciences: Alaska's EDGE project

    NASA Astrophysics Data System (ADS)

    Prakash, A.; Connor, C.

    2008-12-01

    Funded in 2005-2008, by the National Science Foundation's Geoscience Education Division, the Experiential Discoveries in Geoscience Education (EDGE) project was designed to use glacier and watershed field experiences as venues for geospatial data collected by Alaska's grade 6-12 middle and high school teachers and their students. EDGE participants were trained in GIS and learned to analyze geospatial data to answer questions about the warming Alaska environment and to determine rates of ongoing glacier recession. Important emphasis of the program was the recruitment of Alaska Native students of Inupiat, Yup'ik, Athabascan, and Tlingit populations, living in both rural and urban areas around the state. Twelve of Alaska's 55 school districts have participated in the EDGE program. To engage EDGE students in the practice of scientific inquiry, each was required to carry out a semester scale research project using georeferenced data, guided by their EDGE teacher and mentor. Across Alaska students investigated several Earth systems processes including freezing conditions of lake ice; the changes in water quality in storm drains after rainfall events; movements of moose, bears, and bison across Alaskan landscapes; changes in permafrost depth in western Alaska; and the response of migrating waterfowl to these permafrost changes. Students correlated the substrate beneath their schools with known earthquake intensities; measured cutbank and coastal erosion on northern rivers and southeastern shorelines; tracked salmon infiltration of flooded logging roads; noted the changing behavior of eagles during late winter salmon runs; located good areas for the use of tidal power for energy production; tracked the extent and range of invasive plant species with warming; and the change of forests following deglaciation. Each cohort of EDGE students and teachers finished the program by attended a 3-day EDGE symposium at which students presented their research projects first in a

  12. A seismotectonic study of the Southeastern Alaska Region

    NASA Astrophysics Data System (ADS)

    Doser, Diane I.; Rodriguez, Hugo

    2011-01-01

    We compare relocations of recent (1973-2005) and historic (1919-1972) earthquakes to geologic and geophysical (gravity, aeromagnetic, and uplift) information to determine the relationship of seismicity to crustal deformation in southeastern Alaska. Our results suggest that along strike changes in the structure of the Pacific plate may control the location of the ends of rupture zones for large earthquakes along the offshore Queen Charlotte fault system in the southern portion of the study area. There is a marked increase in background seismicity in the northern portion of the study area where the Fairweather fault begins to bend toward the northwest and crustal uplift due to glacial unloading exceeds 20 mm/year. Focal mechanisms indicate that thrust and reverse mechanisms predominate in the region of maximum uplift, as might be expected by the decrease in ice sheet thickness. The diffuse nature of seismicity between the Fairweather and Denali faults in the northern study area suggests a complex interaction between plate/microplate interactions and glacial unloading, making it difficult to determine the optimal fault orientation for failure in moderate magnitude (5.5 to 6.5) earthquakes within this region.

  13. Undergraduate Studies in Earthquake Information Technology (UseIT): Preparing Students for the Twenty-First Century Work Force via a Multidisciplinary and Collaborative Learning Experience

    NASA Astrophysics Data System (ADS)

    Degroot, R. M.; Jordan, T. H.; Benthien, M. L.; Ihrig, M.; Berti, R.

    2009-12-01

    UseIT is one of the three undergraduate research programs sponsored by the Southern California Earthquake Center (SCEC). The program allows students to work in multi-disciplinary collaborative teams to tackle a scientific “Grand Challenge.” The topic varies each year but it always entails performing computer science research that is needed by earthquake scientists, educators, and other target audiences. The program allows undergraduates to use the advanced tools of information technology to solve important problems in interdisciplinary earthquake research. Since the program began in 2002, 145 students have participated in UseIT. The program stresses problem solving and interdisciplinary cross training. A key aspect of the UseIT program is its flexible, yet structured, team approach. Students share their diverse skills and interests, creating a powerful synergy through this peer mentoring. The majority of UseIT interns have considerable computer science skill or aptitude, but successful UseIT interns have hailed from nearly three-dozen disciplines, all class levels, and all skill levels. Successful UseIT interns have in common a willingness to step outside their comfort zones and try new things. During the 2009 internship the focus of the program was to deliver SCEC Virtual Display of Objects (VDO) images and animations of faults and earthquake sequences to SCEC, the Earthquake Country Alliance, and other virtual organizations via a content management system that captures the metadata and guides the user. SCEC-VDO is the SCEC intern-developed visualization software that allows the user to see earthquake related phenomena in three and four dimensions. The 2009 Grand Challenge had special relevance for the interns because the products they created were used for The Great California ShakeOut. This talk will discuss lessons learned from this program, how it addresses the needs of the 21st century STEM work force, and highlights of the 2009 internship.

  14. Using Braid Plain Ecology and Geomorphology to Inform Bank Erosion Management along a Braided River, Matanuska River, Alaska

    NASA Astrophysics Data System (ADS)

    Curran, J. H.; McTeague, M. L.

    2010-12-01

    Braided rivers are inherently dynamic but quantifying the nature and implications of this dynamism can contribute to more comprehensive understanding of these systems and management of the river corridor. Bank erosion along the glacial, braided Matanuska River in southcentral Alaska has challenged generations of officials and generated a host of proposed solutions such as riprapped banks, dikes, gravel mining, and trenching. Increasingly, assessment of the technical feasibility of these methods has been accompanied by consideration of ecological factors and nonstructural solutions. The Matanuska River is braided over 85 percent of its course and clearwater side channels in abandoned braid plain areas provide as much as 90 percent of the spawning habitat in the basin for chum and sockeye salmon (Oncorhynchus keta and O. nerka). An assessment of braid plain vegetation, bank erosion rates, effects of a large flood, and distribution of clearwater side channels establishes a scientific basis for ecological and geomorphological considerations and recently helped guide development of a management plan for the river corridor. A historical analysis of braid plain features, marginal positions, and vegetation patterns from 1949, 1962, and 2006 orthophotographs showed that the 2006 braid plain was 43 percent vegetated and had an average age of 16 years. Only about 4 percent of the braid plain contained vegetated islands and over 60 percent of these were young and sparsely vegetated, implying that a suite of active channels migrated frequently across the braid plain and that vegetation did not appreciably limit channel movement. Rates of erosion to the braid plain margins averaged 0.3 m/yr from 1949 to 2006 but erosion was localized, with 64 percent of the erosion at only 8 percent of the banks. Cumulative bank change was twice as great along banks consisting of Holocene fluvial deposits (fans and terraces) identified during Geographic Information System (GIS) mapping than on

  15. PAGER--Rapid assessment of an earthquake?s impact

    USGS Publications Warehouse

    Wald, D.J.; Jaiswal, K.; Marano, K.D.; Bausch, D.; Hearne, M.

    2010-01-01

    PAGER (Prompt Assessment of Global Earthquakes for Response) is an automated system that produces content concerning the impact of significant earthquakes around the world, informing emergency responders, government and aid agencies, and the media of the scope of the potential disaster. PAGER rapidly assesses earthquake impacts by comparing the population exposed to each level of shaking intensity with models of economic and fatality losses based on past earthquakes in each country or region of the world. Earthquake alerts--which were formerly sent based only on event magnitude and location, or population exposure to shaking--now will also be generated based on the estimated range of fatalities and economic losses.

  16. Eastern Alaska

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In this SeaWiFS image of eastern Alaska, the Aleutian Islands, Kodiak Island, Yukon and Tanana rivers are clearly visible. Also visible, but slightly hidden beneath the clouds, is a bloom in Bristol Bay. Credit: Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  17. Geologic map of Alaska

    USGS Publications Warehouse

    Wilson, Frederic H.; Hults, Chad P.; Mull, Charles G.; Karl, Susan M.

    2015-12-31

    This Alaska compilation is unique in that it is integrated with a rich database of information provided in the spatial datasets and standalone attribute databases. Within the spatial files every line and polygon is attributed to its original source; the references to these sources are contained in related tables, as well as in stand-alone tables. Additional attributes include typical lithology, geologic setting, and age range for the map units. Also included are tables of radiometric ages.

  18. Response of the Yellowstone Volcanic Field to the M 7.9 Denali earthquake

    NASA Astrophysics Data System (ADS)

    Husen, S.; Nava, S.; Smith, R. B.; Terra, F.; Pankow, K.

    2002-12-01

    The November 3, 2002, Alaska earthquake had a profound effect on the Yellowstone volcanic field including an unexpected increase in seismicity and pronounced changes in hydrothermal features. Following passage of the Denali main-shock surface waves, numerous earthquakes of -1< M< 2.7, were recorded throughout Yellowstone National Park. In the first four hours following the main shock, more than 130 earthquakes were recorded. The seismicity rate diminished to ~35 events per day for the next few days, but earthquake swarms continued to occur for at least ten days. Waveform and spectral analysis from broadband seismographs indicate that the initial triggered earthquakes began at the onset of the first surface waves. These had a peak dynamic stress value of ~2 bars (~2 cm/sec.) at 20 sec. periods. Seismic activity was vigorous within the first hours, including spasmodic burst-like behavior with many high-frequency events with overlapping codas. Variations in spatial and temporal seismicity in Yellowstone are not unusual as earthquake swarms dominate much of the background seismicity. However, the seismicity following the Denali earthquake was markedly different from background Yellowstone seismicity. The earthquakes were extant over the entire Yellowstone volcanic field with notable activity in the vicinity of the southeast and northwest caldera. In addition, much of the triggered seismicity was associated with areas of hydrothermal activity and with unusual variations in geothermal activity. For example, visual observations at Norris Geyser Basin revealed rapid changes in normally non-boiling hot springs that caused geysering up to 90 cm and heavy boiling. Water temperatures increased rapidly from 42°C to 93°C and accompanied increases in pH at the time of the seismic wave passage. At the Upper Geyser Basin, one geyser decreased its eruption interval from ~2 hrs to one. These observations suggest that the Yellowstone hydrothermal field responded to the same large

  19. Reassessment of seismically induced, tsunamigenic submarine slope failures in Port Valdez, Alaska, USA

    USGS Publications Warehouse

    Lee, H.J.; Haeussler, P.J.; Kayen, R.E.; Hampton, M.A.; Locat, Jacques; Suleimani, E.; Alexander, C.R.

    2007-01-01

    The M9.2 Alaska earthquake of 1964 caused major damage to the port facilities and town of Valdez, most of it the result of submarine landslide and the consequent tsunamis. Recent bathymetric multibeam surveys, high-resolution subbottom profiles, and dated sediment cores in Port Valdez supply new information about the morphology and character of the landslide deposits. A comparison of pre- and post-earthquake bathymetry provides an estimate of the net volume of landslide debris deposited in the basin and the volume of sediment removed from the source region. Landslide features include (1) large blocks (up to 40-m high) near the location of the greatest tsunamiwave runup (~50 m), (2) two debris lobes associated with the blocks, (3) a series of gullies, channels and talus, near the fjord-head delta and badly damaged old town of Valdez, and (4) the front of a debris lobe that flowed half-way down the fjord from the east end.

  20. Distance Learning in Alaska's Rural Schools.

    ERIC Educational Resources Information Center

    Bramble, William J.

    1986-01-01

    The distance education and instructional technology projects that have been undertaken in Alaska over the last decade are detailed in this paper. The basic services offered by the "Learn Alaska Network" are described in relation to three user groups: K-12 education; postsecondary education; and general public education and information.…

  1. OMG Earthquake! Can Twitter improve earthquake response?

    NASA Astrophysics Data System (ADS)

    Earle, P. S.; Guy, M.; Ostrum, C.; Horvath, S.; Buckmaster, R. A.

    2009-12-01

    The U.S. Geological Survey (USGS) is investigating how the social networking site Twitter, a popular service for sending and receiving short, public, text messages, can augment its earthquake response products and the delivery of hazard information. The goal is to gather near real-time, earthquake-related messages (tweets) and provide geo-located earthquake detections and rough maps of the corresponding felt areas. Twitter and other social Internet technologies are providing the general public with anecdotal earthquake hazard information before scientific information has been published from authoritative sources. People local to an event often publish information within seconds via these technologies. In contrast, depending on the location of the earthquake, scientific alerts take between 2 to 20 minutes. Examining the tweets following the March 30, 2009, M4.3 Morgan Hill earthquake shows it is possible (in some cases) to rapidly detect and map the felt area of an earthquake using Twitter responses. Within a minute of the earthquake, the frequency of “earthquake” tweets rose above the background level of less than 1 per hour to about 150 per minute. Using the tweets submitted in the first minute, a rough map of the felt area can be obtained by plotting the tweet locations. Mapping the tweets from the first six minutes shows observations extending from Monterey to Sacramento, similar to the perceived shaking region mapped by the USGS “Did You Feel It” system. The tweets submitted after the earthquake also provided (very) short first-impression narratives from people who experienced the shaking. Accurately assessing the potential and robustness of a Twitter-based system is difficult because only tweets spanning the previous seven days can be searched, making a historical study impossible. We have, however, been archiving tweets for several months, and it is clear that significant limitations do exist. The main drawback is the lack of quantitative information

  2. Earthquake Facts

    MedlinePlus

    ... May 22, 1960. The earliest reported earthquake in California was felt in 1769 by the exploring expedition ... by wind or tides. Each year the southern California area has about 10,000 earthquakes . Most of ...

  3. Hydra—The National Earthquake Information Center’s 24/7 seismic monitoring, analysis, catalog production, quality analysis, and special studies tool suite

    USGS Publications Warehouse

    Patton, John M.; Guy, Michelle R.; Benz, Harley M.; Buland, Raymond P.; Erickson, Brian K.; Kragness, David S.

    2016-08-18

    This report provides an overview of the capabilities and design of Hydra, the global seismic monitoring and analysis system used for earthquake response and catalog production at the U.S. Geological Survey National Earthquake Information Center (NEIC). Hydra supports the NEIC’s worldwide earthquake monitoring mission in areas such as seismic event detection, seismic data insertion and storage, seismic data processing and analysis, and seismic data output.The Hydra system automatically identifies seismic phase arrival times and detects the occurrence of earthquakes in near-real time. The system integrates and inserts parametric and waveform seismic data into discrete events in a database for analysis. Hydra computes seismic event parameters, including locations, multiple magnitudes, moment tensors, and depth estimates. Hydra supports the NEIC’s 24/7 analyst staff with a suite of seismic analysis graphical user interfaces.In addition to the NEIC’s monitoring needs, the system supports the processing of aftershock and temporary deployment data, and supports the NEIC’s quality assurance procedures. The Hydra system continues to be developed to expand its seismic analysis and monitoring capabilities.

  4. PBO Operations in Alaska and Cascadia, Combining Regions and Collaborating with our Regional Partners

    NASA Astrophysics Data System (ADS)

    Austin, K. E.; Boyce, E. S.; Dausz, K.; Feaux, K.; Mattioli, G. S.; Pyatt, C.; Willoughby, H.; Woolace, A. C.

    2015-12-01

    During the last year, the Alaska and the Cascadia regions of the EarthScope Plate Boundary Observatory (PBO) network were combined into a single management unit. While both remain distinct regions with their own challenges and engineering staff, every effort has been made to operate as a single team to improve efficiency and provide the highest possible data quality and uptime. Over the last several years a concerted effort has been made to work collaboratively with other institutions and stakeholders to defray ongoing costs by sharing staff and resources. UNAVCO currently operates four integrated GPS/seismic stations in collaboration with the Alaska Earthquake Center, eight with the Alaska Volcano Observatory, and three with the EarthScope TA. By the end of 2015, PBO and TA plan to install another 3 integrated and/or co-located geodetic and seismic systems. While most of these are designed around existing PBO stations, the 2014 installation at Middleton Island is a new station for both groups, providing PBO with an opportunity to expand geodetic data in Alaska. There were two major joint maintenance efforts in 2015:, the largest was a 5 day mission among PBO, AVO, and TA, which shared boat, helicopter, and staff on and around Augustine Volcano; the second, was a 10 day helicopter mission shared between AVO and PBO on Unimak Island. PBO Pacific Northwest is working closely with University of Washington to co-locate at least 9 Earthquake Early Warning Systems, which include the addition of strong motion sensors and high speed RT telemetry at PBO sites. The project is managed by University of Washington but UNAVCO is providing land contact information and infrastructure support. Summer 2015 upgrades include a complete overhaul of aging radio technology at two major networks and several small radio networks in Cascadia. The upgrades will increase reliability and enhance the speed of existing telemetry infrastructure and will continue through summer 2018.

  5. An Alaska Soil Carbon Database

    NASA Astrophysics Data System (ADS)

    Johnson, Kristofer; Harden, Jennifer

    2009-05-01

    Database Collaborator's Meeting; Fairbanks, Alaska, 4 March 2009; Soil carbon pools in northern high-latitude regions and their response to climate changes are highly uncertain, and collaboration is required from field scientists and modelers to establish baseline data for carbon cycle studies. The Global Change Program at the U.S. Geological Survey has funded a 2-year effort to establish a soil carbon network and database for Alaska based on collaborations from numerous institutions. To initiate a community effort, a workshop for the development of an Alaska soil carbon database was held at the University of Alaska Fairbanks. The database will be a resource for spatial and biogeochemical models of Alaska ecosystems and will serve as a prototype for a nationwide community project: the National Soil Carbon Network (http://www.soilcarb.net). Studies will benefit from the combination of multiple academic and government data sets. This collaborative effort is expected to identify data gaps and uncertainties more comprehensively. Future applications of information contained in the database will identify specific vulnerabilities of soil carbon in Alaska to climate change, disturbance, and vegetation change.

  6. A Promising Tool to Assess Long Term Public Health Effects of Natural Disasters: Combining Routine Health Survey Data and Geographic Information Systems to Assess Stunting after the 2001 Earthquake in Peru

    PubMed Central

    Rydberg, Henny; Marrone, Gaetano; Strömdahl, Susanne; von Schreeb, Johan

    2015-01-01

    Background Research on long-term health effects of earthquakes is scarce, especially in low- and middle-income countries, which are disproportionately affected by disasters. To date, progress in this area has been hampered by the lack of tools to accurately measure these effects. Here, we explored whether long-term public health effects of earthquakes can be assessed using a combination of readily available data sources on public health and geographic distribution of seismic activity. Methods We used childhood stunting as a proxy for public health effects. Data on stunting were attained from Demographic and Health Surveys. Earthquake data were obtained from U.S. Geological Survey’s ShakeMaps, geographic information system-based maps that divide earthquake affected areas into different shaking intensity zones. We combined these two data sources to categorize the surveyed children into different earthquake exposure groups, based on how much their area of residence was affected by the earthquake. We assessed the feasibility of the approach using a real earthquake case – an 8.4 magnitude earthquake that hit southern Peru in 2001. Results and conclusions Our results indicate that the combination of health survey data and disaster data may offer a readily accessible and accurate method for determining the long-term public health consequences of a natural disaster. Our work allowed us to make pre- and post- earthquake comparisons of stunting, an important indicator of the well-being of a society, as well as comparisons between populations with different levels of exposure to the earthquake. Furthermore, the detailed GIS based data provided a precise and objective definition of earthquake exposure. Our approach should be considered in future public health and disaster research exploring the long-term effects of earthquakes and potentially other natural disasters. PMID:26090999

  7. The Alaskan mineral resource assessment program; background information to accompany folio of geologic and mineral resource maps of the Nabesna Quadrangle, Alaska

    USGS Publications Warehouse

    Richter, Donald H.; Albert, N.R.D.; Barnes, D.F.; Griscom, Andrew; Marsh, S.P.; Singer, D.A.

    1975-01-01

    The Nabesna quadrangle in south-central Alaska is the first of the l:250,000-scale Alaskan quadrangles to be investigated by an interdisciplinary research team in order to furnish a mineral resource assessment of the State. The assessment of the 17,600-km 2 16,800-mi21 quadrangle is based on field and laboratory investigations of the geology, geochemistry, geophysics, and satellite imagery. The results of the investigations are published as a folio of maps, diagrams, and accompanying discussions. This report provides background information on the investigations and integrates the published components of the resource assessment. A comprehensive bibliography cites both specific and general references to the geology and mineral deposits of the Nabesna quadrangle.

  8. Catalog of earthquake hypocenters at Alaskan volcanoes: January 1, 1994 through December 31, 1999

    USGS Publications Warehouse

    Jolly, Arthur D.; Stihler, Scott D.; Power, John A.; Lahr, John C.; Paskievitch, John; Tytgat, Guy; Estes, Steve; Lockhart, Andrew B.; Moran, Seth C.; McNutt, Stephen R.; Hammond, William R.

    2001-01-01

    The Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, the Geophysical Institute of the University of Alaska - Fairbanks, and the Alaska Division of Geological and Geophysical Surveys, has maintained a seismic monitoring program at potentially active volcanoes in Alaska since 1988 (Power and others, 1993; Jolly and others, 1996). The primary objectives of this program are the seismic surveillance of active, potentially hazardous, Alaskan volcanoes and the investigation of seismic processes associated with active volcanism.Between 1994 and 1999, the AVO seismic monitoring program underwent significant changes with networks added at new volcanoes during each summer from 1995 through 1999. The existing network at Katmai –Valley of Ten Thousand Smokes (VTTS) was repaired in 1995, and new networks were installed at Makushin (1996), Akutan (1996), Pavlof (1996), Katmai - south (1996), Aniakchak (1997), Shishaldin (1997), Katmai - north (1998), Westdahl, (1998), Great Sitkin (1999) and Kanaga (1999). These networks added to AVO's existing seismograph networks in the Cook Inlet area and increased the number of AVO seismograph stations from 46 sites and 57 components in 1994 to 121 sites and 155 components in 1999. The 1995–1999 seismic network expansion increased the number of volcanoes monitored in real-time from 4 to 22, including Mount Spurr, Redoubt Volcano, Iliamna Volcano, Augustine Volcano, Mount Snowy, Mount Griggs, Mount Katmai, Novarupta, Trident Volcano, Mount Mageik, Mount Martin, Aniakchak Crater, Pavlof Volcano, Mount Dutton, Isanotski volcano, Shisaldin Volcano, Fisher Caldera, Westdahl volcano, Akutan volcano, Makushin Volcano, Great Sitkin volcano, and Kanaga Volcano (see Figures 1-15). The network expansion also increased the number of earthquakes located from about 600 per year in1994 and 1995 to about 3000 per year between 1997 and 1999.Highlights of the catalog period include: 1) a large volcanogenic seismic

  9. Forecasting Earthquakes

    NASA Technical Reports Server (NTRS)

    1994-01-01

    In this video there are scenes of damage from the Northridge Earthquake and interviews with Dr. Andrea Donnelan, Geophysics at JPL, and Dr. Jim Dolan, earthquake geologist from Cal. Tech. The interviews discuss earthquake forecasting by tracking changes in the earth's crust using antenna receiving signals from a series of satellites called the Global Positioning System (GPS).

  10. Nowcasting earthquakes

    NASA Astrophysics Data System (ADS)

    Rundle, J. B.; Turcotte, D. L.; Donnellan, A.; Grant Ludwig, L.; Luginbuhl, M.; Gong, G.

    2016-11-01

    Nowcasting is a term originating from economics and finance. It refers to the process of determining the uncertain state of the economy or markets at the current time by indirect means. We apply this idea to seismically active regions, where the goal is to determine the current state of the fault system and its current level of progress through the earthquake cycle. In our implementation of this idea, we use the global catalog of earthquakes, using "small" earthquakes to determine the level of hazard from "large" earthquakes in the region. Our method does not involve any model other than the idea of an earthquake cycle. Rather, we define a specific region and a specific large earthquake magnitude of interest, ensuring that we have enough data to span at least 20 or more large earthquake cycles in the region. We then compute the earthquake potential score (EPS) which is defined as the cumulative probability distribution P(n < n(t)) for the current count n(t) for the small earthquakes in the region. From the count of small earthquakes since the last large earthquake, we determine the value of EPS = P(n < n(t)). EPS is therefore the current level of hazard and assigns a number between 0% and 100% to every region so defined, thus providing a unique measure. Physically, the EPS corresponds to an estimate of the level of progress through the earthquake cycle in the defined region at the current time.

  11. Hidden Earthquakes.

    ERIC Educational Resources Information Center

    Stein, Ross S.; Yeats, Robert S.

    1989-01-01

    Points out that large earthquakes can take place not only on faults that cut the earth's surface but also on blind faults under folded terrain. Describes four examples of fold earthquakes. Discusses the fold earthquakes using several diagrams and pictures. (YP)

  12. CISN Display Progress to Date - Reliable Delivery of Real-Time Earthquake Information, and ShakeMap to Critical End Users

    NASA Astrophysics Data System (ADS)

    Rico, H.; Hauksson, E.; Thomas, E.; Friberg, P.; Frechette, K.; Given, D.

    2003-12-01

    The California Integrated Seismic Network (CISN) has collaborated to develop a next-generation earthquake notification system that is nearing its first operations-ready release. The CISN Display actively alerts users of seismic data, and vital earthquake hazards information following a significant event. It will primarily replace the Caltech/USGS Broadcast of Earthquakes (CUBE) and Rapid Earthquake Data Integration (REDI) Display as the principal means of delivering geographical seismic data to emergency operations centers, utility companies and media outlets. A subsequent goal is to provide automated access to the many Web products produced by regional seismic networks after an earthquake. Another aim is to create a highly configurable client, allowing user organizations to overlay infrastructure data critical to their roles as first-responders, or lifeline operators. And the final goal is to integrate these requirements, into a package offering several layers of reliability to ensure delivery of services. Central to the CISN Display's role as a gateway to Web-based earthquake products is its comprehensive XML-messaging schema. The message model uses many of the same attributes in the CUBE format, but extends the old standard by provisioning additional elements for products currently available, and others yet to be considered. The client consumes these XML-messages, sorts them through a resident Quake Data Merge filter, and posts updates that also include hyperlinks associated to specific event IDs on the display map. Earthquake products available for delivery to the CISN Display are ShakeMap, focal mechanisms, waveform data, felt reports, aftershock forecasts and earthquake commentaries. By design the XML-message schema can evolve as products and information needs change, without breaking existing applications that rely on it. The latest version of the CISN Display can also automatically download ShakeMaps and display shaking intensity within the GIS system. This

  13. CISN Display - Reliable Delivery of Real-time Earthquake Information, Including Rapid Notification and ShakeMap to Critical End Users

    NASA Astrophysics Data System (ADS)

    Rico, H.; Hauksson, E.; Thomas, E.; Friberg, P.; Given, D.

    2002-12-01

    The California Integrated Seismic Network (CISN) Display is part of a Web-enabled earthquake notification system alerting users in near real-time of seismicity, and also valuable geophysical information following a large earthquake. It will replace the Caltech/USGS Broadcast of Earthquakes (CUBE) and Rapid Earthquake Data Integration (REDI) Display as the principal means of delivering graphical earthquake information to users at emergency operations centers, and other organizations. Features distinguishing the CISN Display from other GUI tools are a state-full client/server relationship, a scalable message format supporting automated hyperlink creation, and a configurable platform-independent client with a GIS mapping tool; supporting the decision-making activities of critical users. The CISN Display is the front-end of a client/server architecture known as the QuakeWatch system. It is comprised of the CISN Display (and other potential clients), message queues, server, server "feeder" modules, and messaging middleware, schema and generators. It is written in Java, making it platform-independent, and offering the latest in Internet technologies. QuakeWatch's object-oriented design allows components to be easily upgraded through a well-defined set of application programming interfaces (APIs). Central to the CISN Display's role as a gateway to other earthquake products is its comprehensive XML-schema. The message model starts with the CUBE message format, but extends it by provisioning additional attributes for currently available products, and those yet to be considered. The supporting metadata in the XML-message provides the data necessary for the client to create a hyperlink and associate it with a unique event ID. Earthquake products deliverable to the CISN Display are ShakeMap, Ground Displacement, Focal Mechanisms, Rapid Notifications, OES Reports, and Earthquake Commentaries. Leveraging the power of the XML-format, the CISN Display provides prompt access to

  14. Earthquake engineering in Peru

    USGS Publications Warehouse

    Vargas, N.J

    1983-01-01

    During the last decade, earthquake engineering research in Peru has been carried out at the Catholic University of Peru and at the Universidad Nacional de Ingeniera (UNI). The Geophysical Institute (IGP) under the auspices of the Organization of American States (OAS) has initiated in Peru other efforts in regional seismic hazard assessment programs with direct impact to the earthquake engineering program. Further details on these programs have been reported by L. Ocola in the Earthquake Information Bulletin, January-February 1982, vol. 14, no. 1, pp. 33-38. 

  15. Seabirds in Alaska

    USGS Publications Warehouse

    Hatch, Scott A.; Piatt, John F.

    1995-01-01

    Techniques for monitoring seabird populations vary according to habitat types and the breeding behavior of individual species (Hatch and Hatch 1978, 1989; Byrd et al. 1983). An affordable monitoring program can include but a few of the 1,300 seabird colonies identified in Alaska, and since the mid-1970's, monitoring effotrts have emphasized a small selection of surface-feeding and diving species, primarily kittiwakes (Rissa spp.) and murres (Uria spp.). Little or no information on trends is available for other seabirds (Hatch 1993a). The existing monitoring program occurs largely on sites within the Alaska Maritime National Wildlife Refuge, which was established primarily for the conservation of marine birds. Data are collected by refuge staff, other state and federal agencies, private organizations, university faculty, and students.

  16. Alaska Resource Data File, Noatak Quadrangle, Alaska

    USGS Publications Warehouse

    Grybeck, Donald J.; Dumoulin, Julie A.

    2006-01-01

    This report gives descriptions of the mineral occurrences in the Noatak 1:250,000-scale quadrangle, Alaska. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

  17. Digital release of the Alaska Quaternary fault and fold database

    NASA Astrophysics Data System (ADS)

    Koehler, R. D.; Farrell, R.; Burns, P.; Combellick, R. A.; Weakland, J. R.

    2011-12-01

    The Alaska Division of Geological & Geophysical Surveys (DGGS) has designed a Quaternary fault and fold database for Alaska in conformance with standards defined by the U.S. Geological Survey for the National Quaternary fault and fold database. Alaska is the most seismically active region of the United States, however little information exists on the location, style of deformation, and slip rates of Quaternary faults. Thus, to provide an accurate, user-friendly, reference-based fault inventory to the public, we are producing a digital GIS shapefile of Quaternary fault traces and compiling summary information on each fault. Here, we present relevant information pertaining to the digital GIS shape file and online access and availability of the Alaska database. This database will be useful for engineering geologic studies, geologic, geodetic, and seismic research, and policy planning. The data will also contribute to the fault source database being constructed by the Global Earthquake Model (GEM), Faulted Earth project, which is developing tools to better assess earthquake risk. We derived the initial list of Quaternary active structures from The Neotectonic Map of Alaska (Plafker et al., 1994) and supplemented it with more recent data where available. Due to the limited level of knowledge on Quaternary faults in Alaska, pre-Quaternary fault traces from the Plafker map are shown as a layer in our digital database so users may view a more accurate distribution of mapped faults and to suggest the possibility that some older traces may be active yet un-studied. The database will be updated as new information is developed. We selected each fault by reviewing the literature and georegistered the faults from 1:250,000-scale paper maps contained in 1970's vintage and earlier bedrock maps. However, paper map scales range from 1:20,000 to 1:500,000. Fault parameters in our GIS fault attribute tables include fault name, age, slip rate, slip sense, dip direction, fault line type

  18. Earthquake Engineering Research Center: 25th anniversry edition

    NASA Astrophysics Data System (ADS)

    1993-10-01

    The Earthquake Engineering Research Center exists to conduct research and develop technical information in all areas pertaining to earthquake engineering, including strong ground motion and ground failure, response of natural and manmade structures to earthquakes, design of structures to resist earthquakes, development of new systems for earthquake protection, and development of architectural and public policy aspects of earthquake engineering. The annual report for 1992-93 presents information on: Current Research Programs; Contracts and Grants; Public Service Program; National Information Service for Earthquake Engineering; Core Administration; Committees of the Earthquake Engineering Research Center; Research Participants - Faculty; and Research Participants - Students.

  19. Earthquakes in the United States

    USGS Publications Warehouse

    Stover, C.

    1977-01-01

    To supplement data in the report Preliminary Determination of Epicenters (PDE), the National earthquake Information Service (NEIS) also publishes a quarterly circular, Earthquakes in the United States. This provides information on the felt area of U.S earthquakes and their intensity. The main purpose is to describe the larger effects of these earthquakes so that they can be used in seismic risk studies, site evaluations for nuclear power plants, and answering inquiries by the general public.

  20. Earthquakes & Volcanoes, Volume 23, Number 6, 1992

    USGS Publications Warehouse

    ,; Gordon, David W.

    1993-01-01

    Earthquakes and Volcanoes is published bimonthly by the U.S. Geological Survey to provide current information on earthquakes and seismology, volcanoes, and related natural hazards of interest to both generalized and specialized readers.

  1. Modeling Interseismic and Transient Deformation in Southcentral Alaska

    NASA Astrophysics Data System (ADS)

    Freed, A. M.; Ali, T.

    2009-12-01

    The convergent margin of Southern Alaska marks the active tectonic boundary between the North American and Pacific plates. Here we numerically model the response of the Alaskan lithosphere to interseismic, coseismic and postseismic loading in order to interpret the contemporary velocity field from GPS observations. Results suggest that, to first order, the surface velocities can be explained by the combination of interseismic deformation associated with a locked megathrust and postseismic viscous relaxation following large earthquakes, particularly the 1964 M9.2 Great Alaska earthquake. The best fitting model requires a weak mantle wedge sandwiched between a strong crust and the subducting slab. Most of the trenchward directed velocities observed in the GPS data, near the Kenai Peninsula and Kodiak Island as well in interior Alaska north of the Denali Fault, are a viscous relaxation response to the 1964 earthquake. In a few decades we should begin to see these velocities decay and subsequently point northwestwards. Postseismic viscous relaxation associated with large strike slip earthquakes since 1949 on the Queen Charlotte-Fairweather faults only provide a small contribution (~5mm/yr) to the present day GPS velocity field in that region. Our models demonstrate how subduction of the Pacific plate tends to load all the major faults at the margin including the central and eastern segments of the Denali fault and show how the 1964 earthquake and associated postseismic relaxation combined to increase Coulomb stress at the fault segment that ruptured during the 2002 M7.9 Denali earthquake.

  2. A geologic guide to Wrangell-Saint Elias National Park and Preserve, Alaska; a tectonic collage of northbound terranes

    USGS Publications Warehouse

    Winkler, Gary R.; with contributions by MacKevett, E. M.; Plafker, George; Richter, D.H.; Rosenkrans, D.S.; Schmoll, H.R.

    2000-01-01

    Wrangell-Saint Elias National Park and Preserve, the largest unit in the U.S. National Park System, encompasses near 13.2 million acres of geological wonderments. This geologic guide presents history of exploration and Earth-science investigation; describes the complex geologic makeup; characterizes the vast college of accretion geologic terranes in this area of Alaska's continental margin; recapitulates the effects of earthquakes, volcanoes, and glaciers; characterizes the copper and gold resources of the parklands; and describes outstanding locales within the park and preserve area. A glossary of geologic terms and a categorized list of additional sources of information complete this report.

  3. Earthquake history of the United States

    USGS Publications Warehouse

    Coffman, Jerry L.; Von Hake, Carl A.; Stover, Carl W.; Coffman, Jerry L.; von Hake, Carl A.; Stover, Carl W.

    1982-01-01

    This publication is a history of the prominent earthquakes in the United States from historical times through 1970. It supersedes all previous editions with the same or similar titles (see page ii) and, in addition to updating earthquake listings through 1970, contains several additions and corrections to previous issues. It also brings together under a common cover earthquake data previously listed in two separate reports: Earthquake History of the United States, Part I, Stronger Earthquakes of the United States (Exclusive of California and Western Nevada) and Earthquake History of the United States, Part II, Stronger Earthquakes of California and Western Nevada. Another addition to this publication is the inclusion of a section describing earthquakes in the Puerto Rico region. For the purpose of listing and describing earthquakes, the United States has been divided into nine regions: (1) Northeastern Region, which includes New England and New York activity and observations of the principal earthquakes of eastern Canada; (2) Eastern Region, including the central Appalachian seismic region activity and the area near Charleston, S.C.; (3) Central Region, which consists of the area between the region just described and the Rocky Mountains; (4) Western Mountain Region, which includes all remaining states except those on the Pacific coast; (5) Washington and Oregon; (6) Alaska; (7) Hawaii; (8) Puerto Rico; and (9) California and Western Nevada. This arrangement has been made chiefly with reference to the natural seismic divisions. It also is a convenient arrangement because there are only three states where there is an important division of earthquake activity: In Tennessee, there are quite distinct areas at opposite ends of the state that fall into different regions. Only central and eastern Nevada are included in the Western Mountain Region, as the activity of the western part is closely associated with that of California. Some earthquake activity has occurred in the

  4. BAID: The Barrow Area Information Database - an interactive web mapping portal and cyberinfrastructure for scientific activities in the vicinity of Barrow, Alaska

    NASA Astrophysics Data System (ADS)

    Cody, R. P.; Kassin, A.; Gaylord, A. G.; Tweedie, C. E.

    2013-12-01

    In 2013, the Barrow Area Information Database (BAID, www.baid.utep.edu) project resumed field operations in Barrow, AK. The Barrow area of northern Alaska is one of the most intensely researched locations in the Arctic. BAID is a cyberinfrastructure (CI) that details much of the historic and extant research undertaken within in the Barrow region in a suite of interactive web-based mapping and information portals (geobrowsers). The BAID user community and target audience for BAID is diverse and includes research scientists, science logisticians, land managers, educators, students, and the general public. BAID contains information on more than 11,000 Barrow area research sites that extend back to the 1940's and more than 640 remote sensing images and geospatial datasets. In a web-based setting, users can zoom, pan, query, measure distance, and save or print maps and query results. Data are described with metadata that meet Federal Geographic Data Committee standards and are archived at the University Corporation for Atmospheric Research Earth Observing Laboratory (EOL) where non-proprietary BAID data can be freely downloaded. Highlights for the 2013 season include the addition of more than 2000 additional research sites, providing differential global position system (dGPS) support to visiting scientists, surveying over 80 miles of coastline to document rates of erosion, training of local GIS personal, deployment of a wireless sensor network, and substantial upgrades to the BAID website and web mapping applications.

  5. 78 FR 73144 - Subsistence Management Program for Public Lands in Alaska; Western Interior Alaska Federal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-05

    ... Subsistence Management Program for Public Lands in Alaska; Western Interior Alaska Federal Subsistence... purpose of the Council is to provide recommendations and information to the Federal Subsistence Board, to review policies and management plans, and to provide a public forum for subsistence issues. DATES:...

  6. Hydrologic Alterations from Climate Change Inform Assessment of Ecological Risk to Pacific Salmon in Bristol Bay, Alaska

    PubMed Central

    Wobus, Cameron; Prucha, Robert; Albert, David; Woll, Christine; Loinaz, Maria; Jones, Russell

    2015-01-01

    We developed an integrated hydrologic model of the upper Nushagak and Kvichak watersheds in the Bristol Bay region of southwestern Alaska, a region under substantial development pressure from large-scale copper mining. We incorporated climate change scenarios into this model to evaluate how hydrologic regimes and stream temperatures might change in a future climate, and to summarize indicators of hydrologic alteration that are relevant to salmon habitat ecology and life history. Model simulations project substantial changes in mean winter flow, peak flow dates, and water temperature by 2100. In particular, we find that annual hydrographs will no longer be dominated by a single spring thaw event, but will instead be characterized by numerous high flow events throughout the winter. Stream temperatures increase in all future scenarios, although these temperature increases are moderated relative to air temperatures by cool baseflow inputs during the summer months. Projected changes to flow and stream temperature could influence salmon through alterations in the suitability of spawning gravels, changes in the duration of incubation, increased growth during juvenile stages, and increased exposure to chronic and acute temperature stress. These climate-modulated changes represent a shifting baseline in salmon habitat quality and quantity in the future, and an important consideration to adequately assess the types and magnitude of risks associated with proposed large-scale mining in the region. PMID:26645380

  7. Hydrologic Alterations from Climate Change Inform Assessment of Ecological Risk to Pacific Salmon in Bristol Bay, Alaska.

    PubMed

    Wobus, Cameron; Prucha, Robert; Albert, David; Woll, Christine; Loinaz, Maria; Jones, Russell; Travers, Constance

    2015-01-01

    We developed an integrated hydrologic model of the upper Nushagak and Kvichak watersheds in the Bristol Bay region of southwestern Alaska, a region under substantial development pressure from large-scale copper mining. We incorporated climate change scenarios into this model to evaluate how hydrologic regimes and stream temperatures might change in a future climate, and to summarize indicators of hydrologic alteration that are relevant to salmon habitat ecology and life history. Model simulations project substantial changes in mean winter flow, peak flow dates, and water temperature by 2100. In particular, we find that annual hydrographs will no longer be dominated by a single spring thaw event, but will instead be characterized by numerous high flow events throughout the winter. Stream temperatures increase in all future scenarios, although these temperature increases are moderated relative to air temperatures by cool baseflow inputs during the summer months. Projected changes to flow and stream temperature could influence salmon through alterations in the suitability of spawning gravels, changes in the duration of incubation, increased growth during juvenile stages, and increased exposure to chronic and acute temperature stress. These climate-modulated changes represent a shifting baseline in salmon habitat quality and quantity in the future, and an important consideration to adequately assess the types and magnitude of risks associated with proposed large-scale mining in the region.

  8. Alaska Resource Data File, Talkeetna Mountains quadrangle, Alaska

    USGS Publications Warehouse

    Rogers, Robert K.; Schmidt, Jeanine M.

    2003-01-01

    Descriptions of the mineral occurrences shown on the accompanying figure follow. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

  9. Alaska Resource Data File, McCarthy quadrangle, Alaska

    USGS Publications Warehouse

    Hudson, Travis L.

    2003-01-01

    Descriptions of the mineral occurrences shown on the accompanying figure follow. See U.S. Geological Survey (1996) for a description of the information content of each field in the records. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

  10. 2D Modelling of the Gorkha earthquake through the joint exploitation of Sentinel 1-A DInSAR measurements and geological, structural and seismological information

    NASA Astrophysics Data System (ADS)

    De Novellis, Vincenzo; Castaldo, Raffaele; Solaro, Giuseppe; De Luca, Claudio; Pepe, Susi; Bonano, Manuela; Casu, Francesco; Zinno, Ivana; Manunta, Michele; Lanari, Riccardo; Tizzani, Pietro

    2016-04-01

    A Mw 7.8 earthquake struck Nepal on 25 April 2015 at 06:11:26 UTC, killing more than 9,000 people, injuring more than 23,000 and producing extensive damages. The main seismic event, known as the Gorkha earthquake, had its epicenter localized at ~82 km NW of the Kathmandu city and the hypocenter at a depth of approximately 15 km. After the main shock event, about 100 aftershocks occurred during the following months, propagating toward the south-east direction; in particular, the most energetic shocks were the Mw 6.7 and Mw 7.3 occurred on 26 April and 12 May, respectively. In this study, we model the causative fault of the earthquake by jointly exploiting surface deformation retrieved by the DInSAR measurements collected through the Sentinel 1-A (S1A) space-borne sensor and the available geological, structural and seismological information. We first exploit the analytical solution performing a back-analysis of the ground deformation detected by the first co-seismic S1A interferogram, computed by exploiting the 17/04/2015 and 29/04/2015 SAR acquisitions and encompassing the main earthquake and some aftershocks, to search for the location and geometry of the fault plane. Starting from these findings and by benefiting from the available geological, structural and seismological data, we carry out a Finite Element (FE)-based 2D modelling of the causative fault, in order to evaluate the impact of the geological structures activated during the seismic event on the distribution of the ground deformation field. The obtained results show that the causative fault has a rather complex compressive structure, dipping northward, formed by segments with different dip angles: 6° the deep segment and 60° the shallower one. Therefore, although the hypocenters of the main shock and most of the more energetic aftershocks are located along the deeper plane, corresponding to a segment of the Main Himalayan Thrust (MHT), the FE solution also indicates the contribution of the shallower

  11. Exploring the Use of Historic Earthquake Information to Differentiate Between Deposit Triggers for the High-resolution Stratigraphy from Squaw Lakes, Oregon, USA

    NASA Astrophysics Data System (ADS)

    Morey, A. E.; Gavin, D. G.; Goldfinger, C.; Nelson, A. R.

    2014-12-01

    The unique setting and high-resolution stratigraphy at Squaw Lakes, Oregon provides an opportunity to apply lake paleoseismology to southern Cascadia forearc lakes. These lakes were formed when a landslide dammed Squaw Creek located ~100 km from the Oregon coast at the Oregon/California border separating the drainages at the confluence of Squaw and Slickear Creeks. The upper lake contains evidence of disturbance events much too frequent to be the result of earthquakes alone. A link to historic events provides information that may be used to differentiate between deposit triggers and improve the interpretation of the prehistoric portion of the sedimentary record. Regional newspapers published historic accounts of earthquakes experienced by the local people, the most notable of which is the November 23 (or 22nd), 1873 Crescent City, CA earthquake. Although the 1906 San Francisco earthquake was also felt in this region, reports indicate that shaking was much stronger near Jacksonville, Oregon (only 25 miles to the north of Squaw Lakes) as a result of the 1873 earthquake. The depth range that most likely contains sediment deposited within a few years of 1873 can be determined using a new high-resolution age model for the Upper Squaw Lake sediment core (Gavin et al., in prep). This depth range in the core contains a thick deposit that is similar in structure to deposits deeper in the core that have been proposed to correlate with the marine record of Cascadia great earthquakes. These disturbance event deposits are thicker, graded deposits, where grading is dominated by the percentage of organic content as compared to those interpreted to be a result of watershed disturbances. Recently acquired radiocarbon ages for the Lower Squaw Lake core suggests the thicker Upper Squaw Lake deposits correlate to those recorded in the lower-resolution sedimentary record at Lower Squaw Lake. The character of the likely contemporaneous deposits from the lower lake show grading more

  12. New mapping and structural constraints on the Queen Charlotte-Fairweather Fault system, southeast Alaska

    NASA Astrophysics Data System (ADS)

    Levoir, M. A.; Roland, E. C.; Gulick, S. P.; Haeussler, P. J.; Christeson, G. L.; Van Avendonk, H. J.

    2013-12-01

    The dextral Queen Charlotte-Fairweather Fault lies along the western margin of Canada and southeastern Alaska, a transform plate boundary accommodating motion between the North American and Pacific Plates. The Fairweather Fault is the northern extension of the Queen Charlotte Fault and has numerous and complex splays, including the Chichagof-Baranof Fault, the Peril Strait Fault, the Chatham Strait Fault, and the Icy Point-Lituya Bay Fault. Except for a few small areas, these fault systems have not been mapped in detail. We present updated geometries and fault maps of the entirety of the strike-slip system using seismic reflection and bathymetric data, including a 2004 seismic reflection survey (EW0408), 2005 United Nations Commission on Law of the Sea multibeam bathymetry, and legacy data from the U.S. Geological Survey (USGS) and the National Geophysical Data Center. This work is highly relevant for earthquake hazard research and mitigation in southeast Alaska. Several large (> Mw 7.0) earthquakes have occurred along this margin in the last century, impacting communities of southeastern Alaska and western Canada. Two large, recent events include 1) a Mw 7.7 earthquake that took place on 28 October 2012 near the Haida Gwaii Islands offshore of western Canada, and 2) a Mw 7.5 event which occurred on 05 January 2013, 330 km to the northwest and offshore of Craig, Alaska. Interestingly, the Haida Gwaii earthquake ruptured as a thrust event and the Craig earthquake ruptured with a near-vertical dextral strike-slip mechanism. Since a change in Pacific Plate motion around 4 million years ago, the southern Queen Charlotte Fault system has been obliquely converging at a rate of 20 mm/year, with the boundary accommodating about 80 km of perpendicular motion over that time. This convergence explains the Haida Gwaii thrust earthquake, but leaves questions about the along-strike fault structure. Two opposing end-member theories suggest convergence is accommodated by either: 1

  13. Mitigating the consequences of future earthquakes in historical centres: what perspectives from the joined use of past information and geological-geophysical surveys?

    NASA Astrophysics Data System (ADS)

    Terenzio Gizzi, Fabrizio; Moscatelli, Massimiliano; Potenza, Maria Rosaria; Zotta, Cinzia; Simionato, Maurizio; Pileggi, Domenico; Castenetto, Sergio

    2015-04-01

    To mitigate the damage effects of earthquakes in urban areas and particularly in historical centres prone to high seismic hazard is an important task to be pursued. As a matter of fact, seismic history throughout the world informs us that earthquakes have caused deep changes in the ancient urban conglomerations due to their high building vulnerability. Furthermore, some quarters can be exposed to an increase of seismic actions if compared with adjacent areas due to the geological and/or topographical features of the site on which the historical centres lie. Usually, the strategies aimed to estimate the local seismic hazard make only use of the geological-geophysical surveys. Thorough this approach we do not draw any lesson from what happened as a consequences of past earthquakes. With this in mind, we present the results of a joined use of historical data and traditional geological-geophysical approach to analyse the effects of possible future earthquakes in historical centres. The research activity discussed here is arranged into a joint collaboration between the Department of Civil Protection of the Presidency of Council of Ministers, the Institute of Environmental Geology and Geoengineering and the Institute of Archaeological and Monumental Heritage of the National (Italian) Research Council. In order to show the results, we discuss the preliminary achievements of the integrated study carried out on two historical towns located in Southern Apennines, a portion of the Italian peninsula exposed to high seismic hazard. Taking advantage from these two test sites, we also discuss some methodological implications that could be taken as a reference in the seismic microzonation studies.

  14. An evaluation of the science needs to inform decisions on Outer Continental Shelf energy development in the Chukchi and Beaufort Seas, Alaska

    USGS Publications Warehouse

    Holland-Bartels, Leslie; Pierce, Brenda

    2011-01-01

    On March 31, 2010, Secretary of the Interior Ken Salazar announced a national strategy for Outer Continental Shelf (OCS) oil and gas development. In that announcement, the Administration outlined a three-pronged approach (U.S. Department of the Interior, 2010a): Development: "...expand development and production throughout the Gulf of Mexico, including resource-rich areas of the Eastern Gulf of Mexico..." Exploration: "...expand oil and gas exploration in frontier areas, such as the Arctic Ocean and areas in the Atlantic Ocean, to gather the information necessary to develop resources in the right places and the right ways." Conservation: "...calls for the protection of special areas like Bristol Bay in Alaska...national treasure[s] that we must protect for future generations." In a companion announcement (U.S. Department of the Interior, 2010b), within the Administration's "Exploration" component, the Secretary asked the U.S. Geological Survey (USGS) to conduct an initial, independent evaluation of the science needs that would inform the Administration's consideration of the right places and the right ways in which to develop oil and gas resources in the Arctic OCS, particularly focused on the Beaufort and Chukchi Seas (fig. 1).

  15. An evaluation of the science needs to inform decisions on Outer Continental Shelf energy development in the Chukchi and Beaufort Seas, Alaska

    USGS Publications Warehouse

    Holland-Bartels, Leslie; Pierce, Brenda

    2011-01-01

    The U. S. Geological Survey (USGS) was asked to conduct an initial, independent evaluation of the science needs that would inform the Administration's consideration of the right places and the right ways in which to develop oil and gas resources in the Arctic Outer Continental Shelf (OCS), particularly focused on the Beaufort and Chukchi Seas. Oil and gas potential is significant in Arctic Alaska. Beyond petroleum potential, this region supports unique fish and wildlife resources and ecosystems, and indigenous people who rely on these resources for subsistence. This report summarizes key existing scientific information and provides initial guidance of what new and (or) continued research could inform decision making. This report is presented in a series of topical chapters and various appendixes each written by a subset of the USGS OCS Team based on their areas of expertise. Three chapters (Chapters 2, 3, and 4) provide foundational information on geology; ecology and subsistence; and climate settings important to understanding the conditions pertinent to development in the Arctic OCS. These chapters are followed by three chapters that examine the scientific understanding, science gaps, and science sufficiency questions regarding oil-spill risk, response, and impact (Chapter 5), marine mammals and anthropogenic noise (Chapter 6), and cumulative impacts (Chapter 7). Lessons learned from the 1989 Exxon Valdez Oil Spill are included to identify valuable "pre-positioned" science and scientific approaches to improved response and reduced uncertainty in damage assessment and restoration efforts (appendix D). An appendix on Structured Decision Making (appendix C) is included to illustrate the value of such tools that go beyond, but incorporate, science in looking at what can/should be done about policy and implementation of Arctic development. The report provides a series of findings and recommendations for consideration developed during the independent examination of

  16. Listening to Earthquakes with Infrasound

    NASA Astrophysics Data System (ADS)

    Mucek, A. E.; Langston, C. A.

    2011-12-01

    A tripartite infrasound array was installed to listen to earthquakes occurring along the Guy-Greenbrier fault in Arkansas. The active earthquake swarm is believed to be caused by deep waste water injections and will allow us to explain the mechanisms causing earthquake "booms" that have been heard during an earthquake. The array has an aperture of 50 meters and is installed next to the X301 seismograph station run by the Center for Earthquake Research and Information (CERI). This arrangement allows simultaneous recording of seismic and acoustic changes from the arrival of an earthquake. Other acoustic and seismic sources that have been found include thunder from thunderstorms, gunshots, quarry explosions and hydraulic fracturing activity from the local gas wells. The duration of the experiment is from the last week of June to the last week of September 2011. During the first month and a half, seven local earthquakes were recorded, along with numerous occurrences of the other infrasound sources. Phase arrival times of the recorded waves allow us to estimate wave slowness and azimuth of infrasound events. Using these two properties, we can determine whether earthquake "booms" occur at a site from the arrival of the P-wave or whether the earthquake "booms" occur elsewhere and travel through the atmosphere. Preliminary results show that the infrasound correlates well to the ground motion during an earthquake for frequencies below 15 Hertz.

  17. Geologic studies in Alaska by the U.S. Geological Survey, 1997

    USGS Publications Warehouse

    Kelley, Karen D.

    1999-01-01

    Geologic Framework studies provide background information that is the scientific basis for present and future studies of the environment, mineral and energy resources, paleoclimate, and hazards in Alaska. One paper presents the results of sedimentologic and paleontologic comparisons of lower Paleozoic, deep-water-facies rock units in central Alaska (Dumoulin and others). The authors show which of these units are likely to correlate with one another, suggest likely source regions, and provide a structural restoration of units that have been fragmented by large fault motions. A second framework paper provides a map, rock descriptions, and chemical compositions of volcanic rocks in a newly recognized, geologically young volcanic center in the Aleutian volcanic arc (Hildreth and others). A third paper presents an interesting summary of gravity changes that occurred in south-central Alaska during the great earthquake of 1964 and for the following 25 years (Barnes). Gravity changes correlate with land-elevation changes in some cases, but not in others, which means that different processes are responsible for the gravity changes.

  18. BAID: The Barrow Area Information Database - an interactive web mapping portal and cyberinfrastructure for scientific activities in the vicinity of Barrow, Alaska.

    NASA Astrophysics Data System (ADS)

    Cody, R. P.; Kassin, A.; Kofoed, K. B.; Copenhaver, W.; Laney, C. M.; Gaylord, A. G.; Collins, J. A.; Tweedie, C. E.

    2014-12-01

    The Barrow area of northern Alaska is one of the most intensely researched locations in the Arctic and the Barrow Area Information Database (BAID, www.barrowmapped.org) tracks and facilitates a gamut of research, management, and educational activities in the area. BAID is a cyberinfrastructure (CI) that details much of the historic and extant research undertaken within in the Barrow region in a suite of interactive web-based mapping and information portals (geobrowsers). The BAID user community and target audience for BAID is diverse and includes research scientists, science logisticians, land managers, educators, students, and the general public. BAID contains information on more than 12,000 Barrow area research sites that extend back to the 1940's and more than 640 remote sensing images and geospatial datasets. In a web-based setting, users can zoom, pan, query, measure distance, save or print maps and query results, and filter or view information by space, time, and/or other tags. Data are described with metadata that meet Federal Geographic Data Committee standards and are archived at the University Corporation for Atmospheric Research Earth Observing Laboratory (EOL) where non-proprietary BAID data can be freely downloaded. Recent advances include the addition of more than 2000 new research sites, provision of differential global position system (dGPS) and Unmanned Aerial Vehicle (UAV) support to visiting scientists, surveying over 80 miles of coastline to document rates of erosion, training of local GIS personal to better make use of science in local decision making, deployment and near real time connectivity to a wireless micrometeorological sensor network, links to Barrow area datasets housed at national data archives and substantial upgrades to the BAID website and web mapping applications.

  19. Earthquake prediction

    NASA Technical Reports Server (NTRS)

    Turcotte, Donald L.

    1991-01-01

    The state of the art in earthquake prediction is discussed. Short-term prediction based on seismic precursors, changes in the ratio of compressional velocity to shear velocity, tilt and strain precursors, electromagnetic precursors, hydrologic phenomena, chemical monitors, and animal behavior is examined. Seismic hazard assessment is addressed, and the applications of dynamical systems to earthquake prediction are discussed.

  20. Earthquake Hazards.

    ERIC Educational Resources Information Center

    Donovan, Neville

    1979-01-01

    Provides a survey and a review of earthquake activity and global tectonics from the advancement of the theory of continental drift to the present. Topics include: an identification of the major seismic regions of the earth, seismic measurement techniques, seismic design criteria for buildings, and the prediction of earthquakes. (BT)

  1. Sea-level changes before large earthquakes

    USGS Publications Warehouse

    Wyss, M.

    1978-01-01

    Changes in sea level have long been used as a measure of local uplift and subsidence associated with large earthquakes. For instance, in 1835, the British naturalist Charles Darwin observed that sea level dropped by 2.7 meters during the large earthquake in Concepcion, CHile. From this piece of evidence and the terraces along the beach that he saw, Darwin concluded that the Andes had grown to their present height through earthquakes. Much more recently, George Plafker and James C. Savage of the U.S Geological Survey have shown, from barnacle lines, that the great 1960 Chile and the 1964 Alaska earthquakes caused several meters of vertical displacement of the shoreline. 

  2. Safety and survival in an earthquake

    USGS Publications Warehouse

    ,

    1969-01-01

    Many earth scientists in this country and abroad are focusing their studies on the search for means of predicting impending earthquakes, but, as yet, an accurate prediction of the time and place of such an event cannot be made. From past experience, however, one can assume that earthquakes will continue to harass mankind and that they will occur most frequently in the areas where they have been relatively common in the past. In the United States, earthquakes can be expected to occur most frequently in the western states, particularly in Alaska, California, Washington, Oregon, Nevada, Utah, and Montana. The danger, however, is not confined to any one part of the country; major earthquakes have occurred at widely scattered locations.

  3. On subduction zone earthquakes and the Pacific Northwest seismicity

    SciTech Connect

    Chung, Dae H.

    1991-12-01

    A short review of subduction zone earthquakes and the seismicity of the Pacific Northwest region of the United States is provided for the purpose of a basis for assessing issues related to earthquake hazard evaluations for the region. This review of seismotectonics regarding historical subduction zone earthquakes and more recent seismological studies pertaining to rupture processes of subduction zone earthquakes, with specific references to the Pacific Northwest, is made in this brief study. Subduction zone earthquakes tend to rupture updip and laterally from the hypocenter. Thus, the rupture surface tends to become more elongated as one considers larger earthquakes (there is limited updip distance that is strongly coupled, whereas rupture length can be quite large). The great Aleutian-Alaska earthquakes of 1957, 1964, and 1965 had rupture lengths of greater than 650 km. The largest earthquake observed instrumentally, the M{sub W} 9.5, 1960 Chile Earthquake, had a rupture length over 1000 km. However, earthquakes of this magnitude are very unlikely on Cascadia. The degree of surface shaking has a very strong dependency on the depth and style of rupture. The rupture surface during a great earthquake shows heterogeneous stress drop, displacement, energy release, etc. The high strength zones are traditionally termed asperities and these asperities control when and how large an earthquake is generated. Mapping of these asperities in specific subduction zones is very difficult before an earthquake. They show up more easily in inversions of dynamic source studies of earthquake ruptures, after an earthquake. Because seismic moment is based on the total radiated-energy from an earthquake, the moment-based magnitude M{sub W} is superior to all other magnitude estimates, such as M{sub L}, m{sub b}, M{sub bLg}, M{sub S}, etc Probably, just to have a common language, non-moment magnitudes should be converted to M{sub W} in any discussions of subduction zone earthquakes.

  4. Analog earthquakes

    SciTech Connect

    Hofmann, R.B.

    1995-09-01

    Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed. A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository.

  5. Alaska Energy Inventory Project: Consolidating Alaska's Energy Resources

    NASA Astrophysics Data System (ADS)

    Papp, K.; Clough, J.; Swenson, R.; Crimp, P.; Hanson, D.; Parker, P.

    2007-12-01

    Alaska has considerable energy resources distributed throughout the state including conventional oil, gas, and coal, and unconventional coalbed and shalebed methane, gas hydrates, geothermal, wind, hydro, and biomass. While much of the known large oil and gas resources are concentrated on the North Slope and in the Cook Inlet regions, the other potential sources of energy are dispersed across a varied landscape from frozen tundra to coastal settings. Despite the presence of these potential energy sources, rural Alaska is mostly dependent upon diesel fuel for both electrical power generation and space heating needs. At considerable cost, large quantities of diesel fuel are transported to more than 150 roadless communities by barge or airplane and stored in large bulk fuel tank farms for winter months when electricity and heat are at peak demands. Recent increases in the price of oil have severely impacted the price of energy throughout Alaska, and especially hard hit are rural communities and remote mines that are off the road system and isolated from integrated electrical power grids. Even though the state has significant conventional gas resources in restricted areas, few communities are located near enough to these resources to directly use natural gas to meet their energy needs. To address this problem, the Alaska Energy Inventory project will (1) inventory and compile all available Alaska energy resource data suitable for electrical power generation and space heating needs including natural gas, coal, coalbed and shalebed methane, gas hydrates, geothermal, wind, hydro, and biomass and (2) identify locations or regions where the most economic energy resource or combination of energy resources can be developed to meet local needs. This data will be accessible through a user-friendly web-based interactive map, based on the Alaska Department of Natural Resources, Land Records Information Section's (LRIS) Alaska Mapper, Google Earth, and Terrago Technologies' Geo

  6. Earthquake hazards: a national threat

    USGS Publications Warehouse

    ,

    2006-01-01

    Earthquakes are one of the most costly natural hazards faced by the Nation, posing a significant risk to 75 million Americans in 39 States. The risks that earthquakes pose to society, including death, injury, and economic loss, can be greatly reduced by (1) better planning, construction, and mitigation practices before earthquakes happen, and (2) providing critical and timely information to improve response after they occur. As part of the multi-agency National Earthquake Hazards Reduction Program, the U.S. Geological Survey (USGS) has the lead Federal responsibility to provide notification of earthquakes in order to enhance public safety and to reduce losses through effective forecasts based on the best possible scientific information.

  7. Alaska's Economy: What's Ahead?

    ERIC Educational Resources Information Center

    Alaska Review of Social and Economic Conditions, 1987

    1987-01-01

    This review describes Alaska's economic boom of the early 1980s, the current recession, and economic projections for the 1990s. Alaska's economy is largely influenced by oil prices, since petroleum revenues make up 80% of the state government's unrestricted general fund revenues. Expansive state spending was responsible for most of Alaska's…

  8. The CATDAT damaging earthquakes database

    NASA Astrophysics Data System (ADS)

    Daniell, J. E.; Khazai, B.; Wenzel, F.; Vervaeck, A.

    2011-08-01

    The global CATDAT damaging earthquakes and secondary effects (tsunami, fire, landslides, liquefaction and fault rupture) database was developed to validate, remove discrepancies, and expand greatly upon existing global databases; and to better understand the trends in vulnerability, exposure, and possible future impacts of such historic earthquakes. Lack of consistency and errors in other earthquake loss databases frequently cited and used in analyses was a major shortcoming in the view of the authors which needed to be improved upon. Over 17 000 sources of information have been utilised, primarily in the last few years, to present data from over 12 200 damaging earthquakes historically, with over 7000 earthquakes since 1900 examined and validated before insertion into the database. Each validated earthquake includes seismological information, building damage, ranges of social losses to account for varying sources (deaths, injuries, homeless, and affected), and economic losses (direct, indirect, aid, and insured). Globally, a slightly increasing trend in economic damage due to earthquakes is not consistent with the greatly increasing exposure. The 1923 Great Kanto (214 billion USD damage; 2011 HNDECI-adjusted dollars) compared to the 2011 Tohoku (>300 billion USD at time of writing), 2008 Sichuan and 1995 Kobe earthquakes show the increasing concern for economic loss in urban areas as the trend should be expected to increase. Many economic and social loss values not reported in existing databases have been collected. Historical GDP (Gross Domestic Product), exchange rate, wage information, population, HDI (Human Development Index), and insurance information have been collected globally to form comparisons. This catalogue is the largest known cross-checked global historic damaging earthquake database and should have far-reaching consequences for earthquake loss estimation, socio-economic analysis, and the global reinsurance field.

  9. Oil-and-gas resources of Alaska

    SciTech Connect

    Not Available

    1985-01-01

    This is a short information circular on the history of oil-and-gas development in Alaska. It discusses the past discoveries and the future prospects and the estimated reserve base of the state. It also briefly discusses the oil-and-gas leasing program and exploration activity in the Arctic National Wildlife Refuge. A map of Alaska showing oil-and-gas fields, reserves, and lease boundaries is also provided.

  10. Dental caries in rural Alaska Native children--Alaska, 2008.

    PubMed

    2011-09-23

    In April 2008, the Arctic Investigations Program (AIP) of CDC was informed by the Alaska Department of Health and Social Services (DHSS) of a large number of Alaska Native (AN) children living in a remote region of Alaska who required full mouth dental rehabilitations (FMDRs), including extractions and/or restorations of multiple carious teeth performed under general anesthesia. In this remote region, approximately 400 FMDRs were performed in AN children aged <6 years in 2007; the region has approximately 600 births per year. Dental caries can cause pain, which can affect children's normal growth and development. AIP and Alaska DHSS conducted an investigation of dental caries and associated risk factors among children in the remote region. A convenience sample of children aged 4-15 years in five villages (two with fluoridated water and three without) was examined to estimate dental caries prevalence and severity. Risk factor information was obtained by interviewing parents. Among children aged 4-5 years and 12-15 years who were evaluated, 87% and 91%, respectively, had dental caries, compared with 35% and 51% of U.S. children in those age groups. Among children from the Alaska villages, those aged 4-5 years had a mean of 7.3 dental caries, and those aged 12-15 years had a mean of 5.0, compared with 1.6 and 1.8 dental caries in same-aged U.S. children. Of the multiple factors assessed, lack of water fluoridation and soda pop consumption were significantly associated with dental caries severity. Collaborations between tribal, state, and federal agencies to provide effective preventive interventions, such as water fluoridation of villages with suitable water systems and provision of fluoride varnishes, should be encouraged.

  11. Earthquake Facts

    MedlinePlus

    ... the source of earthquakes. Moonquakes (“earthquakes” on the moon) do occur, but they happen less frequently and ... with the varying distance between the Earth and Moon. They also occur at great depth, about halfway ...

  12. Earthquake Analysis.

    ERIC Educational Resources Information Center

    Espinoza, Fernando

    2000-01-01

    Indicates the importance of the development of students' measurement and estimation skills. Analyzes earthquake data recorded at seismograph stations and explains how to read and modify the graphs. Presents an activity for student evaluation. (YDS)

  13. Deep Earthquakes.

    ERIC Educational Resources Information Center

    Frohlich, Cliff

    1989-01-01

    Summarizes research to find the nature of deep earthquakes occurring hundreds of kilometers down in the earth's mantle. Describes further research problems in this area. Presents several illustrations and four references. (YP)

  14. Deep-seated gravitational slope deformations near the Trans-Alaska Pipeline, east-central Alaska Range, Alaska, USA

    NASA Astrophysics Data System (ADS)

    Newman, S. D.; Clague, J. J.; Rabus, B.; Stead, D.

    2013-12-01

    Multiple, active, deep-seated gravitational slope deformations (DSGSD) are present near the Trans-Alaska Pipeline and Richardson Highway in the east-central Alaska Range, Alaska, USA. We documented spatial and temporal variations in rates of surface movement of the DSGSDs between 2003 and 2011 using RADARSAT-1 and RADARSAT-2 D-InSAR images. Deformation rates exceed 10 cm/month over very large areas (>1 km2) of many rock slopes. Recent climatic change and strong seismic shaking, especially during the 2002 M 7.9 Denali Fault earthquake, appear to have exacerbated slope deformation. We also mapped DSGSD geological and morphological characteristics using field- and GIS-based methods, and constructed a conceptual 2D distinct-element numerical model of one of the DSGSDs. Preliminary results indicate that large-scale buckling or kink-band slumping may be occurring. The DSGSDs are capable of generating long-runout landslides that might impact the Trans-Alaska Pipeline and Richardson Highway. They could also block tributary valleys, thereby impounding lakes that might drain suddenly. Wrapped 24-day RADARSAT-2 descending spotlight interferogram showing deformation north of Fels Glacier. The interferogram is partially transparent and is overlaid on a 2009 WorldView-1 panchromatic image. Acquisition interval: August 2 - August 26, 2011. UTM Zone 6N.

  15. Catalog of earthquake hypocenters at Alaskan volcanoes: January 1 through December 31, 2011

    USGS Publications Warehouse

    Dixon, James P.; Stihler, Scott D.; Power, John A.; Searcy, Cheryl K.

    2012-01-01

    Between January 1 and December 31, 2011, the Alaska Volcano Observatory (AVO) located 4,364 earthquakes, of which 3,651 occurred within 20 kilometers of the 33 volcanoes with seismograph subnetworks. There was no significant seismic activity above background levels in 2011 at these instrumented volcanic centers. This catalog includes locations, magnitudes, and statistics of the earthquakes located in 2011 with the station parameters, velocity models, and other files used to locate these earthquakes.

  16. Seismic component of the STEEP project, Alaska: Results of the first field season

    NASA Astrophysics Data System (ADS)

    Hansen, R. A.; Estes, S.; Stachnik, J.; Lafevers, M.; Roush, J.; Sanches, R.; Fuerst, E.; Sandru, J.; Ruppert, N.; Pavlis, G.; Bauer, M.

    2005-12-01

    STEEP (SainT Elias Erosion/tectonics Project) is a five year, multi-disciplinary study that addresses evolution of the highest coastal mountain range on Earth - the St. Elias Mountains of southern Alaska and northwestern Canada. The overall goal of the project is to develop a comprehensive model for the St. Elias orogen that accounts for the interaction of regional plate tectonic processes, structural development, and rapid erosion. The seismic component of this project includes passive seismic experiment utilizing the IRIS PASSCAL Program instruments. The total project consists of 22 new, telemetered, digital broad band seismic stations, most accessible by helicopter only. There are 12 existing short period stations in the area. Eight new stations were installed in the coastal region in June 2005. Freewave IP radios provide the telemetry to the newly installed VSAT at the Bering Glacier camp site. The challenge was to find ice-free locations, on bedrock, large enough to install equipment and still have a helicopter landing zone nearby. The stations consist of Quanterra Q330 digitizers with baler, a STS-2 seismometer installed in a vault, a Freewave IP radio, a Scala 900 Mhz antenna, twenty 100 AH rechargeable batteries with a 2400AH backup Celair primary battery, and three solar panels mounted on hut. The acquired data is recorded in real time at the Alaska Earthquake Information Center located in Fairbanks and is incorporated into the standard data processing procedures. High quality data allows for more reliable automatic earthquake detections in the region with lower magnitude threshold. In addition to tectonic earthquakes, glacial events that occur within the vast ice fields of the region are also regularly detected. Broadband instruments complement regional broadband network for more reliable calculations of the regional moment tensors.

  17. Extending HTDP to address crustal motion across Alaska

    NASA Astrophysics Data System (ADS)

    Pearson, C. F.; Snay, R.

    2008-12-01

    Deformation in the western United States, due to tectonic forces associated with the Pacific-North American plate boundary, causes ongoing changes of the positions of points on the Earth's surface . As a result, accurate surveying in the western US requires an equally accurate description of this deformation to allow survey measurements conducted at different epochs to be corrected for such movement. NOAA's National Geodetic Survey (NGS) has developed the HTDP (horizontal time dependent positioning) software that enables its users to make these corrections for the horizontal component of motion. HTDP contains a model of the secular (continuous) velocity field for the contiguous United States (from 125º to 100ºW longitude and 31º to 49ºN latitude) and separate models for the displacements associated with 28 earthquakes. The software is updated periodically to address the displacements associated with new earthquakes, most recently in June 2008 with the release version 3.0. This presentation describes a major effort to update HTDP to accurately model earth deformation in Alaska. As a start in this process, the recent release of HTDP introduced a model for the Denali Earthquake of 2002 to accompany its pre-existing model for the Prince William Sound earthquake of 1964. The Denali Earthquake produced displacements of several meters near the fault and measurable displacements throughout most of central Alaska. The dislocation model we used was developed by Elliott et al. (2007). We tested the predicted movement associated with the Denali earthquake using a set of 126 measured displacement vectors distributed over most of the interior of Alaska. The agreement between predicted and observed displacements was good with a RMS misfit of 0.1m in both the north and east components. A few large (> 1m) discrepancies were found in the vicinity of the fault trace. These discrepancies probably indicate that complex fault geometry--that no simple dislocation model can match

  18. BAID: The Barrow Area Information Database - An Interactive Web Mapping Portal and Cyberinfrastructure Showcasing Scientific Activities in the Vicinity of Barrow, Arctic Alaska.

    NASA Astrophysics Data System (ADS)

    Escarzaga, S. M.; Cody, R. P.; Kassin, A.; Barba, M.; Gaylord, A. G.; Manley, W. F.; Mazza Ramsay, F. D.; Vargas, S. A., Jr.; Tarin, G.; Laney, C. M.; Villarreal, S.; Aiken, Q.; Collins, J. A.; Green, E.; Nelson, L.; Tweedie, C. E.

    2015-12-01

    The Barrow area of northern Alaska is one of the most intensely researched locations in the Arctic and the Barrow Area Information Database (BAID, www.barrowmapped.org) tracks and facilitates a gamut of research, management, and educational activities in the area. BAID is a cyberinfrastructure (CI) that details much of the historic and extant research undertaken within in the Barrow region in a suite of interactive web-based mapping and information portals (geobrowsers). The BAID user community and target audience for BAID is diverse and includes research scientists, science logisticians, land managers, educators, students, and the general public. BAID contains information on more than 12,000 Barrow area research sites that extend back to the 1940's and more than 640 remote sensing images and geospatial datasets. In a web-based setting, users can zoom, pan, query, measure distance, save or print maps and query results, and filter or view information by space, time, and/or other tags. Additionally, data are described with metadata that meet Federal Geographic Data Committee standards. Recent advances include the addition of more than 2000 new research sites, the addition of a query builder user interface allowing rich and complex queries, and provision of differential global position system (dGPS) and high-resolution aerial imagery support to visiting scientists. Recent field surveys include over 80 miles of coastline to document rates of erosion and the collection of high-resolution sonar data for bathymetric mapping of Elson Lagoon and near shore region of the Chukchi Sea. A network of five climate stations has been deployed across the peninsula to serve as a wireless net for the research community and to deliver near real time climatic data to the user community. Local GIS personal have also been trained to better make use of scientific data for local decision making. Links to Barrow area datasets are housed at national data archives and substantial upgrades have

  19. BAID: The Barrow Area Information Database - an interactive web mapping portal and cyberinfrastructure for scientific activities in the vicinity of Barrow, Alaska

    NASA Astrophysics Data System (ADS)

    Cody, R. P.; Kassin, A.; Gaylord, A.; Brown, J.; Tweedie, C. E.

    2012-12-01

    The Barrow area of northern Alaska is one of the most intensely researched locations in the Arctic. The Barrow Area Information Database (BAID, www.baidims.org) is a cyberinfrastructure (CI) that details much of the historic and extant research undertaken within in the Barrow region in a suite of interactive web-based mapping and information portals (geobrowsers). The BAID user community and target audience for BAID is diverse and includes research scientists, science logisticians, land managers, educators, students, and the general public. BAID contains information on more than 9,600 Barrow area research sites that extend back to the 1940's and more than 640 remote sensing images and geospatial datasets. In a web-based setting, users can zoom, pan, query, measure distance, and save or print maps and query results. Data are described with metadata that meet Federal Geographic Data Committee standards and are archived at the University Corporation for Atmospheric Research Earth Observing Laboratory (EOL) where non-proprietary BAID data can be freely downloaded. BAID has been used to: Optimize research site choice; Reduce duplication of science effort; Discover complementary and potentially detrimental research activities in an area of scientific interest; Re-establish historical research sites for resampling efforts assessing change in ecosystem structure and function over time; Exchange knowledge across disciplines and generations; Facilitate communication between western science and traditional ecological knowledge; Provide local residents access to science data that facilitates adaptation to arctic change; (and) Educate the next generation of environmental and computer scientists. This poster describes key activities that will be undertaken over the next three years to provide BAID users with novel software tools to interact with a current and diverse selection of information and data about the Barrow area. Key activities include: 1. Collecting data on research

  20. Forestry timber typing. Tanana demonstration project, Alaska ASVT. [Alaska

    NASA Technical Reports Server (NTRS)

    Morrissey, L. A.; Ambrosia, V. G.

    1982-01-01

    The feasibility of using LANDSAT digital data in conjunction with topographic data to delineate commercial forests by stand size and crown closure in the Tanana River basin of Alaska was tested. A modified clustering approach using two LANDSAT dates to generate an initial forest type classification was then refined with topographic data. To further demonstrate the ability of remotely sensed data in a fire protection planning framework, the timber type data were subsequently integrated with terrain information to generate a fire hazard map of the study area. This map provides valuable assistance in initial attack planning, determining equipment accessibility, and fire growth modeling. The resulting data sets were incorporated into the Alaska Department of Natural Resources geographic information system for subsequent utilization.

  1. Early Earthquakes of the Americas

    NASA Astrophysics Data System (ADS)

    Ni, James

    2004-11-01

    Robert Kovach's second book looks at the interplay of earthquake and volcanic events, archeology, and history in the Americas. Throughout history, major earthquakes have caused the deaths of millions of people and have damaged countless cities. Earthquakes undoubtedly damaged prehistoric cities in the Americas, and evidence of these events could be preserved in archeological records. Kovach asks, Did indigenous native cultures-Indians of the Pacific Northwest, Aztecs, Mayas, and Incas-document their natural history? Some events have been explicitly documented, for example, in Mayan codices, but many may have been recorded as myth and legend. Kovach's discussions of how early cultures dealt with fearful events such as earthquakes and volcanic eruptions are colorful, informative, and entertaining, and include, for example, a depiction of how the Maya would talk to maize plants in their fields during earthquakes to reassure them.

  2. What Can Sounds Tell Us About Earthquake Interactions?

    NASA Astrophysics Data System (ADS)

    Aiken, C.; Peng, Z.

    2012-12-01

    It is important not only for seismologists but also for educators to effectively convey information about earthquakes and the influences earthquakes can have on each other. Recent studies using auditory display [e.g. Kilb et al., 2012; Peng et al. 2012] have depicted catastrophic earthquakes and the effects large earthquakes can have on other parts of the world. Auditory display of earthquakes, which combines static images with time-compressed sound of recorded seismic data, is a new approach to disseminating information to a general audience about earthquakes and earthquake interactions. Earthquake interactions are influential to understanding the underlying physics of earthquakes and other seismic phenomena such as tremors in addition to their source characteristics (e.g. frequency contents, amplitudes). Earthquake interactions can include, for example, a large, shallow earthquake followed by increased seismicity around the mainshock rupture (i.e. aftershocks) or even a large earthquake triggering earthquakes or tremors several hundreds to thousands of kilometers away [Hill and Prejean, 2007; Peng and Gomberg, 2010]. We use standard tools like MATLAB, QuickTime Pro, and Python to produce animations that illustrate earthquake interactions. Our efforts are focused on producing animations that depict cross-section (side) views of tremors triggered along the San Andreas Fault by distant earthquakes, as well as map (bird's eye) views of mainshock-aftershock sequences such as the 2011/08/23 Mw5.8 Virginia earthquake sequence. These examples of earthquake interactions include sonifying earthquake and tremor catalogs as musical notes (e.g. piano keys) as well as audifying seismic data using time-compression. Our overall goal is to use auditory display to invigorate a general interest in earthquake seismology that leads to the understanding of how earthquakes occur, how earthquakes influence one another as well as tremors, and what the musical properties of these

  3. Earthquake impact scale

    USGS Publications Warehouse

    Wald, D.J.; Jaiswal, K.S.; Marano, K.D.; Bausch, D.

    2011-01-01

    also be both specific (although allowably uncertain) and actionable. In this analysis, an attempt is made at both simple and intuitive color-coded alerting criteria; yet the necessary uncertainty measures by which one can gauge the likelihood for the alert to be over- or underestimated are preserved. The essence of the proposed impact scale and alerting is that actionable loss information is now available in the immediate aftermath of significant earthquakes worldwide on the basis of quantifiable loss estimates. Utilizing EIS, PAGER's rapid loss estimates can adequately recommend alert levels and suggest appropriate response protocols, despite the uncertainties; demanding or awaiting observations or loss estimates with a high level of accuracy may increase the losses. ?? 2011 American Society of Civil Engineers.

  4. United States earthquakes, 1984

    SciTech Connect

    Stover, C.W.

    1988-01-01

    The report contains information for eartthquakes in the 50 states and Puerto Rico and the area near their shorelines. The data consist of earthquake locations (date, time, geographic coordinates, depth, and magnitudes), intensities, macroseismic information, and isoseismal and seismicity maps. Also, included are sections detailing the activity of seismic networks operated by universities and other government agencies and a list of results form strong-motion seismograph records.

  5. Numerical modeling of the 1964 Alaska tsunami runup in Chenega Cove, Alaska: the role of horizontal displacements of ocean bottom

    NASA Astrophysics Data System (ADS)

    Nicolsky, D. J.; Suleimani, E. N.; Hansen, R. A.

    2012-12-01

    On March 27, 1964, the Prince William Sound area of Alaska was struck by the largest earthquake ever recorded in North America. This magnitude Mw9.2 megathrust earthquake generated the most destructive tsunami in Alaska history and, farther south, impacted the west coast of the United States and Canada. A numerical model of the wave dynamics in Chenega Cove, Alaska during the historic Mw9.2 megathrust earthquake is presented. During the earthquake, locally generated waves of unknown origin were identified at the village of Chenega, located in the western part of Prince William Sound. The waves appeared shortly after the shaking began and swept away most of the buildings while the shaking continued. We model the tectonic tsunami in Chenega Cove assuming different tsunami generation processes. We show that the village of Chenega was inundated by local waves triggered by the vertical and horizontal displacements shortly after the beginning of the ground shaking. Modeled results are compared with eyewitness reports and an observed runup. We also present an explanation for the fact that arrivals of later waves in Chenega were unnoticed. Results of the numerical experiments let us claim the importance of including both vertical and horizontal displacement into the 1964 tsunami generation process. The presented results will help to mitigate tsunami hazards and prepare this and other communities in similar geological settings for a potential tsunami.

  6. Information on the Earth's Deep Interior Conveyed by the 2004 Sumatra-Andaman Earthquake Using Superconducting Gravimeter Data

    NASA Astrophysics Data System (ADS)

    Rosat, S.; Watada, S.; Sato, T.; Tamura, Y.

    2005-12-01

    The recent Sumatra-Andaman earthquake of magnitude Mw > 9 on 2004 December 26th has strongly excited the low-frequency seismic modes and, in particular, the degree one 2S1 mode is observed for the first time without any stacking. This mode corresponds to the first overtone of the sub-seismic mode 1S1, the so-called Slichter triplet (Slichter, Proc. Nat. Acad. Sci., 1961). On the one hand, theoretical computations suggest that the Slichter modes could not have been excited with sufficient amplitude to be detected by superconducting gravimeters (SGs) on the Earth's surface. The maximum surface gravity effect of 1S1 after Sumatra event is 0.3 nGal, that is to say 0.3 10-12 g, where g is the mean absolute gravity value on the Earth's surface, corresponding to a free air displacement of 10-3 mm (1 nm). On the other hand, the core-sensitive mode 3S2 and the fundamental radial mode 0S0 were strongly excited, meaning that the earthquake radiated much energy toward the core. 0S0 is a radial fundamental spheroidal mode called "breathing mode" of the Earth and corresponds to changes in the Earth's circumference. The high stability of SG records has enabled us to follow the time decay of 0S0 amplitude till the second Sumatra event on March 28th 2005 and to estimate 0S0 quality factor at a value of 5513 +- 8 from the weighted mean of 12 SG record estimates. Amplitude measurements of 0S0 at most SG sites in the world reveal a latitude dependency that we try to explain by theory. The amplitude deviation of 0S0 reaches +- 2% while the calibration errors of SGs are usually less than 0.2%.

  7. Ultralow-Frequency Magnetic Fields Preceding Large Earthquakes

    NASA Astrophysics Data System (ADS)

    Fraser-Smith, Antony C.

    2008-06-01

    The Great Alaska Earthquake (M 9.2) of 27 March 1964 was the largest earthquake ever to strike the United States in modern times and one of the largest ever recorded anywhere. Later that year, Moore [1964], in a surprisingly rarely cited paper, reported the occurrence of strong ultralow-frequency (ULF; <=10 hertz) magnetic field disturbances at Kodiak, Alaska, in the 1.2 hours before the earthquake. That report has since been followed by others [Fraser-Smith et al., 1990; Kopytenko et al., 1993; Hayakawa et al., 1996; see also Molchanov et al., 1992] similarly describing the occurrence of large-amplitude ULF magnetic field fluctuations before other large earthquakes (``large'' describes earthquakes with magnitudes M ~ 7 or greater). These reports involving four separate, large earthquakes were made by four different groups and the results were published in well-known, refereed scientific journals, so there is no doubt that there is evidence for the existence of comparatively large ULF magnetic field fluctuations preceding large earthquakes.

  8. Recent sedimentation, northeastern Port Valdez, Alaska

    NASA Astrophysics Data System (ADS)

    Palmer, Harold D.

    1981-09-01

    Sediments accumulating on the northeastern shore of Port Valdez, a fjord leading to Prince William Sound in southern Alaska, are derived from both deltaic and alluvial fan processes. The resulting thick wedge of Recent silts, sands, shells and gravels lies atop irregular ridges of local graywacke bedrock and scattered till deposits. Seismic reflection profiling augmented by soil borings indicates that rapid infilling and upbuilding has occurred at this site. Evidence of slumping suggests general instability of steep submarine slopes in an area characterized by strong earthquakes and large tidal ranges.

  9. Deep earthquakes

    SciTech Connect

    Frohlich, C.

    1989-01-01

    Earthquakes are often recorded at depths as great as 650 kilometers or more. These deep events mark regions where plates of the earth's surface are consumed in the mantle. But the earthquakes themselves present a conundrum: the high pressures and temperatures at such depths should keep rock from fracturing suddenly and generating a tremor. This paper reviews the research on this problem. Almost all deep earthquakes conform to the pattern described by Wadati, namely, they generally occur at the edge of a deep ocean and define an inclined zone extending from near the surface to a depth of 600 kilometers of more, known as the Wadati-Benioff zone. Several scenarios are described that were proposed to explain the fracturing and slipping of rocks at this depth.

  10. Inundation Mapping and Hazard Assessment of Tectonic and Landslide Tsunamis in Southeast Alaska

    NASA Astrophysics Data System (ADS)

    Suleimani, E.; Nicolsky, D.; Koehler, R. D., III

    2014-12-01

    The Alaska Earthquake Center conducts tsunami inundation mapping for coastal communities in Alaska, and is currently focused on the southeastern region and communities of Yakutat, Elfin Cove, Gustavus and Hoonah. This activity provides local emergency officials with tsunami hazard assessment, planning, and mitigation tools. At-risk communities are distributed along several segments of the Alaska coastline, each having a unique seismic history and potential tsunami hazard. Thus, a critical component of our project is accurate identification and characterization of potential tectonic and landslide tsunami sources. The primary tectonic element of Southeast Alaska is the Fairweather - Queen Charlotte fault system, which has ruptured in 5 large strike-slip earthquakes in the past 100 years. The 1958 "Lituya Bay" earthquake triggered a large landslide into Lituya Bay that generated a 540-m-high wave. The M7.7 Haida Gwaii earthquake of October 28, 2012 occurred along the same fault, but was associated with dominantly vertical motion, generating a local tsunami. Communities in Southeast Alaska are also vulnerable to hazards related to locally generated waves, due to proximity of communities to landslide-prone fjords and frequent earthquakes. The primary mechanisms for local tsunami generation are failure of steep rock slopes due to relaxation of internal stresses after deglaciation, and failure of thick unconsolidated sediments accumulated on underwater delta fronts at river mouths. We numerically model potential tsunami waves and inundation extent that may result from future hypothetical far- and near-field earthquakes and landslides. We perform simulations for each source scenario using the Alaska Tsunami Model, which is validated through a set of analytical benchmarks and tested against laboratory and field data. Results of numerical modeling combined with historical observations are compiled on inundation maps and used for site-specific tsunami hazard assessment by

  11. Office of Environmental Information (OEI) Tribal Strategy: Partnership to Support Environmental Information and Decision-Making in Indian Country and Alaska Native Villages

    EPA Pesticide Factsheets

    This draft strategy provides a description of goals OEI seeks to accomplish to support tribal information and environmental decision-making. States objectives to facilitate and strengthen tribal capacity to collect, analyze and share data.

  12. Expanding Job Opportunities for Alaska Natives. (Interim Report).

    ERIC Educational Resources Information Center

    McDiarmid, G. Williamson; Goldsmith, Scott; Killorin, Mary; Sharp, Suzanne; Hild, Carl

    A majority of adults in most Alaska Native villages were without jobs in 1990, and the situation was probably not substantially better in 1998. This report summarizes current Alaska Native employment data and employment trends, provides information on public and private programs that target Native hire, and describes promising approaches for…

  13. Alaska Education Directory, School Year 1999-2000.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau.

    This 1999-2000 directory provides information on Alaska's public schools, school districts, education organizations, and institutions of higher education. A statistical summary indicates that in 1998-99, Alaska enrolled 132,905 students in 503 public schools. Breakdowns by grade configuration and enrollment show that about half the schools served…

  14. 78 FR 21597 - Marine Mammals: Alaska Harbor Seal Habitats

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-11

    ... National Oceanic and Atmospheric Administration RIN 0648-BB71 Marine Mammals: Alaska Harbor Seal Habitats... measures to protect glacially-associated harbor seal habitats in Alaska (78 FR 15669; March 12, 2013). During the workshops NMFS will present information regarding harbor seal habitat usage and...

  15. A Summary of Changes in the Status of Alaska Natives.

    ERIC Educational Resources Information Center

    Alaska Univ., Anchorage. Inst. of Social and Economic Research.

    Replication of 78 tables from the 1973 2(c) Report by the Secretary of the Interior using 1980 census information provided data to document the social and economic changes in the status of Alaska Natives since the passage of the Alaska Native Claims Settlement Act. Comparison of 1970 and 1980 data showed an average 2.4% growth rate in the Native…

  16. Alaska Volcano Observatory

    USGS Publications Warehouse

    Venezky, Dina Y.; Murray, Tom; Read, Cyrus

    2008-01-01

    Steam plume from the 2006 eruption of Augustine volcano in Cook Inlet, Alaska. Explosive ash-producing eruptions from Alaska's 40+ historically active volcanoes pose hazards to aviation, including commercial aircraft flying the busy North Pacific routes between North America and Asia. The Alaska Volcano Observatory (AVO) monitors these volcanoes to provide forecasts of eruptive activity. AVO is a joint program of the U.S. Geological Survey (USGS), the Geophysical Institute of the University of Alaska Fairbanks (UAFGI), and the State of Alaska Division of Geological and Geophysical Surveys (ADGGS). AVO is one of five USGS Volcano Hazards Program observatories that monitor U.S. volcanoes for science and public safety. Learn more about Augustine volcano and AVO at http://www.avo.alaska.edu.

  17. The future of successful aging in Alaska

    PubMed Central

    Lewis, Jordan

    2013-01-01

    Background There is a paucity of research on Alaska Natives and their views on whether or not they believe they will age successfully in their home and community. There is limited understanding of aging experiences across generations. Objective This research explores the concept of successful aging from an urban Alaska Native perspective and explores whether or not they believe they will achieve a healthy older age. Design A cultural consensus model (CCM) approach was used to gain a sense of the cultural understandings of aging among young Alaska Natives aged 50 years and younger. Results Research findings indicate that aging successfully is making the conscious decision to live a clean and healthy life, abstaining from drugs and alcohol, but some of Alaska Natives do not feel they will age well due to lifestyle factors. Alaska Natives see the inability to age well as primarily due to the decrease in physical activity, lack of availability of subsistence foods and activities, and the difficulty of living a balanced life in urban settings. Conclusions This research seeks to inform future studies on successful aging that incorporates the experiences and wisdom of Alaska Natives in hopes of developing an awareness of the importance of practicing a healthy lifestyle and developing guidelines to assist others to age well. PMID:23984300

  18. Historic and instrumental earthquake records of Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Jeon, Y.

    2012-12-01

    NIMR(National Institute of Meteorological Researches) published historic earthquake catalogs of Korean Peninsula recently. This catalog contains 2161 events recorded at historic documents such as annals of the Jo-seon dynasty and the chronicles of 3 countries. Among those events, 440 earthquakes classified as intensity greater than 5(Korea intensity scale) and 15 earthquakes having intensity between 8 to 10(Korea intensity scale) are interpreted as damaging earthquake. Kyung-Ju earthquake occurred at 779 was the greatest one with M 6.7 and killed 100 people written by historic records. Several records contained the information of damage and casualties from possible Tsunami event. The purpose of making earthquake catalog is to define potential earthquake hazard of Korean Peninsula. As a result of collecting earthquake records for last 2000 years, the Intensity population distribution of historic earthquake marked similar to that of present instrumental earthquake record of KMA bulletin.

  19. Environmental impact analysis; the example of the proposed Trans-Alaska Pipeline

    USGS Publications Warehouse

    Brew, David A.

    1974-01-01

    loss from the pipeline, from tankers, or in the oil field. Oil losses from the pipeline could be caused by direct or indirect effects of earthquakes, destructive sea waves, slope failure caused by natural or artificial processes, thaw-plug instability (in permafrost), differential settlement of permafrost terrain, and bed scour and bank erosion at stream crossings. Oil loss from tankers could be caused by accidents during transfer operations at Valdez and at destination ports and by casualties involving tankers and other ships. Comparison of alternative routes and transportation systems and of their environmental impacts provided information which indicates to the author that one corridor containing both oil and gas pipelines would have less environmental impact than would separate corridors. Considering also the threat to the marine environment that any tanker system would impose and the threat that zones of high earthquake frequency and magnitude would impose on pipelines, it is apparent to the author that environmental impact and cost would be least for a single-corridor on-land route that avoided earthquake zones. The alternative trans-Alaska-Canada routes would meet these criteria. The decisions of the U.S. Department of the Interior, the U.S. Congress, and the President of the United States in favor of the proposed trans-Alaska pipeline system indicate the relative weight given by the decision makers in balancing the importance of potential environmental consequences against the advantages to be derived from rapid resource development.

  20. Multi-interferogram method for measuring interseismic deformation: Denali Fault, Alaska

    USGS Publications Warehouse

    Biggs, Juliet; Wright, Tim; Lu, Zhong; Parsons, Barry

    2007-01-01

    Studies of interseismic strain accumulation are crucial to our understanding of continental deformation, the earthquake cycle and seismic hazard. By mapping small amounts of ground deformation over large spatial areas, InSAR has the potential to produce continental-scale maps of strain accumulation on active faults. However, most InSAR studies to date have focused on areas where the coherence is relatively good (e.g. California, Tibet and Turkey) and most analysis techniques (stacking, small baseline subset algorithm, permanent scatterers, etc.) only include information from pixels which are coherent throughout the time-span of the study. In some areas, such as Alaska, where the deformation rate is small and coherence very variable, it is necessary to include information from pixels which are coherent in some but not all interferograms. We use a three-stage iterative algorithm based on distributed scatterer interferometry. We validate our method using synthetic data created using realistic parameters from a test site on the Denali Fault, Alaska, and present a preliminary result of 10.5 ?? 5.0 mm yr-1 for the slip rate on the Denali Fault based on a single track of radar data from ERS1/2. ?? 2007 The Authors Journal compilation ?? 2007 RAS.

  1. Earthquake engineering research: 1982

    NASA Astrophysics Data System (ADS)

    The Committee on Earthquake Engineering Research addressed two questions: What progress has research produced in earthquake engineering and which elements of the problem should future earthquake engineering pursue. It examined and reported in separate chapters of the report: Applications of Past Research, Assessment of Earthquake Hazard, Earthquake Ground Motion, Soil Mechanics and Earth Structures, Analytical and Experimental Structural Dynamics, Earthquake Design of Structures, Seismic Interaction of Structures and Fluids, Social and Economic Aspects, Earthquake Engineering Education, Research in Japan.

  2. Earthquake Testing

    NASA Technical Reports Server (NTRS)

    1979-01-01

    During NASA's Apollo program, it was necessary to subject the mammoth Saturn V launch vehicle to extremely forceful vibrations to assure the moonbooster's structural integrity in flight. Marshall Space Flight Center assigned vibration testing to a contractor, the Scientific Services and Systems Group of Wyle Laboratories, Norco, California. Wyle-3S, as the group is known, built a large facility at Huntsville, Alabama, and equipped it with an enormously forceful shock and vibration system to simulate the liftoff stresses the Saturn V would encounter. Saturn V is no longer in service, but Wyle-3S has found spinoff utility for its vibration facility. It is now being used to simulate earthquake effects on various kinds of equipment, principally equipment intended for use in nuclear power generation. Government regulations require that such equipment demonstrate its ability to survive earthquake conditions. In upper left photo, Wyle3S is preparing to conduct an earthquake test on a 25ton diesel generator built by Atlas Polar Company, Ltd., Toronto, Canada, for emergency use in a Canadian nuclear power plant. Being readied for test in the lower left photo is a large circuit breaker to be used by Duke Power Company, Charlotte, North Carolina. Electro-hydraulic and electro-dynamic shakers in and around the pit simulate earthquake forces.

  3. Deep-seated gravitational slope deformations near the Trans-Alaska Pipeline, east-central Alaska Range

    NASA Astrophysics Data System (ADS)

    Newman, Stephen Delmont, Jr.

    I investigated active deep-seated gravitational slope deformation (DSGSD) near the Trans-Alaska Pipeline and Richardson Highway in the east-central Alaska Range, Alaska, USA. I documented the presence, spatial extent, and rates of DSGSD using field-geology methods and optical, SAR, and D-InSAR remote-sensing images. I also documented and mapped many of the morphological, geological, and structural characteristics of slopes undergoing DSGSD, and constructed conceptual numerical models to better understand potential deformation mechanisms. Results confirm that many large DSGSD slopes in the study area are actively deforming. Deformation rates range from less than a millimetre per month to more than ten centimetres per month, and are spatially and temporally varient within each slope. Deforming slopes are characterized by differential movement of kilometre-scale rock blocks. Recent climatic changes and strong seismic shaking, especially during the recent 2002 Denali Fault earthquake, have exacerbated ongoing deformation. Study-area DSGSDs should be considered capable of generating long-runout rock avalanches that could directly sever the Trans-Alaska Pipeline and Richardson Highway, or that could dam up valleys and lead to the buildup and catastrophic failure of landslide-dammed lakes capable of impacting said infrastructure. Keywords: Deep-seated gravitational slope deformation; sackung; Trans-Alaska Pipeline; geomorphology; InSAR; Alaska Range.

  4. 76 FR 11811 - Environmental Document Prepared in Support of Oil and Gas Activities on the Alaska Outer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-03

    ... of Oil and Gas Activities on the Alaska Outer Continental Shelf AGENCY: Bureau of Ocean Energy... activities proposed on the Alaska Outer Continental Shelf (OCS). FOR FURTHER INFORMATION CONTACT:...

  5. The Alaska Mineral Resource Assessment Program

    SciTech Connect

    Detterman, R.L.; Case, J.E.; Church, S.E.; Frisken, J.G.; Wilson, F.H.; Yount, M.E.

    1990-01-01

    This book provides background information for the folio of maps that covers the geology, paleontology, geochronology, geochemistry, aeromagnetics, and mineral and energy resources of the Ugashik, Bristol Bay, and western Karluk quadrangles, Alaska Peninsula. Information on two U.S. Geological Survey miscellaneous investigations series maps and three derivative bulletins that resulted from this investigation are described also.

  6. The United States National Climate Assessment - Alaska Technical Regional Report

    USGS Publications Warehouse

    Markon, Carl J.; Trainor, Sarah F.; Chapin, F. Stuart; Markon, Carl J.; Trainor, Sarah F.; Chapin, F. Stuart

    2012-01-01

    The Alaskan landscape is changing, both in terms of effects of human activities as a consequence of increased population, social and economic development and their effects on the local and broad landscape; and those effects that accompany naturally occurring hazards such as volcanic eruptions, earthquakes, and tsunamis. Some of the most prevalent changes, however, are those resulting from a changing climate, with both near term and potential upcoming effects expected to continue into the future. Alaska's average annual statewide temperatures have increased by nearly 4°F from 1949 to 2005, with significant spatial variability due to the large latitudinal and longitudinal expanse of the State. Increases in mean annual temperature have been greatest in the interior region, and smallest in the State's southwest coastal regions. In general, however, trends point toward increases in both minimum temperatures, and in fewer extreme cold days. Trends in precipitation are somewhat similar to those in temperature, but with more variability. On the whole, Alaska saw a 10-percent increase in precipitation from 1949 to 2005, with the greatest increases recorded in winter. The National Climate Assessment has designated two well-established scenarios developed by the Intergovernmental Panel on Climate Change (Nakicenovic and others, 2001) as a minimum set that technical and author teams considered as context in preparing portions of this assessment. These two scenarios are referred to as the Special Report on Emissions Scenarios A2 and B1 scenarios, which assume either a continuation of recent trends in fossil fuel use (A2) or a vigorous global effort to reduce fossil fuel use (B1). Temperature increases from 4 to 22°F are predicted (to 2070-2099) depending on which emissions scenario (A2 or B1) is used with the least warming in southeast Alaska and the greatest in the northwest. Concomitant with temperature changes, by the end of the 21st century the growing season is expected

  7. Earthquake tectonics

    SciTech Connect

    Steward, R.F. )

    1991-02-01

    Earthquakes release a tremendous amount of energy into the subsurface in the form of seismic waves. The seismic wave energy of the San Francisco 1906 (M = 8.2) earthquake was equivalent to over 8 billion tons of TNT (3.3 {times} 10{sup 19} joules). Four basic wave types are propagated form seismic sources, two non-rotational and two rotational. As opposed to the non-rotational R and SH waves, the rotational compressional (RC) and rotational shear (RS) waves carry the bulk of the energy from a seismic source. RC wavefronts propagate in the subsurface and refract similarly to P waves, but are considerably slower. RC waves are critically refracted beneath the air surface interface at velocities less than the velocity of sound in air because they refract at the velocity of sound in air minus the retrograde particle velocity at the top of the wave. They propagate at tsunami waves in the open ocean, and produce loud sounds on land that are heard by humans and animals during earthquakes. The energy of the RS wave dwarfs that of the P, SH, and even the RC wave. The RS wave is the same as what is currently called the S wave in earthquake seismology, and produces both folding and strike-slip faulting at considerable distances from the epicenter. RC and RS waves, propagated during earthquakes from the Santa Ynez fault and a right-slip fault on trend with the Red Mountain fault, produced the Santa Ynez Mountains in California beginning in the middle Pliocene and continuing until the present.

  8. Technology and Engineering Advances Supporting EarthScope's Alaska Transportable Array

    NASA Astrophysics Data System (ADS)

    Miner, J.; Enders, M.; Busby, R.

    2015-12-01

    EarthScope's Transportable Array (TA) in Alaska and Canada is an ongoing deployment of 261 high quality broadband seismographs. The Alaska TA is the continuation of the rolling TA/USArray deployment of 400 broadband seismographs in the lower 48 contiguous states and builds on the success of the TA project there. The TA in Alaska and Canada is operated by the IRIS Consortium on behalf of the National Science Foundation as part of the EarthScope program. By Sept 2015, it is anticipated that the TA network in Alaska and Canada will be operating 105 stations. During the summer of 2015, TA field crews comprised of IRIS and HTSI station specialists, as well as representatives from our partner agencies the Alaska Earthquake Center and the Alaska Volcano Observatory and engineers from the UNAVCO Plate Boundary Observatory will have completed a total of 36 new station installations. Additionally, we will have completed upgrades at 9 existing Alaska Earthquake Center stations with borehole seismometers and the adoption of an additional 35 existing stations. Continued development of battery systems using LiFePO4 chemistries, integration of BGAN, Iridium, Cellular and VSAT technologies for real time data transfer, and modifications to electronic systems are a driving force for year two of the Alaska Transportable Array. Station deployment utilizes custom heliportable drills for sensor emplacement in remote regions. The autonomous station design evolution include hardening the sites for Arctic, sub-Arctic and Alpine conditions as well as the integration of rechargeable Lithium Iron Phosphate batteries with traditional AGM batteries We will present new design aspects, outcomes, and lessons learned from past and ongoing deployments, as well as efforts to integrate TA stations with other existing networks in Alaska including the Plate Boundary Observatory and the Alaska Volcano Observatory.

  9. A smartphone application for earthquakes that matter!

    NASA Astrophysics Data System (ADS)

    Bossu, Rémy; Etivant, Caroline; Roussel, Fréderic; Mazet-Roux, Gilles; Steed, Robert

    2014-05-01

    Smartphone applications have swiftly become one of the most popular tools for rapid reception of earthquake information for the public, some of them having been downloaded more than 1 million times! The advantages are obvious: wherever someone's own location is, they can be automatically informed when an earthquake has struck. Just by setting a magnitude threshold and an area of interest, there is no longer the need to browse the internet as the information reaches you automatically and instantaneously! One question remains: are the provided earthquake notifications always relevant for the public? What are the earthquakes that really matters to laypeople? One clue may be derived from some newspaper reports that show that a while after damaging earthquakes many eyewitnesses scrap the application they installed just after the mainshock. Why? Because either the magnitude threshold is set too high and many felt earthquakes are missed, or it is set too low and the majority of the notifications are related to unfelt earthquakes thereby only increasing anxiety among the population at each new update. Felt and damaging earthquakes are the ones that matter the most for the public (and authorities). They are the ones of societal importance even when of small magnitude. A smartphone application developed by EMSC (Euro-Med Seismological Centre) with the financial support of the Fondation MAIF aims at providing suitable notifications for earthquakes by collating different information threads covering tsunamigenic, potentially damaging and felt earthquakes. Tsunamigenic earthquakes are considered here to be those ones that are the subject of alert or information messages from the PTWC (Pacific Tsunami Warning Centre). While potentially damaging earthquakes are identified through an automated system called EQIA (Earthquake Qualitative Impact Assessment) developed and operated at EMSC. This rapidly assesses earthquake impact by comparing the population exposed to each expected

  10. Alaska geothermal bibliography

    SciTech Connect

    Liss, S.A.; Motyka, R.J.; Nye, C.J.

    1987-05-01

    The Alaska geothermal bibliography lists all publications, through 1986, that discuss any facet of geothermal energy in Alaska. In addition, selected publications about geology, geophysics, hydrology, volcanology, etc., which discuss areas where geothermal resources are located are included, though the geothermal resource itself may not be mentioned. The bibliography contains 748 entries.

  11. Renewable Energy in Alaska

    SciTech Connect

    Not Available

    2013-03-01

    This report examines the opportunities, challenges, and costs associated with renewable energy implementation in Alaska and provides strategies that position Alaska's accumulating knowledge in renewable energy development for export to the rapidly growing energy/electric markets of the developing world.

  12. Catalog of earthquake hypocenters at Alaskan volcanoes: January 1 through December 31, 2007

    USGS Publications Warehouse

    Dixon, James P.; Stihler, Scott D.; Power, John A.

    2008-01-01

    Between January 1 and December 31, 2007, AVO located 6,664 earthquakes of which 5,660 occurred within 20 kilometers of the 33 volcanoes monitored by the Alaska Volcano Observatory. Monitoring highlights in 2007 include: the eruption of Pavlof Volcano, volcanic-tectonic earthquake swarms at the Augustine, Illiamna, and Little Sitkin volcanic centers, and the cessation of episodes of unrest at Fourpeaked Mountain, Mount Veniaminof and the northern Atka Island volcanoes (Mount Kliuchef and Korovin Volcano). This catalog includes descriptions of : (1) locations of seismic instrumentation deployed during 2007; (2) earthquake detection, recording, analysis, and data archival systems; (3) seismic velocity models used for earthquake locations; (4) a summary of earthquakes located in 2007; and (5) an accompanying UNIX tar-file with a summary of earthquake origin times, hypocenters, magnitudes, phase arrival times, location quality statistics, daily station usage statistics, and all files used to determine the earthquake locations in 2007.

  13. Catalog of earthquake hypocenters at Alaskan volcanoes: January 1 through December 31, 2006

    USGS Publications Warehouse

    Dixon, James P.; Stihler, Scott D.; Power, John A.; Searcy, Cheryl

    2008-01-01

    Between January 1 and December 31, 2006, AVO located 8,666 earthquakes of which 7,783 occurred on or near the 33 volcanoes monitored within Alaska. Monitoring highlights in 2006 include: an eruption of Augustine Volcano, a volcanic-tectonic earthquake swarm at Mount Martin, elevated seismicity and volcanic unrest at Fourpeaked Mountain, and elevated seismicity and low-level tremor at Mount Veniaminof and Korovin Volcano. A new seismic subnetwork was installed on Fourpeaked Mountain. This catalog includes: (1) descriptions and locations of seismic instrumentation deployed in the field during 2006, (2) a description of earthquake detection, recording, analysis, and data archival systems, (3) a description of seismic velocity models used for earthquake locations, (4) a summary of earthquakes located in 2006, and (5) an accompanying UNIX tar-file with a summary of earthquake origin times, hypocenters, magnitudes, phase arrival times, location quality statistics, daily station usage statistics, and all files used to determine the earthquake locations in 2006.

  14. Correlation of tertiary formations of Alaska

    USGS Publications Warehouse

    MacNeil, F.S.; Wolfe, J.A.; Miller, D.J.; Hopkins, D.M.

    1961-01-01

    Recent stratigraphic and paleontologic studies have resulted in substantial revision of the age assignments and inter-basin correlations of the Tertiary formations of Alaska as given in both an earlier compilation by P. S. Smith (1939) and a tentative chart prepared for distribution at the First International Symposium on Arctic Geology at Calgary, Alberta (Miller, MacNeil, and Wahrhaftig, 1960). Current work in Alaska by the U. S. Geological Survey and several oil companies is furnishing new information at a rapid rate and further revisions may be expected. The correlation chart (Fig. 1), the first published chart to deal exclusively with the Tertiary of Alaska, had the benefit of a considerable amount of stratigraphic data and fossil collections from some oil companies, but recent surface mapping and drilling by other oil companies in several Tertiary basins undoubtedly must have produced much more information. Nevertheless, the extent of available data justifies the publication of a revised correlation chart at this time.

  15. Alaska Village Electric Load Calculator

    SciTech Connect

    Devine, M.; Baring-Gould, E. I.

    2004-10-01

    As part of designing a village electric power system, the present and future electric loads must be defined, including both seasonal and daily usage patterns. However, in many cases, detailed electric load information is not readily available. NREL developed the Alaska Village Electric Load Calculator to help estimate the electricity requirements in a village given basic information about the types of facilities located within the community. The purpose of this report is to explain how the load calculator was developed and to provide instructions on its use so that organizations can then use this model to calculate expected electrical energy usage.

  16. Organic geochemistry data of Alaska

    USGS Publications Warehouse

    complied by Threlkeld, Charles N.; Obuch, Raymond C.; Gunther, G.L.

    2000-01-01

    In order to archive the results of various petroleum geochemical analyses of the Alaska resource assessment, the USGS developed an Alaskan Organic Geochemical Data Base (AOGDB) in 1978 to house the data generated from USGS and subcontracted laboratories. Prior to the AOGDB, the accumulated data resided in a flat data file entitled 'PGS' that was maintained by Petroleum Information Corporation with technical input from the USGS. The information herein is a breakout of the master flat file format into a relational data base table format (akdata).

  17. Alaska Humans Factors Safety Study: The Northern Area

    NASA Technical Reports Server (NTRS)

    Connell, Linda; Reynard, William (Technical Monitor)

    1995-01-01

    At the request of the Alaska Air Carriers Association, researchers from the NASA Aviation Safety Reporting System, at NASA Ames Research Center, conducted a study on aspects of safety in Alaskan Part 135 air taxi operations. An interview form on human factors safety issues was created by a representative team from the FAA-Alaska, NTSB-Alaska, NASAASRS, and representatives of the Alaska Air Carriers Association which was subsequently used in the interviews of pilots and managers. Because of the climate and operational differences, the study was broken into two geographical areas, the southern coastal areas and the northern portion of the state. This presentation addresses the northern area, specifically: Bethel, Fairbanks, Nome, Kotzebue, and Barrow. The interview questions dealt with many of the potential pressures on pilots and managers associated with the daily air taxi operations in Alaska. The impact of the environmental factors such as the lack of available communication, navigation and weather information systems was evaluated. The results of this study will be used by government and industry working in Alaska. These findings will contribute important information on specific Alaska safety issues for eventual incorporation into training materials and policies that will help to assure the safe conduct of air taxi flights in Alaska.

  18. Alaska Humans Factors Safety Study: The Southern Coastal Area

    NASA Technical Reports Server (NTRS)

    Chappell, Sheryl L.; Reynard, William (Technical Monitor)

    1995-01-01

    At the request of the Alaska Air Carriers Association, researchers from the NASA Aviation Safety Reporting System, at NASA Ames Research Center, conducted a study on aspects of safety in Alaskan Part 135 air taxi operations. An interview form on human factors safety issues was created by a representative team from the FAA-Alaska, NTSB-Alaska, NASA-ASRS, and representatives of the Alaska Air Carriers Association which was subsequently used in the interviews of pilots and managers. Because of the climate and operational differences, the study was broken into two geographical areas, the southern coastal areas and the northern portion of the state. This presentation addresses the southern coastal areas, specifically: Anchorage, Dillingham, King Salmon, Kodiak, Cold Bay, Juneau, and Ketchikan. The interview questions dealt with many of the potential pressures on pilots and managers associated with the daily air taxi operations in Alaska. The impact of the environmental factors such as the lack of available communication, navigation and weather information systems was evaluated. The results of this study will be used by government and industry working in Alaska. These findings will contribute important information on specific Alaska safety issues for eventual incorporation into training materials and policies that will help to assure the safe conduct of air taxi flights in Alaska.

  19. Darwin's earthquake.

    PubMed

    Lee, Richard V

    2010-07-01

    Charles Darwin experienced a major earthquake in the Concepción-Valdivia region of Chile 175 years ago, in February 1835. His observations dramatically illustrated the geologic principles of James Hutton and Charles Lyell which maintained that the surface of the earth was subject to alterations by natural events, such as earthquakes, volcanoes, and the erosive action of wind and water, operating over very long periods of time. Changes in the land created new environments and fostered adaptations in life forms that could lead to the formation of new species. Without the demonstration of the accumulation of multiple crustal events over time in Chile, the biologic implications of the specific species of birds and tortoises found in the Galapagos Islands and the formulation of the concept of natural selection might have remained dormant.

  20. Triggered tremor sweet spots in Alaska

    USGS Publications Warehouse

    Gomberg, Joan; Prejean, Stephanie

    2013-01-01

    To better understand what controls fault slip along plate boundaries, we have exploited the abundance of seismic and geodetic data available from the richly varied tectonic environments composing Alaska. A search for tremor triggered by 11 large earthquakes throughout all of seismically monitored Alaska reveals two tremor “sweet spots”—regions where large-amplitude seismic waves repeatedly triggered tremor between 2006 and 2012. The two sweet spots locate in very different tectonic environments—one just trenchward and between the Aleutian islands of Unalaska and Akutan and the other in central mainland Alaska. The Unalaska/Akutan spot corroborates previous evidence that the region is ripe for tremor, perhaps because it is located where plate-interface frictional properties transition between stick-slip and stably sliding in both the dip direction and laterally. The mainland sweet spot coincides with a region of complex and uncertain plate interactions, and where no slow slip events or major crustal faults have been noted previously. Analyses showed that larger triggering wave amplitudes, and perhaps lower frequencies (<~0.03 Hz), may enhance the probability of triggering tremor. However, neither the maximum amplitude in the time domain or in a particular frequency band, nor the geometric relationship of the wavefield to the tremor source faults alone ensures a high probability of triggering. Triggered tremor at the two sweet spots also does not occur during slow slip events visually detectable in GPS data, although slow slip below the detection threshold may have facilitated tremor triggering.

  1. Active Tectonics and Seismic Potential of Alaska

    NASA Astrophysics Data System (ADS)

    Freymueller, Jeffrey T.; Haeussler, Peter J.; Wesson, Robert L.; Ekström, Göran

    This multidisciplinary monograph provides the first modern integrative summary focused on the most spectacular active tectonic systems in North America. Encompassing seismology, tectonics, geology, and geodesy, it includes papers that summarize the state of knowledge, including background material for those unfamiliar with the region; address global hypotheses using data from Alaska; and test important global hypotheses using data from this region. It is organized around four major themes: • subduction and great earthquakes at the Aleutian Arc, • the transition from strike slip to accretion and subduction of the Yakutat microplate, • the Denali fault and related structures and their role in accommodating permanent deformation of the overriding plate, and • regional integration and large-scale models and the use of data from Alaska to address important global questions and hypotheses. The book's publication near the beginning of the National Science Foundation's EarthScope project makes it especially timely because Alaska is perhaps the least understood area within the EarthScope footprint, and interest in the region can be expected to rise with time as more EarthScope data become available.

  2. Alaska Problem Resource Manual: Alaska Future Problem Solving Program. Alaska Problem 1985-86.

    ERIC Educational Resources Information Center

    Gorsuch, Marjorie, Ed.

    "Alaska's Image in the Lower 48," is the theme selected by a Blue Ribbon panel of state and national leaders who felt that it was important for students to explore the relationship between Alaska's outside image and the effect of that image on the federal programs/policies that impact Alaska. An overview of Alaska is presented first in…

  3. Comparison of two large earthquakes: the 2008 Sichuan Earthquake and the 2011 East Japan Earthquake.

    PubMed

    Otani, Yuki; Ando, Takayuki; Atobe, Kaori; Haiden, Akina; Kao, Sheng-Yuan; Saito, Kohei; Shimanuki, Marie; Yoshimoto, Norifumi; Fukunaga, Koichi

    2012-01-01

    Between August 15th and 19th, 2011, eight 5th-year medical students from the Keio University School of Medicine had the opportunity to visit the Peking University School of Medicine and hold a discussion session titled "What is the most effective way to educate people for survival in an acute disaster situation (before the mental health care stage)?" During the session, we discussed the following six points: basic information regarding the Sichuan Earthquake and the East Japan Earthquake, differences in preparedness for earthquakes, government actions, acceptance of medical rescue teams, earthquake-induced secondary effects, and media restrictions. Although comparison of the two earthquakes was not simple, we concluded that three major points should be emphasized to facilitate the most effective course of disaster planning and action. First, all relevant agencies should formulate emergency plans and should supply information regarding the emergency to the general public and health professionals on a normal basis. Second, each citizen should be educated and trained in how to minimize the risks from earthquake-induced secondary effects. Finally, the central government should establish a single headquarters responsible for command, control, and coordination during a natural disaster emergency and should centralize all powers in this single authority. We hope this discussion may be of some use in future natural disasters in China, Japan, and worldwide.

  4. Defeating Earthquakes

    NASA Astrophysics Data System (ADS)

    Stein, R. S.

    2012-12-01

    The 2004 M=9.2 Sumatra earthquake claimed what seemed an unfathomable 228,000 lives, although because of its size, we could at least assure ourselves that it was an extremely rare event. But in the short space of 8 years, the Sumatra quake no longer looks like an anomaly, and it is no longer even the worst disaster of the Century: 80,000 deaths in the 2005 M=7.6 Pakistan quake; 88,000 deaths in the 2008 M=7.9 Wenchuan, China quake; 316,000 deaths in the M=7.0 Haiti, quake. In each case, poor design and construction were unable to withstand the ferocity of the shaken earth. And this was compounded by inadequate rescue, medical care, and shelter. How could the toll continue to mount despite the advances in our understanding of quake risk? The world's population is flowing into megacities, and many of these migration magnets lie astride the plate boundaries. Caught between these opposing demographic and seismic forces are 50 cities of at least 3 million people threatened by large earthquakes, the targets of chance. What we know for certain is that no one will take protective measures unless they are convinced they are at risk. Furnishing that knowledge is the animating principle of the Global Earthquake Model, launched in 2009. At the very least, everyone should be able to learn what his or her risk is. At the very least, our community owes the world an estimate of that risk. So, first and foremost, GEM seeks to raise quake risk awareness. We have no illusions that maps or models raise awareness; instead, earthquakes do. But when a quake strikes, people need a credible place to go to answer the question, how vulnerable am I, and what can I do about it? The Global Earthquake Model is being built with GEM's new open source engine, OpenQuake. GEM is also assembling the global data sets without which we will never improve our understanding of where, how large, and how frequently earthquakes will strike, what impacts they will have, and how those impacts can be lessened by

  5. Libraries in Alaska: MedlinePlus

    MedlinePlus

    ... this page: https://medlineplus.gov/libraries/alaska.html Libraries in Alaska To use the sharing features on ... JavaScript. Anchorage University of Alaska Anchorage Alaska Medical Library 3211 Providence Drive Anchorage, AK 99508-8176 907- ...

  6. Investigating the pre- and post-eruptive stress regime at Redoubt volcano, Alaska, from 2008-1010 using seismic anisotropy and stress-tensor inversions

    NASA Astrophysics Data System (ADS)

    Gardine, M.; Roman, D. C.

    2010-12-01

    Redoubt volcano, located on the west side of Cook Inlet approximately 170 km southwest of Anchorage, Alaska, began erupting in March 2009. The eruption, which consisted of at least 17 explosive events over a three-week time period followed by three months of dome-building, significantly impacted both aviation and oil production operations in the area. Pre-eruptive seismicity was generally limited to deep (>20 km) long-period (DLP) earthquakes starting in late 2008, transitioning to bursts of strong, shallow volcanic tremor for nearly three months prior to the eruption. The near-complete absence of precursory volcano-tectonic (VT) earthquakes is unusual for eruptions of this type and complicates understanding of the dynamics of the Redoubt magmatic system. However, the strong volcanic tremor preceding the eruption suggests that magma was ascending and the system was pressurizing for months prior to the first explosion - a situation during which VT earthquakes typically occur. The study of subtle changes in stress conditions at Redoubt may elucidate the reasons for the observed near-complete lack of precursory VT seismicity. Using first-motion data from waveforms recorded by seismic stations operated in the vicinity of Redoubt by the Alaska Volcano Observatory (AVO) and the Alaska Earthquake Information Center (AEIC), we computed double-couple fault-plane solutions for approximately 200 VT earthquakes occurring in the months prior to and immediately following the first eruption in March 2009. The analysis of the fault-plane solutions using spatial and temporal stress-tensor inversions combined with cumulative misfit analysis will help to constrain if, when, and where localized precursory changes in stress occurred. In addition, we performed an analysis of shear-wave splitting using data from deep slab events located by AEIC within a 70 km radius for one year prior to and one year following the eruption, which resulted in approximately 500 high-quality measurements on

  7. Earthquake triggering at alaskan volcanoes following the 3 November 2002 denali fault earthquake

    USGS Publications Warehouse

    Moran, S.C.; Power, J.A.; Stihler, S.D.; Sanchez, J.J.; Caplan-Auerbach, J.

    2004-01-01

    The 3 November 2002 Mw 7.9 Denali fault earthquake provided an excellent opportunity to investigate triggered earthquakes at Alaskan volcanoes. The Alaska Volcano Observatory operates short-period seismic networks on 24 historically active volcanoes in Alaska, 247-2159 km distant from the mainshock epicenter. We searched for evidence of triggered seismicity by examining the unfiltered waveforms for all stations in each volcano network for ???1 hr after the Mw 7.9 arrival time at each network and for significant increases in located earthquakes in the hours after the mainshock. We found compelling evidence for triggering only at the Katmai volcanic cluster (KVC, 720-755 km southwest of the epicenter), where small earthquakes with distinct P and 5 arrivals appeared within the mainshock coda at one station and a small increase in located earthquakes occurred for several hours after the mainshock. Peak dynamic stresses of ???0.1 MPa at Augustine Volcano (560 km southwest of the epicenter) are significantly lower than those recorded in Yellowstone and Utah (>3000 km southeast of the epicenter), suggesting that strong directivity effects were at least partly responsible for the lack of triggering at Alaskan volcanoes. We describe other incidents of earthquake-induced triggering in the KVC, and outline a qualitative magnitude/distance-dependent triggering threshold. We argue that triggering results from the perturbation of magmatic-hydrothermal systems in the KVC and suggest that the comparative lack of triggering at other Alaskan volcanoes could be a result of differences in the nature of magmatic-hydrothermal systems.

  8. Satellite Sounder Data Assimilation for Improving Alaska Region Weather Forecast

    NASA Technical Reports Server (NTRS)

    Zhu, Jiang; Stevens, E.; Zavodsky, B. T.; Zhang, X.; Heinrichs, T.; Broderson, D.

    2014-01-01

    Data assimilation has been demonstrated very useful in improving both global and regional numerical weather prediction. Alaska has very coarser surface observation sites. On the other hand, it gets much more satellite overpass than lower 48 states. How to utilize satellite data to improve numerical prediction is one of hot topics among weather forecast community in Alaska. The Geographic Information Network of Alaska (GINA) at University of Alaska is conducting study on satellite data assimilation for WRF model. AIRS/CRIS sounder profile data are used to assimilate the initial condition for the customized regional WRF model (GINA-WRF model). Normalized standard deviation, RMSE, and correlation statistic analysis methods are applied to analyze one case of 48 hours forecasts and one month of 24-hour forecasts in order to evaluate the improvement of regional numerical model from Data assimilation. The final goal of the research is to provide improved real-time short-time forecast for Alaska regions.

  9. Putting down roots in earthquake country-Your handbook for earthquakes in the Central United States

    USGS Publications Warehouse

    Contributors: Dart, Richard; McCarthy, Jill; McCallister, Natasha; Williams, Robert A.

    2011-01-01

    This handbook provides information to residents of the Central United States about the threat of earthquakes in that area, particularly along the New Madrid seismic zone, and explains how to prepare for, survive, and recover from such events. It explains the need for concern about earthquakes for those residents and describes what one can expect during and after an earthquake. Much is known about the threat of earthquakes in the Central United States, including where they are likely to occur and what can be done to reduce losses from future earthquakes, but not enough has been done to prepare for future earthquakes. The handbook describes such preparations that can be taken by individual residents before an earthquake to be safe and protect property.

  10. Twitter earthquake detection: Earthquake monitoring in a social world

    USGS Publications Warehouse

    Earle, Paul S.; Bowden, Daniel C.; Guy, Michelle R.

    2011-01-01

    The U.S. Geological Survey (USGS) is investigating how the social networking site Twitter, a popular service for sending and receiving short, public text messages, can augment USGS earthquake response products and the delivery of hazard information. Rapid detection and qualitative assessment of shaking events are possible because people begin sending public Twitter messages (tweets) with in tens of seconds after feeling shaking. Here we present and evaluate an earthquake detection procedure that relies solely on Twitter data. A tweet-frequency time series constructed from tweets containing the word "earthquake" clearly shows large peaks correlated with the origin times of widely felt events. To identify possible earthquakes, we use a short-term-average, long-term-average algorithm. When tuned to a moderate sensitivity, the detector finds 48 globally-distributed earthquakes with only two false triggers in five months of data. The number of detections is small compared to the 5,175 earthquakes in the USGS global earthquake catalog for the same five-month time period, and no accurate location or magnitude can be assigned based on tweet data alone. However, Twitter earthquake detections are not without merit. The detections are generally caused by widely felt events that are of more immediate interest than those with no human impact. The detections are also fast; about 75% occur within two minutes of the origin time. This is considerably faster than seismographic detections in poorly instrumented regions of the world. The tweets triggering the detections also provided very short first-impression narratives from people who experienced the shaking.

  11. Alaska geology revealed

    USGS Publications Warehouse

    Wilson, Frederic H.; Labay, Keith A.

    2016-11-09

    This map shows the generalized geology of Alaska, which helps us to understand where potential mineral deposits and energy resources might be found, define ecosystems, and ultimately, teach us about the earth history of the State. Rock units are grouped in very broad categories on the basis of age and general rock type. A much more detailed and fully referenced presentation of the geology of Alaska is available in the Geologic Map of Alaska (http://dx.doi.org/10.3133/sim3340). This product represents the simplification of thousands of individual rock units into just 39 broad groups. Even with this generalization, the sheer complexity of Alaskan geology remains evident.

  12. Thermal infrared anomalies of several strong earthquakes.

    PubMed

    Wei, Congxin; Zhang, Yuansheng; Guo, Xiao; Hui, Shaoxing; Qin, Manzhong; Zhang, Ying

    2013-01-01

    In the history of earthquake thermal infrared research, it is undeniable that before and after strong earthquakes there are significant thermal infrared anomalies which have been interpreted as preseismic precursor in earthquake prediction and forecasting. In this paper, we studied the characteristics of thermal radiation observed before and after the 8 great earthquakes with magnitude up to Ms7.0 by using the satellite infrared remote sensing information. We used new types of data and method to extract the useful anomaly information. Based on the analyses of 8 earthquakes, we got the results as follows. (1) There are significant thermal radiation anomalies before and after earthquakes for all cases. The overall performance of anomalies includes two main stages: expanding first and narrowing later. We easily extracted and identified such seismic anomalies by method of "time-frequency relative power spectrum." (2) There exist evident and different characteristic periods and magnitudes of thermal abnormal radiation for each case. (3) Thermal radiation anomalies are closely related to the geological structure. (4) Thermal radiation has obvious characteristics in abnormal duration, range, and morphology. In summary, we should be sure that earthquake thermal infrared anomalies as useful earthquake precursor can be used in earthquake prediction and forecasting.

  13. Ground Motion Characteristics and Source Process of the 2002 Denali Earthquake Inferred from the Strong Motion Records

    NASA Astrophysics Data System (ADS)

    Asano, K.; Iwata, T.; Irikura, K.

    2003-12-01

    -lateral +/- 45 ° slip for other faults, were included (Sekiguchi et al., 2000). The appropriate strength of smoothing constraint was evaluated using Akaike's Bayesian Information Criterion (Akaike, 1980). Three components of velocity waveforms obtained at 10 strong motion stations including PS10 were inverted. We tried to include the detailed information of the surface displacement distributions compiled by Eberhart-Phillips et al. (2003) as constraint information in our analysis to make up the insufficiency of strong motion data. We could reproduce observed ground motion in low-frequency range (0.1-0.5 Hz for Alyeska stations, 0.05-0.5 Hz for others) based on the source model obtained by the inversion analysis. The inversion result showed that the ground motion at PS10 was mainly controlled by the nearest asperity. Large slips on the fault from the inversion result were observed at about 90 km east and about 170 km east from the epicenter. We are grateful to United States Geological Survey, University of Alaska, and Alyeska Pipeline Service Company for releasing digital strong motion records and to Alaska Earthquake Information Center for which we retrieved hypocentral information.

  14. The Electronic Encyclopedia of Earthquakes

    NASA Astrophysics Data System (ADS)

    Benthien, M.; Marquis, J.; Jordan, T.

    2003-12-01

    The Electronic Encyclopedia of Earthquakes is a collaborative project of the Southern California Earthquake Center (SCEC), the Consortia of Universities for Research in Earthquake Engineering (CUREE) and the Incorporated Research Institutions for Seismology (IRIS). This digital library organizes earthquake information online as a partner with the NSF-funded National Science, Technology, Engineering and Mathematics (STEM) Digital Library (NSDL) and the Digital Library for Earth System Education (DLESE). When complete, information and resources for over 500 Earth science and engineering topics will be included, with connections to curricular materials useful for teaching Earth Science, engineering, physics and mathematics. Although conceived primarily as an educational resource, the Encyclopedia is also a valuable portal to anyone seeking up-to-date earthquake information and authoritative technical sources. "E3" is a unique collaboration among earthquake scientists and engineers to articulate and document a common knowledge base with a shared terminology and conceptual framework. It is a platform for cross-training scientists and engineers in these complementary fields and will provide a basis for sustained communication and resource-building between major education and outreach activities. For example, the E3 collaborating organizations have leadership roles in the two largest earthquake engineering and earth science projects ever sponsored by NSF: the George E. Brown Network for Earthquake Engineering Simulation (CUREE) and the EarthScope Project (IRIS and SCEC). The E3 vocabulary and definitions are also being connected to a formal ontology under development by the SCEC/ITR project for knowledge management within the SCEC Collaboratory. The E3 development system is now fully operational, 165 entries are in the pipeline, and the development teams are capable of producing 20 new, fully reviewed encyclopedia entries each month. Over the next two years teams will

  15. The State of Adolescent Health in Alaska.

    ERIC Educational Resources Information Center

    Alaska State Office of the Commissioner, Juneau.

    A survey was conducted to provide a profile of the health status and risk behaviors of youth in Alaska. The goal was to develop a statewide database which, when coupled with morbidity and mortality data, would provide information that would allow those who plan and develop services at state and local levels to better target those services. During…

  16. Discovering Alaska's Salmon: A Children's Activity Book.

    ERIC Educational Resources Information Center

    Devaney, Laurel

    This children's activity book helps students discover Alaska's salmon. Information is provided about salmon and where they live. The salmon life cycle and food chains are also discussed. Different kinds of salmon such as Chum Salmon, Chinook Salmon, Coho Salmon, Sockeye Salmon, and Pink Salmon are introduced, and various activities on salmon are…

  17. Alaska's Adolescents: A Plan for the Future.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Health and Social Services, Anchorage.

    The goal of this first comprehensive report on adolescent health in Alaska is to stimulate interest, activity, and support for improved health among teenagers (ages 10-19). This plan was developed as a tool for use by governments, organizations, and communities. The plan seeks to provide information on the scope and nature of adolescent health…

  18. Quilts of Alaska--Student Activities.

    ERIC Educational Resources Information Center

    Alaska State Museum, Juneau.

    This student activities booklet, "Quilts of Alaska," contains historical and educational information on quilts. It is colorfully illustrated with examples of different types of quilts. The booklet describes album or signature quilts, which from 1840 to the 1890s, were a U.S. fad, such as were autograph albums. As the name suggests, these…

  19. Indians, Eskimos and Aleuts of Alaska.

    ERIC Educational Resources Information Center

    Bureau of Indian Affairs (Dept. of Interior), Washington, DC.

    Brief descriptions of the historical and cultural background of the Eskimo, Aleut, Athapascan, Tlingit, and Haida Indian groups of Alaska are presented. Further information is given concerning the educational, health, employment, and economic opportunities available to the natives today. A list is included of activities and points of interest in…

  20. Alaska telemedicine: growth through collaboration.

    PubMed

    Patricoski, Chris

    2004-12-01

    The last thirty years have brought the introduction and expansion of telecommunications to rural and remote Alaska. The intellectual and financial investment of earlier projects, the more recent AFHCAN Project and the Universal Service Administrative Company Rural Health Care Division (RHCD) has sparked a new era in telemedicine and telecommunication across Alaska. This spark has been flamed by the dedication and collaboration of leaders at he highest levels of organizations such as: AFHCAN member organizations, AFHCAN Office, Alaska Clinical Engineering Services, Alaska Federal Health Care Partnership, Alaska Federal Health Care Partnership Office, Alaska Native health Board, Alaska Native Tribal health Consortium, Alaska Telehealth Advisory Council, AT&T Alascom, GCI Inc., Health care providers throughout the state of Alaska, Indian Health Service, U.S. Department of Health and Human Services, Office of U.S. Senator Ted Steens, State of Alaska, U.S. Department of Homeland Security--United States Coast Guard, United States Department of Agriculture, United States Department of Defense--Air Force and Army, United States Department of Veterans Affairs, University of Alaska, and University of Alaska Anchorage. Alaska now has one of the largest telemedicine programs in the world. As Alaska moves system now in place become self-sustaining, and 2) collaborating with all stakeholders in promoting the growth of an integrated, state-wide telemedicine network.

  1. Hydrological signatures of earthquake strain

    SciTech Connect

    Muir-Wood, R.; King, G.C.P. |

    1993-12-01

    The character of the hydrological changes that follow major earthquakes has been investigated and found to be dependent on the style of faulting. The most significant response is found to accompany major normal fault earthquakes. Increases in spring and river discharges peak a few days after the earthquake, and typically, excesss flow is sustained for a period of 6-12 months. In contrast, hydrological changes accompanying pure reverse fault earthquakes are either undetected or indicate lowering of well levels and spring flows. Strike-slip and oblique-slip fault movements are associated with a mixture of responses but appear to release no more than 10% of the water volume of the same sized normal fault event. For two major normal fault earthquakes in the western United States (those of Hebgen Lake on August 17, 1959, and Borah Peak on October 28, 1983), there is sufficient river flow information to allow the magnitude and extent of the postseismic discharge to be quantified. The discharge has been converted to a rainfall equivalent, which is found to exceed 100 mm close to the fault and to remain above 10 mm at distances greater than 50 km. Results suggest that water-filled craks are ubiquitous throughout the brittle continental crust and that these cracks open and close throughout the earthquake cycle. The existence of tectonically induced fluid flows on the scale that we demonstrate has major implications for our understanding of the mechanical and chemical behavior of crustal rocks.

  2. Proceedings of the third U. S. national conference on earthquake engineering. Volume II

    SciTech Connect

    Not Available

    1986-01-01

    During the past quarter century the North American continent has experienced a number of damaging earthquakes, among which were the 1964 Alaska earthquake, the 1971 San Fernando, California, earthquake, and most recently the 1985 Mexico City earthquake. A large number of smaller earthquakes have occurred during this period, all of which, along with large earthquakes that have occurred in other parts of the world, serve to remind one that the earthquake hazard is real. In view of potential loss of life and the economic losses that could result from large earthquakes, it is important that the United States continue its vigorous efforts towards mitigating the hazards of earthquakes including developing and implementing safe and economic methods of earthquake-resistant design and construction. In the light of the foregoing observations it it fitting that this Third U.S. National Conference on Earthquake Engineering be held in 1986 at Charleston, South Carolina, on the one-hundred-year anniversary of the 1886 Charleston earthquake. Although intended primarily for participation by U.S. practitioners and researchers, participants from many other parts of the world are also present. From the more than 300 papers offered for publication and presentation, over 200 papers are published in the three volumes of Proceedings and the single volume of Post-Conference Proceedings.

  3. 75 FR 50749 - Advisory Committee on Earthquake Hazards Reduction Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-17

    ... National Institute of Standards and Technology Advisory Committee on Earthquake Hazards Reduction Meeting... meeting. SUMMARY: The Advisory Committee on Earthquake Hazards Reduction (ACEHR or Committee), will meet....m. The primary purpose of this meeting is to receive information on NEHRP earthquake...

  4. 77 FR 53225 - National Earthquake Prediction Evaluation Council (NEPEC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-31

    ... Geological Survey National Earthquake Prediction Evaluation Council (NEPEC) AGENCY: Department of the... National Earthquake Prediction Evaluation Council (NEPEC) will hold a 1\\1/2\\ day meeting on September 17 and 18, 2012, at the U.S. Geological Survey National Earthquake Information Center (NEIC),...

  5. New research and tools lead to improved earthquake alerting protocols

    USGS Publications Warehouse

    Wald, David J.

    2009-01-01

    What’s the best way to get alerted about the occurrence and potential impact of an earthquake? The answer to that question has changed dramatically of late, in part due to improvements in earthquake science, and in part by the implementation of new research in the delivery of earthquake information

  6. Earthquakes in Arkansas and vicinity 1699-2010

    USGS Publications Warehouse

    Dart, Richard L.; Ausbrooks, Scott M.

    2011-01-01

    This map summarizes approximately 300 years of earthquake activity in Arkansas. It is one in a series of similar State earthquake history maps. Work on the Arkansas map was done in collaboration with the Arkansas Geological Survey. The earthquake data plotted on the map are from several sources: the Arkansas Geological Survey, the Center for Earthquake Research and Information, the National Center for Earthquake Engineering Research, and the Mississippi Department of Environmental Quality. In addition to earthquake locations, other materials presented include seismic hazard and isoseismal maps and related text. Earthquakes are a legitimate concern in Arkansas and parts of adjacent states. Arkansas has undergone a number of significant felt earthquakes since 1811. At least two of these events caused property damage: a magnitude 4.7 earthquake in 1931, and a magnitude 4.3 earthquake in 1967. The map shows all historical and instrumentally located earthquakes in Arkansas and vicinity between 1811 and 2010. The largest historic earthquake in the vicinity of the State was an intensity XI event, on December 16, 1811; the first earthquake in the New Madrid sequence. This violent event and the earthquakes that followed caused considerable damage to the then sparsely settled region.

  7. 76 FR 76177 - Agency Information Collection Activities: Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-06

    ... distribute publish information concerning earthquakes. Respondents will have an opportunity to voluntarily supply information concerning the effects of shaking from an earthquake--on themselves, buildings, other... include proprietary information volunteered by respondents. ] II. Data Title: USGS Earthquake Report....

  8. Attu, Alaska

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Attu, the westernmost Aleutian island, is nearly 1760 km from the Alaskan mainland and 1200 km northeast of the northernmost of the Japanese Kurile Islands. Attu is about 32 by 56 km in size, and is today the home of a small number of U. S. Coast Guard personnel operating a Loran station. The weather on Attu is typical of Aleutian weather in general...cloudy, rain, fog, and occasional high winds. The weather becomes progressively worse as you travel from the easternmost islands to the west. On Attu, five or six days a week are likely to be rainy, with hardly more than eight or ten clear days a year. The image was acquired July 4, 2000, covers an area of 31.2 by 61.1 km, and is centered near 52.8 degrees north latitude, 173 degrees east longitude.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of

  9. Alaska: A frontier divided

    SciTech Connect

    O'Dell, R. )

    1986-09-01

    The superlatives surrounding Alaska are legion. Within the borders of the 49th US state are some of the world's greatest concentrations of waterfowl, bald eagles, fur seals, walrus, sea lions, otters, and the famous Kodiak brown bear. Alaska features the highest peak of North America, the 20,320-foot Mount McKinley, and the longest archipelago of small islands, the Aleutians. The state holds the greatest percentage of protected wilderness per capita in the world. The expanse of some Alaskan glaciers dwarfs entire countries. Like the periodic advance and retreat of its glaciers, Alaska appears with some regularity on the national US agenda. It last achieved prominence when President Jimmy Carter signed the Alaska National Interest Lands Conservation Act in 1980. Since then the conflict between environmental protection and economic development has been played out throughout the state, and Congress is expected to turn to Alaskan issues again in its next sessions.

  10. Hawkweed Control in Alaska

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several hawkweed species from Europe have escaped ornamental planting and have colonized roadsides and grasslands in south central and southeast Alaska. These plants form near monotypic stands, reducing plant diversity and decreasing pasture productivity. A replicated greenhouse study was conducted ...

  11. Large magnitude (M > 7.5) offshore earthquakes in 2012: few examples of absent or little tsunamigenesis, with implications for tsunami early warning

    NASA Astrophysics Data System (ADS)

    Pagnoni, Gianluca; Armigliato, Alberto; Tinti, Stefano

    2013-04-01

    We take into account some examples of offshore earthquakes occurred worldwide in year 2012 that were characterised by a "large" magnitude (Mw equal or larger than 7.5) but which produced no or little tsunami effects. Here, "little" is intended as "lower than expected on the basis of the parent earthquake magnitude". The examples we analyse include three earthquakes occurred along the Pacific coasts of Central America (20 March, Mw=7.8, Mexico; 5 September, Mw=7.6, Costa Rica; 7 November, Mw=7.5, Mexico), the Mw=7.6 and Mw=7.7 earthquakes occurred respectively on 31 August and 28 October offshore Philippines and offshore Alaska, and the two Indian Ocean earthquakes registered on a single day (11 April) and characterised by Mw=8.6 and Mw=8.2. For each event, we try to face the problem related to its tsunamigenic potential from two different perspectives. The first can be considered purely scientific and coincides with the question: why was the ensuing tsunami so weak? The answer can be related partly to the particular tectonic setting in the source area, partly to the particular position of the source with respect to the coastline, and finally to the focal mechanism of the earthquake and to the slip distribution on the ruptured fault. The first two pieces of information are available soon after the earthquake occurrence, while the third requires time periods in the order of tens of minutes. The second perspective is more "operational" and coincides with the tsunami early warning perspective, for which the question is: will the earthquake generate a significant tsunami and if so, where will it strike? The Indian Ocean events of 11 April 2012 are perfect examples of the fact that the information on the earthquake magnitude and position alone may not be sufficient to produce reliable tsunami warnings. We emphasise that it is of utmost importance that the focal mechanism determination is obtained in the future much more quickly than it is at present and that this

  12. Reassessment of seismically induced, tsunamigenic submarine slpe failures in Port Valdez, Alaska, USA

    USGS Publications Warehouse

    Lee, H.J.; Ryan, H.F.; Haeussler, P.J.; Kayen, R.E.; Hampton, M.A.; Locat, Jacques; Suleimani, E.; Alexander, C.R.; Lykousis, Vasilios; Sakellariou, Dimitris; Locat, Jacques

    2007-01-01

    The M9.2 Alaska earthquake of 1964 caused major damage to the port facilities and town of Valdez, most of it the result of submarine landslide and the consequent tsunamis. Recent bathymetric multibeam surveys, high-resolution subbottom profiles, and dated sediment cores in Port Valdez supply new information about the morphology and character of the landslide deposits. A comparison of pre- and post-earthquake bathymetry provides an estimate of the net volume of landslide debris deposited in the basin and the volume of sediment removed from the source region. Landslide features include (1) large blocks (up to 40-m high) near the location of the greatest tsunami wave runup (~50 m), (2) two debris lobes associated with the blocks, (3) a series of gullies, channels and talus, near the fjord-head delta and badly damaged old town of Valdez, and (4) the front of a debris lobe that flowed half-way down the fjord from the east end.

  13. Alaska Resource Data File, Point Lay quadrangle, Alaska

    USGS Publications Warehouse

    Grybeck, Donald J.

    2006-01-01

    This report gives descriptions of the mineral occurrences in the Point Lay 1:250,000-scale quadrangle, Alaska. The data presented here are maintained as part of a statewide database on mines, prospects and mineral occurrences throughout Alaska.

  14. Malaspina Glacier, Alaska

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra satellite covers an area of 55 by 40 kilometers (34 by 25 miles) over the southwest part of the Malaspina Glacier and Icy Bay in Alaska. The composite of infrared and visible bands results in the snow and ice appearing light blue, dense vegetation is yellow-orange and green, and less vegetated, gravelly areas are in orange. According to Dr. Dennis Trabant (U.S. Geological Survey, Fairbanks, Alaska), the Malaspina Glacier is thinning. Its terminal moraine protects it from contact with the open ocean; without the moraine, or if sea level rises sufficiently to reconnect the glacier with the ocean, the glacier would start calving and retreat significantly. ASTER data are being used to help monitor the size and movement of some 15,000 tidal and piedmont glaciers in Alaska. Evidence derived from ASTER and many other satellite and ground-based measurements suggests that only a few dozen Alaskan glaciers are advancing. The overwhelming majority of them are retreating.

    This ASTER image was acquired on June 8, 2001. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next six years to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18,1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. science team leader; Bjorn Eng of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The Terra mission is part of NASA's Earth Science Enterprise, along-term research and

  15. Alaska looks HOT!

    SciTech Connect

    Belcher, J.

    1997-07-01

    Production in Alaska has been sluggish in recent years, with activity in the Prudhoe Bay region in the North Slope on a steady decline. Alaska North Slope (ANS) production topped out in 1988 at 2.037 MMbo/d, with 1.6 MMbo/d from Prudhoe Bay. This year operators expect to produce 788 Mbo/d from Prudhoe Bay, falling to 739 Mbo/d next year. ANS production as a whole should reach 1.3 MMbo/d this year, sliding to 1.29 MMbo/d in 1998. These declining numbers had industry officials and politicians talking about the early death of the Trans-Alaskan Pipeline System-the vital link between ANS crude and markets. But enhanced drilling technology coupled with a vastly improved relationship between the state government and industry have made development in Alaska more economical and attractive. Alaska`s Democratic Gov. Tommy Knowles is fond of telling industry {open_quotes}we`re open for business.{close_quotes} New discoveries on the North Slope and in the Cook Inlet are bringing a renewed sense of optimism to the Alaska exploration and production industry. Attempts by Congress to lift a moratorium on exploration and production activity in the Arctic National Wildlife Refuge (ANWR) have been thwarted thus far, but momentum appears to be with proponents of ANWR drilling.

  16. Afterslip, tremor, and the Denali fault earthquake

    USGS Publications Warehouse

    Gomberg, Joan; Prejean, Stephanie; Ruppert, Natalia

    2012-01-01

    We tested the hypothesis that afterslip should be accompanied by tremor using observations of seismic and aseismic deformation surrounding the 2002 M 7.9 Denali fault, Alaska, earthquake (DFE). Afterslip happens more frequently than spontaneous slow slip and has been observed in a wider range of tectonic environments, and thus the existence or absence of tremor accompanying afterslip may provide new clues about tremor generation. We also searched for precursory tremor, as a proxy for posited accelerating slip leading to rupture. Our search yielded no tremor during the five days prior to the DFE or in several intervals in the three months after. This negative result and an array of other observations all may be explained by rupture penetrating below the presumed locked zone into the frictional transition zone. While not unique, such an explanation corroborates previous models of megathrust and transform earthquake ruptures that extend well into the transition zone.

  17. Assessing the earthquake hazards in urban areas

    USGS Publications Warehouse

    Hays, W.W.; Gori, P.L.; Kockelman, W.J.

    1988-01-01

    Major urban areas in widely scattered geographic locations across the United States are a t varying degrees of risk from earthquakes. the locations of these urban areas include Charleston, South Carolina; Memphis Tennessee; St.Louis, Missouri; Salt Lake City, Utah; Seattle-Tacoma, Washington; Portland, Oregon; and Anchorage, Alaska; even Boston, Massachusetts, and Buffalo New York, have a history of large earthquakes. Cooperative research during the past decade has focused on assessing the nature and degree of the risk or seismic hazard i nthe broad geographic regions around each urban area. The strategy since the 1970's has been to bring together local, State, and Federal resources to solve the problem of assessing seismic risk. Successfl sooperative programs have been launched in the San Francisco Bay and Los Angeles regions in California and the Wasatch Front region in Utah. 

  18. Catalog of earthquake hypocenters at Alaskan volcanoes: January 1 through December 31, 2008

    USGS Publications Warehouse

    Dixon, James P.; Stihler, Scott D.

    2009-01-01

    Between January 1 and December 31, 2008, the Alaska Volcano Observatory (AVO) located 7,097 earthquakes of which 5,318 occurred within 20 kilometers of the 33 volcanoes monitored by the AVO. Monitoring highlights in 2008 include the eruptions of Okmok Caldera, and Kasatochi Volcano, as well as increased unrest at Mount Veniaminof and Redoubt Volcano. This catalog includes descriptions of: (1) locations of seismic instrumentation deployed during 2008; (2) earthquake detection, recording, analysis, and data archival systems; (3) seismic velocity models used for earthquake locations; (4) a summary of earthquakes located in 2008; and (5) an accompanying UNIX tar-file with a summary of earthquake origin times, hypocenters, magnitudes, phase arrival times, location quality statistics, daily station usage statistics, and all files used to determine the earthquake locations in 2008.

  19. Terpane biomarkers and carbon isotopes in environmental geochemistry-application of a case study from Prince William Sound, Alaska

    SciTech Connect

    Kvenvolden, K.A.; Hostettler, F.D.; Rosenbauer, R.J.; Hostetter, D.E.; Castle, W.T.

    1996-12-31

    Geochemical studies in Prince William Sound, Alaska, following the 1989 Exxon Valdez oil spill have provided information that is being used to interpret preliminary environmental geochemical observations made in coastal California. Although the shorelines of Prince William Sound still retain traces of the 1989 oil spill, most of the flattened tar balls that can be found today on these shorelines are not residues of Exxon Valdez oil. Rather, the hydrocarbon-biomarker and carbon-isotopic signatures of these tar balls have remarkably similar characteristics that are consistent with those of oil products that originated from Monterey Formation source rocks of California. Some of these products were spilled into the sound during the 1964 Alaskan earthquake. Selected terpane biomarker ratios and carbon isotope composition of whole oil samples can geochemically distinguish Exxon Valdez residues from the tar balls. Results are discussed.

  20. Identification of Deep Earthquakes

    DTIC Science & Technology

    2010-09-01

    develop a ground truth dataset of earthquakes at both normal crustal depths and earthquakes from subduction zones , below the overlying crust. Many...deep earthquakes (depths between about 50 and 300 km). These deep earthquakes are known to occur in the Asia-India continental collision zone ...and/or NIL, as these stations are within a few hundred km of the zone where deep earthquakes are known to occur. To date we have selected about 300

  1. Fault and Fracture Intersections and Earthquake Nucleation

    NASA Astrophysics Data System (ADS)

    Brumbaugh, D. S.

    2008-05-01

    Laboratory experments and computer modeling studies have shown in some detail that when stresses are applied to prefractured materials the result is a complex change in the stress field in the vicinity of fracture intersections (Shengri, 2003; Gangopadhyay and Talwani, 2005). This can result in slip on the fractures and energy release simulating earthquake triggering. A search of the literature reveals a number of cases where earthquakes have nucleated on or near fracture intersections of two intersecting strike-slip faults or a strike-slip fault and a fracture linear. The acute angle between the two fractures/faults ranges from 18 degrees to a maximum of 90 degrees. The cases cited had epicentral locations near to or possibly on the intersection site. Magnitudes of events ranged from microearthquake size up to M7.9. A few cases exist where the initial event was not located at the intersection but triggered a second event at the intersection site (Elmore Ranch;Tango,Japan), or where an earthquake at the intersection triggered a second event elsewhere (Denali,Alaska). The recognition of the potential of stresses concentrated at intersection points of faults/fractures to nucleate potentially damaging earthquakes is important in seismic hazard studies.

  2. Earthquakes in Mississippi and vicinity 1811-2010

    USGS Publications Warehouse

    Dart, Richard L.; Bograd, Michael B.E.

    2011-01-01

    This map summarizes two centuries of earthquake activity in Mississippi. Work on the Mississippi map was done in collaboration with the Mississippi Department of Environmental Quality, Office of Geology. The earthquake data plotted on the map are from several sources: the Mississippi Department of Environmental Quality, the Center for Earthquake Research and Information, the National Center for Earthquake Engineering Research, and the Arkansas Geological Survey. In addition to earthquake locations, other materials include seismic hazard and isoseismal maps and related text. Earthquakes are a legitimate concern in Mississippi and parts of adjacent States. Mississippi has undergone a number of felt earthquakes since 1811. At least two of these events caused property damage: a magnitude 4.7 earthquake in 1931, and a magnitude 4.3 earthquake in 1967. The map shows all historical and instrumentally located earthquakes in Mississippi and vicinity between 1811 and 2010. The largest historic earthquake in the vicinity of the State was an intensity XI event, on December 16, 1811; the first earthquake in the New Madrid sequence. This violent event and the earthquakes that followed caused considerable damage to the then sparsely settled region.

  3. Characterization of Fault Networks and Diffusion of Aftershock Epicenters From Earthquake Catalogs: Fuzzy C-means Clustering and a Modified ETAS Model

    NASA Astrophysics Data System (ADS)

    Moulik, P.; Tiampo, K. F.

    2009-05-01

    The information on three-dimensional geometry as well as the identification of active fault segments is critical to our assessment of seismic risks. Numerical modeling of the aftershock locations, times and magnitudes are also crucial to characterize a fault zone. In this study, a pattern recognition technique based on the Fuzzy C- means clustering algorithm (Bezdek, 1981) is proposed to allow each earthquake to be associated with different fault segments. The spatial covariance tensor for each cluster and the associated earthquakes are used to find optimal anisotropic clusters and designate them as faults, similar to the OADC method (Ouillon et al., 2008). The location, size and orientation of the reconstructed faults segments are characterized using a fuzzy covariance matrix (Gustafson and Kessel, 1978). The output consists of a set of distinct fault segments along with the associated earthquakes at different fuzzy membership grades (Zadeh, 1965). A resultant matrix consists of the fuzzy membership grade for different earthquakes and corresponding faults segments specifying their degree of association with values from zero to one. The spatial distribution of earthquakes of different magnitudes and membership grades for a fault segment is incorporated in an anisotropic spatial kernel which characterizes the aftershock density at a distance vector in the ETAS model (Kagan and Knopoff, 1987; Ogata, 1988). An optimal spatio-temporal distribution of aftershocks is obtained for each fault segment without considering a priori distributions such as Gaussian or power law (Helmstetter et al., 2006; Helmstetter and Sornette, 2002). The model is tested on the aftershock sequence from the Denali, 2002 earthquake in Alaska and the fault reconstruction results compared with the known faults in the area. Therefore, a new method to incorporate the anisotropic nature of aftershock diffusion along with the reconstruction of fault networks from seismicity catalogs is formulated in

  4. Understanding earthquake hazards in urban areas - Evansville Area Earthquake Hazards Mapping Project

    USGS Publications Warehouse

    Boyd, Oliver S.

    2012-01-01

    The region surrounding Evansville, Indiana, has experienced minor damage from earthquakes several times in the past 200 years. Because of this history and the proximity of Evansville to the Wabash Valley and New Madrid seismic zones, there is concern among nearby communities about hazards from earthquakes. Earthquakes currently cannot be predicted, but scientists can estimate how strongly the ground is likely to shake as a result of an earthquake and are able to design structures to withstand this estimated ground shaking. Earthquake-hazard maps provide one way of conveying such information and can help the region of Evansville prepare for future earthquakes and reduce earthquake-caused loss of life and financial and structural loss. The Evansville Area Earthquake Hazards Mapping Project (EAEHMP) has produced three types of hazard maps for the Evansville area: (1) probabilistic seismic-hazard maps show the ground motion that is expected to be exceeded with a given probability within a given period of time; (2) scenario ground-shaking maps show the expected shaking from two specific scenario earthquakes; (3) liquefaction-potential maps show how likely the strong ground shaking from the scenario earthquakes is to produce liquefaction. These maps complement the U.S. Geological Survey's National Seismic Hazard Maps but are more detailed regionally and take into account surficial geology, soil thickness, and soil stiffness; these elements greatly affect ground shaking.

  5. Earthquake and Tsunami booklet based on two Indonesia earthquakes

    NASA Astrophysics Data System (ADS)

    Hayashi, Y.; Aci, M.

    2014-12-01

    Many destructive earthquakes occurred during the last decade in Indonesia. These experiences are very important precepts for the world people who live in earthquake and tsunami countries. We are collecting the testimonies of tsunami survivors to clarify successful evacuation process and to make clear the characteristic physical behaviors of tsunami near coast. We research 2 tsunami events, 2004 Indian Ocean tsunami and 2010 Mentawai slow earthquake tsunami. Many video and photographs were taken by people at some places in 2004 Indian ocean tsunami disaster; nevertheless these were few restricted points. We didn't know the tsunami behavior in another place. In this study, we tried to collect extensive information about tsunami behavior not only in many places but also wide time range after the strong shake. In Mentawai case, the earthquake occurred in night, so there are no impressive photos. To collect detail information about evacuation process from tsunamis, we contrived the interview method. This method contains making pictures of tsunami experience from the scene of victims' stories. In 2004 Aceh case, all survivors didn't know tsunami phenomena. Because there were no big earthquakes with tsunami for one hundred years in Sumatra region, public people had no knowledge about tsunami. This situation was highly improved in 2010 Mentawai case. TV programs and NGO or governmental public education programs about tsunami evacuation are widespread in Indonesia. Many people know about fundamental knowledge of earthquake and tsunami disasters. We made drill book based on victim's stories and painted impressive scene of 2 events. We used the drill book in disaster education event in school committee of west Java. About 80 % students and teachers evaluated that the contents of the drill book are useful for correct understanding.

  6. Overview of environmental and hydrogeologic conditions at King Salmon, Alaska

    USGS Publications Warehouse

    Waythomas, C.F.

    1994-01-01

    The Federal Aviation Administration is conducting preliminary environmental assessments at most of its present or former facilities in Alaska. Information about environmental conditions at King Salmon, Alaska are presented in this report. This report gives an overview of the geology, hydro- logy, and climate of the King Salmon area and describes general geohydrologic conditions. A thick alluvial aquifer underlies King Salmon and both ground water and surface water are plentiful in the area.

  7. Radionuclide Site Survey Report Salchaket (Eielson), Alaska (RN-76)

    DTIC Science & Technology

    2007-11-02

    Volcanic Hazard Map of Alaska 32 Annex K: Airborne Gamma Spectrometry Map This information is not applicable. 33 Annex L: Equipment Used During...Concentration Annual Graphs 25 Annex H: Topographic Maps 27 Annex I: Tectonic Area Map 29 Annex J: Hazard Maps of Alaska 31 Annex K: Airborne Gamma ... gamma spectrometry : N/A d. Aerosol filter measurement: Aerosol sample concentration measurements are shown in Table 4 and Figure 1 below. Table 4

  8. Earthquake Loss Estimation Uncertainties

    NASA Astrophysics Data System (ADS)

    Frolova, Nina; Bonnin, Jean; Larionov, Valery; Ugarov, Aleksander

    2013-04-01

    The paper addresses the reliability issues of strong earthquakes loss assessment following strong earthquakes with worldwide Systems' application in emergency mode. Timely and correct action just after an event can result in significant benefits in saving lives. In this case the information about possible damage and expected number of casualties is very critical for taking decision about search, rescue operations and offering humanitarian assistance. Such rough information may be provided by, first of all, global systems, in emergency mode. The experience of earthquakes disasters in different earthquake-prone countries shows that the officials who are in charge of emergency response at national and international levels are often lacking prompt and reliable information on the disaster scope. Uncertainties on the parameters used in the estimation process are numerous and large: knowledge about physical phenomena and uncertainties on the parameters used to describe them; global adequacy of modeling techniques to the actual physical phenomena; actual distribution of population at risk at the very time of the shaking (with respect to immediate threat: buildings or the like); knowledge about the source of shaking, etc. Needless to be a sharp specialist to understand, for example, that the way a given building responds to a given shaking obeys mechanical laws which are poorly known (if not out of the reach of engineers for a large portion of the building stock); if a carefully engineered modern building is approximately predictable, this is far not the case for older buildings which make up the bulk of inhabited buildings. The way population, inside the buildings at the time of shaking, is affected by the physical damage caused to the buildings is not precisely known, by far. The paper analyzes the influence of uncertainties in strong event parameters determination by Alert Seismological Surveys, of simulation models used at all stages from, estimating shaking intensity

  9. 1996 volcanic activity in Alaska and Kamchatka: summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    Neal, Christina A.; McGimsey, Robert G.

    1997-01-01

    During 1996, the Alaska Volcano Observatory (AVO) responded to eruptive activity, anomalous seismicity, or suspected volcanic activity at 10 of the approximately 40 active volcanic centers in the state of Alaska. As part of a formal role in KVERT (the Kamchatkan Volcano Eruption Response Team), AVO staff also disseminated information about eruptions and other volcanic unrest at six volcanic centers on the Kamchatka Peninsula and in the Kurile Islands, Russia.

  10. Parallelization of the Coupled Earthquake Model

    NASA Technical Reports Server (NTRS)

    Block, Gary; Li, P. Peggy; Song, Yuhe T.

    2007-01-01

    This Web-based tsunami simulation system allows users to remotely run a model on JPL s supercomputers for a given undersea earthquake. At the time of this reporting, predicting tsunamis on the Internet has never happened before. This new code directly couples the earthquake model and the ocean model on parallel computers and improves simulation speed. Seismometers can only detect information from earthquakes; they cannot detect whether or not a tsunami may occur as a result of the earthquake. When earthquake-tsunami models are coupled with the improved computational speed of modern, high-performance computers and constrained by remotely sensed data, they are able to provide early warnings for those coastal regions at risk. The software is capable of testing NASA s satellite observations of tsunamis. It has been successfully tested for several historical tsunamis, has passed all alpha and beta testing, and is well documented for users.

  11. AK State Profile. Alaska: Alaska High School Graduation Qualifying Exam (HSGOE)

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper provides information about Alaska High School Graduation Qualifying Exam (HSGQE), a comprehensive standards-based exam. Its purpose is to meet a state mandate. A bill to remove the HSGQE as a graduation requirement by July 1, 2011 was presented to the state legislature as SB 109. However, it did not pass both houses of the legislature.…

  12. Accretion of southern Alaska

    USGS Publications Warehouse

    Hillhouse, J.W.

    1987-01-01

    Paleomagnetic data from southern Alaska indicate that the Wrangellia and Peninsular terranes collided with central Alaska probably by 65 Ma ago and certainly no later than 55 Ma ago. The accretion of these terranes to the mainland was followed by the arrival of the Ghost Rocks volcanic assemblage at the southern margin of Kodiak Island. Poleward movement of these terranes can be explained by rapid motion of the Kula oceanic plate, mainly from 85 to 43 Ma ago, according to recent reconstructions derived from the hot-spot reference frame. After accretion, much of southwestern Alaska underwent a counterclockwise rotation of about 50 ?? as indicated by paleomagnetic poles from volcanic rocks of Late Cretaceous and Early Tertiary age. Compression between North America and Asia during opening of the North Atlantic (68-44 Ma ago) may account for the rotation. ?? 1987.

  13. Tidal triggering of earthquakes in the Northeast Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Wilcock, William S. D.

    2009-11-01

    There have been many searches for evidence of tidal triggering in earthquake catalogues. With the exception of volcanically active regions, the more rigorous studies in continental settings tend to find no correlation or only a very weak correlation. In the oceans, the effect of loading by the ocean tides can increase tidal stresses by about an order of magnitude over continental settings. In recent years, several studies have reported evidence of tidal triggering in oceanic regions and such observations can represent a useful constraint on models of earthquake rupture. In this paper, I systematically search for a link between ocean tide height and the incidence of earthquakes in the Northeast Pacific Ocean, a region of high-amplitude open ocean tides. The focal mechanisms of most of the earthquakes in these catalogues are unknown but it can be shown that tidal stresses will in most instances promote failure at low tides. I investigate three declustered data sets comprising (1) earthquakes from 1980 to 2007 on the Juan de Fuca plate and in the Queen Charlotte Fault region from land based catalogues; (2) earthquakes from 1992 to 2001 on the Juan de Fuca plate located with the US Navy's Sound Surveillance System (SOSUS) hydrophone array and (3) earthquakes from 1980 to 2001 south of Alaska and the Aleutians located with land based networks. I look at the distributions of earthquakes with ocean tide phase, height, and tidal range and apply Schuster and binomial tests and Monte Carlo simulations to determine if they deviate significantly from random. The results show no evidence of triggering during intervals of increased tidal range but all three data sets show a significant increase in earthquake incidence at low tides. The signal is particularly strong in the land-based catalogue for the Juan de Fuca Plate and Queen Charlotte Fault regions where there is a 15 per cent increase in the rate of seismicity within 15° of the lowest tides. The signal is weakest in the

  14. Catalog of earthquake hypocenters at Alaskan volcanoes: January 1 through December 31, 2010

    USGS Publications Warehouse

    Dixon, James P.; Stihler, Scott D.; Power, John A.; Searcy, Cheryl K.

    2011-01-01

    Between January 1 and December 31, 2010, the Alaska Volcano Observatory (AVO) located 3,405 earthquakes, of which 2,846 occurred within 20 kilometers of the 33 volcanoes with seismograph subnetworks. There was no significant seismic activity in 2010 at these monitored volcanic centers. Seismograph subnetworks with severe outages in 2009 were repaired in 2010 resulting in three volcanic centers (Aniakchak, Korovin, and Veniaminof) being relisted in the formal list of monitored volcanoes. This catalog includes locations and statistics of the earthquakes located in 2010 with the station parameters, velocity models, and other files used to locate these earthquakes.

  15. Using 1-Hz GPS data to measure deformations caused by the denali fault earthquake

    USGS Publications Warehouse

    Larson, K.M.; Bodin, P.; Gomberg, J.

    2003-01-01

    The 3 November 2002 moment magnitude 7.9 Denali fault earthquake generated large, permanent surface displacements in Alaska and large-amplitude surface waves throughout western North America. We find good agreement between strong ground-motion records integrated to displacement and 1-hertz Global Positioning System (GPS) position estimates collected ??? 140 kilometers from the earthquake epicenter. One-hertz GPS receivers also detected seismic surface waves 750 to 3800 kilometers from the epicenter, whereas these waves saturated many of the seismic instruments in the same region. High-frequency GPS increases the dynamic range and frequency bandwidth of ground-motion observations, providing another tool for studying earthquake processes.

  16. Earthquake friction

    NASA Astrophysics Data System (ADS)

    Mulargia, Francesco; Bizzarri, Andrea

    2016-12-01

    Laboratory friction slip experiments on rocks provide firm evidence that the static friction coefficient μ has values ∼0.7. This would imply large amounts of heat produced by seismically active faults, but no heat flow anomaly is observed, and mineralogic evidence of frictional heating is virtually absent. This stands for lower μ values ∼0.2, as also required by the observed orientation of faults with respect to the maximum compressive stress. We show that accounting for the thermal and mechanical energy balance of the system removes this inconsistence, implying a multi-stage strain release process. The first stage consists of a small and slow aseismic slip at high friction on pre-existent stress concentrators within the fault volume but angled with the main fault as Riedel cracks. This introduces a second stage dominated by frictional temperature increase inducing local pressurization of pore fluids around the slip patches, which is in turn followed by a third stage in which thermal diffusion extends the frictionally heated zones making them coalesce into a connected pressurized region oriented as the fault plane. Then, the system enters a state of equivalent low static friction in which it can undergo the fast elastic radiation slip prescribed by dislocation earthquake models.

  17. Teshekpuk Lake, Alaska

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This ASTER image of Teshekpuk Lake on Alaska's North Slope, within the National Petroleum Reserve, was acquired on August 15, 2000. It covers an area of 58.7 x 89.9 km, and is centered near 70.4 degrees north latitude, 153 degrees west longitude.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

    Size: 58.7 by 89.9 kilometers (36.4 by 55.7 miles) Location: 70.4 degrees North latitude, 153 degrees West longitude Orientation: North at top Image Data: ASTER Bands 3, 2, and 1 Original Data Resolution: ASTER 30 meters (98.4 feet) Dates Acquired: August 15, 2000

  18. Mexican Earthquakes and Tsunamis Catalog Reviewed

    NASA Astrophysics Data System (ADS)

    Ramirez-Herrera, M. T.; Castillo-Aja, R.

    2015-12-01

    Today the availability of information on the internet makes online catalogs very easy to access by both scholars and the public in general. The catalog in the "Significant Earthquake Database", managed by the National Center for Environmental Information (NCEI formerly NCDC), NOAA, allows access by deploying tabular and cartographic data related to earthquakes and tsunamis contained in the database. The NCEI catalog is the product of compiling previously existing catalogs, historical sources, newspapers, and scientific articles. Because NCEI catalog has a global coverage the information is not homogeneous. Existence of historical information depends on the presence of people in places where the disaster occurred, and that the permanence of the description is preserved in documents and oral tradition. In the case of instrumental data, their availability depends on the distribution and quality of seismic stations. Therefore, the availability of information for the first half of 20th century can be improved by careful analysis of the available information and by searching and resolving inconsistencies. This study shows the advances we made in upgrading and refining data for the earthquake and tsunami catalog of Mexico since 1500 CE until today, presented in the format of table and map. Data analysis allowed us to identify the following sources of error in the location of the epicenters in existing catalogs: • Incorrect coordinate entry • Place name erroneous or mistaken • Too general data that makes difficult to locate the epicenter, mainly for older earthquakes • Inconsistency of earthquakes and the tsunami occurrence: earthquake's epicenter located too far inland reported as tsunamigenic. The process of completing the catalogs directly depends on the availability of information; as new archives are opened for inspection, there are more opportunities to complete the history of large earthquakes and tsunamis in Mexico. Here, we also present new earthquake and

  19. 2012 Alaska Performance Scholarship Outcomes Report

    ERIC Educational Resources Information Center

    Rae, Brian

    2012-01-01

    As set forth in Alaska Statute 14.43.840, Alaska's Departments of Education & Early Development (EED) and Labor and Workforce Development (DOLWD), the University of Alaska (UA), and the Alaska Commission on Postsecondary Education (ACPE) present this first annual report on the Alaska Performance Scholarship to the public, the Governor, and the…

  20. CE-PA: A user`s manual for determination of controlling earthquakes and development of seismic hazard information data base for the central and eastern United States

    SciTech Connect

    Short, C.

    1995-05-01

    The CE-PA, Controlling Earthquake(s) through Probabilistic Analysis, software package developed at Lawrence Livermore National Laboratory (LLNL) is a research program used as part of a study performed for the US Office of Nuclear Regulatory Research Division Engineering project on Geosciences Issues in the revision of geological siting criteria. The objectives of this study were to explore ways on how to use results from probabilistic seismic hazard characterization (PSHC) to determine hazard-consistent scenario earthquakes and to develop design ground motion. The purpose of this document is to describe the CE-PA software to users. The software includes two operating system and process controllers plus several fortran routines and input decks. This manual gives an overview of the methodology to estimate controlling earthquakes in Section I. A descriptive overview of the procedures and the organization of the program modules used in CE-PA is provided in Section II. Section III contains four example executions with comments and a graphical display of each execution path, plus an overview of the directory/file structure. Section IV provides some general observations regarding the model.

  1. "Breaking Ground" in the Use of Social Media: A Case Study of a University Earthquake Response to Inform Educational Design with Facebook

    ERIC Educational Resources Information Center

    Dabner, Nicki

    2012-01-01

    On September 4 2010, a massive 7.1 magnitude earthquake struck the Canterbury region in the South Island of New Zealand. The response from the University of Canterbury was immediate and carefully co-ordinated, with the university's web-based environment and a responsive site developed on the social media platform "Facebook" becoming…

  2. Frequency dependent Lg attenuation in south-central Alaska

    USGS Publications Warehouse

    McNamara, D.E.

    2000-01-01

    The characteristics of seismic energy attenuation are determined using high frequency Lg waves from 27 crustal earthquakes, in south-central Alaska. Lg time-domain amplitudes are measured in five pass-bands and inverted to determine a frequency-dependent quality factor, Q(f), model for south-central Alaska. The inversion in this study yields the frequency-dependent quality factor, in the form of a power law: Q(f) = Q0fη = 220(±30) f0.66(±0.09) (0.75≤f≤12Hz). The results from this study are remarkably consistent with frequency dependent quality factor estimates, using local S-wave coda, in south-central Alaska. The consistency between S-coda Q(f) and Lg Q(f) enables constraints to be placed on the mechanism of crustal attenuation in south-central Alaska. For the range of frequencies considered in this study both scattering and intrinsic attenuation mechanisms likely play an equal role.

  3. Integrated resource inventory for southcentral Alaska (INTRISCA)

    NASA Technical Reports Server (NTRS)

    Burns, T.; Carson-Henry, C.; Morrissey, L. A.

    1981-01-01

    The Integrated Resource Inventory for Southcentral Alaska (INTRISCA) Project comprised an integrated set of activities related to the land use planning and resource management requirements of the participating agencies within the southcentral region of Alaska. One subproject involved generating a region-wide land cover inventory of use to all participating agencies. Toward this end, participants first obtained a broad overview of the entire region and identified reasonable expectations of a LANDSAT-based land cover inventory through evaluation of an earlier classification generated during the Alaska Water Level B Study. Classification of more recent LANDSAT data was then undertaken by INTRISCA participants. The latter classification produced a land cover data set that was more specifically related to individual agency needs, concurrently providing a comprehensive training experience for Alaska agency personnel. Other subprojects employed multi-level analysis techniques ranging from refinement of the region-wide classification and photointerpretation, to digital edge enhancement and integration of land cover data into a geographic information system (GIS).

  4. USGS Alaska State Mosaic

    USGS Publications Warehouse

    ,

    2008-01-01

    The Alaska State Mosaic consists of portions of scenes from the Multi-Resolution Land Characteristics 2001 (MRLC 2001) collection. The 172 selected scenes have been geometrically and radiometrically aligned to produce a seamless, relatively cloud-free image of the State. The scenes were acquired between July 1999 and September 2002, resampled to 120-meter pixels, and cropped to the State boundary. They were reprojected into a standard Alaska Albers projection with the U.S. National Elevation Dataset (NED) used to correct for relief.

  5. Earthquakes: hydrogeochemical precursors

    USGS Publications Warehouse

    Ingebritsen, Steven E.; Manga, Michael

    2014-01-01

    Earthquake prediction is a long-sought goal. Changes in groundwater chemistry before earthquakes in Iceland highlight a potential hydrogeochemical precursor, but such signals must be evaluated in the context of long-term, multiparametric data sets.

  6. The size of earthquakes

    USGS Publications Warehouse

    Kanamori, H.

    1980-01-01

    How we should measure the size of an earthquake has been historically a very important, as well as a very difficult, seismological problem. For example, figure 1 shows the loss of life caused by earthquakes in recent times and clearly demonstrates that 1976 was the worst year for earthquake casualties in the 20th century. However, the damage caused by an earthquake is due not only to its physical size but also to other factors such as where and when it occurs; thus, figure 1 is not necessarily an accurate measure of the "size" of earthquakes in 1976. the point is that the physical process underlying an earthquake is highly complex; we therefore cannot express every detail of an earthquake by a simple straightforward parameter. Indeed, it would be very convenient if we could find a single number that represents the overall physical size of an earthquake. This was in fact the concept behind the Richter magnitude scale introduced in 1935. 

  7. Earthquakes for Kids

    MedlinePlus

    ... lab. Earthquake Animations A trench dug across a fault to learn about past earthquakes. Science Fair Projects ... History A scientist stands in front of a fault scarp in southern California. Damage to badly-constructed ...

  8. Earthquakes: Predicting the unpredictable?

    USGS Publications Warehouse

    Hough, S.E.

    2005-01-01

    The earthquake prediction pendulum has swung from optimism in the 1970s to rather extreme pessimism in the 1990s. Earlier work revealed evidence of possible earthquake precursors: physical changes in the planet that signal that a large earthquake is on the way. Some respected earthquake scientists argued that earthquakes are likewise fundamentally unpredictable. The fate of the Parkfield prediction experiment appeared to support their arguments: A moderate earthquake had been predicted along a specified segment of the central San Andreas fault within five years of 1988, but had failed to materialize on schedule. At some point, however, the pendulum began to swing back. Reputable scientists began using the "P-word" in not only polite company, but also at meetings and even in print. If the optimism regarding earthquake prediction can be attributed to any single cause, it might be scientists' burgeoning understanding of the earthquake cycle.

  9. Estimating earthquake potential

    USGS Publications Warehouse

    Page, R.A.

    1980-01-01

    The hazards to life and property from earthquakes can be minimized in three ways. First, structures can be designed and built to resist the effects of earthquakes. Second, the location of structures and human activities can be chosen to avoid or to limit the use of areas known to be subject to serious earthquake hazards. Third, preparations for an earthquake in response to a prediction or warning can reduce the loss of life and damage to property as well as promote a rapid recovery from the disaster. The success of the first two strategies, earthquake engineering and land use planning, depends on being able to reliably estimate the earthquake potential. The key considerations in defining the potential of a region are the location, size, and character of future earthquakes and frequency of their occurrence. Both historic seismicity of the region and the geologic record are considered in evaluating earthquake potential. 

  10. Identification, definition and mapping of terrestrial ecosystems in interior Alaska

    NASA Technical Reports Server (NTRS)

    Anderson, J. H. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. A transect of the Tanana River Flats to Murphy Dome, Alaska was accomplished. The transect includes an experimental forest and information on the range of vegetation-land form types. Multispectral black and white prints of the Eagle Summit Research Area, Alaska, were studied in conjunction with aerial photography and field notes to determine the characteristics of the vegetation. Black and white MSS prints were compared with aerial photographs of the village of Wiseman, Alaska. No positive identifications could be made without reference to aerial photographs or ground truth data. Color coded density slice scenes of the Eagle Summit Research Area were produced from black and white NASA aerial photographs. Infestations of the spruce beetle in the Cook Inlet, Alaska, were studied using aerial photographs.

  11. Earthquake outlook for the San Francisco Bay region 2014–2043

    USGS Publications Warehouse

    Aagaard, Brad T.; Blair, James Luke; Boatwright, John; Garcia, Susan H.; Harris, Ruth A.; Michael, Andrew J.; Schwartz, David P.; DiLeo, Jeanne S.; Jacques, Kate; Donlin, Carolyn

    2016-06-13

    Using information from recent earthquakes, improved mapping of active faults, and a new model for estimating earthquake probabilities, the 2014 Working Group on California Earthquake Probabilities updated the 30-year earthquake forecast for California. They concluded that there is a 72 percent probability (or likelihood) of at least one earthquake of magnitude 6.7 or greater striking somewhere in the San Francisco Bay region before 2043. Earthquakes this large are capable of causing widespread damage; therefore, communities in the region should take simple steps to help reduce injuries, damage, and disruption, as well as accelerate recovery from these earthquakes.

  12. Multi-segment earthquakes and tsunami potential of the Aleutian megathrust

    USGS Publications Warehouse

    Shennan, I.; Bruhn, R.; Plafker, G.

    2009-01-01

    Large to great earthquakes and related tsunamis generated on the Aleutian megathrust produce major hazards for both the area of rupture and heavily populated coastlines around much of the Pacific Ocean. Here we use paleoseismic records preserved in coastal sediments to investigate whether segment boundaries control the largest ruptures or whether in some seismic cycles segments combine to produce earthquakes greater than any observed since instrumented records began. Virtually the entire megathrust has ruptured since AD1900, with four different segments generating earthquakes >M8.0. The largest was the M9.2 great Alaska earthquake of March 1964 that ruptured ???800 km of the eastern segment of the megathrust. The tsunami generated caused fatalities in Alaska and along the coast as far south as California. East of the 1964 zone of deformation, the Yakutat microplate experienced two >M8.0 earthquakes, separated by a week, in September 1899. For the first time, we present evidence that earthquakes ???900 and ???1500 years ago simultaneously ruptured adjacent segments of the Aleutian megathrust and the Yakutat microplate, with a combined area ???15% greater than 1964, giving an earthquake of greater magnitude and increased tsunamigenic potential. ?? 2008 Elsevier Ltd. All rights reserved.

  13. Engaging Elements of Cancer-Related Digital Stories in Alaska.

    PubMed

    Cueva, Melany; Kuhnley, Regina; Revels, Laura; Schoenberg, Nancy E; Lanier, Anne; Dignan, Mark

    2016-09-01

    The tradition of storytelling is an integral part of Alaska Native cultures that continues to be a way of passing on knowledge. Using a story-based approach to share cancer education is grounded in Alaska Native traditions and people's experiences and has the potential to positively impact cancer knowledge, understandings, and wellness choices. Community health workers (CHWs) in Alaska created a personal digital story as part of a 5-day, in-person cancer education course. To identify engaging elements of digital stories among Alaska Native people, one focus group was held in each of three different Alaska communities with a total of 29 adult participants. After viewing CHWs' digital stories created during CHW cancer education courses, focus group participants commented verbally and in writing about cultural relevance, engaging elements, information learned, and intent to change health behavior. Digital stories were described by Alaska focus group participants as being culturally respectful, informational, inspiring, and motivational. Viewers shared that they liked digital stories because they were short (only 2-3 min); nondirective and not preachy; emotional, told as a personal story and not just facts and figures; and relevant, using photos that showed Alaskan places and people.

  14. Earthquake Scenarios and Comparison with Historical Earthquakes, Hatay Region, SE Turkey

    NASA Astrophysics Data System (ADS)

    Uskuplu, S.; Tuysuz, O.

    2012-04-01

    Hatay Province (Antioch on Orontes) and its surroundings, SE Turkey, have been studied in this research. Tectonically, the East Anatolian Fault Zone (EAFZ), Dead Sea Fault Zone (DAFZ) and Cyprus Arc juxtapose in this region and form a triple junction. Historical records, which extend back to 300 BC, indicate that repeated destructive earthquakes affected this historical region for many times. It is still a matter of debate in this region that which fault produced these earthquakes. It is indisputable for this region that the probability of occurrence of future big and destructive earthquakes are quite high. For that purpose, the damage distributions of the historical earthquakes of this region, which are compiled from various catalogues, have been investigated in this study. The active faults in the region are determined by field studies and the maximum magnitudes of the earthquakes that can be produced by those faults are calculated by using empirical formulas. In the next step we produced synthetic earthquake scenarios by using Geographical Information System (GIS) analysis techniques to estimate the damage distribution of earthquakes that would possibly be produced by different fault segments. In the last step we compared results of damage distribution of synthetic earthquake scenarios with the damage distribution from historical records. Based on these results we tried to estimate which fault segment produced which historical earthquake. Results of our study indicate that the historical earthquakes in the Hatay Province were mainly produced by different segments of the Dead Sea Fault, and the Antakya-Samandag Fault. Keywords; Earthquake scenarios, GIS, historical earthquakes, Hatay, intensity

  15. Redefining Earthquakes and the Earthquake Machine

    ERIC Educational Resources Information Center

    Hubenthal, Michael; Braile, Larry; Taber, John

    2008-01-01

    The Earthquake Machine (EML), a mechanical model of stick-slip fault systems, can increase student engagement and facilitate opportunities to participate in the scientific process. This article introduces the EML model and an activity that challenges ninth-grade students' misconceptions about earthquakes. The activity emphasizes the role of models…

  16. Children's Ideas about Earthquakes

    ERIC Educational Resources Information Center

    Simsek, Canan Lacin

    2007-01-01

    Earthquake, a natural disaster, is among the fundamental problems of many countries. If people know how to protect themselves from earthquake and arrange their life styles in compliance with this, damage they will suffer will reduce to that extent. In particular, a good training regarding earthquake to be received in primary schools is considered…

  17. Earthquake and Schools. [Videotape].

    ERIC Educational Resources Information Center

    Federal Emergency Management Agency, Washington, DC.

    Designing schools to make them more earthquake resistant and protect children from the catastrophic collapse of the school building is discussed in this videotape. It reveals that 44 of the 50 U.S. states are vulnerable to earthquake, but most schools are structurally unprepared to take on the stresses that earthquakes exert. The cost to the…

  18. School Safety and Earthquakes.

    ERIC Educational Resources Information Center

    Dwelley, Laura; Tucker, Brian; Fernandez, Jeanette

    1997-01-01

    A recent assessment of earthquake risk to Quito, Ecuador, concluded that many of its public schools are vulnerable to collapse during major earthquakes. A subsequent examination of 60 buildings identified 15 high-risk buildings. These schools were retrofitted to meet standards that would prevent injury even during Quito's largest earthquakes. US…

  19. Real Earthquakes, Real Learning

    ERIC Educational Resources Information Center

    Schomburg, Aaron

    2003-01-01

    One teacher took her class on a year long earthquake expedition. The goal was to monitor the occurrences of real earthquakes during the year and mark their locations with push pins on a wall-sized world map in the hallway outside the science room. The purpose of the project was to create a detailed picture of the earthquakes that occurred…

  20. Smartphone MEMS accelerometers and earthquake early warning

    NASA Astrophysics Data System (ADS)

    Kong, Q.; Allen, R. M.; Schreier, L.; Kwon, Y. W.

    2015-12-01

    The low cost MEMS accelerometers in the smartphones are attracting more and more attentions from the science community due to the vast number and potential applications in various areas. We are using the accelerometers inside the smartphones to detect the earthquakes. We did shake table tests to show these accelerometers are also suitable to record large shakings caused by earthquakes. We developed an android app - MyShake, which can even distinguish earthquake movements from daily human activities from the recordings recorded by the accelerometers in personal smartphones and upload trigger information/waveform to our server for further analysis. The data from these smartphones forms a unique datasets for seismological applications, such as earthquake early warning. In this talk I will layout the method we used to recognize earthquake-like movement from single smartphone, and the overview of the whole system that harness the information from a network of smartphones for rapid earthquake detection. This type of system can be easily deployed and scaled up around the global and provides additional insights of the earthquake hazards.

  1. New geological perspectives on earthquake recurrence models

    SciTech Connect

    Schwartz, D.P.

    1997-02-01

    In most areas of the world the record of historical seismicity is too short or uncertain to accurately characterize the future distribution of earthquakes of different sizes in time and space. Most faults have not ruptured once, let alone repeatedly. Ultimately, the ability to correctly forecast the magnitude, location, and probability of future earthquakes depends on how well one can quantify the past behavior of earthquake sources. Paleoseismological trenching of active faults, historical surface ruptures, liquefaction features, and shaking-induced ground deformation structures provides fundamental information on the past behavior of earthquake sources. These studies quantify (a) the timing of individual past earthquakes and fault slip rates, which lead to estimates of recurrence intervals and the development of recurrence models and (b) the amount of displacement during individual events, which allows estimates of the sizes of past earthquakes on a fault. When timing and slip per event are combined with information on fault zone geometry and structure, models that define individual rupture segments can be developed. Paleoseismicity data, in the form of timing and size of past events, provide a window into the driving mechanism of the earthquake engine--the cycle of stress build-up and release.

  2. Evidence for dike emplacement beneath Iliamna Volcano, Alaska in 1996

    USGS Publications Warehouse

    Roman, D.C.; Power, J.A.; Moran, S.C.; Cashman, K.V.; Doukas, M.P.; Neal, C.A.; Gerlach, T.M.

    2004-01-01

    Two earthquake swarms, comprising 88 and 2833 locatable events, occurred beneath Iliamna Volcano, Alaska, in May and August of 1996. Swarm earthquakes ranged in magnitude from -0.9 to 3.3. Increases in SO2 and CO2 emissions detected during the fall of 1996 were coincident with the second swarm. No other physical changes were observed in or around the volcano during this time period. No eruption occurred, and seismicity and measured gas emissions have remained at background levels since mid-1997. Earthquake hypocenters recorded during the swarms form a cluster in a previously aseismic volume of crust located to the south of Iliamna's summit at a depth of -1 to 4 km below sea level. This cluster is elongated to the NNW-SSE, parallel to the trend of the summit and southern vents at Iliamna and to the regional axis of maximum compressive stress determined through inversion of fault-plane solutions for regional earthquakes. Fault-plane solutions calculated for 24 swarm earthquakes located at the top of the new cluster suggest a heterogeneous stress field acting during the second swarm, characterized by normal faulting and strike-slip faulting with p-axes parallel to the axis of regional maximum compressive stress. The increase in earthquake rates, the appearance of a new seismic volume, and the elevated gas emissions at Iliamna Volcano indicate that new magma intruded beneath the volcano in 1996. The elongation of the 1996-1997 earthquake cluster parallel to the direction of regional maximum compressive stress and the accelerated occurrence of both normal and strike-slip faulting in a small volume of crust at the top of the new seismic volume may be explained by the emplacement and inflation of a subvertical planar dike beneath the summit of Iliamna and its southern satellite vents. ?? 2003 Elsevier B.V. All rights reserved.

  3. Alaska's Cold Desert.

    ERIC Educational Resources Information Center

    Brune, Jeff; And Others

    1996-01-01

    Explores the unique features of Alaska's Arctic ecosystem, with a focus on the special adaptations of plants and animals that enable them to survive in a stressful climate. Reviews the challenges facing public and private land managers who seek to conserve this ecosystem while accommodating growing demands for development. Includes classroom…

  4. Alaska Glaciers and Rivers

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured this image on October 7, 2007, showing the Alaska Mountains of south-central Alaska already coated with snow. Purple shadows hang in the lee of the peaks, giving the snow-clad land a crumpled appearance. White gives way to brown on the right side of the image where the mountains yield to the lower-elevation Susitna River Valley. The river itself cuts a silver, winding path through deep green forests and brown wetlands and tundra. Extending from the river valley, are smaller rivers that originated in the Alaska Mountains. The source of these rivers is evident in the image. Smooth white tongues of ice extend into the river valleys, the remnants of the glaciers that carved the valleys into the land. Most of the water flowing into the Gulf of Alaska from the Susitna River comes from these mountain glaciers. Glacier melt also feeds glacier lakes, only one of which is large enough to be visible in this image. Immediately left of the Kahiltna River, the aquamarine waters of Chelatna Lake stand out starkly against the brown and white landscape.

  5. Venetie, Alaska energy assessment.

    SciTech Connect

    Jensen, Richard Pearson; Baca, Michael J.; Schenkman, Benjamin L.; Brainard, James Robert

    2013-07-01

    This report summarizes the Energy Assessment performed for Venetie, Alaska using the principals of an Energy Surety Microgrid (ESM) The report covers a brief overview of the principals of ESM, a site characterization of Venetie, a review of the consequence modeling, some preliminary recommendations, and a basic cost analysis.

  6. Alaska's Logging Camp School.

    ERIC Educational Resources Information Center

    Millward, Robert E.

    1999-01-01

    A visit to Ketchikan, Alaska, reveals a floating, one-teacher logging-camp school that uses multiage grouping and interdisciplinary teaching. There are 10 students. The school gym and playground, bunkhouse, fuel tanks, mess hall, and students' homes bob up and down and are often moved to other sites. (MLH)

  7. Sensor emplacement testing at Poker Flat, Alaska

    NASA Astrophysics Data System (ADS)

    Reusch, A.; Beaudoin, B. C.; Anderson, K. E.; Azevedo, S.; Carothers, L.; Love, M.; Miller, P. E.; Parker, T.; Pfeifer, M.; Slad, G.; Thomas, D.; Aderhold, K.

    2013-12-01

    PASSCAL provides equipment and support for temporary seismic projects. Speed and efficiency of deployments are essential. A revised emplacement technique of putting broadband sensors directly into soil (aka direct burial) is being tested. The first phase (fall 2011 to spring 2013) comparing data quality and sensor stability between the direct burial and the traditional 1 m deep temporary PASSCAL-style vault in a wet and noisy site near San Antonio, NM is complete. Results suggest there is little or no difference in sensor performance in the relatively high-noise environment of this initial test. The second phase was started in November 2012 with the goal of making the same comparison, but at Poker Flat, Alaska, in a low-noise, high-signal, cold and wet environment, alongside a Transportable Array (TA) deployment to be used as a performance control. This location is in an accessible and secure area with very low site noise. In addition to benefiting future worldwide PASSCAL deployments, the Poker Flat experiment serves a secondary purpose of testing modifications necessary to successfully deploy and recover broadband stations in a cold environment with the limited logistics anticipated for remote Flexible Array (FA) and PASSCAL Program deployments in Alaska. Developing emplacement techniques that maintain high data quality and data return while minimizing logistics is critical to enable principle investigators to effectively and efficiently co-locate within the future TA Alaska footprint. Three Nanometrics sensors were installed in November 2012 in power-augered holes 76 cm in depth: a Trillium Compact Posthole (PH) and two Trillium 120PH units (one standard PH and one enhanced PHQ). The installations took less than 8 hours in -30°C conditions with 4 hours of usable daylight. The Compact PH and the 120PHQ are delivering data in realtime, while the 120PH is testing standalone power and data collection systems. Preliminary results compare favorably to each other as

  8. Do oil and gold mix in Alaska

    SciTech Connect

    Bailey, R.V.

    1985-04-01

    Excellent potential for sea-floor-placer heavy mineral deposits exists locally along the coast of Alaska within lands owned by the state. Aspen Exploration first applied for precious metal offshore prospecting permits (OPPs) from the state in 1980 for certain lands in Cook Inlet, including lands that are prospective for oil and gas production. Exploration to date has included geologic mapping, beach sampling at many locations, and a 6400 mile low-level aeromagnetic survey. More than 20,000 ft of sediments underlie areas that appear most prospective for placer gold deposits, thereby facilitating geophysical interpretation of sea-floor magnetic anomalies. Work to date, now suspended, suggests large, linear, offshore heavy mineral concentrations, which likely include gold. Obtaining permits in Alaska is difficult, frustrating, and expensive. After 5 years of effort, no permits have been issues to Aspen. Primary opposition has come from the Alaska Department of Fish and Game, which has taken the position that insufficient biological resource information is available in the prospect areas. These same offshore areas, however, are held under oil and gas leases from the state by various companies. The difficulties encountered by smaller oil companies in attempting to carry out exploration in Alaska, which have forced virtually all of them to abandon their efforts in this state, are compared with difficulties hard-mineral companies are encountering. It is important to recognize that income to the state of Alaska from oil royalties and taxes is of such magnitude, that needed support for hard-mineral exploration and mining is being suppressed by a hostile bureaucracy and by preservationists.

  9. PAGER - Rapid Assessment of an Earthquake's Impact

    USGS Publications Warehouse

    Earle, Paul S.; Wald, David J.

    2007-01-01

    PAGER (Prompt Assessment of Global Earthquakes for Response) is an automated system to rapidly assess the number of people and regions exposed to severe shaking by an earthquake, and inform emergency responders, government agencies, and the media to the scope of the potential disaster. PAGER monitors the U.S. Geological Survey?s near real-time U.S. and global earthquake detections and automatically identifies events that are of societal importance, well in advance of ground-truth or news accounts.

  10. Sea Ice, Bristol Bay, Alaska, USA

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This north looking view shows the coast of Alaska, north of the Aleutians, and the eastern margin of the Bering Sea (58.0N, 159.5W). Bristol Bay is apparent in the foreground and Nunivak Island can be seen just below the Earth's horizon, at a distance of about 300 nautical miles. Similar views, photographed during previous missions, when analyzed with these recent views may yield information about regional ice drift and breakup of ice packs.

  11. Reindeer ranges inventory in western Alaska

    NASA Technical Reports Server (NTRS)

    George, T. H.

    1981-01-01

    The use of LANDSAT data as a tool for reindeer range inventory on the tundra of northwestern Alaska is addressed. The specific goal is to map the range resource and estimate plant productivity of the Seward Peninsula. Information derived from these surveys is needed to develop range management plans for reindeer herding and to evaluate potential conflicting use between reindeer and caribou. The development of computer image classification techniques is discussed.

  12. Multiplicative earthquake likelihood models incorporating strain rates

    NASA Astrophysics Data System (ADS)

    Rhoades, D. A.; Christophersen, A.; Gerstenberger, M. C.

    2017-01-01

    SUMMARYWe examine the potential for strain-rate variables to improve long-term <span class="hlt">earthquake</span> likelihood models. We derive a set of multiplicative hybrid <span class="hlt">earthquake</span> likelihood models in which cell rates in a spatially uniform baseline model are scaled using combinations of covariates derived from <span class="hlt">earthquake</span> catalogue data, fault data, and strain-rates for the New Zealand region. Three components of the strain rate estimated from GPS data over the period 1991-2011 are considered: the shear, rotational and dilatational strain rates. The hybrid model parameters are optimised for <span class="hlt">earthquakes</span> of M 5 and greater over the period 1987-2006 and tested on <span class="hlt">earthquakes</span> from the period 2012-2015, which is independent of the strain rate estimates. The shear strain rate is overall the most <span class="hlt">informative</span> individual covariate, as indicated by Molchan error diagrams as well as multiplicative modelling. Most models including strain rates are significantly more <span class="hlt">informative</span> than the best models excluding strain rates in both the fitting and testing period. A hybrid that combines the shear and dilatational strain rates with a smoothed seismicity covariate is the most <span class="hlt">informative</span> model in the fitting period, and a si