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Sample records for cave lava beds

  1. Selected caves and lava-tube systems in and near Lava Beds National Monument, California

    USGS Publications Warehouse

    Waters, Aaron Clement; Donnelly-Nolan, Julie M.; Rogers, Bruce W.

    1990-01-01

    Much of the north and south flanks of the Medicine Lake shield were built from molten lava transmitted through lava tubes. These tubes formed beneath the congealing surface of basalt flows in somewhat the same way that a brook may continue to flow beneath a cover of its own winter ice. As molten lava emerges from a vent and flows downslope, congealing lava from the top and sides of the central channel often forms a bridge over the lava stream. The sticking together of bits of lava spatter and fragile lava crusts strengthens the bridge in the manner that thin crusts of floating ice raft together to cover a brook during early stages of a winter freeze. Eruption of basalt lava, however, is a much more violent and spasmodic process than the steady gathering of water that feeds a brook. If liquid lava stops rising from its source deep within the earth, the still-molten lava moving beneath the crusted-over top of a lava flow will continue to drain downhill and may ultimately leave an open lavatube cave-often large enough for people to walk through. It is rare, however, to find such a simple scenario recorded intact among the hundreds of lava-tube caves in the monument. Even before the top and walls of a lava flow have time to cool during a pause in lava supply, a new and violent eruption of lava may refill the open tube, overflow its upper end, and spread a new lava flow beside or on top of the first flow. Even if the original tube is large enough to contain the renewed supply of lava, this tube must deliver the new lava beyond the end of its original flow and thus the lava field extends farther and farther downslope. If the gradient of flow flattens, the tube may subdivide into a number of smaller distributaries, which spread laterally over the more gently sloping ground. 

  2. Lava tubes and basaltic caves as astrobiological targets on Earth and Mars: A review

    NASA Astrophysics Data System (ADS)

    Léveillé, Richard J.; Datta, Saugata

    2010-03-01

    Lava tubes and basaltic caves are common features in volcanic terrains on Earth. Lava tubes and cave-like features have also been identified on Mars based on orbital imagery and remote-sensing data. Caves are unique environments where both secondary mineral precipitation and microbial growth are enhanced by stable physico-chemical conditions. Thus, they represent excellent locations where traces of microbial life, or biosignatures, are formed and preserved in minerals. By analogy with terrestrial caves, caves on Mars may contain a record of secondary mineralization that would inform us on past aqueous activity. They may also represent the best locations to search for biosignatures. The study of caves on Earth can be used to test hypotheses and better understand biogeochemical processes, and the signatures that these processes leave in mineral deposits. Caves may also serve as test beds for the development of exploration strategies and novel technologies for future missions to Mars. Here we review recent evidence for the presence of caves or lava tubes on Mars, as well as the geomicrobiology of lava tubes and basaltic caves on Earth. We also propose future lines of investigation, including exploration strategies and relevant technologies.

  3. White Sands, Carrizozo Lava Beds, NM

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A truly remarkable view of White Sands and the nearby Carrizozo Lava Beds in southeast NM (33.5N, 106.5W). White Sands, site of the WW II atomic bomb development and testing facility and later post war nuclear weapons testing that can still be seen in the cleared circular patterns on the ground.

  4. Lunar Pit Craters Presumed to be the Entrances of Lava Caves by Analogy to the Earth Lava Tube Pits

    NASA Astrophysics Data System (ADS)

    Hong, Ik-Seon; Yi, Yu; Kim, Eojin

    2014-06-01

    Lava caves could be useful as outposts for the human exploration of the Moon. Lava caves or lava tubes are formed when the external surface of the lava flows cools more quickly to make a hardened crust over subsurface lava flows. The lava flow eventually ceases and drains out of the tube, leaving an empty space. The frail part of the ceiling of lava tube could collapse to expose the entrance to the lava tubes which is called a pit crater. Several pit craters with the diameter of around 100 meters have been found by analyzing the data of SELENE and LRO lunar missions. It is hard to use these pit craters for outposts since these are too large in scale. In this study, small scale pit craters which are fit for outposts have been investigated using the NAC image data of LROC. Several topographic patterns which are believed to be lunar caves have been found and the similar pit craters of the Earth were compared and analyzed to identify caves. For this analysis, the image data of satellites and aerial photographs are collected and classified to construct a database. Several pit craters analogous to lunar pit craters were derived and a morphological pit crater model was generated using the 3D printer based on this database.

  5. Erosion by flowing lava: Geochemical evidence in the Cave Basalt, Mount St. Helens, Washington

    USGS Publications Warehouse

    Williams, D.A.; Kadel, S.D.; Greeley, R.; Lesher, C.M.; Clynne, M.A.

    2004-01-01

    We sampled basaltic lava flows and underlying dacitic tuff deposits in or near lava tubes of the Cave Basalt, Mount St. Helens, Washington to determine whether the Cave Basalt lavas contain geochemical evidence of substrate contamination by lava erosion. The samples were analyzed using a combination of wavelength-dispersive X-ray fluorescence spectrometry and inductively-coupled plasma mass spectrometry. The results indicate that the oldest, outer lava tube linings in direct contact with the dacitic substrate are contaminated, whereas the younger, inner lava tube linings are uncontaminated and apparently either more evolved or enriched in residual liquid. The most heavily contaminated lavas occur closer to the vent and in steeper parts of the tube system, and the amount of contamination decreases with increasing distance downstream. These results suggest that erosion by lava and contamination were limited to only the initially emplaced flows and that erosion was localized and enhanced by vigorous laminar flow over steeper slopes. After cooling, the initial Cave Basalt lava flows formed an insulating lining within the tubes that prevented further erosion by later flows. This interpretation is consistent with models of lava erosion that predict higher erosion rates closer to sources and over steeper slopes. A greater abundance of xenoliths and xenocrysts relative to xenomelts in hand samples indicates that mechanical erosion rather than thermal erosion was the dominant erosional process in the Cave Basalt, but further sampling and petrographic analyses must be performed to verify this hypothesis. ?? Springer-Verlag 2003.

  6. Comparison of Bacterial Diversity in Azorean and Hawai’ian Lava Cave Microbial Mats

    PubMed Central

    MARSHALL HATHAWAY, JENNIFER J.; GARCIA, MATTHEW G.; BALASCH, MONICA MOYA; SPILDE, MICHAEL N.; STONE, FRED D.; DAPKEVICIUS, MARIA DE LURDES N. E.; AMORIM, ISABEL R.; GABRIEL, ROSALINA; BORGES, PAULO A. V.; NORTHUP, DIANA E.

    2015-01-01

    Worldwide, lava caves host colorful microbial mats. However, little is known about the diversity of these microorganisms, or what role they may play in the subsurface ecosystem. White and yellow microbial mats were collected from four lava caves each on the Azorean island of Terceira and the Big Island of Hawai’i, to compare the bacterial diversity found in lava caves from two widely separated archipelagos in two different oceans at different latitudes. Scanning electron microscopy of mat samples showed striking similarities between Terceira and Hawai’ian microbial morphologies. 16S rRNA gene clone libraries were constructed to determine the diversity within these lava caves. Fifteen bacterial phyla were found across the samples, with more Actinobacteria clones in Hawai’ian communities and greater numbers of Acidobacteria clones in Terceira communities. Bacterial diversity in the subsurface was correlated with a set of factors. Geographical location was the major contributor to differences in community composition (at the OTU level), together with differences in the amounts of organic carbon, nitrogen and copper available in the lava rock that forms the cave. These results reveal, for the first time, the similarity among the extensive bacterial diversity found in lava caves in two geographically separate locations and contribute to the current debate on the nature of microbial biogeography. PMID:26924866

  7. Wintering bats of the upper Snake River Plain: occurrence in lava-tube caves

    SciTech Connect

    Genter, D.L.

    1986-04-30

    Distribution and habitat selection of hibernating bats at the Idaho National Engineering Laboratory (INEL) and adjacent area are reported. Exploration of over 30 lava-tube caves revealed that two species, Myotis leibii and Plecotus townsendii, hibernate in the upper Snake River Plain. Five species, M. lucifugus, M. evotis, Eptesicus fuscus, Lasionycteris noctivagans, and Lasiurus cinereus are considered migratory. Myotis leibii and P. townsendii hibernate throughout much of the area, occasionally in mixed-species groups. Myotis leibii uses the dark and protected regions of the cave, usually wedged into tiny pockets and crevices near or at the highest portion of the ceiling. Individuals of P. townsendii may be found at any height or depth in the cave. Temperature appears to be primary limiting factor in habitat selection. Myotis leibii was found in significantly cooler air temperatures than P. townsendii. Neither species tolerated continuous temperatures below 1.5 C. Relative humidity does not seem to be a significant factor in the distribution or habitat selection of the two species in lava-tube caves. 18 references, 1 figure, 1 table.

  8. Assessing the origin of unusual organic formations in lava caves from Canary Islands (Spain)

    NASA Astrophysics Data System (ADS)

    Miller, Ana Z.; de la Rosa, Jose M.; Garcia-Sanchez, Angela M.; Pereira, Manuel F. C.; Jurado, Valme; Fernández, Octavio; Knicker, Heike; Saiz-Jimenez, Cesareo

    2016-04-01

    Lava tubes, like other caves, contain a variety of speleothems formed in the initial stage of a lava tube formation or due to leaching and subsequent precipitation of secondary minerals. Primary and secondary mineral formations in lava caves are mainly composed of silicate minerals, although secondary minerals common in limestone caves have been also reported in this type of caves. In addition, unusual colored deposits have been found on the walls and ceilings of lava tubes, some of them of unknown origin and composition. A brown to black-colored mud-like deposits was observed in "Llano de los Caños" Cave, La Palma Island, Canary Islands, Spain. These black deposits coat the wall and ceiling of the lava tube where sub-horizontal fractures occur. FESEM-EDS, X-ray micro-computed tomography and mineralogical analyses were conducted for morphological, 3D microstructural and compositional characterization of these unusual speleothem samples. These techniques revealed that they are mainly composed of amorphous materials, suggesting an organic carbon composition. Hence, analytical pyrolysis (Py-GC/MS), solid-state 13C Nuclear Magnetic Resonance (NMR) and stable isotope analysis were applied to assess the nature and origin of the black deposits. The combination of these analytical tools permits the identification of specific biomarkers (di- and triterpenoids) for tracing the potential sources of the organic compounds in the speleothems. For comparison purposes, samples from the topsoil and overlaying vegetation were also analyzed. Chromatograms resulting from the Py-GC/MS showed an abundance of polysaccharides, lipids and terpenoids typically derived from the vegetation of the area (Erica arborea). In addition, levoglucosan, polycyclic aromatic hydrocarbons and N-containing heterocyclic compounds were detected. They probably derived from the leaching of charred vegetation resulting from a wildfire occurred in the area in 2012. The lack of the typical pattern of odd

  9. Evaluation of Lava Tube Formation Mechanisms Using Three-Dimensional Mapping, and Viscosity Modeling: Lava Beds National Monument, California.

    NASA Astrophysics Data System (ADS)

    Dedecker, J.; Gant, M.

    2014-12-01

    This study explores the relationships between lava tube morphology, lava effusion rate estimates, and the mechanism of lava tube formation. Effusion rate estimates for extinct lava tubes were calculated using a combination of three-dimensional mapping of lava tube caves, and viscosity models utilizing whole-rock compositions (Giordano et al., 2008, Earth Planet. Sci. Lett.), and petrographic data (Harris and Allen, 2008, J. Geophys. Res.). The mechanism of lava tube formation was evaluated using measured tube lengths and effusion rate estimates and comparing these data with observations from Hawaiian channel- and tube-fed flows (Pinkerton and Wilson, 1994, J. Volcanol. Geoth. Res.). Three-dimensional map data for lava tube caves were collected using a laser rangefinder to measure the cross-sectional shape and down-tube distance, and a tandem compass/inclinometer to measure the azimuth and inclination between survey stations in the tube. Total tube length consists of the mapped tube length plus the distance between collapse pits and trenches along the trend of the tube. Effusion rates were estimated using the Hagen-Poiseuille equation, measured mean cross-sectional radii and slope of lava tubes, and estimated effective viscosities of rock samples collected from mapped tubes at temperatures between 1080-1160 °C and water contents of 0-1 wt.%. A lava density of 1560 g/cm3was used for 0.40 vesicle fraction basalt. There is a positive correlation between measured tube lengths and cross-sectional radii (Fig. 1). We propose that this relationship reflects the positive correlation between flow lengths and effusion rates in active Hawaiian channel-fed flows. Measured tube lengths vs. effusion rate estimates were compared with data for Hawaiian channel-fed flows (Fig. 2). The two data sets overlap and have parallel trends. These results suggest that the lava tube caves studied formed by the roofing-over of channel-fed flows or had segments of channel-fed flow. We propose

  10. Diversity of Ammonia Oxidation (amoA) and Nitrogen Fixation (nifH) Genes in Lava Caves of Terceira, Azores, Portugal

    PubMed Central

    Hathaway, Jennifer J. Marshall; Sinsabaugh, Robert L.; Dapkevicius, Maria De Lurdes N. E.; Northup, Diana E.

    2015-01-01

    Lava caves are an understudied ecosystem in the subterranean world, particularly in regard to nitrogen cycling. The diversity of ammonia oxidation (amoA) and nitrogen fixation (nifH) genes in bacterial mats collected from lava cave walls on the island of Terceira (Azores, Portugal) was investigated using denaturing gradient gel electrophoresis (DGGE). A total of 55 samples were collected from 11 lava caves that were selected with regard to surface land use. Land use types above the lava caves were categorized into pasture, forested, and sea/urban, and used to determine if land use influenced the ammonia oxidizing and nitrogen fixing bacterial communities within the lava caves. The soil and water samples from each lava cave were analyzed for total organic carbon, inorganic carbon, total nitrogen, ammonium, nitrate, phosphate and sulfate, to determine if land use influences either the nutrient content entering the lava cave or the nitrogen cycling bacteria present within the cave. Nitrosospira-like sequences dominated the ammonia-oxidizing bacteria (AOB) community, and the majority of the diversity was found in lava caves under forested land. The nitrogen fixation community was dominated by Klebsiella pneumoniae-like sequences, and diversity was evenly distributed between pasture and forested land, but very little overlap in diversity was observed. The results suggest that land use is impacting both the AOB and the nitrogen fixing bacterial communities. PMID:26778867

  11. 76 FR 4721 - Minor Boundary Revision of Lava Beds National Monument

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-26

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR National Park Service Minor Boundary Revision of Lava Beds National Monument AGENCY: National Park Service....S.C. 460l- 9(c)(1), the boundary of the Petroglyph Point unit of Lava Beds National Monument...

  12. Lava cave microbial communities within mats and secondary mineral deposits: implications for life detection on other planets.

    PubMed

    Northup, D E; Melim, L A; Spilde, M N; Hathaway, J J M; Garcia, M G; Moya, M; Stone, F D; Boston, P J; Dapkevicius, M L N E; Riquelme, C

    2011-09-01

    Lava caves contain a wealth of yellow, white, pink, tan, and gold-colored microbial mats; but in addition to these clearly biological mats, there are many secondary mineral deposits that are nonbiological in appearance. Secondary mineral deposits examined include an amorphous copper-silicate deposit (Hawai'i) that is blue-green in color and contains reticulated and fuzzy filament morphologies. In the Azores, lava tubes contain iron-oxide formations, a soft ooze-like coating, and pink hexagons on basaltic glass, while gold-colored deposits are found in lava caves in New Mexico and Hawai'i. A combination of scanning electron microscopy (SEM) and molecular techniques was used to analyze these communities. Molecular analyses of the microbial mats and secondary mineral deposits revealed a community that contains 14 phyla of bacteria across three locations: the Azores, New Mexico, and Hawai'i. Similarities exist between bacterial phyla found in microbial mats and secondary minerals, but marked differences also occur, such as the lack of Actinobacteria in two-thirds of the secondary mineral deposits. The discovery that such deposits contain abundant life can help guide our detection of life on extraterrestrial bodies.

  13. Lava Cave Microbial Communities Within Mats and Secondary Mineral Deposits: Implications for Life Detection on Other Planets

    PubMed Central

    Melim, L.A.; Spilde, M.N.; Hathaway, J.J.M.; Garcia, M.G.; Moya, M.; Stone, F.D.; Boston, P.J.; Dapkevicius, M.L.N.E.; Riquelme, C.

    2011-01-01

    Abstract Lava caves contain a wealth of yellow, white, pink, tan, and gold-colored microbial mats; but in addition to these clearly biological mats, there are many secondary mineral deposits that are nonbiological in appearance. Secondary mineral deposits examined include an amorphous copper-silicate deposit (Hawai‘i) that is blue-green in color and contains reticulated and fuzzy filament morphologies. In the Azores, lava tubes contain iron-oxide formations, a soft ooze-like coating, and pink hexagons on basaltic glass, while gold-colored deposits are found in lava caves in New Mexico and Hawai‘i. A combination of scanning electron microscopy (SEM) and molecular techniques was used to analyze these communities. Molecular analyses of the microbial mats and secondary mineral deposits revealed a community that contains 14 phyla of bacteria across three locations: the Azores, New Mexico, and Hawai‘i. Similarities exist between bacterial phyla found in microbial mats and secondary minerals, but marked differences also occur, such as the lack of Actinobacteria in two-thirds of the secondary mineral deposits. The discovery that such deposits contain abundant life can help guide our detection of life on extraterrestrial bodies. Key Words: Biosignatures—Astrobiology—Bacteria—Caves—Life detection—Microbial mats. Astrobiology 11, 601–618. PMID:21879833

  14. Martian Ice Caves

    NASA Astrophysics Data System (ADS)

    Frederick, R. D.; Billings, T. L.; McGown, R. D.; Walden, B. E.

    2000-07-01

    Ice in Martian lava tube caves would have scientific and developmental value. These natural channels in rock may hold keys to Mars' past as well as potential resources for humanity's futures. Terrestrial lava tube caves are natural receptacles for accumulations of water. Often, due to lower temperatures coupled with the superior insulation properties of the surrounding rock, these accumulations are in the form of ice. Historically, ice was mined from some lava tube caves. Many of the lava tubes in the Central Oregon area sport such names as "Arnolds Ice Cave," "Surveyors Ice Cave," "South Ice Cave," etc. These caves are not caves in ice, but rather common lava tubes with seasonal, and sometimes perennial ice deposits. Locating and cataloging similar features on Mars, could be of value for the colonization of Mars and the search for life. Such features may also prove useful in helping to determine past climatic conditions on the Red Planet.

  15. Cave microbial community composition in oceanic islands: disentangling the effect of different colored mats in diversity patterns of Azorean lava caves.

    PubMed

    Riquelme, Cristina; Rigal, François; Hathaway, Jennifer J M; Northup, Diana E; Spilde, Michael N; Borges, Paulo A V; Gabriel, Rosalina; Amorim, Isabel R; Dapkevicius, Maria de Lurdes N E

    2015-12-01

    Processes determining diversity and composition of bacterial communities in island volcanic caves are still poorly understood. Here, we characterized colored microbial mats in 14 volcanic caves from two oceanic islands of the Azores using 16S rRNA gene sequences. Factors determining community diversity (α) and composition (β) were explored, namely colored mats, caves and islands, as well as environmental and chemical characteristics of caves. Additive partitioning of diversity using OTU occurrence showed a greater influence of β-diversity between islands and caves that may relate to differences in rare OTUs (singletons and doubletons) across scales. In contrast, Shannon diversity partitioning revealed the importance of the lowest hierarchical level (α diversity, colored mat), suggesting a dominance of cosmopolitan OTUs (>1%) in most samples. Cosmopolitan OTUs included members involved in nitrogen cycling, supporting the importance of this process in Azorean caves. Environmental and chemical conditions in caves did not show any significant relationship to OTU diversity and composition. The absence of clear differences between mat colors and across scales may be explained by (1) the geological youth of the cave system (cave communities have not had enough time to diverge) or/and (2) community convergence, as the result of selection pressure in extreme environments.

  16. High-resolution Digital Mapping of Historical Lava Flows as a Test-bed for Lava Flow Models

    NASA Astrophysics Data System (ADS)

    Pyle, D. M.; Parks, M.; Nomikou, P.; Mather, T. A.; Simou, E.; Kalnins, L. M.; Paulatto, M.; Watts, A. B.

    2013-12-01

    Quantitative analysis of high-resolution lava flow morphology can improve our understanding of past effusive eruptions by providing insight into eruptive processes and the rheological properties of erupted magmas. We report the results of an ongoing investigation into the young dacite lava flows of the Kameni islands, Santorini volcano, Greece, which were emplaced during both subaerial and shallow submarine eruptions over the past 3000 years. Historical eruptions of the Kameni islands since 1866 have been very carefully documented in contemporaneous scientific reports. Eruptions since 1573 appear to be time-predictable, with a close relationship between eruption length, the size of extruded lava domes, and the time elapsed since the previous eruption. A new NERC - Airborne Survey and Research Facility LiDAR survey of the Kameni islands was completed in May 2012, using a Leica ALS50 Airborne Laser Scanner mounted on a Dornier 228 aircraft. The topographic surface was mapped at an average point density of 2.1 points per square metre, and covers the entire extent of the youngest subaerial lava flow fields on Santorini. A 2-m DEM derived from the 2012 LiDAR dataset was merged with a 5-m resolution bathymetric grid, based on multibeam surveys carried out by the Hellenic Centre for Marine Research, during cruises in 2001 and 2006, using a SEABEAM 2120 hull-mounted swath system. The resultant grid provides the first high resolution map of both subaerial and submarine historic lava flows emplaced in the centre of the Santorini caldera, and includes several previously unidentified submarine flows and cones. Attribute maps were used to delineate and identify discrete lava flows both onshore and offshore; and morphometric profiles were used to compute accurate volumetric estimates for each of the historic flows, and to determine bulk rheological properties of the lavas, assuming a Bingham rheology. This ongoing work will improve our analysis of the relationship between

  17. Bald eagle winter roost characteristics in Lava Beds National Monument, California

    USGS Publications Warehouse

    Stohlgren, Thomas J.

    1993-01-01

    This study provided a survey of bald eagle (Haliaeetus leucocephalus) winter roost habitat (in 4 km2 of potential roost areas) in southern Lava Beds National Monument, California. A systematic-clustered sampling design (n=381 plots) was used to compare forest stand characteristics in two primary roost areas (Caldwell Butte and Eagle Nest Butte) and two potential roost areas (Hidden Valley and Island Butte). A 100 percent inventory of roost trees in Caldwell Butte (n=103 trees) and Eagle Nest Butte (n=44 trees) showed they were spatially clumped and restricted to 12.7 percent and 2.8 percent, respectively, of the study areas. Roost trees, primarily ponderosa pine (Pinus ponderosa), averaged 81.1 ± 1.3 cm dbh (mean ± 1 S.E.) compared to non-roost trees (>35 cm dbh) that averaged 52.2 ± 1.0 cm dbh. Roost trees were generally taller and more open-structured than non-roost trees. All four study sites had adequate numbers of mid-sized trees (10 to 50 cm dbh) to replace the current stock of older, larger roost trees. However, seedling and small trees (<10 cm dbh) in the roost areas were spatially clumped and few, suggesting that maintaining a continuous population of roost trees may be a problem in the distant future. Long-term studies of changing winter roost habitat and eagle use are essential to protect the bald eagle in the northwestern US.

  18. A geologic and hydrologic reconnaissance of Lava Beds National Monument and vicinity, California

    USGS Publications Warehouse

    Hotchkiss, W.R.

    1968-01-01

    Lava Beds National Monument is on the Modoc Plateau in Modoc and Siskiyou Counties. The principal geologic units in the vicinity are volcanic rocks, which in places are highly permeable and poorly permeable lake sedimentary deposits, all probably post-Oligocene in age. Yields and specific capacities of wells in the unconfined water body within volcanic rocks and lake deposits range widely, but in general are low in the lake deposits and higher in the volcanic rocks. A confined water body occurring in volcanic rocks underlying the lake deposits yields large quantities of water to three wells in the study area. Dissolved-solids content of ground water generally increases in proportion to the thickness of lake deposits penetrated and to proximity of the lake deposits. Water from wells drilled in the volcanic rocks several miles from the lake deposits and from wells penetrating the confined water body in volcanic rocks underlying the lake deposits contains small to moderate quantities of dissolved solids. Ground-water supplies can be developed almost anywhere in the study area by drilling wells to depths below the water table. In addition, there is a reasonable possibility of developing wells in a confined water body underlying the water-table system.

  19. Little ice age and global warming trends recorded in the late Holocene stalagmite from the Yongcheon lava tube cave in Jeju Island, Korea

    NASA Astrophysics Data System (ADS)

    Woo, K.; Jo, K.; Li, H.; Luo, S.; Wan, N.; Suk, B.; Park, B.

    2007-05-01

    Yongcheon Cave is located on Jeju Island, the southernmost part of Korea. The island is under the strong influence of East Asian monsoon climate. The Yongcheon cave which contains numerous carbonate speleothems was the typical lava tube cave that probably formed between 0.2~0.4 Ma ago. A 11cm-long stalagmite, YC-1, was collected in its growth position in 2005. The 210Pb dating results show that the top 0.9cm of YC-1 is less than 100 years old with a growth rate of 0.033mm/yr. Assuming the constant growth rate of the stalagmite with this growth rate, it is estimated that the stalagmite is about 3,300 years old. Currently, about 100 samples were analyzed for 18O and 13C compositions in the upper 1.25cm part with a sampling interval of 0.125mm. The 18O ranges from -7.4 to -5.8 (PDB), and the 13C varies from -8.0 to -1.7 (PDB). Both 18O and 13C values have decreasing trends during the last 60 years, with the decreases of 1.2 and 4 for 18O and 13C, respectively. Carbon isotopic compositions are more enriched in SGL (Zone of spaced growth laminae; ca -2.5, PDB) than DGL (Zone of dense growth laminae; ca -7.5). This indicates that the carbon in SGL was mostly supplied from the overlying carbonate sediments. Also, more depleted carbon isotopic values in DGL should reflect more influence by organic carbon within the overlying vegetation cover and soil. Elemental results show that there are anti-phase correlations between Mg/Ca and Sr/Ca, and between Ba/Ca and P/Ca. The strong increase in Al/Ca ratio in the upper a few mm indicates that significant change occurred in the overlying sediments above the cave during the past 50 years. These preliminary results imply that the stalagmite of the Yongcheon Cave may have been affected by groundwater residence time related to variation of regional precipitation and carbonate dissolution rate. Oxygen isotopic variation of YC-1 in particular, clearly shows the period of the Little Ice Age and coincides with the instrumental records of

  20. Cultivation and Complete Genome Sequencing of Gloeobacter kilaueensis sp. nov., from a Lava Cave in Kīlauea Caldera, Hawai'i

    PubMed Central

    Saw, Jimmy H. W.; Schatz, Michael; Brown, Mark V.; Kunkel, Dennis D.; Foster, Jamie S.; Shick, Harry; Christensen, Stephanie; Hou, Shaobin; Wan, Xuehua; Donachie, Stuart P.

    2013-01-01

    The ancestor of Gloeobacter violaceus PCC 7421T is believed to have diverged from that of all known cyanobacteria before the evolution of thylakoid membranes and plant plastids. The long and largely independent evolutionary history of G. violaceus presents an organism retaining ancestral features of early oxygenic photoautotrophs, and in whom cyanobacteria evolution can be investigated. No other Gloeobacter species has been described since the genus was established in 1974 (Rippka et al., Arch Microbiol 100:435). Gloeobacter affiliated ribosomal gene sequences have been reported in environmental DNA libraries, but only the type strain's genome has been sequenced. However, we report here the cultivation of a new Gloeobacter species, G. kilaueensis JS1T, from an epilithic biofilm in a lava cave in Kīlauea Caldera, Hawai'i. The strain's genome was sequenced from an enriched culture resembling a low-complexity metagenomic sample, using 9 kb paired-end 454 pyrosequences and 400 bp paired-end Illumina reads. The JS1T and G. violaceus PCC 7421T genomes have little gene synteny despite sharing 2842 orthologous genes; comparing the genomes shows they do not belong to the same species. Our results support establishing a new species to accommodate JS1T, for which we propose the name Gloeobacter kilaueensis sp. nov. Strain JS1T has been deposited in the American Type Culture Collection (BAA-2537), the Scottish Marine Institute's Culture Collection of Algae and Protozoa (CCAP 1431/1), and the Belgian Coordinated Collections of Microorganisms (ULC0316). The G. kilaueensis holotype has been deposited in the Algal Collection of the US National Herbarium (US# 217948). The JS1T genome sequence has been deposited in GenBank under accession number CP003587. The G+C content of the genome is 60.54 mol%. The complete genome sequence of G. kilaueensis JS1T may further understanding of cyanobacteria evolution, and the shift from anoxygenic to oxygenic photosynthesis. PMID:24194836

  1. Cultivation and complete genome sequencing of Gloeobacter kilaueensis sp. nov., from a lava cave in Kīlauea Caldera, Hawai'i.

    PubMed

    Saw, Jimmy H W; Schatz, Michael; Brown, Mark V; Kunkel, Dennis D; Foster, Jamie S; Shick, Harry; Christensen, Stephanie; Hou, Shaobin; Wan, Xuehua; Donachie, Stuart P

    2013-01-01

    The ancestor of Gloeobacter violaceus PCC 7421(T) is believed to have diverged from that of all known cyanobacteria before the evolution of thylakoid membranes and plant plastids. The long and largely independent evolutionary history of G. violaceus presents an organism retaining ancestral features of early oxygenic photoautotrophs, and in whom cyanobacteria evolution can be investigated. No other Gloeobacter species has been described since the genus was established in 1974 (Rippka et al., Arch Microbiol 100:435). Gloeobacter affiliated ribosomal gene sequences have been reported in environmental DNA libraries, but only the type strain's genome has been sequenced. However, we report here the cultivation of a new Gloeobacter species, G. kilaueensis JS1(T), from an epilithic biofilm in a lava cave in Kīlauea Caldera, Hawai'i. The strain's genome was sequenced from an enriched culture resembling a low-complexity metagenomic sample, using 9 kb paired-end 454 pyrosequences and 400 bp paired-end Illumina reads. The JS1(T) and G. violaceus PCC 7421(T) genomes have little gene synteny despite sharing 2842 orthologous genes; comparing the genomes shows they do not belong to the same species. Our results support establishing a new species to accommodate JS1(T), for which we propose the name Gloeobacter kilaueensis sp. nov. Strain JS1(T) has been deposited in the American Type Culture Collection (BAA-2537), the Scottish Marine Institute's Culture Collection of Algae and Protozoa (CCAP 1431/1), and the Belgian Coordinated Collections of Microorganisms (ULC0316). The G. kilaueensis holotype has been deposited in the Algal Collection of the US National Herbarium (US# 217948). The JS1(T) genome sequence has been deposited in GenBank under accession number CP003587. The G+C content of the genome is 60.54 mol%. The complete genome sequence of G. kilaueensis JS1(T) may further understanding of cyanobacteria evolution, and the shift from anoxygenic to oxygenic photosynthesis.

  2. The challenge of pollen analysis in palaeoenvironmental studies of hominid beds: the record from Sterkfontein caves.

    PubMed

    Carrión, J S; Scott, L

    1999-04-01

    The search for pollen in carbonate-rich sediments from the hominid site Sterkfontein has been justified because previous investigations suggested that although pollen contamination is a problem, speleothems (e.g. travertines and stalagmites) are most likely to contain reliable assemblages. The new results confirm that, although they have some potential, most sediment types from the site, even speleothems, are usually not suitable for analysis and that they contain very low concentrations of pollen, if any. The extraction of pollen from them is complicated by the problem of contamination from the modern environment. Such contamination has shown up in many previous investigations at this and similar sites and judging from published literature, its significance has not been fully appreciated. Cave palynology can be a very valuable tool in palaeoenvironmental research but the caveats associated with palynology of different sediment types especially carbonate impregnated sediments must be emphasized.

  3. Olivine-respiring bacteria isolated from the rock-ice interface in a lava-tube cave, a Mars analog environment.

    PubMed

    Popa, Radu; Smith, Amy R; Popa, Rodica; Boone, Jane; Fisk, Martin

    2012-01-01

    The boundary between ice and basalt on Earth is an analogue for some near-surface environments of Mars. We investigated neutrophilic iron-oxidizing microorganisms from the basalt-ice interface in a lava tube from the Oregon Cascades with perennial ice. One of the isolates (Pseudomonas sp. HerB) can use ferrous iron Fe(II) from the igneous mineral olivine as an electron donor and O(2) as an electron acceptor. The optimum growth temperature is ∼12-14°C, but growth also occurs at 5°C. Bicarbonate is a facultative source of carbon. Growth of Pseudomonas sp. HerB as a chemolithotrophic iron oxidizer with olivine as the source of energy is favored in low O(2) conditions (e.g., 1.6% O(2)). Most likely, microbial oxidation of olivine near pH 7 requires low O(2) to offset the abiotic oxidation of iron. The metabolic capabilities of this bacterium would allow it to live in near-surface, icy, volcanic environments of Mars in the present or recent geological past and make this type of physiology a prime candidate in the search for life on Mars.

  4. Olivine-Respiring Bacteria Isolated from the Rock-Ice Interface in a Lava-Tube Cave, a Mars Analog Environment

    PubMed Central

    Smith, Amy R.; Popa, Rodica; Boone, Jane; Fisk, Martin

    2012-01-01

    Abstract The boundary between ice and basalt on Earth is an analogue for some near-surface environments of Mars. We investigated neutrophilic iron-oxidizing microorganisms from the basalt-ice interface in a lava tube from the Oregon Cascades with perennial ice. One of the isolates (Pseudomonas sp. HerB) can use ferrous iron Fe(II) from the igneous mineral olivine as an electron donor and O2 as an electron acceptor. The optimum growth temperature is ∼12–14°C, but growth also occurs at 5°C. Bicarbonate is a facultative source of carbon. Growth of Pseudomonas sp. HerB as a chemolithotrophic iron oxidizer with olivine as the source of energy is favored in low O2 conditions (e.g., 1.6% O2). Most likely, microbial oxidation of olivine near pH 7 requires low O2 to offset the abiotic oxidation of iron. The metabolic capabilities of this bacterium would allow it to live in near-surface, icy, volcanic environments of Mars in the present or recent geological past and make this type of physiology a prime candidate in the search for life on Mars. Key Words: Extremophiles—Mars—Olivine—Iron-oxidizing bacteria—Redox. Astrobiology 12, 9–18. PMID:22165996

  5. Lunar Lava Tubes as Potential Human Settlements and Refuge Sites

    NASA Astrophysics Data System (ADS)

    Lemke, K. A.; Mardon, A. A.

    2015-10-01

    Lava tubes have been detected on the surface of Earth's moon via satellite images. Upon further exploration of these caves through robotic technology and other means, a refuge place for astronauts may be installed.

  6. Caves on Mars: Candidate Sites for Astrobiological Exploration

    NASA Astrophysics Data System (ADS)

    Cushing, G. E.; Titus, T. N.

    2010-04-01

    Cave entrances are identified in lava tubes and volcano-tectonic fractures on Mars. Caves are among the only environments protected from harsh surface conditions, and may contain pristine evidence of microbial life—if such has ever existed on Mars.

  7. 14C AMS dating Yongcheon cave

    NASA Astrophysics Data System (ADS)

    Lee, J. H.; Choe, K.; Kim, J. C.; Choi, S. H.; Kang, J.; Song, S.; Song, Y. M.; Jang, J. G.

    2013-01-01

    The biggest island in South Korea is Jeju Island, which lies 80 km south of the mainland and has one shield volcano, Mt. Halla. The volcanic island and its lava tubes were added to the world heritage list by UNESCO in 2007. Among the many lava tubes on the island, a unique cave had been accidentally found in 2005 while some workers were replacing a telephone pole. Until the discovery, it had been completely isolated from the outside by naturally-built sand blocks. Yongcheon cave is a lime-decorated lava tube showing both the properties of a volcanic lava tube and a limestone cave. This cave, about 3 km in length, is acknowledged to be the best of this type in the world and includes a large clean-water lake, lava falls, and richly developed speleothems inside it. Even though there is archaeological evidence from well preserved pottery that ancient people entered this place, the preservation of artifacts was ensured by a geological change that made later entrance difficult. We have collected charcoal samples scattered around the cave and dated them using AMS. Ages were in the range of ca. 1570-1260 BP (A.D. 340-880) and this corresponds to the Ancient Three Kingdoms and the Unified Silla era in Korean history. The 14C AMS measurement results presented in this paper on wood charcoal provide precise dates which will be very useful not only to clarify the nature of human activities in this cave but also to provide reference dates when comparing other dating methods.

  8. Geology of Caves.

    ERIC Educational Resources Information Center

    Davies, W. E.; Morgan, I. M.

    One of a series of general interest publications on science topics, the booklet provides those interested in the study of caves (speleology) with a nontechnical introduction to the subject. Separate sections examine types of caves, how caves form, cave features, minerals found in caves, uses of caves, and caves as natural underground laboratories.…

  9. Lava Lamp

    ERIC Educational Resources Information Center

    Leif, Todd R.

    2008-01-01

    This past semester I brought a Lava Lite[R] Lamp into my classroom. Why bring such a thing into class? Many of today's students are part of the "retro" movement. They buy clothes from the '60s, they wear their hair like people did in the '60s, and they look for the ideals and themes related to living in the 1960s. Physics education reform is also…

  10. Three long lava flows in north Queensland

    NASA Astrophysics Data System (ADS)

    Stephenson, P. J.; Burch-Johnston, A. T.; Stanton, D.; Whitehead, P. W.

    1998-11-01

    The Kinrara, Toomba, and Undara basaltic lava flows are from 55 to 160 km long and range in age from 13 to 190 ka. The lavas were emplaced down low gradients (0.2° to 0.4°) with volumes ranging up to 30 km3. They were not unusually hot at eruption (1130°-1160°) nor unusually fluid. Gentle topography controlled the flows, and shallow drainage lines captured them. Lava tubes operated in places, and some drained to form caves. Injection under surface crust was widespread, producing inflation features ranging from tumuli and low plateaus to extensive ridges. Sustained eruption was essential for the development of the long flows, but each is composite, with pauses between successive pulses that partially covered the earlier, longer flows. The lava structures are mainly pahoehoe but some 'a'a lavas are present. Of the three volcanoes involved, Undara is a simple low-angle lava cone with a 200-m-wide crater, Toomba is a low-angled cone with several eruption centers, and Kinrara has a deep crater with evidence of strong fountaining. Effusion rates are not known but may have been relatively low, similar to those observed in Hawaiian volcanoes. Lava tubes, most of which remained undrained, are believed to have been of major importance in flow emplacement. Given the evidence of successive flows and the time needed to develop widespread inflation, it is suggested that the two long flows over 100 km involved many decades of eruption.

  11. Lava Flows

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA03658 Lava Flows

    These relatively young lava flows are part of Arsia Mons.

    Image information: VIS instrument. Latitude -22.5N, Longitude 242.3E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  12. Candidate cave entrances on Mars

    USGS Publications Warehouse

    Cushing, Glen E.

    2012-01-01

    This paper presents newly discovered candidate cave entrances into Martian near-surface lava tubes, volcano-tectonic fracture systems, and pit craters and describes their characteristics and exploration possibilities. These candidates are all collapse features that occur either intermittently along laterally continuous trench-like depressions or in the floors of sheer-walled atypical pit craters. As viewed from orbit, locations of most candidates are visibly consistent with known terrestrial features such as tube-fed lava flows, volcano-tectonic fractures, and pit craters, each of which forms by mechanisms that can produce caves. Although we cannot determine subsurface extents of the Martian features discussed here, some may continue unimpeded for many kilometers if terrestrial examples are indeed analogous. The features presented here were identified in images acquired by the Mars Odyssey's Thermal Emission Imaging System visible-wavelength camera, and by the Mars Reconnaissance Orbiter's Context Camera. Select candidates have since been targeted by the High-Resolution Imaging Science Experiment. Martian caves are promising potential sites for future human habitation and astrobiology investigations; understanding their characteristics is critical for long-term mission planning and for developing the necessary exploration technologies.

  13. Lava Lamp

    NASA Astrophysics Data System (ADS)

    Leif, Todd R.

    2008-04-01

    This past semester I brought a Lava Lite® Lamp into my classroom. Why bring such a thing into class? Many of today's students are part of the "retro" movement. They buy clothes from the '60s, they wear their hair like people did in the '60s, and they look for the ideals and themes related to living in the 1960s. Physics education reform is also examining ideas from the "retro" world of science. This was the post-Sputnik era, a time when science was done by actually doing it and not necessarily by lecturing about it. Cliff Swartz, former TPT editor, once mentioned during a presentation at a Texas AAPT meeting, "The world of physics teaching is cyclic, like a swinging pendulum. We as physics teachers jump from `new ideas' back to our old ones, each generation testing what works best for them."

  14. CAVE WINDOW

    DOEpatents

    Levenson, M.

    1960-10-25

    A cave window is described. It is constructed of thick glass panes arranged so that interior panes have smaller windowpane areas and exterior panes have larger areas. Exterior panes on the radiation exposure side are remotely replaceable when darkened excessively. Metal shutters minimize exposure time to extend window life.

  15. Caving in the Classroom

    ERIC Educational Resources Information Center

    Yoder, Holly

    2010-01-01

    During Cave Week, more than 200 students explore a simulated cave environment and participate in cave-related activities. Active cavers from a local club bring in equipment and photos and speak about their caving experiences. As student groups explore the simulated cave, other groups participate in different activities where they can create bat…

  16. Founder effects initiated rapid species radiation in Hawaiian cave planthoppers.

    PubMed

    Wessel, Andreas; Hoch, Hannelore; Asche, Manfred; von Rintelen, Thomas; Stelbrink, Björn; Heck, Volker; Stone, Fred D; Howarth, Francis G

    2013-06-01

    The Hawaiian Islands provide the venue of one of nature's grand experiments in evolution. Here, we present morphological, behavioral, genetic, and geologic data from a young subterranean insect lineage in lava tube caves on Hawai'i Island. The Oliarus polyphemus species complex has the potential to become a model for studying rapid speciation by stochastic events. All species in this lineage live in extremely similar environments but show strong differentiation in behavioral and morphometric characters, which are random with respect to cave age and geographic distribution. Our observation that phenotypic variability within populations decreases with increasing cave age challenges traditional views on founder effects. Furthermore, these cave populations are natural replicates that can be used to test the contradictory hypotheses. Moreover, Hawaiian cave planthoppers exhibit one of the highest speciation rates among animals and, thus, radically shift our perception on the evolutionary potential of obligate cavernicoles.

  17. Lava Flows On Ascraeus Mons Volcano

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Ascraeus Mons Volcano: Like Earth, Mars has many volcanoes and volcanic features. This high-resolution view shows some of the lava flows near the summit of Ascraeus Mons, one of the three giant shield volcanoes known as the 'Tharsis Montes'. Volcanoes form when magma (molten rock) erupts out onto the surface of a planet. Based on Viking-era observations, Ascraeus Mons is considered to be one of the tallest volcanoes on Mars... its summit is more than 11 km (6.8 miles) above the surrounding plain. The summit is more than 23 km (14 miles) higher in elevation than the place where Mars Pathfinder landed in July 1997.

    Description of MOC Image: This picture shows an area that is about 20 km (12 miles) higher in elevation than the Mars Pathfinder landing site. The picture shows three main features: (1) a crater at the center-right, (2) a sinuous, discontinuous channel across the upper half, and (3) a rough and pitted, elevated surface across the lower half of the image.

    (1) Crater at center right. Distinguishing meteor craters from volcanic craters can sometimes be a challenge on Mars. This particular crater was most likely formed by meteor impact because it has a raised rim and a faint radial ejecta pattern around the outside of it. This crater is 600 m (2000 feet) across, about 3/4 the size of the famous 'Meteor Crater' near Winslow, Arizona.

    (2) Sinuous channel. The type of discontinuous channel running across the upper half of the image is sometimes referred to as a 'sinuous rille'. These are common on the volcanic plains of the Moon and among volcanoes and volcanic plains on Earth. Such a channel was once a lava tube. It is running down the middle of an old lava flow. The 'tube' looks like a 'channel' because its roof has collapsed. The discontinuous nature of this channel is the result of the collapse, or 'cave-in' of what was once the roof of the lava tube. It is common for certain types of relatively fluid lavas to form

  18. Lava Flows On Ascraeus Mons Volcano

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Ascraeus Mons Volcano: Like Earth, Mars has many volcanoes and volcanic features. This high-resolution view shows some of the lava flows near the summit of Ascraeus Mons, one of the three giant shield volcanoes known as the 'Tharsis Montes'. Volcanoes form when magma (molten rock) erupts out onto the surface of a planet. Based on Viking-era observations, Ascraeus Mons is considered to be one of the tallest volcanoes on Mars... its summit is more than 11 km (6.8 miles) above the surrounding plain. The summit is more than 23 km (14 miles) higher in elevation than the place where Mars Pathfinder landed in July 1997.

    Description of MOC Image: This picture shows an area that is about 20 km (12 miles) higher in elevation than the Mars Pathfinder landing site. The picture shows three main features: (1) a crater at the center-right, (2) a sinuous, discontinuous channel across the upper half, and (3) a rough and pitted, elevated surface across the lower half of the image.

    (1) Crater at center right. Distinguishing meteor craters from volcanic craters can sometimes be a challenge on Mars. This particular crater was most likely formed by meteor impact because it has a raised rim and a faint radial ejecta pattern around the outside of it. This crater is 600 m (2000 feet) across, about 3/4 the size of the famous 'Meteor Crater' near Winslow, Arizona.

    (2) Sinuous channel. The type of discontinuous channel running across the upper half of the image is sometimes referred to as a 'sinuous rille'. These are common on the volcanic plains of the Moon and among volcanoes and volcanic plains on Earth. Such a channel was once a lava tube. It is running down the middle of an old lava flow. The 'tube' looks like a 'channel' because its roof has collapsed. The discontinuous nature of this channel is the result of the collapse, or 'cave-in' of what was once the roof of the lava tube. It is common for certain types of relatively fluid lavas to form

  19. The Science of Exploring Caves.

    ERIC Educational Resources Information Center

    Reid, Frank S.

    1991-01-01

    An introduction to the science of speleology is presented. Discussed is why people explore caves--for the physical challenge, the thrill of discovery, and the joy of viewing their beauty. Cave conservation, cave biology, caving safety, and caving equipment are topics of discussion. A reading list on caves is included. (KR)

  20. Lunar Lava Tube Sensing

    NASA Technical Reports Server (NTRS)

    York, Cheryl Lynn; Walden, Bryce; Billings, Thomas L.; Reeder, P. Douglas

    1992-01-01

    Large (greater than 300 m diameter) lava tube caverns appear to exist on the Moon and could provide substantial safety and cost benefits for lunar bases. Over 40 m of basalt and regolith constitute the lava tube roof and would protect both construction and operations. Constant temperatures of -20 C reduce thermal stress on structures and machines. Base designs need not incorporate heavy shielding, so lightweight materials can be used and construction can be expedited. Identification and characterization of lava tube caverns can be incorporated into current precursor lunar mission plans. Some searches can even be done from Earth. Specific recommendations for lunar lava tube search and exploration are (1) an Earth-based radar interferometer, (2) an Earth-penetrating radar (EPR) orbiter, (3) kinetic penetrators for lunar lava tube confirmation, (4) a 'Moon Bat' hovering rocket vehicle, and (5) the use of other proposed landers and orbiters to help find lunar lava tubes.

  1. BELLE STARR CAVE WILDERNESS STUDY AREA, ARKANSAS.

    USGS Publications Warehouse

    Haley, Boyd R.; Stroud, Raymond B.

    1984-01-01

    A mineral survey of the Belle Starr Cave Wilderness Study Area in Arkansas concluded that there is little promise for the occurrence of metallic mineral resources in the area. There is a probable resource potential for small quantities of natural gas. A coal bed that underlies the area contains demonstrated coal resources of about 22. 5 million tons in a bed that averages less than 28 in. thick. Despite its contained coal, this area is not shown as having a coal resource potential.

  2. Come to our Cave.

    ERIC Educational Resources Information Center

    Cassidy, Joan

    2001-01-01

    Describes an activity for first-grade students in which they learn about cave paintings and become spelunkers, or people who explore caves as a hobby, making their own paper head-lanterns. Explains that students draw animals on the walls of their "cave" (a dark hallway lined with brown kraft paper). (CMK)

  3. Upper Pleistocene interstratal piping-cave speleogenesis: The Seso Cave System (Central Pyrenees, Northern Spain)

    NASA Astrophysics Data System (ADS)

    Bartolomé, M.; Sancho, C.; Moreno, A.; Oliva-Urcia, B.; Belmonte, Á.; Bastida, J.; Cheng, H.; Edwards, R. L.

    2015-01-01

    The Seso Cave System (SCS, South Central Pyrenees, Northeastern Spain) develops in poorly soluble marly interstratum between limestone beds of Eocene age. We propose an innovative and singular pseudokarstic speleogenetic model under vadose conditions based on cave morphological evidence, physicochemical and mineralogical characteristics of the Eocene marly host rock, U-Th dating of cave deposits, and local geological and geomorphological information. Eocene marls are shown to be sensitive to dispersion processes supported by their high clay content and the high concentration of sodium and low electrical conductivity in the seepage water. Runoff inside the cave results from water that infiltrates through joints and seepage water in cave walls. Thereby piping processes become very active, triggering mechanical scouring and outwashing mechanisms. The hydraulic gradient required to develop piping activity is determined by regional fluvial incision. The base level controlling water discharge during opening of the SCS coincides with a terrace of the Ara River dated at 65 ka BP. Considering this age, as well as the U-Th age of the oldest speleothems dated in the cave at 38 ka BP, the timing of the SCS interstratal piping-cave speleogenesis is constrained to the Upper Pleistocene; very likely at the end of Marine Isotope Stage 4 during a period characterized by high water availability following glacial retreat in northern Iberian mountains.

  4. Distinction between epigenic and hypogenic maze caves

    NASA Astrophysics Data System (ADS)

    Palmer, Arthur N.

    2011-11-01

    Certain caves formed by dissolution of bedrock have maze patterns composed of closed loops in which many intersecting fractures or pores have enlarged simultaneously. Their origin can be epigenic (by shallow circulation of meteoric groundwater) or hypogenic (by rising groundwater or production of deep-seated solutional aggressiveness). Epigenic mazes form by diffuse infiltration through a permeable insoluble caprock or by floodwater supplied by sinking streams. Most hypogenic caves involve deep sources of aggressiveness. Transverse hypogenic cave origin is a recently proposed concept in which groundwater of mainly meteoric origin rises across strata in the distal portions of large flow systems, to form mazes in soluble rock sandwiched between permeable but insoluble strata. The distinction between maze types is debated and is usually based on examination of diagnostic cave features and relation of caves to their regional setting. In this paper, the principles of mass transfer are applied to clarify the limits of each model, to show how cave origin is related to groundwater discharge, dissolution rate, and time. The results show that diffuse infiltration and floodwater can each form maze caves at geologically feasible rates (typically within 500 ka). Transverse hypogenic mazes in limestone, to enlarge significantly within 1 Ma, require an unusually high permeability of the non-carbonate beds (generally ≥ 10-4 cm/s), large discharge, and calcite saturation no greater than 90%, which is rare in deep diffuse flow in sedimentary rocks. Deep sources of aggressiveness are usually required. The origin of caves by transverse hypogenic flow is much more favorable in evaporite rocks than in carbonate rocks.

  5. Lava Flow Dynamics

    NASA Technical Reports Server (NTRS)

    Taylor, G. Jeffrey

    1996-01-01

    This grant originally had four major tasks, all of which were addressed to varying extents during the course of the research: (1) Measure the fractal dimensions of lava flows as a function of topography, substrate, and rheology; (2) The nature of lava tube systems and their relation to flow fields; (3) A quantitative assessment of lava flow dynamics in light of the fractal nature of lava flow margins; and (4) Development and application of a new remote sensing tool based on fractal properties. During the course of the research, the project expanded to include the following projects: (1) A comparison of what we can-learn from remote sensing studies of lava flow morphology and from studies of samples of lava flows; (2) Study of a terrestrial analog of the nakhlites, one of the groups of meteorites from Mars; and (3) Study of the textures of Hawaiian basalts as an aid in understanding the dynamics (flow rates, inflation rates, thermal history) of flow interiors. In addition, during the first year an educational task (development and writing of a teacher's guide and activity set to accompany the lunar sample disk when it is sent to schools) was included.

  6. Geology of caves

    USGS Publications Warehouse

    Morgan, I.M.

    1991-01-01

    A cave is a natural opening in the ground extending beyond the zone of light and large enough to permit the entry of man. Occurring in a wide variety of rock types and caused by widely differing geological processes, caves range in size from single small rooms to intercorinecting passages many miles long. The scientific study of caves is called speleology (from the Greek words spelaion for cave and logos for study). It is a composite science based on geology, hydrology, biology, and archaeology, and thus holds special interest for earth scientists of the U.S. Geological Survey.

  7. Basaltic Lava Channels

    NASA Astrophysics Data System (ADS)

    Cashman, K. V.; Griffiths, R. W.; Kerr, R. C.

    2004-12-01

    In Hawaii, the mode of lava transport - through open channels or through insulating lava tubes - determines the thermal, rheological, and emplacement history of a lava flow. Most Hawaiian lavas are erupted at near-liquidus temperatures and are therefore crystal-poor; lava transport through open channels allows rapid cooling and consequent rapid increases in lava crystallinity. Solidified aa flows resulting from channelized flow are typically fine-grained throughout their thickness, indicating cooling of the entire flow thickness during transport. In contrast, transport of lava through insulating tubes permits flow over long distances with little cooling. Flows emerging from such tubes typically have pahoehoe flow surfaces with glassy crusts. Groundmass textures that coarsen from the flow rind to the interior reflect rates of post-emplacement, rather than syn-emplacement, cooling. To distinguish eruption conditions that result in lava channels from those that allow formation of lava tubes, we have performed a series of laboratory experiments involving injection of PEG 600 (a wax with a Newtonian rheology and freezing temperature of 19ºC) into cold water through both uniform and non-uniform sloping channels. In uniform channels, tube formation can be distinguished from open channel flow using a dimensionless parameter based on a solidification time scale, an advection time scale, and a Rayleigh number that describes convection by heat loss from crust-free shear zones. Theoretical analysis predicts that in the open channel regime, the width of the crust (dc) will vary with the channel width (W) as dc = W5/3. Crustal coverage of non-uniform channels in both laboratory experiments and field examples from Kilauea Volcano, Hawaii, is consistent with this prediction. However, experiments in non-uniform channels illustrate additional controls on the surface coverage of lava channels. Most important is crustal extension resulting from flow acceleration through constrictions

  8. Empowering Women through Caving.

    ERIC Educational Resources Information Center

    Gabert, Julie

    1997-01-01

    Describes an introductory horizontal caving experience for college-age women who were uncomfortable with their bodies, insecure with movement, and unwilling to take big risks. The darkness and quiet of the cave released inhibitions and promoted group cohesion, feelings of intimacy and safety, self-discovery, and self-confidence. (SV)

  9. Cave Water Studies.

    ERIC Educational Resources Information Center

    O'Keefe, Elizabeth S.

    1996-01-01

    Describes a comparative study project where seventh grade students tested water samples from 10 cave sites that had been tested 24 years ago in a study that had attempted to determine if pollution in the environment had reached cave water. Discusses lab skills and some results of the study. (JRH)

  10. New Species of Campodeidae (Diplura) from Mexican caves.

    PubMed

    Sendra, Alberto; Palacios, Jose; Garcia, Arturo; Montejo, Maira

    2016-02-04

    Six new taxa of Campodeidae (Diplura) are described in the genera Litocampa, Juxtlacampa, Oncinocampa, and Tachycampa. We also redescribe the interesting species Juxtlacampa juxtlahucensis Wygodzinsky, 1944 from Juxtlahuaca cave in Guerrero, Mexico. All of these taxa are cave-dwelling species with more or less noticeable troglobiomorphic features They inhabit the subterranean ecosystem in six limestone massifs and one lava tube cave in the central states of Mexico. Four of these species are included in the "tachycampoide" group and one species in the "podocampoide" group (sensu Bareth & Conde). Nine species already known in Central and South America of the "tachycampoide" group, in such poorly-sampled regions compared with the eight species in the well-sampled Mediterranean region (Ibero-Sardinia and north Africa), suggest an American origin for this group.

  11. New Species of Campodeidae (Diplura) from Mexican caves.

    PubMed

    Sendra, Alberto; Palacios, Jose; Garcia, Arturo; Montejo, Maira

    2016-01-01

    Six new taxa of Campodeidae (Diplura) are described in the genera Litocampa, Juxtlacampa, Oncinocampa, and Tachycampa. We also redescribe the interesting species Juxtlacampa juxtlahucensis Wygodzinsky, 1944 from Juxtlahuaca cave in Guerrero, Mexico. All of these taxa are cave-dwelling species with more or less noticeable troglobiomorphic features They inhabit the subterranean ecosystem in six limestone massifs and one lava tube cave in the central states of Mexico. Four of these species are included in the "tachycampoide" group and one species in the "podocampoide" group (sensu Bareth & Conde). Nine species already known in Central and South America of the "tachycampoide" group, in such poorly-sampled regions compared with the eight species in the well-sampled Mediterranean region (Ibero-Sardinia and north Africa), suggest an American origin for this group. PMID:27395944

  12. The foaming of lavas

    NASA Technical Reports Server (NTRS)

    Okeefe, J. A.; Walton, W.

    1976-01-01

    Foaming is of great practical and theoretical significance for volcanic processes on the earth, the moon, and perhaps the meteorite parent bodies. The theory of foams agrees with steelmaking experience to indicate that their presence depends on the existence of solutes in the lavas which reduce the surface tension, and are not saturated. These solutes concentrate at the surface, and are called surfactants. The surfactant responsible for the formation of volcanic ash was not identified; it appears to be related to the oxygen partial pressure above the lava. This fact may explain why lunar and meteoritic melts are not observed to foam. Experimental studies are needed to clarify the process.

  13. Carroll Cave: a Missouri legend

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carroll Cave is one of the premiere caves of Missouri and the Ozarks region. At over 20 miles of surveyed passage, it is the 2nd longest cave in the state and 33rd longest in the nation. It is also the largest known cave formed in the Ordovician aged (443-485 million years ago) Gasconade Dolomite o...

  14. LAVA Applications to Open Rotors

    NASA Technical Reports Server (NTRS)

    Kiris, Cetin C.; Housman, Jeff; Barad, Mike; Brehm, Christoph

    2015-01-01

    Outline: LAVA (Launch Ascent Vehicle Aerodynamics); Introduction; Acoustics Related Applications; LAVA Applications to Open Rotor; Structured Overset Grids; Cartesian Grid with Immersed Boundary; High Speed Case; High Speed Case with Plate Low Speed Case.

  15. Gas discharges in fumarolic ice caves of Erebus volcano, Antarctica

    NASA Astrophysics Data System (ADS)

    Fischer, T. P.; Curtis, A. G.; Kyle, P. R.; Sano, Y.

    2013-12-01

    Fumarolic ice caves and towers on Erebus are the surface expression of flank degassing on the world's southernmost active volcano. The caves are formed by warm gases and steam escaping from small vents on the lava flow floors that melts the overlying ice and snow. Extremophiles in the caves may be analogues for extraterrestrial environments. Over the past four Austral summers, mapping, gas and thermal monitoring conducted under the Erebus Caves Project has provided insights into the ice cave formation processes and the relationships between cave structures, magmatic processes, and weather. Gas samples were collected during the 2012 - 2013 field season in 4 ice caves (Warren, Harry's Dream, Sauna, Haggis Hole) as well as the thermal ground at Tramway Ridge. The vents at all of these sites are characterized by diffuse degassing through loose lava or cracks in the lava flow floor. Vent temperatures ranged from 5 to 17°C in most caves and at Tramway Ridge. In Sauna cave the temperature was 40°C. Gases were sampled by inserting a perforated 1 m long, 5 mm diameter stainless steel tube, into the vents or hot ground. Giggenbach bottles, copper tubes and lead glass bottles were connected in series. The gases were pumped at a slow rate (about 20 ml per minute) using a battery pump for 12-24 hours to flush the system. After flushing samples were collected for later analyses. All samples are dominated by atmospheric components, however, carbon dioxide (0.1 to 1.9%), methane (0.005 to 0.01%), hydrogen (0.002 to 0.07%), and helium (0.0009 to 0.002 %) are above air background. Nitrogen (average 74%) and oxygen (23.5%) are slightly below and above air values, respectively. Helium isotopes show minor input of mantle derived helium-3 with 3He4He ratios ranging from 1.03 to 1.18 RA (where RA is the ratio of air). This represents the first detection of hydrogen and helium in the caves. Methane could be produced by anaerobic respiration of subsurface microbes or hydrothermal

  16. Flow direction determination of lava flows.

    NASA Technical Reports Server (NTRS)

    Smith, E. I.; Rhodes, R. C.

    1972-01-01

    The flow direction technique, previously applied to ash-flow sheets, can be used to determine direction of movement and locate eruptive centers for lava flows. The method provides statistically stronger and more consistent flow direction data for lava than ash-flow tuff. The accuracy and reliability of the technique was established on the porphyritic basaltic andesite of Mount Taylor, New Mexico, which erupted from a known center, the Mount Taylor Amphitheater. The technique was then applied to volcanic units with unknown sources: the John Kerr Peak Quartz Latite and mid-Tertiary andesite flows in the Mogollon Mountains, both in southwestern New Mexico. The flow direction technique indicated flow patterns and suggested source areas for each rock unit. In the Mogollon Mountains flow direction measurements were supported by independent directional criteria such as dips of cross beds, stratigraphic thickening, facies changes, and megascopic textures.-

  17. Platy Lava Surface

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    This VIS image was taken in the Tartarus region of Mars. The lava flows covering the upper right portion of the image have a very different texture than the Arsia Mons flows. These flows illustrate a platy lava surface. This surface type develops when the top of a lava flows cools and then is broken into pieces by continued movement of the flow. Molten lava will squeeze up between the plates of cooled lava, forming the ridges seen in the image.

    Image information: VIS instrument. Latitude 5.9, Longitude 157.8 East (202.2 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  18. A multi-method approach for speleogenetic research on alpine karst caves. Torca La Texa shaft, Picos de Europa (Spain)

    NASA Astrophysics Data System (ADS)

    Ballesteros, Daniel; Jiménez-Sánchez, Montserrat; Giralt, Santiago; García-Sansegundo, Joaquín; Meléndez-Asensio, Mónica

    2015-10-01

    Speleogenetic research on alpine caves has advanced significantly during the last decades. These investigations require techniques from different geoscience disciplines that must be adapted to the methodological constraints of working in deep caves. The Picos de Europa mountains are one of the most important alpine karsts, including 14% of the World's Deepest Caves (caves with more than 1 km depth). A speleogenetic research is currently being developed in selected caves in these mountains; one of them, named Torca La Texa shaft, is the main goal of this article. For this purpose, we have proposed both an optimized multi-method approach for speleogenetic research in alpine caves, and a speleogenetic model of the Torca La Texa shaft. The methodology includes: cave surveying, dye-tracing, cave geometry analyses, cave geomorphological mapping, Uranium series dating (234U/230Th) and geomorphological, structural and stratigraphical studies of the cave surroundings. The SpeleoDisc method was employed to establish the structural control of the cavity. Torca La Texa (2653 m length, 215 m depth) is an alpine cave formed by two cave levels, vadose canyons and shafts, soutirage conduits, and gravity-modified passages. The cave was formed prior to the Middle Pleistocene and its development was controlled by the drop of the base level, producing the development of the two cave levels. Coevally to the cave levels formation, soutirage conduits originated connecting phreatic and epiphreatic conduits and vadose canyons and shafts were formed. Most of the shafts were created before the local glacial maximum (43-45 ka) and only two cave passages are related to dolines developed in recent times. The cave development is strongly related to the structure, locating the cave in the core of a gentle fold with the conduits' geometry and orientation controlled by the bedding and five families of joints.

  19. Cave speleothems as repositories of microbial biosignatures

    NASA Astrophysics Data System (ADS)

    Miller, Ana Z.; Jurado, Valme; Pereira, Manuel F. C.; Fernández, Octavio; Calaforra, José M.; Dionísio, Amélia; Saiz-Jimenez, Cesareo

    2015-04-01

    The need to better understand the biodiversity, origins of life on Earth and on other planets, and the wide applications of the microbe-mineral interactions have led to a rapid expansion of interest in subsurface environments. Recently reported results indicated signs of an early wet Mars and rather recent volcanic activity which suggest that Mars's subsurface can house organic molecules or traces of microbial life, making the search for microbial life on Earth's subsurface even more compelling. Caves on Earth are windows into the subsurface that harbor a wide variety of mineral-utilizing microorganisms, which may contribute to the formation of biominerals and unusual microstructures recognized as biosignatures. These environments contain a wide variety of redox interfaces and stable physicochemical conditions, which enhance secondary mineral precipitation and microbial growth under limited organic nutrient inputs. Enigmatic microorganisms and unusual mineral features have been found associated with secondary mineral deposits or speleothems in limestone caves and lava tubes. In this study, Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray spectroscopy (EDS) analyses were conducted on cave speleothem samples to assess microbe-mineral interactions, evaluate biogenicity, as well as to describe unusual mineral formations and microbial features. Microbial mats, extracellular polymeric substances, tubular empty sheaths, mineralized cells, filamentous fabrics, as well as "cell-sized" etch pits or microborings produced by bacterial cells were observed on minerals. These features evidence microbe-mineral interactions and may represent mineralogical signatures of life. We can thus consider that caves on Earth are plausible repositories of terrestrial biosignatures where we can look for microbial signatures. Acknowledgments: AZM acknowledges the support from the Marie Curie Intra-European Fellowship within the 7th European Community Framework

  20. Lava Tube Collapse Pits

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    We will be looking at collapse pits for the next two weeks. Collapse pits on Mars are formed in several ways. In volcanic areas, channelized lava flows can form roofs which insulate the flowing lava. These features are termed lava tubes on Earth and are common features in basaltic flows. After the lava has drained, parts of the roof of the tube will collapse under its own weight. These collapse pits will only be as deep as the bottom of the original lava tube. Another type of collapse feature associated with volcanic areas arises when very large eruptions completely evacuate the magma chamber beneath the volcano. The weight of the volcano will cause the entire edifice to subside into the void space below it. Structural features including fractures and graben will form during the subsidence. Many times collapse pits will form within the graben. In addition to volcanic collapse pits, Mars has many collapse pits formed when volatiles (such as subsurface ice) are released from the surface layers. As the volatiles leave, the weight of the surrounding rock causes collapse pits to form.

    These collapse pits are found in the southern hemisphere of Mars. They are likely lava tube collapse pits related to flows from Hadriaca Patera.

    Image information: VIS instrument. Latitude -36.8, Longitude 89.6 East (270.4 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space

  1. Lava tubes and aquifer vulnerability in the upper Actopan River basin, Veracruz, México

    NASA Astrophysics Data System (ADS)

    Espinasa-Pereña, R.; Delgado Granados, H.

    2011-12-01

    Rapid infiltration leads to very dry conditions on the surface of some volcanic terrains, with large allogenic streams sometimes sinking underground upon reaching a lava flow. Aquifers in lava flows tend to be heterogeneous and discontinuous, generally unconfined and fissured, and have high transmissivity. Springs associated with basalts may be very large but are typically restricted to lava-flow margins. Concern has been expressed regarding the potential for lava-tube caves to facilitate groundwater contamination similar to that afflicting some karst aquifers (Kempe et al., 2003; Kiernan et al., 2002; Halliday 2003). The upper Actopan River basin is a series of narrow valleys excavated in Tertiary volcanic brechias. Several extensive Holocene basaltic tube-fed lava flows have partially filled these valleys. The youngest and longest flow originates at El Volcancillo, a 780 ybP monogenetic volcano. It is over 50 km long, and was fed through a major master tube, the remains of which form several lava-tube caves (Gassos and Espinasa-Pereña, 2008). Another tube-fed flow initiates at a vent at the bottom of Barranca Huichila and can be followed for 7 km to where it is covered by the Volcancillo flow. The Huichila River is captured by this system of lava tubes and can be followed through several underground sections. In dry weather the stream disappears at a sump in one of these caves, although during hurricanes it overflows the tube, floods the Tengonapa plain, and finally sinks through a series of skylights into the master tube of the Volcancillo flow. Near villages, the cave entrances are used as trash dumps, which are mobilized during floods. These include household garbage, organic materials associated with agriculture and even medical supplies. This is a relatively recent phenomenon, caused by population growth and the building of houses above the lava flows. The water resurges at El Descabezadero, gushing from fractures in the lava above the underlying brechias

  2. Lava flows are fractals

    NASA Technical Reports Server (NTRS)

    Bruno, B. C.; Taylor, G. J.; Rowland, S. K.; Lucey, P. G.; Self, S.

    1992-01-01

    Results are presented of a preliminary investigation of the fractal nature of the plan-view shapes of lava flows in Hawaii (based on field measurements and aerial photographs), as well as in Idaho and the Galapagos Islands (using aerial photographs only). The shapes of the lava flow margins are found to be fractals: lava flow shape is scale-invariant. This observation suggests that nonlinear forces are operating in them because nonlinear systems frequently produce fractals. A'a and pahoehoe flows can be distinguished by their fractal dimensions (D). The majority of the a'a flows measured have D between 1.05 and 1.09, whereas the pahoehoe flows generally have higher D (1.14-1.23). The analysis is extended to other planetary bodies by measuring flows from orbital images of Venus, Mars, and the moon. All are fractal and have D consistent with the range of terrestrial a'a and have D consistent with the range of terrestrial a'a and pahoehoe values.

  3. Role of Tectonics in Forming of the Kalahrood Cave, North Isfahan, Iran

    NASA Astrophysics Data System (ADS)

    Nadimi, A.; Sohrabi, A.

    2009-04-01

    Caves are perhaps the most spectacular examples of the combined effects of weathering and erosion by groundwater. As groundwater percolate through carbonate rocks, it dissolves and enlarges fractures and openings to form a complex interconnecting system of crevices, caves, caverns and underground streams. Caves and caverns form as a result of the dissolution of carbonate rocks by weakly acidic groundwater. Groundwater percolating through the zone of aeration slowly dissolves the carbonate rock and enlarges its fractures and bedding planes. During dissolving and deposition of calcite, many various dripstone deposits, stalactite and stalagmite structures form. There are many caves in Iran that have formed with the above procedure. Opposite of the procedure, the Kalahrood Cave, in the north of Isfahan has another scenario for its forming. The cave located in southwestern boundary of high mountains of the Urumieh-Dokhtar Magmatic Belt of Central Iran. It has formed in Lower Cretaceous grey limestones. There are many NW-SE-trending faults in the study area. The faults have thrust and dextral strike-slip motions. The Kalahrood cave formed in footwall of the Kalahrood thrust. Structural studies and filed observations in the Kalahrood area and in the cave indicated that the Kalahrood cave has formed during thrusting and dropping the cave roof in footwall and littering the floor with fallen debris. We have considered three episodes for forming the Kalahrood cave: 1- Thrusting and motion of hangingwall. There are many traces of faulting on the walls and roofs of the cave. 2- Dropping of crushed rocks and separated blocks of the roof in footwall and creating the cave space. Maximum distance between floor and roof has measured about 15 m. 3- Affect of groundwater on the rock units and increase of disbandment and enlarging the fractures. Some small stalagmite and stalactite structures have formed in internal part of the cave.

  4. Bubble-Induced Cave Collapse

    PubMed Central

    Girihagama, Lakshika; Nof, Doron; Hancock, Cathrine

    2015-01-01

    Conventional wisdom among cave divers is that submerged caves in aquifers, such as in Florida or the Yucatan, are unstable due to their ever-growing size from limestone dissolution in water. Cave divers occasionally noted partial cave collapses occurring while they were in the cave, attributing this to their unintentional (and frowned upon) physical contact with the cave walls or the aforementioned “natural” instability of the cave. Here, we suggest that these cave collapses do not necessarily result from cave instability or contacts with walls, but rather from divers bubbles rising to the ceiling and reducing the buoyancy acting on isolated ceiling rocks. Using familiar theories for the strength of flat and arched (un-cracked) beams, we first show that the flat ceiling of a submerged limestone cave can have a horizontal expanse of 63 meters. This is much broader than that of most submerged Florida caves (~ 10 m). Similarly, we show that an arched cave roof can have a still larger expanse of 240 meters, again implying that Florida caves are structurally stable. Using familiar bubble dynamics, fluid dynamics of bubble-induced flows, and accustomed diving practices, we show that a group of 1-3 divers submerged below a loosely connected ceiling rock will quickly trigger it to fall causing a “collapse”. We then present a set of qualitative laboratory experiments illustrating such a collapse in a circular laboratory cave (i.e., a cave with a circular cross section), with concave and convex ceilings. In these experiments, a metal ball represented the rock (attached to the cave ceiling with a magnet), and the bubbles were produced using a syringe located at the cave floor. PMID:25849088

  5. Bubble-induced cave collapse.

    PubMed

    Girihagama, Lakshika; Nof, Doron; Hancock, Cathrine

    2015-01-01

    Conventional wisdom among cave divers is that submerged caves in aquifers, such as in Florida or the Yucatan, are unstable due to their ever-growing size from limestone dissolution in water. Cave divers occasionally noted partial cave collapses occurring while they were in the cave, attributing this to their unintentional (and frowned upon) physical contact with the cave walls or the aforementioned "natural" instability of the cave. Here, we suggest that these cave collapses do not necessarily result from cave instability or contacts with walls, but rather from divers bubbles rising to the ceiling and reducing the buoyancy acting on isolated ceiling rocks. Using familiar theories for the strength of flat and arched (un-cracked) beams, we first show that the flat ceiling of a submerged limestone cave can have a horizontal expanse of 63 meters. This is much broader than that of most submerged Florida caves (~ 10 m). Similarly, we show that an arched cave roof can have a still larger expanse of 240 meters, again implying that Florida caves are structurally stable. Using familiar bubble dynamics, fluid dynamics of bubble-induced flows, and accustomed diving practices, we show that a group of 1-3 divers submerged below a loosely connected ceiling rock will quickly trigger it to fall causing a "collapse". We then present a set of qualitative laboratory experiments illustrating such a collapse in a circular laboratory cave (i.e., a cave with a circular cross section), with concave and convex ceilings. In these experiments, a metal ball represented the rock (attached to the cave ceiling with a magnet), and the bubbles were produced using a syringe located at the cave floor. PMID:25849088

  6. Surface Structures of Hawaiian Lavas

    NASA Technical Reports Server (NTRS)

    Rowland, S. K.; Walker, G. P. L.

    1985-01-01

    Surface and internal lava structures can be valid indicators of lava viscosity and rheology, provided that care is taken to identify and eliminate structures which are strain-rate-dependent. Here, a spectrum of types among Hawaiian basaltic flows is found ranging from pahoehoe to a'a, that are interpreted as marking a progression in lava viscosity and a change in rheology. The most fluid type in this spectrum is normal pahoehoe that has a smooth but commonly wrinkled or folded (ropy) surface. The next type, distinctly more viscous and probably non-Newtonian in rheology, is spiny pahoehoe which is characterized by a spinose surface and an absence of ropy structures. Preliminary studies on the long lavas of Mauna Loa indicated, perhaps surprisingly, that there is no clear-cut correlation of lava length with type in this spectrum of lavas, indicating that viscosity/yield strength of the basaltic lavas per se are not the primary controls determining flow length. Flowage of the lava through lava tubes, while it may help to account for the long flow distance of some lavas, is not a generally applicable explanation for long flow length.

  7. Winter distribution and use of high elevation caves as foraging sites by the endangered Hawaiian hoary bat, Lasiurus cinereus semotus

    USGS Publications Warehouse

    Bonaccorso, Frank; Montoya-Aiona, Kristina; Pinzari, Corinna A.; Todd, Christopher M.

    2016-01-01

    We examine altitudinal movements involving unusual use of caves by Hawaiian hoary bats, Lasiurus cinereus semotus, during winter and spring in the Mauna Loa Forest Reserve (MLFR), Hawai‘i Island. Acoustic detection of hoary bat vocalizations, were recorded with regularity outside 13 lava tube cave entrances situated between 2,200 to 3,600 m asl from November 2012 to April 2013. Vocalizations were most numerous in November and December with the number of call events and echolocation pulses decreasing through the following months. Bat activity was positively correlated with air temperature and negatively correlated with wind speed. Visual searches found no evidence of hibernacula nor do Hawaiian hoary bats appear to shelter by day in these caves. Nevertheless, bats fly deep into caves as evidenced by numerous carcasses found in cave interiors. The occurrence of feeding buzzes around cave entrances and visual observations of bats flying in acrobatic fashion in cave interiors point to the use of these spaces as foraging sites. Peridroma moth species (Noctuidae), the only abundant nocturnal, flying insect sheltering in large numbers in rock rubble and on cave walls in the MLFR, apparently serve as the principal prey attracting hoary bats during winter to lava tube caves in the upper MLFR. Caves above 3,000 m on Mauna Loa harbor temperatures suitable for Pseudogymnoascus destructansfungi, the causative agent of White-nose Syndrome that is highly lethal to some species of North American cave-dwelling bats. We discuss the potential for White-nose Syndrome to establish and affect Hawaiian hoary bats.

  8. The Hypothesis of Caves on Mars Revisited Through MGS Data; Their Potential as Targets for the Surveyor Program

    NASA Astrophysics Data System (ADS)

    Grin, E. A.; Cabrol, N. A.; McKay, C. P.

    1999-01-01

    In a previous publication, we proposed the formation of caves at mega and microscale on Mars and emphasized their potential for the exobiology exploration. The recent MOC images have shown promising indicators that caves are actually existing on Mars. In the first section, we develop the theoretical potential formation of martian caves. Then, we show how MOC is supporting this hypothesis of their formation and the new types of environments it suggests. The existence of caves on Mars from microscale to microscale structures can be predicted according to the Mars geological and climatic history. A first global approach is to consider caves as a result of underground water activity combined with tectonic movement. They can be formed by: (1) diversion of channel courses in underground conduits; (2) fractures of surface drainage patterns; chaotic terrain and collapsed areas in general; (4) seepage face in valley walls and/or headwaters; (5) inactive hydrothermal vents and lava tubes.

  9. Phenocryst fragments in rhyolitic lavas and lava domes

    NASA Astrophysics Data System (ADS)

    Allen, S. R.; McPhie, J.

    2003-08-01

    Although rhyolitic lavas and lava domes are characterised by evenly porphyritic textures, not all the phenocrysts are whole euhedra. We undertook image analysis of 46 rhyolitic lava and lava dome samples to determine the abundance and shape of quartz and feldspar phenocryst fragments. Phenocryst fragments were identified in nearly all samples. On average, fragments amount to ˜5% of the total phenocryst population, or ˜0.5 modal%. The abundance of fragments in lavas and lava domes is not related to the groundmass texture (whether vesicular, flow banded, massive, glassy or crystalline), nor to distance from source. Fragments are, however, more abundant in samples with higher phenocryst contents. The phenocryst fragments in rhyolitic lavas and lava domes are mainly medium to large (0.5-3.5 mm), almost euhedral crystals with only a small portion removed, or chunky, equant, subhedral fragments, and occur in near-jigsaw-fit or clast-rotated pairs or groups. The fragments probably formed in response to decompression of large melt inclusions. Shear during laminar flow then dismembered the phenocrysts; continued laminar shear separated and rotated the fragments. Fractures probably formed preferentially along weaknesses in the phenocrysts, such as zones of melt inclusions, cleavage planes and twin composition planes. Rare splintery fragments are also present, especially within devitrified domains. Splinters are attributed to comminution of solid lava adjacent to fractures that were later healed. For comparison, we measured crystal abundance in a further 12 rhyolite samples that include block and ash flow deposits and ignimbrite. Phenocryst fragments within clasts in the block and ash flow samples showed similar shapes and abundances to those fragments within the lava and lava domes. Crystal fragments are much more abundant in ignimbrite (exceeding 67% of the crystal population) however, and dominated by small, equant, anhedral chunks or splinters. The larger crystals in

  10. A new millipede, Austrotyla awishoshola n. sp., (Diplopoda, Chordeumatida, Conotylidae) from New Mexico, USA, and the importance of cave moss gardens as refugial habitats.

    PubMed

    Wynne, J Judson; Shear, William A

    2016-01-01

    Austrotyla awishoshola n. sp. is described from the moss gardens of one lava tube cave in El Malpais National Monument, Cibola Co., New Mexico. Most chordeumatidans require mesic conditions, and these environments are limited to moss gardens in several cave entrances and beneath cave skylights in El Malpais. Presently, this species is known from the moss gardens of a single of cave in the monument. We suggest A. awishoshola may be a climatic relict, having become restricted to the cave environment following the end of the Pleistocene. We discuss the importance of cave moss gardens as refugial and relictual habitats. Recommendations are provided to aid in the conservation and management of A. awishoshola and these habitats. PMID:27394265

  11. A new millipede, Austrotyla awishoshola n. sp., (Diplopoda, Chordeumatida, Conotylidae) from New Mexico, USA, and the importance of cave moss gardens as refugial habitats.

    PubMed

    Wynne, J Judson; Shear, William A

    2016-02-25

    Austrotyla awishoshola n. sp. is described from the moss gardens of one lava tube cave in El Malpais National Monument, Cibola Co., New Mexico. Most chordeumatidans require mesic conditions, and these environments are limited to moss gardens in several cave entrances and beneath cave skylights in El Malpais. Presently, this species is known from the moss gardens of a single of cave in the monument. We suggest A. awishoshola may be a climatic relict, having become restricted to the cave environment following the end of the Pleistocene. We discuss the importance of cave moss gardens as refugial and relictual habitats. Recommendations are provided to aid in the conservation and management of A. awishoshola and these habitats.

  12. Egyptian Sea Cave

    ERIC Educational Resources Information Center

    Journal of College Science Teaching, 2005

    2005-01-01

    This brief article describes an archaeological expedition to the Red Sea coast area of Egypt in 2004. Kathryn Bard, an associate professor of archaeology at Boston University, along with her team, discovered the well-preserved cedar timbers of an ancient Egyptian seafaring vessel near the entrance to a large man-made cave. Limestone tablets with…

  13. Glacioclimatological study of Perennial Ice in the Fuji Ice Cave, Japan. Part I. Seasonal variation and mechanism of maintenance

    SciTech Connect

    Ohata, Tetsuo; Furukawa, Teruo; Higuchi, Keiji )

    1994-08-01

    Perennial cave ice in a cave located at Mt. Fuji in central Japan was studied to investigate the basic characteristics and the cause for existence of such ice under warm ground-level climate considering the ice cave as a thermal and hydrological system. Fuji Ice Cave is a lava tube cave 150 m in length with a collapsed part at the entrance. Measurements from 1984 to 1986 showed that the surface-level change of floor ice occurred due to freezing and melting at the surface and that melting at the bottom of the ice was negligible. The annual amplitude of change in surface level was larger near the entrance. Meterological data showed that the cold air inflow to the cave was strong in winter, but in summer the cave was maintained near 0[degrees]C with only weak inflow of warm air. The predominant wind system was from the entrance to the interior in both winter and summer, but the spatial scale of the wind system was different. Heat budget consideration of the cave showed that the largest component was the strong inflow of subzero dry air mass in winter. Cooling in winter was compensated for by summer inflow of warm air, heat transport from the surrounding ground layer, and loss of sensible heat due to cooling of the cave for the observed year. Strong inflow of cold air and weak inflow of warm air, which is extremely low compared to the ground level air, seemed to be the most important condition. Thus the thermal condition of the cave is quasi-balanced at the presence condition below 0[degrees]C with ice. It can be said that the interrelated result of the climatological and special structural conditions makes this cave very cold, and allows perennial ice to exist in the cave. Other climatological factors such as precipitation seem to be minor factors. 17 refs., 3 figs., 3 tabs.

  14. Degassing driving crystallization of plagioclase phenocrysts in lava tube stalactites on Mount Etna (Sicily, Italy)

    NASA Astrophysics Data System (ADS)

    Lanzafame, Gabriele; Ferlito, Carmelo

    2014-10-01

    Basaltic lava flows can form tubes in response to the cooling of the outer surface. We collected lava stalactites (frozen lava tears) and sampled lava from the ceilings of three lava tubes on Mount Etna. Comparison of the petrographic characters between ceiling lavas and relative stalactites reveals surprising differences in the groundmass textures and crystal compositions. Major and trace element contents in stalactites show only a slight increase in alkali and SiO2 compared to ceiling lava, whereas significant differences exist in composition and textures between plagioclases within the ceiling lava and those within the stalactites, being in the last case definitively more An-rich. We advance the hypothesis that the high temperature reached in the cave caused the exsolution of the volatiles still trapped in the dripping melt. The volatiles, mainly H2O, formed bubbles and escaped from the melt; such a water-loss might have promoted the silicate polymerization in the stalactites resulting in the growth of An-rich plagioclase phenocrysts. Our results have important implications: in fact plagioclase phenocrysts are usually associated with intratelluric growth and are often considered as the main petrologic evidence for the existence of a magma chamber. The textural and chemical features of plagioclases in stalactites prove that phenocryst growth in syn to post-eruptive conditions is plausible and clearly explains the relatively low viscosity of many phenocryst-rich lava flows on Mount Etna, as well as on many other volcanoes around the world. Therefore, we can conclude that plagioclase phenocrysts cannot exclusively be considered as having originated within a magma chamber.

  15. Deriving Lava Eruption Temperatures on Io Using Lava Tube Skylights

    NASA Astrophysics Data System (ADS)

    Davies, A. G.; Keszthelyi, L. P.; McEwen, A. S.

    2015-12-01

    The eruption temperature of Io's silicate lavas constrains Io's interior state and composition [1] but reliably measuring this temperature remotely is a challenge that has not yet been met. Previously, we established that eruption processes that expose large areas at the highest temperatures, such as roiling lava lakes or lava fountains, are suitable targets for this task [2]. In this study we investigate the thermal emission from lava tube skylights for basaltic and ultramafic composition lavas. Tube-fed lava flows are known on Io so skylights could be common. Unlike the surfaces of lava flows, lava lakes, and lava fountains which all cool very rapidly, skylights have steady thermal emission on a scale of days to months. The thermal emission from such a target, measured at multiple visible and NIR wavelengths, can provide a highly accurate diagnostic of eruption temperature. However, the small size of skylights means that close flybys of Io are necessary, requiring a dedicated Io mission [3]. We have modelled the thermal emission spectrum for different skylight sizes, lava flow stream velocities, end-member lava compositions, and skylight radiation shape factors, determining the flow surface cooling rates. We calculate the resulting thermal emission spectrum as a function of viewing angle. From the resulting 0.7:0.9 μm ratios, we see a clear distinction between basaltic and ultramafic compositions for skylights smaller than 20 m across, even if sub-pixel. If the skylight is not resolved, observations distributed over weeks that show a stationary and steady hot spot allow the presence of a skylight to be confidently inferred. This inference allows subsequent refining of observation design to improve viewing geometry of the target. Our analysis will be further refined as accurate high-temperature short-wavelength emissivity values become available [4]. This work was performed at the Jet Propulsion Laboratory-California Institute of Technology, under contract to

  16. Lava crusts and flow dynamics

    NASA Technical Reports Server (NTRS)

    Kilburn, C. R. J.

    1993-01-01

    Lava flows can be considered as hot viscous cores within thinner, solidified crusts. Interaction between crust and core determines a flow's morphological and dynamical evolution. When the lava core dominates, flow advance approaches a steady state. When crusts are the limiting factor, advance is more irregular. These two conditions can be distinguished by a timescale ratio comparing rates of core deformation and crustal formation. Aa and budding pahoehoe lavas are used as examples of core- and crustal-dominated flows, respectively. A simple model describes the transition between pahoehoe and aa flow in terms of lava discharge rate, underlying slope, and either the thickness or velocity of the flow front. The model shows that aa morphologies are characterized by higher discharge rates and frontal velocities and yields good quantitative agreement with empirical relations distinguishing pahoehoe and aa emplacement on Hawaii.

  17. Lava flows and volcanic landforms

    NASA Astrophysics Data System (ADS)

    Tarquini, Simone

    2016-04-01

    Lava flows constitute a large portion of the edifice of basaltic volcanoes. The substantial difference existing between the emplacement dynamics of different basaltic lava flows suggests a relation between the dominant flow dynamic and the overall shape of the ensuing volcano. Starting from the seminal works of Walker (1971, 1973) it is proposed that the rate of heat dissipation per unit volume of lava can be the founding principium at the roots of the emplacement dynamics of lava flows. Within the general framework of the thermodynamics of irreversible processes, a conceptual model is presented, in which the dynamic of lava flows can evolve in a linear or in a nonlinear regime on the basis of the constraint active on the system: a low constraint promotes a linear dynamic (i.e. fluctuations are damped), a high constraint a nonlinear one (i.e. fluctuations are enhanced). Two cases are considered as end-members for a linear and a nonlinear dynamic in lava flows: the typical "Hawaiian" sheet flow and the classic "Etnean" channelized flow (respectively). In lava flows, the active constraint is directly proportional to the slope of the topography and to the thermal conductivity and thermal capacity of the surrounding environment, and is inversely proportional to the lava viscosity and to the supply rate. The constraint indicates the distance from the equilibrium conditions of the system, and determines the rate of heat dissipation per unit volume. In subaerial flows, the heat dissipated during the emplacement is well approximated by the heat lost through radiation, which can be retrieved through remote-sensing techniques and can be used to correlate dynamic and dissipation. The model presented recombines previously unrelated concepts regarding the dynamics and the thermal regimes observed in different lava flows, providing a global consistent picture. References Walker GPL (1971) Compound and simple lava flows and flood basalts. Bull Volcanol 35:579-590 Walker GPL (1973

  18. Wind, Water, and Lava

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 18 June 2003

    The three main geological agents acting on the Martian surface are visible in this image, within an outflow channel to the east of the Tharsis volcanos and north of Valles Marineris. In a wide channel previously eroded by water, linear features have been eroded into the rock by the wind. Later, lava flows embayed the streamlined rocks. A second, younger flow lobe is visible at the bottom of the image.

    Image information: VIS instrument. Latitude 17, Longitude 283.6 East (76.4 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  19. Caves: A Course of Study.

    ERIC Educational Resources Information Center

    Phillips, Jan

    Middle school students from The College School, a private school in Webster Groves (Missouri) have completed a class called "Caves and Crystallography." A thematic approach was used in the course in which students and teachers read books telling how caves were formed, saw movies which explained the delicate balance of life underground, made…

  20. Important caves to be identified

    NASA Astrophysics Data System (ADS)

    Criteria to identify significant caves on federal land are being developed by the Interior Department's Bureau of Land Management and the Agriculture Department's Forest Service under requirements of the Federal Cave Resources Protection Act of 1988. The departments gave advance notice of proposed rulemaking March 3 and invited suggestions and comments from the public for 30 days.The law requires protection, to the extent practical, of significant caves on lands administered by the Secretaries of Agriculture and Interior and includes authority to issue and revoke permits for collection and removal of cave resources and special provisions for regulation of cave resources on Indian lands. Final regulations must be published by August 18, 1989.

  1. The Unicorn Cave, Southern Harz Mountains, Germany: From known passages to unknown extensions with the help of geophysical surveys

    NASA Astrophysics Data System (ADS)

    Kaufmann, Georg; Nielbock, Ralf; Romanov, Douchko

    2015-12-01

    In soluble rocks (limestone, dolomite, anhydrite, gypsum, …), fissures and bedding partings can be enlarged with time by both physical and chemical dissolution of the host rock. With time, larger cavities evolve, and a network of cave passages can evolve. If the enlarged cave voids are not too deep under the surface, geophysical measurements can be used to detect, identify and trace these karst structures, e.g.: (i) gravity revealing air- and sediment-filled cave voids through negative Bouguer anomalies, (ii) electrical resistivity imaging (ERI) mapping different infillings of cavities either as high resistivities from air-filled voids or dry soft sediments, or low resistivities from saturated sediments, and (iii) groundwater flow through electrical potential differences (SP) arising from dislocated ionic charges from the walls of the underground flow paths. We have used gravity, ERI, and SP methods both in and above the Unicorn Cave located in the southern Harz Mountains in Germany. The Unicorn Cave is a show cave developed in the Werra dolomite formation of the Permian Zechstein sequence, characterised by large trunk passages interrupted by larger rooms. The overburden of the cave is only around 15 m, and passages are filled with sediments reaching infill thicknesses up to 40 m. We present results from our geophysical surveys above the known cave and its northern and southern extension, and from the cave interior. We identify the cave geometry and its infill from gravity and ERI measurements, predict previously unknown parts of the cave, and subsequently confirm the existence of these new passages through drilling. From the wealth of geophysical data acquired we derive a three-dimensional structural model of the Unicorn Cave and its surrounding, especially the cave infill.

  2. Survey and hydrogeology of Carroll Cave

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carroll Cave, located in Camden County, Missouri, is the largest known cave formed in the Gasconade Dolomite of the Salem Plateau. Despite extensive visitation over the last 50 years and multiple survey efforts, a comprehensive map of the cave has never been produced. In 2002, the Carroll Cave Conse...

  3. Radon and thoron in cave dwellings (Yan'an, China)

    SciTech Connect

    Wiegand, J.; Feige, S.; Xie Quingling; Schreiber, U.; Wieditz, K.; Wittmann, C.; Luo Xiarong

    2000-04-01

    {sup 222}Rn and {sup 220}Rn concentrations were measured in cave dwellings and brick houses in the region of Yan'an (China) during summer 1997. The underground dwellings are built into Quaternary loess, and all investigated houses are founded on it. The median values of indoor {sup 222}Rn and {sup 220}Rn concentrations are 42 (n = 18) and 77Bq m{sup {minus}3} (n = 15) for brick houses and 92 (n = 23) and 215 (n = 17) Bq m{sup {minus}3} for cave dwellings. To classify the dwellings in respect to their cave-character, the fraction of walls having a direct contact to the loess is calculated for each dwelling. While the {sup 222}Rn concentrations are increasing with higher fractions, the {sup 220}Rn concentrations are not correlated with this fraction. On the other hand, due to the short half-life of {sup 220}Rn the distance from the measuring point to the walls is negatively correlated with the {sup 220}Rn concentration, while there is no correlation with the {sup 222}Rn concentration. Therefore, concentric isolines of {sup 220}Rn concentrations showing a strong gradient were detected in cave dwellings. An influence of the ventilation rate is distinct for {sup 222}Rn but weak for {sup 220}Rn. The effective dose rates for {sup 222}Rn and {sup 220}Rn and their progenies are calculated for brick houses (2.7 mSv y{sup {minus}1}), cave dwellings (7.1 mSv y{sup {minus}1}), and for traditional cave dwellings with a bed foundation built with loess (16.7 mSv y{sup {minus}1}). These calculations are based on summer measurements only. It is expected that the true effective dose rates will be significantly higher.

  4. Identification of flood events inside karst cavities: Fria Cave (Asturias - NW Spain)

    NASA Astrophysics Data System (ADS)

    Gonzalez Lemos, Saul; Stoll, Heather

    2013-04-01

    Fluvial records may be well preserved in subterranean karst drainage networks and fluvial deposits cemented in speleothems may provide good chronology of past flood events. In several karst systems in Asturias (NW. Spain), moments of extreme precipitation events produce deposits from flood events in the bed and walls of caves which we propose are also recorded in the calcium carbonate stalagmites growing in the cave. The final stretch of the studied cave (Fria Cave), with a development of 360 m in length, intersects a small perennial stream which in our observation has maintained a minimum discharge of about 0.022 m3/s but periodically overflows into the vadose cave passage. Immediately after a flood overflow event, water marks and foam detritus are visible at various levels on the cave walls and corresponding to heights of bottlenecks in overflow drainage through the cave passage. Flood events deposit sand on terraces on the cave wall and move large volumes of sand in the cave bed. These extreme events leave a long-term record in i) wall coloration or water marks on the cave walls; and ii) detrital particles preserved as inclusions inside the stalagmites. Throughout this cave, it is possible to recognize chromatic changes in the walls, such as manganese oxide stains, which coincide with one of the water marks left during a recent flood event. The most salient manganese oxide on the walls rises up to 1.5 m measured from the thalweg and we interpreted it as the result of a frequent process of wetting - drying related to frequent flooding of the cave. Since 3-4 ka, drapery flowstone has been deposited over this oxide coating in some parts of the cave and the drapery remains free of oxide coating. We interpret this as indicating a reduction in the frequency and/or duration of flooding to this height, coincident with a regional drying trend in late Holocene. Stalagmites growing in the bed of the cave appear to trap fluvial sediments like sand or silts particles, which

  5. Compositionally Constraining Elysium Lava Fields

    NASA Astrophysics Data System (ADS)

    Karunatillake, S.; Button, N. E.; Skok, J. R.

    2013-12-01

    Chemical provinces of Mars defined recently [1-3] became possible with the maps of elemental mass fractions generated with Mars Odyssey Gamma and Neutron Spectrometer (GS) data [4,5]. These provide a unique perspective by representing compositional signatures distinctive of the regolith vertically at decimeter depths and laterally at hundreds of kilometer scale. Some provinces overlap compellingly with regions highlighted by other remote sensing observations, such as the Mars Radar Stealth area [3]. The spatial convergence of mutually independent data with the consequent highlight of a region provides a unique opportunity of insight not possible with a single type of remote sensing observation. Among such provinces, previous work [3] highlighted Elysium lava flows as a promising candidate on the basis of convergence with mapped geologic units identifying Elysium's lava fields generally, and Amazonian-aged lava flows specifically. The South Eastern lava flows of Elysium Mons, dating to the recent Amazonian epoch, overlap compellingly with a chemical province of K and Th depletion relative to the Martian midlatitudes. We characterize the composition, geology, and geomorphology of the SE Elysium province to constrain the confluence of geologic and alteration processes that may have contributed to its evolution. We compare this with the North Western lava fields, extending the discussion on chemical products from the thermal evolution of Martian volcanism as discussed by Baratoux et al. [6]. The chemical province, by regional proximity to Cerberus Fossae, may also reflect the influence of recently identified buried flood channels [7] in the vicinity of Orcus Patera. Despite the compelling chemical signature from γ spectra, fine grained unconsolidated sediment hampers regional VNTIR (Visible, Near, and Thermal Infrared) spectral analysis. But some observations near scarps and fresh craters allow a view of small scale mineral content. The judicious synthesis of

  6. Reproducing Actual Morphology of Planetary Lava Flows

    NASA Astrophysics Data System (ADS)

    Miyamoto, H.; Sasaki, S.

    1996-03-01

    Assuming that lava flows behave as non-isothermal laminar Bingham fluids, we developed a numerical code of lava flows. We take the self gravity effects and cooling mechanisms into account. The calculation method is a kind of cellular automata using a reduced random space method, which can eliminate the mesh shape dependence. We can calculate large scale lava flows precisely without numerical instability and reproduce morphology of actual lava flows.

  7. Newberry Volcano's youngest lava flows

    USGS Publications Warehouse

    Robinson, Joel E.; Donnelly-Nolan, Julie M.; Jensen, Robert A.

    2015-01-01

    The central caldera is visible in the lower right corner of the center map, outlined by the black dashed line. The caldera collapsed about 75,000 years ago when massive explosions sent volcanic ash as far as the San Francisco Bay area and created a 3,000-ft-deep hole in the center of the volcano. The caldera is now partly refilled by Paulina and East Lakes, and the byproducts from younger eruptions, including Newberry Volcano’s youngest rhyolitic lavas, shown in red and orange. The majority of Newberry Volcano’s many lava flows and cinder cones are blanketed by as much as 5 feet of volcanic ash from the catastrophic eruption of Mount Mazama that created Crater Lake caldera approximately 7,700 years ago. This ash supports abundant tree growth and obscures the youthful appearance of Newberry Volcano. Only the youngest volcanic vents and lava flows are well exposed and unmantled by volcanic ash. More than one hundred of these young volcanic vents and lava flows erupted 7,000 years ago during Newberry Volcano’s northwest rift zone eruption.

  8. Lava Flows of Daedalia Planum

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site]

    This THEMIS image captures a portion of several lava flows in Daedalia Planum southwest of the Arsia Mons shield volcano. Textures characteristic of the variable surface roughness associated with different lava flows in this region are easily seen. The lobate edges of the flows are distinctive, and permit the discrimination of many overlapping individual flows. The surfaces of some flows look wrinkly and ropy, probably indicating a relatively fluid type of lava flow referred to as pahoehoe. The surface textures of lava flows can thus sometimes be used for comparative purposes to infer lava viscosity and effusion rates. Numerous parallel curved ridges are visible on the upper surfaces of some of the lava flows. These ridges make the flow surface look somewhat ropy, and at smaller scales this flow might be referred to as pahoehoe, however, these features are probably better referred to as pressure ridges. Pressure ridges form on the surface of a lava flow when the upper part of the flow is exposed to air, cooling it, but the insulated much warmer interior of the flow continues to move down slope (and more material is pushed forward from behind), causing the surface to compress and pile up like a rug.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with

  9. Lava Flow at Kilauea, Hawaii

    NASA Technical Reports Server (NTRS)

    2007-01-01

    On July 21, 2007, the world's most active volcano, Kilauea on Hawaii's Big Island, produced a new fissure eruption from the Pu'u O'o vent, which fed an open lava channel and lava flows toward the east. Access to the Kahauale'a Natural Area Reserve was closed due to fire and gas hazards. The two Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) nighttime thermal infrared images were acquired on August 21 and August 30, 2007. The brightest areas are the hottest lava flows from the recent fissure eruption. The large lava field extending down to the ocean is part of the Kupaianaha field. The most recent activity there ceased on June 20, but the lava is still hot and appears bright on the images. Magenta areas are cold lava flows from eruptions that occurred between 1969 and 2006. Clouds are cold (black) and the ocean is a uniform warm temperature, and light gray in color. These images are being used by volcanologists at the U.S. Geological Survey Hawaii Volcano Observatory to help monitor the progress of the lava flows.

    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 spacecraft. 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

  10. Origin and Evolution of Limestone Caves of Chhattisgarh and Orissa, India: Role of Geomorphic, Tectonic and Hydrological Processes

    NASA Astrophysics Data System (ADS)

    Gautam, P. K.; Allu, N. C.; Ramesh, R.; Yadava, M. G.; Panigrahi, C. P.

    2014-12-01

    Carbonate rocks undergo karstic process and karst morphology is a key to understand the nature and genesis of caves. The primary energy source for the formation of karst landforms is hydrological cycle. Geomorphic features along with hydrological characteristics provide important information not only on karst formation but also climate and environmental conditions. In this paper, we present the tectonic and geomorphic features that played a role in evolution of caves located in Chhattisgarh and Orissa States of India. The geomorphic and tectonic aspects of Kotumsar, Kailash, and Gupteshwar caves are discussed in relation to the origin and evolution of these caves. Caves are located near the water falls. The area is folded and faulted along the Eastern Ghat Mobile Belt (EGMB) due to tectonic reactivation. Shaly-limestone beds exhibit vertical dipping near Gupteshwar cave, and steeply inclined near Kotumsar and Kailash caves. Indrāvati and Sabari/Kolab tributaries of the Godavari River drain the area. The landscape evolution and the origin of caves in the region is a multistage process, where the lithology, orogeny, fluvial action, and monsoon are the main agents, which is similar to the four state model (Ford and Ewers, 1978). The river basin evolution and regional tectonism also caused the initiation of karstification in the region. The evolution of caves is believed to have taken place in Pre-Pliocene under more humid conditions that coincided with the initiation of monsoon in India. Further, during the Quaternary wet-dry/cold-warm phases altered physical and chemical weathering of limestone rocks. Contrasting relief features of Bastar plateau have also helped the extensive cave formation in the region. The dissolution along weak planes initiated the openings of caves, further enlarged by geomorphic agents. Both monsoon and tectonics have caused fluctuations in water levels along river courses, which acted as active agents in evolution of caves.

  11. Infectious diseases associated with caves.

    PubMed

    Igreja, Ricardo Pereira

    2011-06-01

    In recent times, caving has become increasingly popular, with almost 2 million people visiting national park caves each year in the United States. Although the 2 million tourist visits are extremely low risk, smaller numbers of sport cavers are at risk for some high risk conditions, and expedition cavers are at risk for some obscure infections. Infectious diseases like histoplasmosis, rabies, leptospirosis, and tick-borne relapsing fever may be transmitted by the underground fauna. To reduce the risk of illness or injury while caving, knowledge of potential risks before engaging in this activity is important. Caving preparation needs to be carefully planned and executed, including vaccinations, prophylactic medications, and advice regarding safe conduct and behaviors. PMID:21664559

  12. Groundmass Crystallinities of Proximal and Distal Lavas from Cinder Cone, Lassen Volcanic Field

    NASA Astrophysics Data System (ADS)

    Szymanski, M. E.; Teasdale, R.

    2015-12-01

    Cinder Cone is located in the northeast corner of Lassen Volcanic Center, approximately 35 km southeast of Old Station, California. The area consists of a cinder cone constructed of loose scoria, lava flows and a 13-16 km diameter ash deposit. According to radiocarbon ages from trees affected by the lava flows and paleomagnetic data, Cinder Cone erupted in about 1650 AD (1). The youngest products of the Cinder Cone eruption are two Fantastic Lava Beds flows which are basaltic andesite and andesite with olivine (1). Samples were collected along the longest flow from Cinder Cone, the Fantastic Lava Beds Flow 2 (4.5 km) at approximately 0.5 km interval. The samples contain olivine, plagioclase and clinopyroxene phenocrysts in fine grained groundmass with varying vesicularity. Quartz xenocrysts also occur. SEM-Back Scatter Electron images are used to map and quantify groundmass crystallinities along the length of the Fantastic Lava Beds flow 2 and of tephra units. The average area of groundmass plagioclase crystals increases along the length of the lava flow from 94.7 to 292.6 μm2. The number of groundmass plagioclase crystals per area (μm2) decreases from 0.0045 to 0.0018 from proximal to distal samples. Crystals also become blockier in distal samples along the lava flow. The larger number of crystals per area in near vent samples establishes a baseline from which we interpret crystal growth and nucleation to have occurred in the flow channel. Increasing crystal size and a decrease in the number of crystals per area indicates growth dominated nucleation during cooling and crystallization in the flow channel. Relative cooling rates along the length of the flow from proximal to distal samples can be inferred based on groundmass crystallinities, distance travelled and estimates of flow and crystallization rates. (1) Muffler and Clynne, 2015.

  13. Cave development by frost weathering

    NASA Astrophysics Data System (ADS)

    Oberender, Pauline; Plan, Lukas

    2015-01-01

    This paper deals with the description and genesis of a special type of shelter cave. In German they are termed Auswitterungshöhlen which goes back to the 19th century and the genesis is supposed to be related to frost weathering, but to our knowledge, detailed studies are missing so far. This type of cave is very common in the area of investigation that comprises pre-Alpine and Alpine regions in the north-eastern part of the Eastern Alps: They make up 32% of the 5138 registered caves but surprisingly they entirely developed in carbonate rocks. Although most of them are smaller than a dozen metres, some have lengths of more than 50 m and entrances can be more than 100 m wide or similarly high. Besides general observations that lead to a list of characteristics for these caves, two of them in a pre-Alpine setting were studied in-depth. A detailed map, descriptions, and measurements concerning cave morphology, host rock geology, and climate are given. The thickness and composition of clastic sediments were investigated by small trenches and electric resistivity measurements. Sediment thicknesses reach up to 2 m inside the caves and below the entrances. For one year nets were installed to measure rockfall in both caves. In warm periods generally less than 5 g/month of debris could be collected, but a few 100 g/month for frost periods. This strong correlation and the significant amount of debris together with other observations suggest that frost weathering is an on-going and very important process for the formation of these caves. Grain-size distribution of the collected debris argues for the activity of both microgelivation and ice segregation. Therefore we suggest that the term frost weathering caves should be used for shelter caves whose genesis is related to frost weathering. As dissolution seems to be of marginal importance for the genesis they are a paradox as they develop in karstic rock but have pseudokarst features.

  14. Evolution of Hang Son Doong, Vietnam: the largest cave passage in the world

    NASA Astrophysics Data System (ADS)

    Granger, D. E.

    2011-12-01

    Hang Son Doong (HSD), or Mountain River Cave, in the Quang Binh province of Vietnam, is considered to be the largest cave passage in the world. It has continuous widths near 100 m, and heights locally exceeding 200 m in a passage >6.5 km long. HSD is one of many extremely large caves in the tropical karst of the Ke Bang massif, a massively bedded limestone surrounded by metamorphic and clastic sedimentary rocks. Why are these caves so large? Is it because they are young and rapidly formed, or instead did they form slowly in exceptionally strong bedrock? To address these questions it is necessary to examine the style and timing of speleogenesis. Hang Son Doong was formed by an allogenic river sinking along a straight subvertical fault. The cave is formed largely within a brecciated fault zone that extends up to 100 m wide. A relict karst valley indicates that speleogenesis occurred due to wholesale capture of the surface river. The cave pattern is strongly fault-controlled with few branches, consistent with a primarily allogenic rather than distributed recharge. The cave is punctuated by two collapse dolines, one of which impedes discharge today. Massive slackwater deposits perhaps 100 m thick accumulated upstream of this doline collapse, and are overlain by corroded flowstone. To place some time constraints on speleogenesis, two samples were collected for cosmogenic nuclide burial dating with 26Al and 10Be in allogenic quartz. One was from the slackwater deposits, and another from a breccia-filled tributary passage at a fault junction. Both samples postdate cave formation, and can only be used to place minimum ages on the cave. Cosmogenic nuclide concentrations are very low, leading to large uncertainties in the ages. Nonetheless, the burial ages yield some important information. Initial results indicate that the slackwater deposits formed recently, during the past 300 ky. The filled passage, on the other hand, is much older and dates to the Pliocene. Re

  15. Basaltic caves at Craters of the Moon National Monument and Preserve as analogs for Mars

    NASA Astrophysics Data System (ADS)

    Hinman, N. W.; Richardson, C. D.; McHenry, L.; Scott, J. R.

    2010-12-01

    Basaltic caves and lava tubes offer stable physicochemical conditions for formation of secondary minerals. Such features, putatively observed on Mars, intercept groundwater to weather country rock, leading to formation of secondary minerals. Further, caves are stable environments to search for evidence of past life, as they could offer protection from the oxidizing martian atmosphere. Searching for signs of life in a cave that could protect bio/organic compounds would preclude the need for risky drilling on Mars. Craters of the Moon National Monument (COM) offers an opportunity to study caves in Holocene iron-rich basalt flows to characterize secondary mineral deposits and search for organic compounds associated with secondary minerals; COM basalts are a good analog for martian basalts because of their high iron but other elements are higher at COM than on Mars. The Blue Dragon flow (~2.1 ka) contains the majority of the accessible caves and lava tubes. Two types of secondary mineral deposits were observed in these caves: ceiling coatings and crack or floor precipitates. Hematite, silica, and calcite comprise ceiling coatings. The crack and floor precipitates are white, efflorescent deposits in cavities along cave walls and ceilings or in localized mounds on cave floors. The secondary minerals in crack and floor precipitates are mainly thenardite and mirabilite with some minor concentrations of trona and/or burkeite. Organic compounds were found associated with the efflorescent deposits. Formation of the deposits is likely due to chemical leaching of basalt by meteoritic water. To test this, fluids collected from the ceiling and walls of the caves were analyzed. Solutions were modeled with the geochemical code, PHREEQC. The model tracked composition as water evaporated. Selected minerals were allowed to precipitate as they became oversaturated. Among the first minerals to become oversaturated were quartz and calcite, which are observed in ceiling deposits. Iron

  16. Exploring old caves

    NASA Astrophysics Data System (ADS)

    Luana Belli, Maria

    2015-04-01

    Quarries, caves and mines often contain fossils. During the '30s in Rome, the urban expansion needs for building materials such as gravel, sand and clay were extracted from quarries that surrounded the city. One of these quarries in particular, in the area of Saccopastore (Nomentana area 3 km from the University Sapienza Roma) returned an ancient human fossil skull belonging to a Neanderthal (most likely a female) who lived in Latium about 120,000 years ago. Detailed studies of this fossil were carried out by Sergio Sergi, the son of the founder of the Museum of Anthropology in Rome, Giuseppe Sergi. The museum was founded in 1884 and was later transferred to the University City (1934) where it is still located. Professor Maria Luana Belli, a science teacher in the Liceo Scientifico "G. Keplero" is a volunteer and collaborator with the Museum "G. Sergi", and she and her students retrace the places of the discovery on the trail of the Neanderthals, for understanding the evolution of the territory in a perspective of interdisciplinary teaching.

  17. Unique Biosignatures in Caves of All Lithologies

    NASA Astrophysics Data System (ADS)

    Boston, P. J.; Schubert, K. E.; Gomez, E.; Conrad, P. G.

    2015-10-01

    Unique maze-like microbial communities on cave surfaces on all lithologies all over the world are an excellent candidate biosignatures for life detection missions into caves and other extraterrestrial environments.

  18. Microbial Diversity in Ozark Region Caves

    NASA Astrophysics Data System (ADS)

    Moreno, M.; Powers, M.; McQueen, V. M.; Kuehl, M. M.; Ong, H. C.; Thomas, D. J.

    2010-04-01

    We are trying isolate and identify photosynthetic, chemosynthetic and other microorganisms in cave environments using metagenetic and classical microbiological methods. Cave environments are potential analogs to extant and extinct extraterrestrial environments.

  19. Lava Flows in Eastern Tharsis

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 31 May 2002) This image may at first appear somewhat bland -- there is little contrast in the surface materials due to dust cover, and there are few impact craters -- but there are some very interesting geologic features here. The great Tharsis volcanoes have produced vast fields of lava flows, such as those shown in this image, to the east of Tharsis Tholus. The flows in this image have moved from west to east, down the regional topographic slope. The lobate edges of the flows are distinctive, and permit the discrimination of many overlapping individual flows that may represent tens, hundreds, thousands, or even millions of years worth of volcanic activity (overlapping relationships are especially evident at the bottom of the image). Viewed at full resolution, the image reveals interesting patterns and textures on the top surfaces of these flows. In particular, at the top of the image, there are numerous parallel curved ridges visible on the upper surfaces of the lava flows. These ridges make the flow surface look somewhat ropy, and at smaller scales this flow might be referred to as pahoehoe, indicative of a relatively fluid type of lava flow. At the scales observed here, however, these features are probably better referred to as pressure ridges. Pressure ridges form on the surface of a lava flow when the upper part of the flow is exposed to air, freezing it, but the insulated unfrozen interior of the flow continues to move down slope (and more material is pushed forward from behind), causing the surface to compress and pile up like a rug. Rough-looking flows with less distinct (more random) patterns on their surfaces may be flows that are more like terrestrial a'a flows, which are distinguished from pahoehoe flows by their higher viscosities and effusion rates. Near the center of the image there is an east-west trending, smooth-floored depression. The somewhat continuous width of this depression suggests that it is not simply formed by the edges of two

  20. Lava Flows around Olympus Mons

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site]

    At first glance, this image of lava flows around the large scarp of Olympus Mons shows little contrast in surface materials due to dust cover, but a closer look reveals textures characteristic of the variable surface roughness associated with different lava flows in this region. The lobate edges of the flows are distinctive, and permit the discrimination of many overlapping individual flows. On small scales, the surfaces of some flows look wrinkly and ropy, indicating a relatively fluid type of lava flow referred to as pahoehoe. Other surfaces appear more rough and broken, and might be referred to as a'a flows, which have higher viscosities and effusion rates compared to pahoehoe flows. The surface textures of lava flows can thus sometimes be used for comparative purposes to infer lava viscosity and effusion rates. There is also a bright streak in the wind shadow of the impact crater in the lower left of the image where dust that settles onto the surface is not easily scoured away.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and

  1. Cave Art: Reflections of Early Human Culture.

    ERIC Educational Resources Information Center

    Sullivan, Brother Nicholas

    1981-01-01

    Discusses Paleolithic and Neolithic cave art and artifacts, stressing the degree of intellectual ability exhibited by the creators of this art. Topics discussed include some misunderstandings about cave art intellect shown by cave artists and the use of light and color. (DS)

  2. The probability of lava inundation at the proposed and existing Kulani prison sites

    USGS Publications Warehouse

    Kauahikaua, J.P.; Trusdell, F.A.; Heliker, C.C.

    1998-01-01

    The State of Hawai`i has proposed building a 2,300-bed medium-security prison about 10 km downslope from the existing Kulani medium-security correctional facility. The proposed and existing facilities lie on the northeast rift zone of Mauna Loa, which last erupted in 1984 in this same general area. We use the best available geologic mapping and dating with GIS software to estimate the average recurrence interval between lava flows that inundate these sites. Three different methods are used to adjust the number of flows exposed at the surface for those flows that are buried to allow a better representation of the recurrence interval. Probabilities are then computed, based on these recurrence intervals, assuming that the data match a Poisson distribution. The probability of lava inundation for the existing prison site is estimated to be 11- 12% in the next 50 years. The probability of lava inundation for the proposed sites B and C are 2- 3% and 1-2%, respectively, in the same period. The probabilities are based on estimated recurrence intervals for lava flows, which are approximately proportional to the area considered. The probability of having to evacuate the prison is certainly higher than the probability of lava entering the site. Maximum warning times between eruption and lava inundation of a site are estimated to be 24 hours for the existing prison site and 72 hours for proposed sites B and C. Evacuation plans should take these times into consideration.

  3. Fish assemblages of Mediterranean marine caves.

    PubMed

    Bussotti, Simona; Di Franco, Antonio; Francour, Patrice; Guidetti, Paolo

    2015-01-01

    Fish assemblages associated with 14 marine caves and adjacent external rocky reefs were investigated at four Marine Protected Areas (MPAs) along the coasts of Italy. Within the caves sampling was carried out in different sub-habitats: walls, ceilings, bottoms and ends of caves. On the whole, 38 species were recorded inside the 14 caves investigated. Eighteen species were exclusively found inside the caves: they were mainly represented by speleophilic (i.e. species preferentially or exclusively inhabiting caves) gobids (e.g. Didogobius splechtnai) and nocturnal species (e.g. Conger conger). Forty-one species were censused outside, 20 of which were shared with cave habitats. Apogon imberbis was the most common fish found in all 14 caves investigated, followed by Thorogobius ephippiatus (recorded in 13 caves), and Diplodus vulgaris and Scorpaena notata (both censused in 12 caves). Distinct fish assemblages were found between external rocky reefs and the different cave sub-habitats. New data on the distribution of some speleophilic gobids were collected, showing the existence of a pool of species shared by marine caves on a large scale (i.e. hundreds of km). Considering the uniqueness of cave fishes (18 exclusive species and different assemblage structures), the inclusion of marine caves among the habitats routinely investigated for fish biodiversity monitoring could facilitate the achievement of more comprehensive inventories. Due to their contribution to local species diversity and the shelter they provide to species valuable for conservation, marine caves should be prioritized for their inclusion not only within future MPAs through the Mediterranean Sea, but also into larger management spatial planning. PMID:25875504

  4. Fish Assemblages of Mediterranean Marine Caves

    PubMed Central

    Bussotti, Simona; Di Franco, Antonio; Francour, Patrice; Guidetti, Paolo

    2015-01-01

    Fish assemblages associated with 14 marine caves and adjacent external rocky reefs were investigated at four Marine Protected Areas (MPAs) along the coasts of Italy. Within the caves sampling was carried out in different sub-habitats: walls, ceilings, bottoms and ends of caves. On the whole, 38 species were recorded inside the 14 caves investigated. Eighteen species were exclusively found inside the caves: they were mainly represented by speleophilic (i.e. species preferentially or exclusively inhabiting caves) gobids (e.g. Didogobius splechtnai) and nocturnal species (e.g. Conger conger). Forty-one species were censused outside, 20 of which were shared with cave habitats. Apogon imberbis was the most common fish found in all 14 caves investigated, followed by Thorogobius ephippiatus (recorded in 13 caves), and Diplodus vulgaris and Scorpaena notata (both censused in 12 caves). Distinct fish assemblages were found between external rocky reefs and the different cave sub-habitats. New data on the distribution of some speleophilic gobids were collected, showing the existence of a pool of species shared by marine caves on a large scale (i.e. hundreds of km). Considering the uniqueness of cave fishes (18 exclusive species and different assemblage structures), the inclusion of marine caves among the habitats routinely investigated for fish biodiversity monitoring could facilitate the achievement of more comprehensive inventories. Due to their contribution to local species diversity and the shelter they provide to species valuable for conservation, marine caves should be prioritized for their inclusion not only within future MPAs through the Mediterranean Sea, but also into larger management spatial planning. PMID:25875504

  5. Lava Flows Cooling: The initial hypothesis

    NASA Astrophysics Data System (ADS)

    Cordonnier, B.; Self, S.; Manga, M.

    2013-12-01

    Many cooling models of lava have one precondition: an instantaneous-thick layer emplacement with a spatially uniform temperature, often as high as the effusion temperature. The cooling is then mostly controlled by conduction and is a function of the thermal parameters and dimensions of the lava flow (most important being thickness). However, many lavas, especially pahoehoe and compound lavas, are not directly emplaced with an established lava thickness but, rather, inflate from their core or result from piling-up of several layers, respectively. In both cases, this leads initially to thin fast-cooling lavas in which the final emplacement temperature may differ strongly from the initial temperature of the liquid lava feeding the flow. Here we investigate both the behavior of inflating flows and superposition layering of lava. With a modified Peclet Number (Pe), where the velocity has been replaced by the inflation rate, we identify the conditions where lavas lose the most of their thermal energy before the final thickness is reached. For a given growth rate, inflating flows are hotter than those that grow through superposition. In the latter case, temperature depends not only with Pe, but also on the discrete lava-layer thickness. A clear quantification of the energy loss during these processes has been established and demonstrates the impact of each of them on the temperature of emplacement. Apart from this simple point, our study raises the question of lava-flow morphology. The two processes described, despite having opposite thermal effects, may be coupled during a single eruptive event. When a lava reaches its emplacement temperature and stops, then the pressing material uphill starts to bifurcate, turn around or superpose the previously emplaced layer. Our Peclet number could be again modified to consider the traditional emplacement condition of a Graetz number of 300. Beyond this point, the inflating process turns into a superposing process and the conditions

  6. Emplacement of Long Lava Flows: Detailed Topography of the Carrizozo Basalt Lava Flow, New Mexico

    NASA Technical Reports Server (NTRS)

    Zimbelman, J. R; Johnston, A. K.

    2000-01-01

    The Carrizozo flow in south-central New Mexico was examined to obtain detailed topography for a long basaltic lava flow. This information will be helpful in evaluating emplacement models for long lava flows.

  7. Characterizing Lava Flows With LiDAR

    NASA Astrophysics Data System (ADS)

    Deligne, N. I.; Cashman, K. V.; Deardorff, N.; Dietterich, H. R.; House, P. K.; Soule, S.

    2009-12-01

    Digital elevation models (DEMs) have been used in volcanology in predictive modeling of lava flow paths, both for assessment of potential hazards and specific predictions of lava flow paths. Topographic analysis of a lava flow is potentially useful for mapping and quantifying flow surface morphologies, which in turn can be used to determine flow emplacement conditions, such as effusion rate, steadiness of flow, and interactions with pre-existing topography and surface water. However, this has been limited in application because of the coarse resolution of most DEMs. In recent years, use of Light Detection and Ranging (LiDAR) airborne laser altimetry, capable of producing high resolution (≤ 1 meter) DEMs, has become increasingly common in the geomorphic and mapping community. However, volcanologists have made little use of airborne LiDAR. Here we compare information obtained using field observations and standard (10 meter) DEMs against LiDAR high resolution DEMs to assess the usefulness, capabilities, and limitations of LiDAR as applicable to lava flows. We compare morphologic characteristics of five lava flows of different compositions, tectonic settings, flow extents, slopes, and eruption duration: (1) 1984 Mauna Loa lava flow, Hawaii; (2) December 1974 Kilauea lava flow, Hawaii; (3) c. 1600 ybp Collier Cone lava flow, central Oregon Cascades; (4) Holocene lava flows from the Sand Mountain volcanic chain, central Oregon Cascades; and (5) Pleistocene lava flows along the Owyhee River, eastern Oregon basin and range. These lava flows range in composition from basalt to andesite, and have eruption durations ranging from 6 hours (observed) to years (inferred). We measure channel width, levee and flow front heights, compression ridge amplitude, wavelength and tumuli dimensions, and surface roughness. For all but the smallest scale features, LiDAR is easily used to quantify these features, which often is impossible or technically challenging to do in the field, while

  8. What factors control superficial lava dome explosivity?

    PubMed Central

    Boudon, Georges; Balcone-Boissard, Hélène; Villemant, Benoît; Morgan, Daniel J.

    2015-01-01

    Dome-forming eruption is a frequent eruptive style and a major hazard on numerous volcanoes worldwide. Lava domes are built by slow extrusion of degassed, viscous magma and may be destroyed by gravitational collapse or explosion. The triggering of lava dome explosions is poorly understood: here we propose a new model of superficial lava-dome explosivity based upon a textural and geochemical study (vesicularity, microcrystallinity, cristobalite distribution, residual water contents, crystal transit times) of clasts produced by key eruptions. Superficial explosion of a growing lava dome may be promoted through porosity reduction caused by both vesicle flattening due to gas escape and syn-eruptive cristobalite precipitation. Both processes generate an impermeable and rigid carapace allowing overpressurisation of the inner parts of the lava dome by the rapid input of vesiculated magma batches. The relative thickness of the cristobalite-rich carapace is an inverse function of the external lava dome surface area. Explosive activity is thus more likely to occur at the onset of lava dome extrusion, in agreement with observations, as the likelihood of superficial lava dome explosions depends inversely on lava dome volume. This new result is of interest for the whole volcanological community and for risk management. PMID:26420069

  9. Utility of Lava Tubes on Other Worlds

    NASA Technical Reports Server (NTRS)

    Walden, Bryce E.; Billings, T. L.; York, Cheryl Lynn; Gillett, S. L.; Herbert, M. V.

    1998-01-01

    On Mars, as on Earth, lava tubes are found in the extensive lava fields associated with shield volcanism. Lunar lava-tube traces are located near mare-highland boundaries, giving access to a variety of minerals and other resources, including steep slopes, prominent heights for local area communications and observation, large-surface areas in shade, and abundant basalt plains suitable for landing sites, mass-drivers, surface transportation, regolith harvesting, and other uses. Methods for detecting lava tubes include visual observations of collapse trenches and skylights, ground-penetrating radar, gravimetry, magnetometry, seismography, atmospheric effects, laser, lidar, infrared, and human or robotic exploration.

  10. Accelerator 14C dates for early upper paleolithic (basal Aurignacian) at El Castillo Cave (Spain)

    USGS Publications Warehouse

    Valdes, V.C.; Bischoff, J.L.

    1989-01-01

    Three fragments of charcoal taken from different parts of the lowermost bed containing Aurignacian artifacts at El Castillo Cave yielded AMS dates of 37??7 (?? 1??8) ka bp, 38??5 (?? 1??8) ka bp, and 40??0 (?? 2??1) ka bp (average 38??7 ?? 1??9 ka bp). These dates are almost identical to new AMS dates from l'Arbreda cave in Catalunya on the same cultural horizon (average 38??5 ?? 1??0 ka bp) and are significantly older than the earliest dates for Aurignacian industries in the Aquitaine and in other parts of Central and Western Europe. ?? 1989.

  11. Propagation style controls lava-snow interactions.

    PubMed

    Edwards, B R; Belousov, A; Belousova, M

    2014-01-01

    Understanding interactions between volcanic eruptions and the cryosphere (a.k.a. glaciovolcanism) is important for climate reconstructions as well as for hazard mitigation at ice-clad volcanoes. Here we present unique field observations of interactions between snowpack and advancing basaltic lava flows during the 2012-13 eruption at Tolbachik volcano, Kamchatka, Russia. Our observations show that lava-snow heat transfer is slow, and that styles of lava propagation control snowpack responses. 'A'a and sheet lava flows advance in a rolling caterpillar-track motion on top of the rigid, snowpack substrate with minor lava-snow interaction. In contrast, pahoehoe lava propagates by inflation of lobes beneath/inside the snowpack, producing rigorous lava-snow interaction via meltwater percolation down into the incandescent lava causing production of voluminous steam, rapid surface cooling and thermal shock fragmentation. The textures produced by pahoehoe-snowpack interactions are distinctive and, where observed at other sites, can be used to infer syn-eruption seasonality and climatic conditions. PMID:25514031

  12. Propagation style controls lava-snow interactions.

    PubMed

    Edwards, B R; Belousov, A; Belousova, M

    2014-01-01

    Understanding interactions between volcanic eruptions and the cryosphere (a.k.a. glaciovolcanism) is important for climate reconstructions as well as for hazard mitigation at ice-clad volcanoes. Here we present unique field observations of interactions between snowpack and advancing basaltic lava flows during the 2012-13 eruption at Tolbachik volcano, Kamchatka, Russia. Our observations show that lava-snow heat transfer is slow, and that styles of lava propagation control snowpack responses. 'A'a and sheet lava flows advance in a rolling caterpillar-track motion on top of the rigid, snowpack substrate with minor lava-snow interaction. In contrast, pahoehoe lava propagates by inflation of lobes beneath/inside the snowpack, producing rigorous lava-snow interaction via meltwater percolation down into the incandescent lava causing production of voluminous steam, rapid surface cooling and thermal shock fragmentation. The textures produced by pahoehoe-snowpack interactions are distinctive and, where observed at other sites, can be used to infer syn-eruption seasonality and climatic conditions.

  13. Propagation style controls lava-snow interactions

    NASA Astrophysics Data System (ADS)

    Edwards, B. R.; Belousov, A.; Belousova, M.

    2014-12-01

    Understanding interactions between volcanic eruptions and the cryosphere (a.k.a. glaciovolcanism) is important for climate reconstructions as well as for hazard mitigation at ice-clad volcanoes. Here we present unique field observations of interactions between snowpack and advancing basaltic lava flows during the 2012-13 eruption at Tolbachik volcano, Kamchatka, Russia. Our observations show that lava-snow heat transfer is slow, and that styles of lava propagation control snowpack responses. ‧A‧a and sheet lava flows advance in a rolling caterpillar-track motion on top of the rigid, snowpack substrate with minor lava-snow interaction. In contrast, pahoehoe lava propagates by inflation of lobes beneath/inside the snowpack, producing rigorous lava-snow interaction via meltwater percolation down into the incandescent lava causing production of voluminous steam, rapid surface cooling and thermal shock fragmentation. The textures produced by pahoehoe-snowpack interactions are distinctive and, where observed at other sites, can be used to infer syn-eruption seasonality and climatic conditions.

  14. Emplacement of Xenolith Nodules in the Kaupulehu Lava Flow, Hualalai Volcano, Hawaii

    NASA Technical Reports Server (NTRS)

    Guest, J. E.; Spudis, P. D.; Greeley, R.; Taylor, G. J.; Baloga, S. M.

    1995-01-01

    The basaltic Kaupulehu 1800-1801 lava flow of Hualalai Volcano, Hawaii contains abundant ultramafic xenoliths. Many of these xenoliths occur as bedded layers of semi-rounded nodules, each thinly coated with a veneer (typically 1 mm thick) of lava. The nodule beds are analogous to cobble deposits of fluvial sedimentary systems. Although several mechanisms have been proposed for the formation of the nodule beds, it was found that, at more than one locality, the nodule beds are overbank levee deposits. The geological occurrence of the nodules, certain diagnostic aspects of the flow morphology and consideration of the inferred emplacement process indicate that the Kaupulehu flow had an exceptionally low viscosity on eruption and that the flow of the lava stream was extremely rapid, with flow velocities of at least 10 m/s (more than 40 km/h. This flow is the youngest on Hualalai Volcano and future eruptions of a similar type would pose considerable hazard to life as well as property.

  15. From Cave Walls to Clay Images

    ERIC Educational Resources Information Center

    Stone, Julie

    2004-01-01

    About 15,000 BC, the bison and other animals roamed the land and cave people, in their spare time, found colorful, chalky rocks with which to play. Over the course of time, they found that the chalky rocks would rub off on the cave walls, thus cave paintings and the pursuit of art was born. This article describes one fourth-grade classroom's…

  16. Computer Assisted Virtual Environment - CAVE

    SciTech Connect

    Erickson, Phillip; Podgorney, Robert; Weingartner, Shawn; Whiting, Eric

    2014-01-14

    Research at the Center for Advanced Energy Studies is taking on another dimension with a 3-D device known as a Computer Assisted Virtual Environment. The CAVE uses projection to display high-end computer graphics on three walls and the floor. By wearing 3-D glasses to create depth perception and holding a wand to move and rotate images, users can delve into data.

  17. Computer Assisted Virtual Environment - CAVE

    ScienceCinema

    Erickson, Phillip; Podgorney, Robert; Weingartner, Shawn; Whiting, Eric

    2016-07-12

    Research at the Center for Advanced Energy Studies is taking on another dimension with a 3-D device known as a Computer Assisted Virtual Environment. The CAVE uses projection to display high-end computer graphics on three walls and the floor. By wearing 3-D glasses to create depth perception and holding a wand to move and rotate images, users can delve into data.

  18. Dynamics of the Mount Nyiragongo lava lake

    NASA Astrophysics Data System (ADS)

    Burgi, P.-Y.; Darrah, T. H.; Tedesco, D.; Eymold, W. K.

    2014-05-01

    The permanent and presently rising lava lake at Mount Nyiragongo constitutes a major potential geological hazard to the inhabitants of the Virunga volcanic region in the Democratic Republic of Congo (DRC) and Rwanda. Based on two field campaigns in June 2010 and 2011, we estimate the lava lake level from the southeastern crater rim (~400 m diameter) and lava lake area (~46,550 m2), which constrains, respectively, the lava lake volume (~9 × 106 m3) and volume flow rate needed to keep the magma in a molten state (0.6 to 3.5 m3 s-1). A bidirectional magma flow model, which includes the characterization of the conduit diameter and funnel-shaped lava lake geometry, is developed to constrain the amount of magma intruded/emplaced within the magmatic chamber and rift-related structures that extend between Mount Nyiragongo's volcanic center and the city of Goma, DRC, since Mount Nyiragongo's last eruption (17 January 2002). Besides matching field data of the lava lake level covering the period 1977 to 2002, numerical solutions of the model indicate that by 2022, 20 years after the January 2002 eruption, between 300 and 1700 × 106 m3 (0.3 to 1.7 km3) of magma could have intruded/emplaced underneath the edifice, and the lava lake volume could exceed 15 × 106 m3.

  19. Lava flow texture LiDAR signatures

    NASA Astrophysics Data System (ADS)

    Whelley, P.; Garry, W. B.; Scheidt, S. P.; Irwin, R. P., III; Fox, J.; Bleacher, J. E.; Hamilton, C. W.

    2014-12-01

    High-resolution point clouds and digital elevation models (DEMs) are used to investigate lava textures on the Big Island of Hawaii. An experienced geologist can distinguish fresh or degraded lava textures (e.g., blocky, a'a and pahoehoe) visually in the field. Lava texture depends significantly on eruption conditions, and it is therefore instructive, if accurately determined. In places where field investigations are prohibitive (e.g., Mercury, Venus, the Moon, Mars, Io and remote regions on Earth) lava texture must be assessed from remote sensing data. A reliable method for differentiating lava textures in remote sensing data remains elusive. We present preliminary results comparing properties of lava textures observed in airborne and terrestrial Light Detection and Ranging (LiDAR) data. Airborne data, in this study, were collected in 2011 by Airborne 1 Corporation and have a ~1m point spacing. The authors collected the terrestrial data during a May 2014 field season. The terrestrial scans have a heterogeneous point density. Points close to the scanner are 1 mm apart while 200 m in the distance points are 10 cm apart. Both platforms offer advantages and disadvantages beyond the differences in scale. Terrestrial scans are a quantitative representation of what a geologist sees "on the ground". Airborne scans are a point of view routinely imaged by other remote sensing tools, and can therefore be quickly compared to complimentary data sets (e.g., spectral scans or image data). Preliminary results indicate that LiDAR-derived surface roughness, from both platforms, is useful for differentiating lava textures, but at different spatial scales. As all lava types are quite rough, it is not simply roughness that is the most advantageous parameter; rather patterns in surface roughness can be used to differentiate lava surfaces of varied textures. This work will lead to faster and more reliable volcanic mapping efforts for planetary exploration as well as terrestrial

  20. A Preliminary Geophysical Study Involving Remote Sensing at the Archaeological Site Trinchera Cave, Colorado

    NASA Astrophysics Data System (ADS)

    McCarthy, L.; Bank, C.

    2003-12-01

    Resistivity, magnetic, seismic, and geodetic surveys were performed at Trinchera cave, an archaeological site ˜50 km east of Trinidad, Colorado, in order to locate the foundation walls of an ancient jacal structure. This structure, a shelter built during the Apishapa phase (earlier than 750 years before present), was reported - and backfilled - during a 1974 excavation; recent excavations have failed to again find it. The cave is a ˜8 m high overhang, the bottom of which marks the contact between the Dakota formation (yellowish-brown, fine-grained sandstone) and the underlying Purgatoire formation (bedded, organic-rich shale). The foundation was reported to be made of blocks of sandstone surrounded by cave fill/soil that is estimated to be 1.5 m thick in the cave. A total station survey mapped the topography beneath the overhang (the cave, ˜30 by 8 m) and within the adjacent creek. This part of the study should be useful to tie together future archaeological and geophysical work. Our magnetic map of the area is inconclusive due to the presence of metallic pipes left at the site by previous excavations and because of the overhang. Seismic refraction tests yielded varying thicknesses of the cave fill (0.7-2.3 m); however we experienced problems with the equipment in the field and realized that a 1-D model is insufficient to explain the data. A future reflection experiment might produce more useful seismic data. Our most reliable results were obtained by resistivity profiling. They show a more resistive structure in the SW part of the cave, about 1 m from the overhang and at a model depth of 2 m. We interpret this as the `lost' foundation.

  1. Early life recorded in archean pillow lavas.

    PubMed

    Furnes, Harald; Banerjee, Neil R; Muehlenbachs, Karlis; Staudigel, Hubert; de Wit, Maarten

    2004-04-23

    Pillow lava rims from the Mesoarchean Barberton Greenstone Belt in South Africa contain micrometer-scale mineralized tubes that provide evidence of submarine microbial activity during the early history of Earth. The tubes formed during microbial etching of glass along fractures, as seen in pillow lavas from recent oceanic crust. The margins of the tubes contain organic carbon, and many of the pillow rims exhibit isotopically light bulk-rock carbonate delta13C values, supporting their biogenic origin. Overlapping metamorphic and magmatic dates from the pillow lavas suggest that microbial life colonized these subaqueous volcanic rocks soon after their eruption almost 3.5 billion years ago. PMID:15105498

  2. Early life recorded in archean pillow lavas.

    PubMed

    Furnes, Harald; Banerjee, Neil R; Muehlenbachs, Karlis; Staudigel, Hubert; de Wit, Maarten

    2004-04-23

    Pillow lava rims from the Mesoarchean Barberton Greenstone Belt in South Africa contain micrometer-scale mineralized tubes that provide evidence of submarine microbial activity during the early history of Earth. The tubes formed during microbial etching of glass along fractures, as seen in pillow lavas from recent oceanic crust. The margins of the tubes contain organic carbon, and many of the pillow rims exhibit isotopically light bulk-rock carbonate delta13C values, supporting their biogenic origin. Overlapping metamorphic and magmatic dates from the pillow lavas suggest that microbial life colonized these subaqueous volcanic rocks soon after their eruption almost 3.5 billion years ago.

  3. Modeling and analysis of caves using voxelization

    NASA Astrophysics Data System (ADS)

    Szeifert, Gábor; Szabó, Tivadar; Székely, Balázs

    2014-05-01

    Although there are many ways to create three dimensional representations of caves using modern information technology methods, modeling of caves has been challenging for researchers for a long time. One of these promising new alternative modeling methods is using voxels. We are using geodetic measurements as an input for our voxelization project. These geodetic underground surveys recorded the azimuth, altitude and distance of corner points of cave systems relative to each other. The diameter of each cave section is estimated from separate databases originating from different surveys. We have developed a simple but efficient method (it covers more than 99.9 % of the volume of the input model on the average) to convert these vector-type datasets to voxels. We have also developed software components to make visualization of the voxel and vector models easier. Since each cornerpoint position is measured relative to another cornerpoints positions, propagation of uncertainties is an important issue in case of long caves with many separate sections. We are using Monte Carlo simulations to analyze the effect of the error of each geodetic instrument possibly involved in a survey. Cross-sections of the simulated three dimensional distributions show, that even tiny uncertainties of individual measurements can result in high variation of positions that could be reduced by distributing the closing errors if such data are available. Using the results of our simulations, we can estimate cave volume and the error of the calculated cave volume depending on the complexity of the cave. Acknowledgements: the authors are grateful to Ariadne Karst and Cave Exploring Association and State Department of Environmental and Nature Protection of the Hungarian Ministry of Rural Development, Department of National Parks and Landscape Protection, Section Landscape and Cave Protection and Ecotourism for providing the cave measurement data. BS contributed as an Alexander von Humboldt Research

  4. Geomagnetic polarity zones for icelandic lavas

    USGS Publications Warehouse

    Dagley, P.; Wilson, R.L.; Ade-Hall, J. M.; Walker, G.P.L.; Haggerty, S.E.; Sigurgeirsson, T.; Watkins, N.D.; Smith, P.J.; Edwards, J.; Grasty, R.L.

    1967-01-01

    Analysis of cores collected from a sequence of lavas in Eastern Iceland has made possible an accurate calculation of the average rate of reversal of the Earth's magnetic field. ?? 1967 Nature Publishing Group.

  5. Taylor instability in rhyolite lava flows

    NASA Technical Reports Server (NTRS)

    Baum, B. A.; Krantz, W. B.; Fink, J. H.; Dickinson, R. E.

    1989-01-01

    A refined Taylor instability model is developed to describe the surface morphology of rhyolite lava flows. The effect of the downslope flow of the lava on the structures resulting from the Taylor instability mechanism is considered. Squire's (1933) transformation is developed for this flow in order to extend the results to three-dimensional modes. This permits assessing why ridges thought to arise from the Taylor instability mechanism are preferentially oriented transverse to the direction of lava flow. Measured diapir and ridge spacings for the Little and Big Glass Mountain rhyolite flows in northern California are used in conjunction with the model in order to explore the implications of the Taylor instability for flow emplacement. The model suggests additional lava flow features that can be measured in order to test whether the Taylor instability mechanism has influenced the flows surface morphology.

  6. Lunar lava tube radiation safety analysis.

    PubMed

    De Angelis, Giovanni; Wilson, J W; Clowdsley, M S; Nealy, J E; Humes, D H; Clem, J M

    2002-12-01

    For many years it has been suggested that lava tubes on the Moon could provide an ideal location for a manned lunar base, by providing shelter from various natural hazards, such as cosmic radiation, meteorites, micrometeoroids, and impact crater ejecta, and also providing a natural environmental control, with a nearly constant temperature, unlike that of the lunar surface showing extreme variation in its diurnal cycle. An analysis of radiation safety issues on lunar lava tubes has been performed by considering radiation from galactic cosmic rays (GCR) and Solar Particle Events (SPE) interacting with the lunar surface, modeled as a regolith layer and rock. The chemical composition has been chosen as typical of the lunar regions where the largest number of lava tube candidates are found. Particles have been transported all through the regolith and the rock, and received particles flux and doses have been calculated. The radiation safety of lunar lava tubes environments has been demonstrated.

  7. Determination of eruption temperature of Io's lavas using lava tube skylights

    NASA Astrophysics Data System (ADS)

    Davies, Ashley Gerard; Keszthelyi, Laszlo P.; McEwen, Alfred S.

    2016-11-01

    Determining the eruption temperature of Io's dominant silicate lavas would constrain Io's present interior state and composition. We have examined how eruption temperature can be estimated at lava tube skylights through synthesis of thermal emission from the incandescent lava flowing within the lava tube. Lava tube skylights should be present along Io's long-lived lava flow fields, and are attractive targets because of their temporal stability and the narrow range of near-eruption temperatures revealed through them. We conclude that these skylights are suitable and desirable targets (perhaps the very best targets) for the purposes of constraining eruption temperature, with a 0.9:0.7-μm radiant flux ratio ≤6.3 being diagnostic of ultramafic lava temperatures. Because the target skylights may be small - perhaps only a few m or 10 s of m across - such observations will require a future Io-dedicated mission that will obtain high spatial resolution (< 100 m/pixel), unsaturated observations of Io's surface at multiple wavelengths in the visible and near-infrared, ideally at night. In contrast to observations of lava fountains or roiling lava lakes, where accurate determination of surface temperature distribution requires simultaneous or near-simultaneous (< 0.1 s) observations at different wavelengths, skylight thermal emission data are superior for the purposes of temperature derivation, as emission is stable on much longer time scales (minutes, or longer), so long as viewing geometry does not greatly change during that time.

  8. Bed bugs.

    PubMed

    Foulke, Galen T; Anderson, Bryan E

    2014-09-01

    The term bed bug is applied to 2 species of genus Cimex: lectularius describes the common or temperate bed bug, and hemipterus its tropical cousin. Cimex lectularius is aptly named; its genus and species derive from the Latin words for bug and bed, respectively. Though the tiny pest is receiving increased public attention and scrutiny, the bed bug is hardly a new problem. PMID:25577850

  9. Gravity for Detecting Caves: Airborne and Terrestrial Simulations Based on a Comprehensive Karstic Cave Benchmark

    NASA Astrophysics Data System (ADS)

    Braitenberg, Carla; Sampietro, Daniele; Pivetta, Tommaso; Zuliani, David; Barbagallo, Alfio; Fabris, Paolo; Rossi, Lorenzo; Fabbri, Julius; Mansi, Ahmed Hamdi

    2016-04-01

    Underground caves bear a natural hazard due to their possible evolution into a sink hole. Mapping of all existing caves could be useful for general civil usages as natural deposits or tourism and sports. Natural caves exist globally and are typical in karst areas. We investigate the resolution power of modern gravity campaigns to systematically detect all void caves of a minimum size in a given area. Both aerogravity and terrestrial acquisitions are considered. Positioning of the gravity station is fastest with GNSS methods the performance of which is investigated. The estimates are based on a benchmark cave of which the geometry is known precisely through a laser-scan survey. The cave is the Grotta Gigante cave in NE Italy in the classic karst. The gravity acquisition is discussed, where heights have been acquired with dual-frequency geodetic GNSS receivers and Total Station. Height acquisitions with non-geodetic low-cost receivers are shown to be useful, although the error on the gravity field is larger. The cave produces a signal of -1.5 × 10-5 m/s2, with a clear elliptic geometry. We analyze feasibility of airborne gravity acquisitions for the purpose of systematically mapping void caves. It is found that observations from fixed wing aircraft cannot resolve the caves, but observations from slower and low-flying helicopters or drones do. In order to detect the presence of caves the size of the benchmark cave, systematic terrestrial acquisitions require a density of three stations on square 500 by 500 m2 tiles. The question has a large impact on civil and environmental purposes, since it will allow planning of urban development at a safe distance from subsurface caves. The survey shows that a systematic coverage of the karst would have the benefit to recover the position of all of the greater existing void caves.

  10. Management issues in a Tasmanian tourist cave: potential microclimatic impacts of cave modifications.

    PubMed

    Russell, Mick J; MacLean, Victoria L

    2008-05-01

    Caves can be difficult to navigate and often require physical modification to allow easy access for visitors. Single entrance caves double the access impact of each visitor. Visitors in tourist caves have direct physical effects such as the introduction of concrete and steel structures; transport of mud, dust, and nutrients; installation of lights and the exhalation of water vapour and carbon dioxide into the air. Indirect physical effects include alteration of the microclimate, both through physical modifications that change the ventilation regime and through the presence of visitors leading to changes in temperature, humidity and CO2 within the cave environment. Anthropomorphic changes to cave physical environments to aid access or to reduce backtracking can have adverse effects on the internal microclimate of cave systems with subsequent changes to the cave environment affecting the quality of decorations and cave art and the diversity of cave fauna. Although often stated that caves operate at or near a constant temperature, closer examination indicates that cave temperatures are neither static nor constant. The degree of variation depends largely on the structure and physical characteristics of the cave. Air temperature and humidity gradients between the inside and outside cave environment can result in air density differences, which create airflow, which will in turn affect the cave microclimate. As part of the development of a management framework for King Solomons Cave, Tasmania, a study of the microclimate was carried out on behalf of Tasmanian Parks and Wildlife Service. Analysis of the variables showed significant differences in air temperature within each site and between sites. These differences range from 4 degrees C variation at one site to 0 degrees C at another site. The data were used to model potential airflow between the cave and the external environment. Results indicate that part of the cave is dominated by airflow between the chimney and the

  11. Management issues in a Tasmanian tourist cave: potential microclimatic impacts of cave modifications.

    PubMed

    Russell, Mick J; MacLean, Victoria L

    2008-05-01

    Caves can be difficult to navigate and often require physical modification to allow easy access for visitors. Single entrance caves double the access impact of each visitor. Visitors in tourist caves have direct physical effects such as the introduction of concrete and steel structures; transport of mud, dust, and nutrients; installation of lights and the exhalation of water vapour and carbon dioxide into the air. Indirect physical effects include alteration of the microclimate, both through physical modifications that change the ventilation regime and through the presence of visitors leading to changes in temperature, humidity and CO2 within the cave environment. Anthropomorphic changes to cave physical environments to aid access or to reduce backtracking can have adverse effects on the internal microclimate of cave systems with subsequent changes to the cave environment affecting the quality of decorations and cave art and the diversity of cave fauna. Although often stated that caves operate at or near a constant temperature, closer examination indicates that cave temperatures are neither static nor constant. The degree of variation depends largely on the structure and physical characteristics of the cave. Air temperature and humidity gradients between the inside and outside cave environment can result in air density differences, which create airflow, which will in turn affect the cave microclimate. As part of the development of a management framework for King Solomons Cave, Tasmania, a study of the microclimate was carried out on behalf of Tasmanian Parks and Wildlife Service. Analysis of the variables showed significant differences in air temperature within each site and between sites. These differences range from 4 degrees C variation at one site to 0 degrees C at another site. The data were used to model potential airflow between the cave and the external environment. Results indicate that part of the cave is dominated by airflow between the chimney and the

  12. The conservation of Britain's limestone cave resource

    NASA Astrophysics Data System (ADS)

    Hardwick, P.; Gunn, J.

    1996-10-01

    Limestone caves are an important scientific and recreational resource in Britain. During the mid- to late 1970s, cavers and statutory conservation bodies cooperated in a review of cave resources which resulted in the designation of 48 caves or cave areas as Sites of Special Scientific Interest (SSSI). During the same period, the Wildlife and Countryside Act 1981 was introduced to provide more effective planning controls on activities such as agriculture carried out within SSSI boundaries. In one case, at Priddy in the Mendip Hills of Somerset, landowners prevented access to a number of caves in protest over the new, tougher restrictions on agriculture. Faced with the closure, and perceiving that their recreational use of caves might also be controlled, local cavers joined the landowners in opposing the proposals for SSSI designation. As a result the proposals were reviewed, three caves were excluded from the site and controls on the remaining area were relaxed. The case emphasized a need for an effective system to take account of all factors affecting cave conservation, a need which has led to a more constructive dialogue between nature conservation bodies, caver organizations and other interested parties.

  13. Keck Geology Consortium Lava Project: Undergraduate Research Linking Natural and Experimental Basaltic Lava Flows

    NASA Astrophysics Data System (ADS)

    Karson, J. A.; Hazlett, R. W.; Wysocki, R.; Bromfield, M. E.; Browne, N. C.; Davis, N. C.; Pelland, C. G.; Rowan, W. L.; Warner, K. A.

    2014-12-01

    Undergraduate students in the Keck Geology Consortium Lava Project participated in a month-long investigation of features of basaltic lava flows from two very different perspectives. The first half of the project focused on field relations in basaltic lava flows from the 1984 Krafla Fires eruption in northern Iceland. Students gained valuable experience in the collection of observations and samples in the field leading to hypotheses for the formation of selected features related to lava flow dynamics. Studies focused on a wide range of features including: morphology and heat loss in lava tubes (pyroducts), growth and collapse of lava ponds and overflow deposits, textural changes of lava falls (flow over steep steps), spaced spatter cones from flows over wet ground, and anisotropy of magnetic susceptibility related to flow kinematics. In the second half of the program students designed, helped execute, documented, and analyzed features similar to those they studied in the field with large-scale (50-250 kg) basaltic lava flows created in the Syracuse University Lava Project (http://lavaproject.syr.edu). Data collected included video from multiple perspectives, infrared thermal (FLIR) images, still images, detailed measurements of flow dimensions and rates, and samples for textural and magnetic analyses. Experimental lava flow features provided critical tests of hypotheses generated in the field and a refined understanding of the behavior and final morphology of basaltic lava flows. The linked field and experimental studies formed the basis for year-long independent research projects under the supervision of their faculty mentors, leading to senior theses at the students' respective institutions.

  14. Flood lavas on Earth, Io and Mars

    USGS Publications Warehouse

    Keszthelyi, L.; Self, S.; Thordarson, T.

    2006-01-01

    Flood lavas are major geological features on all the major rocky planetary bodies. They provide important insight into the dynamics and chemistry of the interior of these bodies. On the Earth, they appear to be associated with major and mass extinction events. It is therefore not surprising that there has been significant research on flood lavas in recent years. Initial models suggested eruption durations of days and volumetric fluxes of order 107 m3 s-1 with flows moving as turbulent floods. However, our understanding of how lava flows can be emplaced under an insulating crust was revolutionized by the observations of actively inflating pahoehoe flows in Hawaii. These new ideas led to the hypothesis that flood lavas were emplaced over many years with eruption rates of the order of 104 m3 s-1. The field evidence indicates that flood lava flows in the Columbia River Basalts, Deccan Traps, Etendeka lavas, and the Kerguelen Plateau were emplaced as inflated pahoehoe sheet flows. This was reinforced by the observation of active lava flows of ??? 100 km length on Io being formed as tube-fed flow fed by moderate eruption rates (102-103 m3 s-1). More recently it has been found that some flood lavas are also emplaced in a more rapid manner. New high-resolution images from Mars revealed 'platy-ridged' flood lava flows, named after the large rafted plates and ridges formed by compression of the flow top. A search for appropriate terrestrial analogues found an excellent example in Iceland: the 1783-1784 Laki Flow Field. The brecciated Laki flow top consists of pieces of pahoehoe, not aa clinker, leading us to call this 'rubbly pahoehoe'. Similar flows have been found in the Columbia River Basalts and the Kerguelen Plateau. We hypothesize that these flows form with a thick, insulating, but mobile crust, which is disrupted when surges in the erupted flux are too large to maintain the normal pahoehoe mode of emplacement Flood lavas emplaced in this manner could have

  15. Investigating lava-substrate interactions through flow experiments with syrup, wax, and molten basalt

    NASA Astrophysics Data System (ADS)

    Rumpf, M. E.; Lev, E.

    2015-12-01

    Among the many factors influencing the complex process of lava flow emplacement, the interaction with the substrate onto which flow is emplaced plays a central role. Lava flows are rarely emplaced onto smooth or regular surfaces. For example, at Kīlauea Volcano, Hawai'i, lava flows regularly flow over solid rock, vegetation, basaltic or silica sand, and man-made materials, including asphalt and concrete. In situ studies of lava-substrate interactions are inherently difficult, and often dangerous, to carry-out, requiring the design of controllable laboratory experiments. We investigate the effects of substrate grain size, cohesion, and roughness on flow mobility and morphology through a series of flow experiments using analog materials and molten basalt. We have developed a series of experiments that allow for adjustable substrate parameters and analyze their effects on lava flow emplacement. The first set of experiments are performed at the Fluids Mechanics Laboratory at the Lamont-Doherty Earth Observatory and focus on two analog materials: polyethylene glycol (PEG), a commercially available wax, and corn syrup. The fluids were each extruded onto a series of scaled substrate beds to replicate the emplacement of lava in a natural environment. Preliminary experiments demonstrated that irregular topography, particularly topography with a height amplitude similar to that of the flow itself, can affect flow morphology, width, and velocity by acting as local barriers or culverts to the fluid. This is expected from observations of fluid flow in natural environments. A follow-up set of experiments will be conducted in Fall 2015 at the Syracuse University (SU) Lava Project Lab. In this set, we will pour molten basalt directly onto a series of substrates representing natural environments found on the Earth and other rocky bodies in the Solar System. These experiments will allow for analysis of the effects of basaltic composition and high temperatures on lava-substrate heat

  16. Characteristics of a young lava-hyaloclastite sheet, Snaebylisheidi, Iceland

    NASA Astrophysics Data System (ADS)

    White, J. D.; Gorny, C. F.; Gudmundsson, M. T.

    2009-12-01

    Extensive sheets of hyaloclastite volcaniclastic debris, coupled with and intruded by largely underlying layers of coherent basalt, are common in the Sida area of southeastern Iceland. They were initially interpreted as submarine deposits, but have recently been re-interpreted as nonmarine deposits formed in the presence of glaciers. Detailed interpretation of the units has been challenging, because their source areas are not preserved. A younger deposit of the same type forms an elongate flat-topped ridge in the Snaebylisheidi area. Its volume of ca. 35 cubic km is similar to that of the larger Sida units, its source area is preserved, and parts of the deposit remain unlithified. Our initial investigation reveals that the source area is dominated by clastic deposits. There is no evidence for a source edifice of pillow or sheet lavas, but there are extensive low-level intrusions near the base, and a plexus of smaller high-level intrusions showing evidence of high viscosities during emplacement. Isolated pillows and other fluidal juvenile clasts near the source lie within matrices of highly vesicular ash and lapilli, or of mixed vesicular and dense glassy fragments. Downstream in the unit, deposits are dominated by dense clasts, and these can in places be demonstrated to have been derived locally from the underlying to intruding basalt sheet. Larger dense clasts are commonly highly irregular, vuggy, and composite; in places many are rolled into subspherical forms enclosing matrix material comprising dense angular glass fragments. The clastic part of the unit has an upper subunit dominated by well-developed bedding in complex geometries with multiple internal truncation surfaces. Lower subunits include thick structureless to alignment-bedded layers, along with intrusion-dominated zones. Soft-sediment deformation is ubiquitous along the edges of the deposit, with many layers broken and tilted to subvertical inclinations. Taken together, these features indicate that

  17. Increased cave dwelling reduces the ability of cave crickets to resist dehydration.

    PubMed

    Yoder, Jay A; Benoit, Joshua B; LaCagnin, Michael J; Hobbs, Horton H

    2011-07-01

    Differential strategies for maintaining water balance are reported for female adults of three cave crickets Hadenoecus cumberlandicus, H. opilionoides and H. jonesi, a species replacement series along the Cumberland Plateau in the southeastern United States. The distribution of H. cumberlandicus is much broader than the range of H. opilionoides, which is much smaller in body size, and that of H. jonesi, which possesses enhanced troglomorphic (cave dwelling) characteristics. Due to high net transpiration (water loss) rates and increased activation energies, H. jonesi and H. opilionoides are more susceptible to dehydration than H. cumberlandicus. To avoid dehydration, H. opilionoides and H. jonesi require more moisture than H. cumberlandicus to counter their higher rates of water loss. The heightened reliance on moisture likely indicates that the more troglomorphic H. jonesi and smaller H. opilionoides are required to spend more time in the moist cave region. Reliance on the cave for H. cumberlandicus is presumably less, allowing them to function in epigean habitats for longer periods and disperse to nearby caves, likely accounting for the more expansive distribution of this cricket. While in the cave habitat, cave crickets are exposed to water-saturated conditions, reducing the pressure of dehydration stress the longer a species remains in this wet environment. This reduced pressure leads to higher water loss rates as cave confinement increases. We conclude that increasing water loss rates associated with increasing troglomorphic adaptation in cave crickets is a side effect of extended residence in stable moist cave environments. PMID:21327632

  18. Mapping lava flow hazards using computer simulation

    SciTech Connect

    Wadge, G.; Young, P.A.V.; Mckendrick, I.J.

    1994-01-01

    Computer simulations of the paths of flowing lava are achieved using a program, FLOWFRONT, that describes the behavior of flow and digital models of the terrain. Two methods of application of simulations of the hazards posed by lava flows are described. The first, deterministic, method requires that program parameters such as vent position, minimum flow thickness, and thickness/slope relationship be based on the ambient eruptive conditions so that the future course of a specific lava flow can be simulated. This is illustrated using retrospective modeling of the first 21 days of the eruption of an andesitic lava flow at Lonquimay volcano, Chile, in 1988-1989. The usefulness of this method for real-time predictive modeling is likely to be limited by the lack of accurate field data on flow characteristics, the simple nature of the model, and the sensitivity to parameter choice of the final planimetric form of the model flow. The second application is probabilistic in nature and creates a map of the likelihood of inundation by lava flows that is useful for long-term land use planning. This method uses the historical record of past eruptions to constrain a series of Monte Carlo simulations and is illustrated using data from Etna volcano in Sicily. A multivariate statistical analysis of nine parameters for the 1763-1989 eruption catalog using simulated annealing permitted a classification of Etna`s flank eruptions into two types: A and B. Type A eruptions are short-lived and produce linear lava flows; type B eruptions are long-lived, and produce lava flows that are much broader in shape, and their vents are restricted to the eastern flank of the volcano.

  19. Mapping of Daedalia Planum Lava Field

    NASA Astrophysics Data System (ADS)

    Giacomini, Lorenza; Carli, Cristian; Massironi, Matteo; Pasquarè, Giorgio; Sgavetti, Maria

    2010-05-01

    Daedalia Planum is one of the Tharsis volcanic plains and is located southwest of the Arsia Mons. MOLA, THEMIS, MOC and OMEGA data have been analysed, providing a multi-scale characterisation of this Martian lava field. According to Mars Global Surveyor's MOLA data, the flanks of Arsia have an average slope <5°, while the surrounding regions, including Daedalia Planum, have slopes <0,5° and commonly <0,1°. Mars Odyssey/THEMIS VIS and IR images show a plain covered by a huge number of lava flows. Older and larger lava flows on the field have a length greater than ~1500 km. Moreover most of the Daedalia flows are associated to wrinkly and ropy surfaces, typical of pahoehoe lavas. On the base of the morphology differences among the flows and through stratigraphic relationships we performed a geological map of the area. MEX/OMEGA spectra were collected in different areas of the lava field. Besides the similar absorption bands OMEGA spectra showed also some differences in reflectance and spectral slope. The spectral map created using the SAM classification reveals that these spectral variations are generally in agreement with the lava flows mapped previously on the base of the flows morphology and stratigraphy. This suggested that such variability is related with different surface textures of the lava flow. Moreover in some cases spectral map highlighted the presence of spectral subunits inside the same stratigraphic unit, due likely to a different mineralogy or rock textures. Therefore spectral analysis revealed useful to improve the geological mapping of the Daedalia Planum region.

  20. The cave that holds clues to life on Mars.

    PubMed

    Nelson, P

    1996-01-01

    Deep in Lechuguilla Cave, a researcher ponders slots carved millions of years ago by dripping sulfuric acid. Though the cave was formed by acid bubbling up from below, here gases condensed on the chamber's ceiling and then rained down as acid. Scientists think Mars may also hold caves carved by sulfuric acid. On Earth, almost all other caves are formed by flowing water.

  1. ACCESS Mars: A Mission Architecture for an initial settlement on Mars; using caves as habitation

    NASA Astrophysics Data System (ADS)

    Perez-Poch, Antoni; Gallardo, Beatriz; Laufer, Ren; Zavaleta, Jhony; Davila, Alfonso; de Carufel, Guy; Antonakopoulos, Konstantinos; Husseini, A. Al; Alvarez Sánchez, L.; Antonakopoulos, K.; Apeldoorn, J.; Ashford, K., Jr.; Atabay, D.; Barrios, I.; Baydaroglu, Y.; Bennell, K. M.; Chen, J.; Chen, X.; Cormier, D.; Crowley, P.; de Carufel, G.; Deper, B.; Drube, L.; Duffy, P.; Edwards, P.; Gutiérrez Fernandez, E.; Haider, O.; Kumar, G.; Henselowsky, C.; Hirano, D.; Hirmer, T.; Hogan, B.; Albalat, A. Jaime; Jens, E.; Jivenescu, I.; Jojaghaian, A.; Kerrigan, M.; Kodachi, Y.; Langston, S.; Macintosh, R.; Miguélez, X.; Panek, N.; Pegg, C.; Peldszus, R.; Peng, X.; Perez-Poch, A.; Perron, A.; Qiu, J.; Renten, P.; Ricardo, J.; Saraceno, T.; Sauceda, F.; Shaghaghi Varzeghani, A.; Shimmin, R.; Solaz, R.; Solé, A.; Suresh, E. R.; Mar Vaquero Escribano, T.; Vargas Muñoz, M.; Vaujour, P. D.; Zeile, D. Veilette, Y. Winetraub, O.

    This paper summarizes a team project report produced during the Summer Space Program of the International Space University, held at Nasa-Ames Research Center (CA, USA) by 56 students from 15 countries. Chair of the team project was Rene Laufer. Facilitators were Alfonso Davila and Jhonny Zavaleta, and teacher associate supporting the team was Beatriz Gallardo. The human race has evolved, grown and expanded through the exploration of Earth. After initial steps on the Moon, our next challenge is to explore the solar system. Mars shows potential for both scientific discovery and future human settlement, and therefore represents a prime candidate for the next leap of human exploration. Such a bold endeavor will be a driver for an unprecedented worldwide cooperative effort and the catalyst for a new era of international, intercultural and interdisciplinary human relations. Scientific and technological progress will also accelerate as mankind is ushered into a new era of space exploration. Currently proposed Mars missions have identified a number of challenges such as high levels of radiation, harsh climate and limited launch windows. Recently discovered lava tubes on Mars present potential solutions to some of these issues, but raise a variety of intriguing new challenges. This paper reviews existing reference missions and identifies areas of further research essential for adapting mission architectures to utilize caves. Different mission scenarios are proposed and analyzed, with a number of different recommendations given. An analysis of the feasibility of using Martian lava tubes as habitation is given in another paper by the same authors at COSPAR 2010 F34 Technical Session. Literature suggests a low radiation environment within Martian caves, allowing for extended duration missions. The ACCESS Mars Team concludes that the use of lava tubes as human habitats will be more beneficial for human Mars exploration than currently proposed surface solutions.

  2. Nornahraun lava morphology and mode of emplacement

    NASA Astrophysics Data System (ADS)

    Pedersen, Gro B. M.; Höskuldsson, Armann; Riishuus, Morten S.; Jónsdóttir, Ingibjörg; Gudmundsson, Magnús T.; Sigmundsson, Freysteinn; Óskarsson, Birgir V.; Drouin, Vincent; Gallagher, Catherine; Askew, Rob; Moreland, William M.; Dürig, Tobias; Dumont, Stephanie; Þórdarson, Þór

    2015-04-01

    The ongoing Nornahraun eruption is the largest effusive eruption in Iceland since the Laki eruption in 1783-84, with an estimated lava volume of ~1.15 km3 covering an area of ~83.4 km2 (as of 5 JAN 2015). The eruption provides an unprecedented opportunity to study i) lava morphologies and their emplacement styles, ii) the transition from from open to closed lava pathways and iii) lava pond formation. Tracking of the lava advancement and morphology has been performed by GPS and GoPro cameras installed in 4×4 vehicles as well as video footage. Complimentary observations have been provided from aircraft platforms and by satellite data. Of particular importance for lava morphology observations are 1-12 m/pixel airborne SAR images (x-band). The Nornahraun flow field comprises a continuum of morphologies from pāhoehoe to 'a'ā, which have varied tem-porally and spatially. At the onset of the eruption 31 AUG, lava flows advanced rapidly (400-800 m/hr) from the 1.5 km long fissure as large slabby pāhoehoe [1-3] sheet lobes, 100-500 m wide and 0.3-1 m thick at the flow fronts. By 1 SEPT, the flows began channeling towards the NE constrained by the older Holuhraun I lava field and the to-pography of flood plain itself. A central open channel developed, feeding a 1-2 km wide active 'a'ā frontal lobe that advanced 1-2 km/day. In addition to its own caterpillar motion, the frontal lobe advanced in a series of 30-50 m long breakouts, predominantly slabby and rubbly pāhoehoe [4,5]. These breakouts had initial velocities of 10-30 m/hr and reached their full length within tens of minutes and subsequently inflated over hours. With the continuous advancement of the 'a'ā flow front, the breakouts were incorporated into the 'a'ā flow fronts and seldom preserved. At the margins of the frontal lava lobe, the breakouts were more sporadic, but predominantly rubbly pāhoehoe and slabby pāhoehoe, as at the flow front. The lava flow advanced ENE into Jökulsá á Fjöllum on 7 SEPT

  3. Mapping lava flow hazards using computer simulation

    NASA Astrophysics Data System (ADS)

    Wadge, G.; Young, P. A. V.; McKendrick, I. J.

    1994-01-01

    Computer simulations of the paths of flowing lava are achieved using a program, FLOWFRONT, that describes the behavior of flow and digital models of the terrain. Two methods of application of simulations of the hazards posed by lava flows are described. The first, deterministic, method requires that program parameters such as vent position, minimum flow thickness, and thickness/slope relationship be based on the ambient eruptive conditions so that the future course of a specific lava flow can be simulated. This is illustrated using retrospective modeling of the first 21 days of the eruption of an andesitic lava flow at Lonquimay volcano, Chile, in 1988-1989. The usefulness of this method for real-time predictive modeling is likely to be limited by the lack of accurate field data on flow characteristics, the simple nature of the model, and the sensitivity to parameter choice of the final planimetric form of the model flow. The second application is probabilistic in nature and creates a map of the likelihood of inundation by lava flows that is useful for long-term land use planning. This method uses the historical record of past eruptions to constrain a series of Monte Carlo simulations and is illustrated using data from Etna volcano in Sicily. A multivariate statistical analysis of nine parameters for the 1763-1989 eruption catalog using simulated annealing permitted a classification of Etna's flank eruptions into two types: A and B. Type A eruptions are short-lived and produce linear lava flows; type B eruptions are long-lived, and produce lava flows that are much broader in shape, and their vents are restricted to the eastern flank of the volcano. The simulation method consists of creating a probability surface of the location of future eruption vents and segmenting the region according to the most likely historical eruption on which to base the simulation. Analysis of the autocorrelation of the historical eruptions shows that type A eruptions are strongly

  4. Glacioclimatological study of perennial ice in the Fuji Ice Cave, Japan. Part 2. Interannual variation and relation to climate

    SciTech Connect

    Ohata, Tetsuo; Furukawa, Teruo; Osada, Kazuo )

    1994-08-01

    A glacioclimatological study of the interannual variation of mass of perennial ice in the Fuji Ice Cave at the foot of Mt. Fuji, in central Japan is presented. The cave is a 150-m-long lava tube located in a dense forest area at an altitude of 1120 m. It has a perennial floor ice of areas approximately 3000 m[sup 3] and mean thickness 2.8 m. Mean annual air temperature at the ground surface level is 8.4[degrees]C. Ice surface levels and air temperatures were measured 39 times from July 1984 to December 1992. Mean ice level showed a 15 cm increase from 1984 to 1989 and suddenly started to decrease from 1989 to 1992. In the increase stage, annual net balance (December to November) was similar at various points, but in the decreasing stage, the lowering of the level near the entrance was very large due to intense melting. Air temperature inside the cave at the end of the annual cycle showed a correlation to net balance of the corresponding year. Comparison of yearly net balance with meterological indices at ground level (winter and summer, annual mean air temperature and total precipitation; and number of days with strong precipitation) showed that net balance of a give year has a high correlation with the average winter air temperature anomaly of the preceding 4 yr. This is probably due to the high heat capacity of the cave system. 6 refs., 7 figs., 2 tabs.

  5. Does the Cave Environment Reduce Functional Diversity?

    PubMed Central

    Fernandes, Camile Sorbo; Batalha, Marco Antonio; Bichuette, Maria Elina

    2016-01-01

    Caves are not colonised by all taxa present in the surface species pool, due to absence of light and the tendency to food limitation when compared to surface communities. Under strong species sorting during colonisation and later by the restrictive environmental filter, traits that are not adaptive in subterranean habitats may be filtered out. We tested whether cave communities were assembled by the restrictive regime propitiated by permanent darkness or by competitive exclusion due to resource scarcity. When compared to surface communities, the restrictive subterranean regime would lead to lower functional diversity and phenotypic clustering inside the caves, and the opposite should be expected in the case of competitive exclusion. Using isopods (Oniscidea) as model taxa, we measured several niche descriptors of taxa from surface and cave habitats, used a multivariate measure of functional diversity, and compared their widths. We found phenotypic overdispersion and higher functional diversity in cave taxa when compared to surface taxa. On the one hand, the dry climate outside of caves hampered the survival of several taxa and their ecological strategies, not viable under severe desiccation risk, culminating in the clustering of functional traits. In contrast, this restriction does not occur inside of caves, where isopods find favourable conditions under lower predation pressures and more amenable environmental parameters that allow occupation and subsequent diversification. Our results showed that, at least for some taxa, caves may not be such a harsh environment as previously thought. The high functional diversity we found inside caves adds an additional reason for the conservation of these sensitive environments. PMID:27003837

  6. Fungal outbreak in a show cave.

    PubMed

    Jurado, V; Porca, E; Cuezva, S; Fernandez-Cortes, A; Sanchez-Moral, S; Saiz-Jimenez, C

    2010-08-01

    Castañar de Ibor Cave (Spain) was discovered in 1967 and declared a Natural Monument in 1997. In 2003 the cave was opened to public visits. Despite of extensive control, on 26 August 2008 the cave walls and sediments appeared colonized by long, white fungal mycelia. This event was the result of an accidental input of detritus on the afternoon of 24 August 2008. We report here a fungal outbreak initiated by Mucor circinelloides and Fusarium solani and the methods used to control it.

  7. Studies of fluid instabilities in flows of lava and debris

    NASA Technical Reports Server (NTRS)

    Fink, Jonathan H.

    1987-01-01

    At least two instabilities have been identified and utilized in lava flow studies: surface folding and gravity instability. Both lead to the development of regularly spaced structures on the surfaces of lava flows. The geometry of surface folds have been used to estimate the rheology of lava flows on other planets. One investigation's analysis assumed that lava flows have a temperature-dependent Newtonian rheology, and that the lava's viscosity decreased exponentially inward from the upper surface. The author reviews studies by other investigators on the analysis of surface folding, the analysis of Taylor instability in lava flows, and the effect of surface folding on debris flows.

  8. The Payun-Matru lava field: a source of analogues for Martian long lava flows

    NASA Astrophysics Data System (ADS)

    Giacomini, L.; Pasquarè, G.; Massironi, M.; Frigeri, A.; Bistacchi, A.; Frederico, C.

    2007-08-01

    The Payun Matru Volcanic complex is a Quaternary fissural structure belonging to the back-arc extensional area of the Andes in the Mendoza Province (Argentina). The eastern portion of the volcanic structure is covered by a basaltic field of pahoehoe lava flows advanced over more than 180 km from the fissural feeding vents that are aligned with a E-W fault system (Carbonilla fault). Thanks to their widespread extension, these flows represent some of the largest lava flows in the world and the Pampas Onduladas flow can be considered the longest sub-aerial individual lava flow on the Earth surface [1,2]. These gigantic flows propagated over the nearly flat surface of the Pampean foreland, moving on a 0.3 degree slope. The very low viscosity of the olivine basalt lavas, coupled with the inflation process and an extensive system of lava tubes are the most probable explanation for their considerable length. The inflation process likely develop under a steady flow rate sustained for a long time [3]. A thin viscoelastic crust, built up at an early stage, is later inflated by the underlying fluid core, which remains hot and fluid thanks to the thermal-shield effect of the crust. The crust is progressively thickened by accretion from below and spreading is due to the continuous creation of new inflated lobes, which develop at the front of the flow. Certain morphological features are considered to be "fingerprints" of inflation [4, 5, 6]; these include tumuli, lava rises, lava lobes and ridges. All these morphologies are present in the more widespread Payun Matru lava flows that, where they form extensive sheetflows, can reach a maximum thickness of more than 20 meters. After the emplacement of the major flows, a second eruptive cycle involved the Payun Matru volcanic structure. During this stage thick and channelized flows of andesitic and dacitic lavas, accompanied the formation of two trachitic and trachiandesitic strato-volcanoes (Payun Matru and Payun Liso) culminated

  9. Fire, Lava Flows, and Human Evolution

    NASA Astrophysics Data System (ADS)

    Medler, M. J.

    2015-12-01

    Richard Wrangham and others argue that cooked food has been obligate for our ancestors since the time of Homo erectus. This hypothesis provides a particularly compelling explanation for the smaller mouths and teeth, shorter intestines, and larger brains that separate us from other hominins. However, natural ignitions are infrequent and it is unclear how earlier hominins may have adapted to cooked food and fire before they developed the necessary intelligence to make or control fire. To address this conundrum, we present cartographical evidence that the massive and long lasting lava flows in the African Rift could have provided our ancestors with episodic access to heat and fire as the front edges of these flows formed ephemeral pockets of heat and ignition and other geothermal features. For the last several million years major lava flows have been infilling the African Rift. After major eruptions there were likely more slowly advancing lava fronts creating small areas with very specific adaptive pressures and opportunities for small isolated groups of hominins. Some of these episodes of isolation may have extended for millennia allowing these groups of early hominins to develop the adaptations Wrangham links to fire and cooked food. To examine the potential veracity of this proposal, we developed a series of maps that overlay the locations of prominent hominin dig sites with contemporaneous lava flows. These maps indicate that many important developments in hominin evolution were occurring in rough spatial and temporal proximity to active lava flows. These maps indicate it is worth considering that over the last several million years small isolated populations of hominins may have experienced unique adaptive conditions while living near the front edges of these slowly advancing lava flows.

  10. South-France caves monitoring : present day cave air dynamics characterization,paleoclimatic and archaeological interests

    NASA Astrophysics Data System (ADS)

    Bourges, F.; Genty, D.; Genthon, P.; Mangin, A.; D'Hulst, D.

    2012-04-01

    Cave climatic environment survey covers different sort of analyses on air and water, and has various interests from the conservation of prehistoric caves to the study of paleoclimates. Depending on the purpose, the cave monitoring can be entirely automatic or combine both automatic and manual data acquisitions. Apparatus are adapted to cave environment to measure specific parameters (i.e. drip rate, air humidity, CO2) and during the long-term monitorings, several generations of techniques have been used. We present here examples of cave monitoring (1996 →) from South-France: Chauvet, Orgnac (Ardèche), Esparros (Hautes-Pyrénées) and Villars (Dordogne). In all these sites, we obtained among the longest series of climatic parameters of inside the caves, coupled sometimes with geochemical and isotopic analyses on air and seepage water, which allow to better understand cave air circulation behaviour and their sensitivity to the external climatic and environmental variations. High precision temperature measurements in Orgnac and Chauvet caves, coupled with pCO2 and radon analyses, allowed the reconstruction of seasonal air circulation patterns in each cave. While the Chauvet and Esparros caves are quite confined environments with temperature changes mainly controlled by air pressure variations, the Orgnac cave, like most caves, shows a well marked summer/winter regime alternation. Quantification of air flows of known CO2 concentration allowed the calculation of carbon fluxes toward the earth atmosphere which is estimated to about 340 gm-2yr-1. Since 15 years, the monitoring made in the Villars cave at two different levels has shown that the air temperature displays small seasonal variations in the upper galleries while it is not detectable in the lower ones. Average annual temperature difference between these two levels is of more than 1°C, showing that local differences in a single cave can be significant. A global warming trend likely correlated with local

  11. Experimental Studies of Lava Dome Fracture

    NASA Astrophysics Data System (ADS)

    Smith, R.; Sammonds, P. R.; Kilburn, C. R.

    2005-12-01

    Renewed extrusion at andesitic to dacitic lava domes and collapses of these domes are usually preceded by fracturing and frictional sliding of material in and around the lava dome and magma conduit. This is observed through the occurrence of shallow high frequency earthquakes. Samples of andesite from Mount Shasta in the Cascades, a typical material for both lava domes and shallow underlying country rock, have been deformed in compression and tension, at temperatures of up to 900°C, and under confining pressures of up to 70MPa. During these tests the axial load, sample deformation and acoustic emissions were recorded, in order to compare the results with field observations of deformation and short period seismicity at lava domes. Typical strengths at room temperature and pressure were 6MPa in tension, and 100MPa in compression. Increased temperatures increased the tensile strength, but reduced the compressive strength, whereas both strengths increased with increasing confining pressure. There were ~10 times more acoustic emissions at room temperature than at maximum test temperatures, indicating that increased temperatures favour ductile, rather than brittle, failure. These results suggest that young, hot lava domes may collapse or erupt with little precursory short period seismicity, whilst older, cooler domes are likely to exhibit stronger short period seismic precursors. However, hotter material is likely to exhibit more recognisable deformation precursors. This is consistent with the seismicity observed after the 18 May 1980 climactic eruption at Mount St Helens, where there was ~100 times more seismicity prior to eruptions in 1985 and 1986 than there was prior to eruptions in 1980 and 1981. During these later eruptions, the interior of the dome would still have been ductile due to its temperature and the overburden weight acting as a confining pressure, but the large amount of pre-failure deformation in this zone could drive fracturing of the cooler outer

  12. Geology of selected lava tubes in the Bend Area, Oregon

    NASA Technical Reports Server (NTRS)

    Greely, R.

    1971-01-01

    Longitudinal profiles representing 5872.5 m of mapped lava tubes and a photogeologic map relating lava tubes to surface geology, regional structure and topography are presented. Three sets of lava tubes were examined: (1) Arnold Lava Tube System (7km long) composed of collapsed and uncollapsed tube segments and lava ponds, (2) Horse Lava Tube System (11 km long) composed of parallel and anastomosing lava tube segments, and (3) miscellaneous lava tubes. Results of this study tend to confirm the layered lava hypothesis of Ollier and Brown (1965) for lava tube formation; however, there are probably several modes of formation for lava tubes in general. Arnold System is a single series of tubes apparently formed in a single basalt flow on a relatively steep gradient. The advancing flow in which the tubes formed was apparently temporarily halted, resulting in the formation of lava ponds which were inflated and later drained by the lava tube system. Horse System probably formed in multiple, interconnected flows. Pre-flow gradient appears to have been less than for Arnold System, and resulted in meandrous, multiple tube networks.

  13. Southwest Caves Reveal New Forms of Life

    USGS Publications Warehouse

    Wynne, J. Judson; Drost, Charles

    2009-01-01

    Caves in northern Arizona and western New Mexico are being researched and inventoried by scientists with the U.S. Geological Survey and cooperating agencies. Southwestern caves have been little studied, and scientists are now finding that these lightless and nutrient-poor natural systems are home to life forms found nowhere else on Earth. This research has identified unique communities of arthropods (insects, arachnids, and crustaceans) that include 3 new genera, or groups of species, and at least 15 new species - some only known to exist in a single cave. This exciting research is yielding information that will be used by resource managers to better understand and protect fragile and important Southwestern cave ecosystems.

  14. Integrated geophysical surveys to assess the structural conditions of a karstic cave of archaeological importance

    NASA Astrophysics Data System (ADS)

    Leucci, G.; de Giorgi, L.

    2005-01-01

    An integrated geophysical survey using both the electrical resistivity tomography (ERT) and ground-penetrating radar (GPR) methods was undertaken over a cave of great archaeological interest in southern Italy. The survey was performed to assess the stability of the carbonate rock roof of the cave. A geophysical survey was preferred to boreholes and geotechnical tests, in order to avoid the risk of mass movements. The interpretation of integrated data from ERT and GPR resulted in an evaluation of some of the electromagnetic (EM) characteristics (such as the EM wave velocity) and the detection of discontinuities (fractures) in the carbonate rock. It is well known that rock fractures constitute a serious problem in cave maintenance, and progressive cracking within the bed rock is considered to be one of the main causes of collapse. An analysis of the back-scattered energy was also required for the GPR data interpretation. Cracks within the bedrock were detected to a depth of about 2 m by using GPR, which allowed for the identification of the loosened zone around the cave.

  15. 9. CRATER RIM DRIVE NEAR THURSTON LAVA TUBE. VIEW OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. CRATER RIM DRIVE NEAR THURSTON LAVA TUBE. VIEW OF CRENELATED LAVA STONE GUARD WALL AND ROCK CUT OPPOSITE. NOTE CATTLE GUARD ACROSS ROAD PARTIALLY PAVED OVER. - Crater Rim Drive, Volcano, Hawaii County, HI

  16. Quantitative constraints on the growth of submarine lava pillars from a monitoring instrument that was caught in a lava flow

    NASA Astrophysics Data System (ADS)

    Chadwick, William W.

    2003-11-01

    Lava pillars are hollow, vertical chimneys of solid basaltic lava that are common features within the collapsed interiors of submarine sheet flows on intermediate and fast spreading mid-ocean ridges. They are morphologically similar to lava trees that form on land when lava overruns forested areas, but the sides of lava pillars are covered with distinctive, evenly spaced, thin, horizontal lava crusts, referred to hereafter as "lava shelves." Lava stalactites up to 5 cm long on the undersides of these shelves are evidence that cavities filled with a hot vapor phase existed temporarily beneath each crust. During the submarine eruption of Axial Volcano in 1998 on the Juan de Fuca Ridge a monitoring instrument, called VSM2, became embedded in the upper crust of a lava flow that produced 3- to 5-m-high lava pillars. A pressure sensor in the instrument showed that the 1998 lobate sheet flow inflated 3.5 m and then drained out again in only 2.5 hours. These data provide the first quantitative constraints on the timescale of lava pillar formation and the rates of submarine lava flow inflation and drainback. They also allow comparisons to lava flow inflation rates observed on land, to theoretical models of crust formation on submarine lava, and to previous models of pillar formation. A new model is presented for the rhythmic formation of alternating lava crusts and vapor cavities to explain how stacks of lava shelves are formed on the sides of lava pillars during continuous lava drainback. Each vapor cavity is created between a stranded crust and the subsiding lava surface. A hot vapor phase forms within each cavity as seawater is syringed through tiny cracks in the stranded crust above. Eventually, the subsiding lava causes the crust above to fail, quenching the hot cavity and forming the next lava crust. During the 1998 eruption at Axial Volcano, this process repeated itself about every 2 min during the 81-min-long drainback phase of the eruption, based on the thickness

  17. Genomic sequencing of Pleistocene cave bears

    SciTech Connect

    Noonan, James P.; Hofreiter, Michael; Smith, Doug; Priest, JamesR.; Rohland, Nadin; Rabeder, Gernot; Krause, Johannes; Detter, J. Chris; Paabo, Svante; Rubin, Edward M.

    2005-04-01

    Despite the information content of genomic DNA, ancient DNA studies to date have largely been limited to amplification of mitochondrial DNA due to technical hurdles such as contamination and degradation of ancient DNAs. In this study, we describe two metagenomic libraries constructed using unamplified DNA extracted from the bones of two 40,000-year-old extinct cave bears. Analysis of {approx}1 Mb of sequence from each library showed that, despite significant microbial contamination, 5.8 percent and 1.1 percent of clones in the libraries contain cave bear inserts, yielding 26,861 bp of cave bear genome sequence. Alignment of this sequence to the dog genome, the closest sequenced genome to cave bear in terms of evolutionary distance, revealed roughly the expected ratio of cave bear exons, repeats and conserved noncoding sequences. Only 0.04 percent of all clones sequenced were derived from contamination with modern human DNA. Comparison of cave bear with orthologous sequences from several modern bear species revealed the evolutionary relationship of these lineages. Using the metagenomic approach described here, we have recovered substantial quantities of mammalian genomic sequence more than twice as old as any previously reported, establishing the feasibility of ancient DNA genomic sequencing programs.

  18. Circulation patterns in active lava lakes

    NASA Astrophysics Data System (ADS)

    Redmond, T. C.; Lev, E.

    2014-12-01

    Active lava lakes provide a unique window into magmatic conduit processes. We investigated circulation patterns of 4 active lava lakes: Kilauea's Halemaumau crater, Mount Erebus, Erta Ale and Nyiragongo, and in an artificial "lava lake" constructed at the Syracuse University Lava Lab. We employed visual and thermal video recordings collected at these volcanoes and use computer vision techniques to extract time-dependent, two-dimensional surface velocity maps. The large amount of data available from Halemaumau enabled us to identify several characteristic circulation patterns. One such pattern is a rapid acceleration followed by rapid deceleration, often to a level lower than the pre-acceleration level, and then a slow recovery. Another pattern is periodic asymmetric peaks of gradual acceleration and rapid deceleration, or vice versa, previously explained by gas pistoning. Using spectral analysis, we find that the dominant period of circulation cycles at approximately 30 minutes, 3 times longer than the dominant period identified previously for Mount Erebus. Measuring a complete surface velocity field allowed us to map and follow locations of divergence and convergence, therefore upwelling and downwelling, thus connecting the surface flow with that at depth. At Nyiragongo, the location of main upwelling shifts gradually, yet is usually at the interior of the lake, for Erebus it is usually along the perimeter yet often there is catastrophic downwelling at the interior; For Halemaumau upwelling/downwelling position is almost always on the perimeter. In addition to velocity fields, we developed an automated tool for counting crustal plates at the surface of the lava lakes, and found a correlation, and a lag time, between changes if circulation vigor and the average size of crustal plates. Circulation in the artificial basaltic lava "lake" was limited by its size and degree of foaming, yet we measured surface velocities and identify patterns. Maximum surface velocity

  19. Lava Flows in the Grand Canyon

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Over vast expanses of time, natural processes like floods and volcanoes deposit layers of rock on the Earth's surface. To delve down through layers of rock is to explore our planet's history. Sometimes rock layers are exposed through human activity, such as drilling or excavation. Other times, rivers carve through the rock. One of the best, and most well-known, examples of a river exposing ancient rocks is Colorado River in Arizona's Grand Canyon. What fewer people know is that the Grand Canyon also has a history of relatively recent (on geologic time scales) volcanism. The evidence--hardened lava--spills down the canyon walls all the way to the river. On June 22, 2003, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of the Grand Canyon, near 36.2 degrees north latitude and 113.2 degrees west longitude. ASTER detects light visible to human eyes as well as 'invisible' infrared light. Because different minerals reflect different portions of the light spectrum, ASTER can see varying mineral compositions of the rocks it observes, as well as detecting vegetation. In this three-dimensional visualization, lava fields appear brownish gray, darker than the layers of limestone, sandstone and other rock in the canyon. Vegetation appears green, and sparsely vegetated areas appear mustard. Water in the Colorado River is blue-purple. Geologists estimate that between 1.8 million and 400,000 years ago, lava flows actually dammed the Colorado River more than a dozen times. Some of the lava dams were as high as 600 meters (about 1,969 feet), forming immense reservoirs. Over time, enough water and sediment built up to push the river flow over the tops of these dams and eventually erode them away. Today, remnants of these lava dams remain throughout the area, along with the much older rock layers they cover. Among the most well known examples of these 'frozen' lava cascades is Lava Falls, which spills down to the

  20. The hydrothermal alteration of cooling lava domes

    NASA Astrophysics Data System (ADS)

    Ball, Jessica L.; Stauffer, Philip H.; Calder, Eliza S.; Valentine, Greg A.

    2015-12-01

    Hydrothermal alteration is a recognized cause of volcanic instability and edifice collapse, including that of lava domes or dome complexes. Alteration by percolating fluids transforms primary minerals in dome lavas to weaker secondary products such as clay minerals; moreover, secondary mineral precipitation can affect the porosity and permeability of dome lithologies. The location and intensity of alteration in a dome depend heavily on fluid pathways and availability in conjunction with heat supply. Here we investigate postemplacement lava dome weakening by hydrothermal alteration using a finite element numerical model of water migration in simplified dome geometries. This is combined with the rock alteration index (RAI) to predict zones of alteration and secondary mineral precipitation. Our results show that alteration potential is highest at the interface between the hot core of a lava dome and its clastic talus carapace. The longest lived alteration potential fields occur in domes with persistent heat sources and permeabilities that allow sufficient infiltration of water for alteration processes, but not so much that domes cool quickly. This leads us to conclude that alteration-induced collapses are most likely to be shallow seated and originate in the talus or talus/core interface in domes which have a sustained supply of magmatic heat. Mineral precipitation at these zones of permeability contrast could create barriers to fluid flow, potentially causing gas pressurization which might promote deeper seated and larger volume collapses. This study contributes to our knowledge of how hydrothermal alteration can affect lava domes and provides constraints on potential sites for alteration-related collapses, which can be used to target hazard monitoring.

  1. Lava flows composition of the Daedalia Planum

    NASA Astrophysics Data System (ADS)

    Carli, Cristian; Giacomini, Lorenza; Sgavetti, Maria; Massironi, Matteo

    2010-05-01

    Daedalia Planum is a large lava plain, consisting of more than 1500 km lava flows emplaced over an almost flat terrain in the south-east area of Arsia Mons. The morphology of this region has been studied by Giacomini et al. (Planet.SpaceSci., 2009) and revealed the presence of various features indicative of inflation mechanisms. Thirteen morphologic units have been delineated and the stratigraphic relationships among these units have been established by the authors. Several compositional data indicate that most of the Mars surface appears to consist of tholeiitic basalts where rocks previously identified as andesite may be basaltic rocks coated with alteration rinds (McSween et al., Science, 2009). Some primitive alkaline olivine-rich basaltic rocks have been also recognized by rover exploration (McSween et al., J.Geophys.Res., 2006). The visible and near-infrared reflectance spectra contain electronic absorptions characteristic of mafic minerals including pyroxenes and olivine. These minerals, together with plagioclase, are the major components of lava's rocks. We have analyzed data acquired by the OMEGA orbiter spectrometer of the Mars Express mission. Several OMEGA's images have been studied collecting sets of spectra from each of the thirteen geological units. The spectra indicate a relatively uniform composition of the lavas, characterized by two wide absorption bands (I and II) at about 1000 and 2000 nm, respectively. These spectral features are diagnostic of the presence of pyroxenes, and the continuum removed spectra permit us to recognize the presence of two different pyroxenes . The precise minima positions of band I, between 950 and 1000 nm, and of band II, between 1800 and 2000 nm, suggest the presence in this region of low calcium and subcalcium clinopyroxene, like pigeonite and augite, with variable relative abundances. The presence of these types of pyroxenes suggests a tholeiitic composition of the Daedalia Planum long lava flows, in agreement with

  2. Ice-Confined Basaltic Lava Flows: Review and Discussion

    NASA Astrophysics Data System (ADS)

    Skilling, I.; Edwards, B. R.

    2012-12-01

    Basaltic lavas that are interpreted as having been emplaced in subglacial or ice-confined subaerial settings are known from several localities in Iceland, British Columbia and Antarctica. At least four different types of observations have been used to date to identify emplacement of basaltic lavas in an ice-rich environment: i) gross flow morphology, ii) surface structures, iii) evidence for ice-confined water during emplacement, and iv) lava fracture patterns. Five types of ice-confined lava are identified: sheets, lobes, mounds, linear ridges and sinuous ridges. While the appearance of lavas is controlled by the same factors as in the submarine environment, such as the geometry and configuration of vents and lava tubes, flow rheology and rates, and underlying topography, the presence of ice can lead to distinct features that are specific to the ice-confined setting. Other types have very similar or identical equivalents in submarine environment, albeit with some oversteepening/ice contact surfaces. Ice-confined lavas can form as (1) subaerial or subaqueous lavas emplaced against ice open to the air, (2) subaqueous lavas emplaced into pre-existing sub-ice drainage networks, and (3) subaqueous lavas emplaced into ponded water beneath ice. Their surface structures reflect the relationship between rates of lava flow emplacement at the site of ice-water-lava contact, ice melting and water drainage. Variations in local lava flow rates could be due to lava cooling, constriction, inflation, tube development, ice melting, ice collapse, lava collapse, changes in eruption rate etc. Episodes of higher lava flow rate would favour direct ice contact and plastic compression against the ice, generating oversteepened and/or overthickened chilled margins, cavities in the lava formed by melting of enveloped ice blocks (cryolith cavities) and structures such as flattened pillows and lava clasts embedded into the glassy margins. Melting back of the confining ice generates space to

  3. The Tony Grove Karst Region in Northern Utah: From Cave Sediments to Fluvial Geomorphology

    NASA Astrophysics Data System (ADS)

    Smith, H. D.

    2013-12-01

    The Tony Grove lake area is a dolomitic karst region in the Bear River Range of the Middle Rocky Mountain Province (Hintze 1973, Wilson 1976). The 5 km study area (Figure 1) is strewn with boulders and consists of a combination of subsurface dissolution caves underlying the highly-eroded karst surface reminiscent of past glaciation. Traces of the dynamic mountain structure can be seen in faults, fractures, and folds with the largest being the Logan Syncline (Wilson, 1976) formed during the Sevier Orogeny. The Tony Grove area stratigraphy is dominated by the Ordovician (505 MYR) Fish Haven dolomite and Silurian (438 MYR) Laketown dolomite units topped with some Devonian (406 MYR) aged inter-bedded quartzite, shale, and dolostone from the Water Canyon Formation (Morgan 1992, Spangler 2001). The 5 km study area contains over 90 karst features formed through vadose water flow due to the alpine proximity. The development and exhumation of these features have been greatly influenced over time by plate tectonics and water. We investigate cave formation and sediments as an indicator of past water flow and watershed dynamics. Figure 1. Site location of the Tony Grove lake area including an image of the karst terrain and geologic map showing the Logan Peak Syncline. The area is home to about 90 karst features including both do lines and caves. Figure 2. The cave sediments in this image of Thundershower Cave in the Tony Grove lake area show the flow pattern and a step and pool channel morphology with a side channel formed to the right during times of higher flow.

  4. The Tony Grove Karst Region in Northern Utah: From Cave Sediments to Fluvial Geomorphology

    NASA Astrophysics Data System (ADS)

    Smith, H. D.

    2012-12-01

    The Tony Grove lake area is a dolomitic karst region in the Bear River Range of the Middle Rocky Mountain Province (Hintze, 1973; Wilson, 1976). Figure 1. The 5 km study area is strewn with boulders and consists of a combination of subsurface dissolution caves underlying the highly-eroded karst surface remnancent of past glaciation. Traces of the dynamic mountain structure can be seen in faults, fractures, and folds with the largest being the Logan Syncline (Wilson, 1976) formed during the Sevier Orogeny. The Tony Grove area stratigraphy is dominated by the Ordovician (505 MYR) Fish Haven dolomite and Silurian (438 MYR) Laketown dolomite units topped with some Devonian (406 MYR) aged inter-bedded quartzite, shale, and dolostone from the Water Canyon Formation (Morgan 1992, Spangler 2001). The 5 km study area contains over 90 karst features formed through vadose water flow due to the alpine proximity. The development and exhumation of these features have been greatly influenced over time by plate tectonics and water. We investigate cave formation and sediments as an indicator of past water flow and watershed dynamics (Figure 2). Figure 1. Site location of the Tony Grove Lake Area including an image of the karst terrain and geologic map showing the Logan Peak Syncline. The area is home to about 90 karst features inculding both dolines and caves. Figure 2. The cave sediments in this image of Thundershower Cave in the Tony Grove Lake Area show the flow pattern and a step and pool channel morphology with a side channel formed to the right during times of higher flow.

  5. NASA Aircraft Aids Earth-Mars Cave Detection Study

    NASA Video Gallery

    The most likely location for discovering potential primitive life forms on Mars to be in caves. A recent NASA-funded airborne and ground study designed to aid in detection of caves on the Earth, th...

  6. Preservation of Microbial-Mineral Biosignatures in Caves

    NASA Astrophysics Data System (ADS)

    Boston, P. J.; Alexander, C.

    2016-05-01

    Earth caves are wonderful preservation environments for distinctive in situ biopatterns and biominerals. Several thousand volcanic caves have been detected on Mars and may contain biosignatures or extant life and are valuable future mission targets.

  7. PATTERNS OF ENDEMISM OF THE EASTERN NORTH AMERICAN CAVE FAUNA

    EPA Science Inventory

    Over 250 species of obligate terrestrial cave-dwelling animals (troglobionts) are known from single caves in the eastern United States. We investigate their geographic distribution, especially in relation to other troglobionts. We relate these patterns to taxonomic group, oppor...

  8. The influence of cave stream sediments on the transport behavior of karst springs

    NASA Astrophysics Data System (ADS)

    Wagner, T.; Winkler, G.; Woessner, W.; Birk, S.

    2012-04-01

    Spring response to recharge in karst systems is influenced by the complex distribution of the rock mass hydraulic properties, fracture systems, and the presence of conduits. In addition the exchange of karst water with unconsolidated sediments in conduits may also further influence spring responses. To evaluate the effects of cave streams and sediments on solute transport in karst systems a small scale tracer experiment using fluorescein as an artificial tracer and water temperature as a natural tracer was conducted within the hyporheic zone of the active cave stream Schmelzbach. This interior stream drains parts of the Lurbach Karst System (Semriach-Peggau, Styria, Austria). The main goal of the experiment was to investigate if measurable cave stream hyporheic exchange (with the stream bottom sediments) occurs and the degree to which this process alters the transport of conservative tracers. One hundred meters downstream of the tracer injection point three cross sections of monitoring wells (9 in total along a distance of approximately 25 m) were constructed and fitted with two vertically isolated activated charcoal bags, 10 cm and 30 cm below the streambed surface. PVC monitoring wells were installed along the three cross sections using hand driven steel pipes as a temporary casing. In two of these wells temperature sensors were placed at different depths within the saturated bed sediment to investigate how post tracer test stream flood events impacted the timing and rate of stream water penetration into the bed sediments. The tracer breakthrough curve was measured with a fluorimeter located 100 m from the injection point. The results show a sharp peak and a modest tailing of the breakthrough. A one-dimensional advection dispersion model that accounts for mass transfer and storage of tracer in immobile fluid zones such as pools or sediments provides a good fit to the measured breakthrough curve. The model results suggest that immobile fluid zones amount to 40% of

  9. Voluminous submarine lava flows from Hawaiian volcanoes

    SciTech Connect

    Holcomb, R.T.; Moore, J.G.; Lipman, P.W.; Belderson, R.H.

    1988-05-01

    The GLORIA long-range sonar imaging system has revealed fields of large lava flows in the Hawaiian Trough east and south of Hawaii in water as deep as 5.5 km. Flows in the most extensive field (110 km long) have erupted from the deep submarine segment of Kilauea's east rift zone. Other flows have been erupted from Loihi and Mauna Loa. This discovery confirms a suspicion, long held from subaerial studies, that voluminous submarine flows are erupted from Hawaiian volcanoes, and it supports an inference that summit calderas repeatedly collapse and fill at intervals of centuries to millenia owing to voluminous eruptions. These extensive flows differ greatly in form from pillow lavas found previously along shallower segments of the rift zones; therefore, revision of concepts of volcano stratigraphy and structure may be required.

  10. Support of LAVA Integration and Testing

    NASA Technical Reports Server (NTRS)

    Jackson, Marcus Algernon

    2014-01-01

    The Lunar Advanced Volatile Analysis (LAVA) subsystem is a part of the Regolith and Environment Science & Oxygen and Lunar Volatile Analysis (RESOLVE) Payload that will fly to the lunar pole on the Resource Prospector Mission (RPM) in 2019. The purpose of the mission is to characterize the water on the surface and subsurface of the moon in various locations in order to map the distribution. This characterization of water will help to understand how feasible water is as a resource that can be used for drinking water, breathable air, and propellants in future missions. This paper describes the key support activities performed during a 10 week internship; specifically, troubleshooting the Near Infrared Spectrometer for the Surge Tank (NIRST) instrument count loss, contributing to a clamp to be used in the installation of Resistive Temperature Detectors (RTDs) to tubing, performing a failure analysis of the LAVA Fluid Subsystem (FSS), and finalizing trade studies for release.

  11. Kilauea Iki lava lake experiment plans

    SciTech Connect

    Dunn, J.C.; Hills, R.G.

    1981-01-01

    Twelve experimental studies are proposed to complete field laboratory work at Kilauea Iki lava lake. Of these twelve experiments, eleven do not require the presence of melt. Some studies are designed to use proven techniques in order to expand our existing knowledge, while others are designed to test new concepts. Experiments are grouped into three main categories: geophysics, energy extraction, and drilling technology. Each experiment is described in terms of its location, purpose, background, configuration, operation, and feasibility.

  12. Geothermometry of Kilauea Iki lava lake, Hawaii

    USGS Publications Warehouse

    Helz, R.T.; Thornber, C.R.

    1987-01-01

    Data on the variation of temperature with time and in space are essential to a complete understanding of the crystallization history of basaltic magma in Kilauea Iki lava lake. Methods used to determine temperatures in the lake have included direct, downhole thermocouple measurements and Fe-Ti oxide geothermometry. In addition, the temperature variations of MgO and CaO contents of glasses, as determined in melting experiments on appropriate Kilauean samples, have been calibrated for use as purely empirical geothermometers and are directly applicable to interstitial glasses in olivine-bearing core from Kilauea Iki. The uncertainty in inferred quenching temperatures is ??8-10?? C. Comparison of the three methods shows that (1) oxide and glass geothermometry give results that are consistent with each other and consistent with the petrography and relative position of samples, (2) downhole thermo-couple measurements are low in all but the earliest, shallowest holes because the deeper holes never completely recover to predrilling temperatures, (3) glass geothermometry provides the greatest detail on temperature profiles in the partially molten zone, much of which is otherwise inaccessible, and (4) all three methods are necessary to construct a complete temperature profile for any given drill hole. Application of glass-based geothermometry to partially molten drill core recovered in 1975-1981 reveals in great detail the variation of temperature, in both time and space, within the partially molten zone of Kilauea Iki lava lake. The geothermometers developed here are also potentially applicable to glassy samples from other Kilauea lava lakes and to rapidly quenched lava samples from eruptions of Kilauea and Mauna Loa. ?? 1987 Springer-Verlag.

  13. Bellholes: Ceiling Cavities Eroded By Bats in Caves of the Neotropical Climates

    NASA Astrophysics Data System (ADS)

    Miller, T.

    2014-12-01

    Hundreds of thousands of symmetrical, vertical, bullet-shaped cavities known as bellholes are present in the ceilings of caves restricted to the tropical Americas. Most have circular diameters (rarely influenced by joints or bedding) of at least 30 cm, and may be several meters in height. They are often paired with bellbasins (shallow depressions located vertically beneath them that contain guano produced by bats). Members of the species Artibeus jamaicensis (Jamaican Fruit Bat) are almost exclusive users of these roosts. Brown streaks flowing down the sides of the bellholes and centimeters-thick rinds of the basins below are largely apatite minerals produced by the reaction of the host limestone with phosphoric acids in the guano.Many bellholes have developed in speleothem in the cave ceilings, disproving early theories that they are the result of solution by phreatic currents in flooded caves. A. jamaicensis roosts singly or in harem groups of 2-14 that commonly cluster in the bellholes and it is likely that these social habits of this species focus corrosion resulting from the transfer of feces to rock (producing altered rock then removed by claws) to create discretely-spaced upward-growing cavities. Fossil evidence from Jamaica supports an arrival there from the mainland in the past 12,000 years, suggesting bellholes and bellbasins are geologically recent features in the Caribbean islands. Their locations (not all cave passages have bellholes) can provide information on the hydrological history or microclimate of a cave, due to the absence of both bellholes and bats in some specific situations, e.g. where physical barriers exist such as sumps, small airspaces above streams or through rock collapses, or with increasing distance from an entrance.Smaller circular, increasingly-indented ceiling cavities demonstrate a sequence of bellhole development. Small (23 cm diameter, 9 cm high), circular, streaked cavities in a limestone drainage tunnel constructed in 1927 in

  14. Modeling steam pressure under martian lava flows

    USGS Publications Warehouse

    Dundas, Colin M.; Keszthelyi, Laszlo P.

    2013-01-01

    Rootless cones on Mars are a valuable indicator of past interactions between lava and water. However, the details of the lava–water interactions are not fully understood, limiting the ability to use these features to infer new information about past water on Mars. We have developed a model for the pressurization of a dry layer of porous regolith by melting and boiling ground ice in the shallow subsurface. This model builds on previous models of lava cooling and melting of subsurface ice. We find that for reasonable regolith properties and ice depths of decimeters, explosive pressures can be reached. However, the energy stored within such lags is insufficient to excavate thick flows unless they draw steam from a broader region than the local eruption site. These results indicate that lag pressurization can drive rootless cone formation under favorable circumstances, but in other instances molten fuel–coolant interactions are probably required. We use the model results to consider a range of scenarios for rootless cone formation in Athabasca Valles. Pressure buildup by melting and boiling ice under a desiccated lag is possible in some locations, consistent with the expected distribution of ice implanted from atmospheric water vapor. However, it is uncertain whether such ice has existed in the vicinity of Athabasca Valles in recent history. Plausible alternative sources include surface snow or an aqueous flood shortly before the emplacement of the lava flow.

  15. 36 CFR 290.4 - Confidentiality of cave location information.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Confidentiality of cave location information. 290.4 Section 290.4 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE CAVE RESOURCES MANAGEMENT § 290.4 Confidentiality of cave location information. (a)...

  16. 36 CFR 290.4 - Confidentiality of cave location information.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Confidentiality of cave location information. 290.4 Section 290.4 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE CAVE RESOURCES MANAGEMENT § 290.4 Confidentiality of cave location information. (a)...

  17. 36 CFR 290.4 - Confidentiality of cave location information.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 2 2014-07-01 2014-07-01 false Confidentiality of cave location information. 290.4 Section 290.4 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE CAVE RESOURCES MANAGEMENT § 290.4 Confidentiality of cave location information. (a)...

  18. 36 CFR 290.4 - Confidentiality of cave location information.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Confidentiality of cave location information. 290.4 Section 290.4 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE CAVE RESOURCES MANAGEMENT § 290.4 Confidentiality of cave location information. (a)...

  19. 36 CFR 290.4 - Confidentiality of cave location information.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false Confidentiality of cave location information. 290.4 Section 290.4 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE CAVE RESOURCES MANAGEMENT § 290.4 Confidentiality of cave location information. (a)...

  20. 75 FR 4417 - Wind Cave National Park, Custer County, SD

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-27

    ... Wind Cave National Park, Custer County, SD AGENCY: National Park Service. ACTION: Notice of... Statement, Wind Cave National Park, Custer County, South Dakota. SUMMARY: Pursuant to Section 102(2)(C) of... Environmental Impact Statement (Plan), Wind Cave National Park, Custer County, South Dakota. On December 3,...

  1. 36 CFR 7.68 - Russell Cave National Monument.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Russell Cave National... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.68 Russell Cave National Monument. (a) Caves—(1) Closed Areas. Entering, exploring, or remaining within any cave area other than the...

  2. 36 CFR 7.68 - Russell Cave National Monument.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Russell Cave National... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.68 Russell Cave National Monument. (a) Caves—(1) Closed Areas. Entering, exploring, or remaining within any cave area other than the...

  3. 36 CFR 7.68 - Russell Cave National Monument.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Russell Cave National... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.68 Russell Cave National Monument. (a) Caves—(1) Closed Areas. Entering, exploring, or remaining within any cave area other than the...

  4. 36 CFR 7.68 - Russell Cave National Monument.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Russell Cave National... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.68 Russell Cave National Monument. (a) Caves—(1) Closed Areas. Entering, exploring, or remaining within any cave area other than the...

  5. ACCESS MARS: Study of the viability of Mars Caves as an alternative to surface-based habitation solutions

    NASA Astrophysics Data System (ADS)

    Perez-Poch, Antoni; Laufer, Ren; Zavaleta, Jhony; Davila, Alfonso; Gallardo, Beatriz; Antonakopoulos, Konstantinos; de Carufel, Guy

    This paper summarizes a team project report that was produced during the Summer Space Program of the International Space University, held at NASA-Ames Research Center (CA, USA), by 56 students from 15 countries. Chair of the team project was René Laufer. Facilitators were Alfonso Dévila and Jhonny Zavaleta, and teacher associate supporting the team was a Beatriz Gallardo. Currently proposed Mars missions have identified a number of challenges such as high levels of radiation, harsh climate and limited launch windows. Recently discovered lava tubes on Mars present potential solutions to some of these issues, but raise a variety of intriguing new challenges. These encompass not only technological and engineering considerations, but also legal, ethical and societal issues such as planetary protection and crew safety. This paper assesses the feasibility of overcoming such challenges through the exploitation of Mars caves. Cave suitability is considered with respect to size, type, location and their potential to mitigate hazards. They are also assessed with respect to their potential for scientific work adhering to astrobiology guidelines and the search for extra-terrestrial life. This report compares surface and subsurface habitat options. Engineering challenges arising from the use of caves are addressed along with proposals for alternate architecture solutions. Different types of habitat are described and evaluated. The implications of sub-surface operations on thermal control, communications and power systems are investigated, and recommendations given. Crew selection, training methods and life support system solutions are also addressed. A Mission architecture analysis from the same Team Project is given in another paper from the same authors, at COSPAR 2010 B02 Technical Session. The ACCESS Mars Team concludes that using lava tubes as human habitats is not merely a viable habitat solution for a Mars expedition, but also potentially more beneficial than proposed

  6. Using Lava Tube Skylights To Derive Lava Eruption Temperatures on Io

    NASA Astrophysics Data System (ADS)

    Davies, Ashley Gerard; Keszthelyi, Laszlo P.; McEwen, Alfred S.

    2015-11-01

    The eruption temperature of Io’s silicate lavas constrains Io’s interior state and composition [1]. We have examined the theoretical thermal emission from lava tube skylights above basaltic and ultramafic lava channels. Assuming that tube-fed lava flows are common on Io, skylights could also be common. Skylights present steady thermal emission on a scale of days to months. We find that the thermal emission from such a target, measured at multiple visible and NIR wavelengths, can provide a highly accurate diagnostic of eruption temperature. However, the small size of skylights means that close flybys of Io are necessary, requiring a dedicated Io mission [2]. Observations would ideally be at night or in eclipse. We have modelled the thermal emission spectrum for different skylight sizes, lava flow stream velocities, end-member lava compositions, and skylight radiation shape factors, determining the resulting flow surface cooling rates. We calculate the resulting thermal emission spectrum as a function of viewing geometry. From the resulting 0.7:0.9 μm ratios, we see a clear distinction between basaltic and ultramafic compositions for skylights smaller than 20 m across, even if sub-pixel. Our analysis will be further refined as accurate high-temperature short-wavelength emissivity values become available [3]. This work was performed at the Jet Propulsion Laboratory-California Institute of Technology, under contract to NASA. We thank the NASA OPR Program for support. References: [1] Keszthelyi et al. (2007) Icarus 192, 491-502 [2] McEwen et al. (2015) The Io Volcano Observer (IVO) LPSC-46 abstract 1627 [3] Ramsey and Harris (2015) IAVCEI-2015, Prague, Cz. Rep., abstract IUGG-3519.

  7. Atmospheric /sup 222/Rn in tourist caves of Slovenia, Yugoslavia

    SciTech Connect

    Kobal, I.; Smodis, B.; Burger, J.; Skofljanec, M.

    1987-04-01

    Radon-222 concentrations in the air of 12 tourist caves in Slovenia, Yugoslavia were measured. In almost all the caves concentrations are higher than in the outdoor air, with the highest concentration in the Tabor Cave at about 6000 Bq m-3. From the /sup 222/Rn concentrations obtained, the activity of /sup 222/Rn inhaled by a visitor breathing cave air was calculated, and the bronchial dose was estimated. The inhaled activity and the bronchial dose were highest in the Tabor Cave with values of 10 kBq and 540 microSv, respectively.

  8. Lava Flows and Lava Tubes: What They Are, How They Form (DVD)

    NASA Astrophysics Data System (ADS)

    Garcia, Michael O.

    This DVD is a treat for volcanologists, Earth scientists, and others who are curious about volcanoes. Beautiful photography of lava flows from the current eruption of Kilauea Volcano in Hawaii is explained by volcanologist Ken Hon, a noted authority on the formation of lava flow fields. Hon and Gansecki are with the Geology Department at the University of Hawaii at Hilo, which provides them with close proximity to document the wonders and changing personality of the ongoing Pu'u'O'o eruption. They are assisted by volcanologist Jenda Johnson.

  9. Is Radon Emission in Caves Causing Deletions in Satellite DNA Sequences of Cave-Dwelling Crickets?

    PubMed Central

    Allegrucci, Giuliana; Sbordoni, Valerio; Cesaroni, Donatella

    2015-01-01

    The most stable isotope of radon, 222Rn, represents the major source of natural radioactivity in confined environments such as mines, caves and houses. In this study, we explored the possible radon-related effects on the genome of Dolichopoda cave crickets (Orthoptera, Rhaphidophoridae) sampled in caves with different concentrations of radon. We analyzed specimens from ten populations belonging to two genetically closely related species, D. geniculata and D. laetitiae, and explored the possible association between the radioactivity dose and the level of genetic polymorphism in a specific family of satellite DNA (pDo500 satDNA). Radon concentration in the analyzed caves ranged from 221 to 26000 Bq/m3. Specimens coming from caves with the highest radon concentration showed also the highest variability estimates in both species, and the increased sequence heterogeneity at pDo500 satDNA level can be explained as an effect of the mutation pressure induced by radon in cave. We discovered a specific category of nuclear DNA, the highly repetitive satellite DNA, where the effects of the exposure at high levels of radon-related ionizing radiation are detectable, suggesting that the satDNA sequences might be a valuable tool to disclose harmful effects also in other organisms exposed to high levels of radon concentration. PMID:25822625

  10. Instrumenting caves to collect hydrologic and geochemical data: case study from James Cave, Virginia

    USGS Publications Warehouse

    Schreiber, Madeline E.; Schwartz, Benjamin F.; Orndorff, William; Doctor, Daniel H.; Eagle, Sarah D.; Gerst, Jonathan D.

    2015-01-01

    Karst aquifers are productive groundwater systems, supplying approximately 25 % of the world’s drinking water. Sustainable use of this critical water supply requires information about rates of recharge to karst aquifers. The overall goal of this project is to collect long-term, high-resolution hydrologic and geochemical datasets at James Cave, Virginia, to evaluate the quantity and quality of recharge to the karst system. To achieve this goal, the cave has been instrumented for continuous (10-min interval) measurement of the (1) temperature and rate of precipitation; (2) temperature, specific conductance, and rate of epikarst dripwater; (3) temperature of the cave air; and (4) temperature, conductivity, and discharge of the cave stream. Instrumentation has also been installed to collect both composite and grab samples of precipitation, soil water, the cave stream, and dripwater for geochemical analysis. This chapter provides detailed information about the instrumentation, data processing, and data management; shows examples of collected datasets; and discusses recommendations for other researchers interested in hydrologic and geochemical monitoring of cave systems. Results from the research, briefly described here and discussed in more detail in other publications, document a strong seasonality of the start of the recharge season, the extent of the recharge season, and the geochemistry of recharge.

  11. Is radon emission in caves causing deletions in satellite DNA sequences of cave-dwelling crickets?

    PubMed

    Allegrucci, Giuliana; Sbordoni, Valerio; Cesaroni, Donatella

    2015-01-01

    The most stable isotope of radon, 222Rn, represents the major source of natural radioactivity in confined environments such as mines, caves and houses. In this study, we explored the possible radon-related effects on the genome of Dolichopoda cave crickets (Orthoptera, Rhaphidophoridae) sampled in caves with different concentrations of radon. We analyzed specimens from ten populations belonging to two genetically closely related species, D. geniculata and D. laetitiae, and explored the possible association between the radioactivity dose and the level of genetic polymorphism in a specific family of satellite DNA (pDo500 satDNA). Radon concentration in the analyzed caves ranged from 221 to 26,000 Bq/m3. Specimens coming from caves with the highest radon concentration showed also the highest variability estimates in both species, and the increased sequence heterogeneity at pDo500 satDNA level can be explained as an effect of the mutation pressure induced by radon in cave. We discovered a specific category of nuclear DNA, the highly repetitive satellite DNA, where the effects of the exposure at high levels of radon-related ionizing radiation are detectable, suggesting that the satDNA sequences might be a valuable tool to disclose harmful effects also in other organisms exposed to high levels of radon concentration.

  12. Comparison of Natural Dams from Lava Flows and Landslides on the Owyhee River, Oregon

    NASA Astrophysics Data System (ADS)

    Ely, L. L.; Brossy, C. C.; Othus, S. M.; Orem, C.; Fenton, C.; House, P. K.; O'Connor, J. E.; Safran, E. B.

    2008-12-01

    Numerous large lava flows and mass movements have temporarily dammed the Owyhee River in southeastern Oregon at various temporal and spatial scales. These channel-encroaching events potentially play a significant role in creating and maintaining the geomorphic features of river canyons in uplifted volcanic terranes that compose a significant part of the western U.S. Abundant landslides and lava flows have the capacity to inhibit incision by altering channel slope, width, and bed character, and burying valley- bottom bedrock under exogenous material; or promote incision by generating cataclysmic floods through natural dam failures. The natural dams vary in their source, morphology, longevity and process of removal, which in turn affects the extent and duration of their impact on the river. The 3 most recent lava flows filled the channel 10-75 m deep and flowed up to 26 kilometers downvalley, creating long, low dams that were subject to gradual, rather than catastrophic, removal. In the last 125 ka, the Saddle Butte and West Crater lava dams created reservoirs into which 10-30 meters of silt and sand were deposited. The river overtopped the dams and in most reaches eventually cut a new channel through the adjacent, less resistant bedrock buttresses. Terraces at several elevations downstream and upstream of the West Crater dam indicate periods of episodic incision ranging from 0.28 to 1.7 mm/yr., based on 3He exposure ages on strath surfaces and boulder-rich fluvial deposits. In contrast to the lava dams, outburst flood deposits associated with landslide dams are common along the river. The mechanisms of failure are related to the geologic setting, and include rotational slump complexes, cantilevered blocks and block slides, and massive earthflows. Most large-scale mass movements occur in reaches where the Owyhee canyon incises through stacks of interbedded fluviolacustrine sediments capped with lava flows. The frequently observed association of landslides and flood

  13. Sampling Elysium lavas (13 deg N, 203 deg W)

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.

    1994-01-01

    The proposed Pathfinder landing site presents the opportunity to determine chemical and mineralogical compositions of an Elysium lava flow. The flow is part of a geologic unit of planetary significance. The proposed site appears suitable for landing, and lava surfaces should be accessible to the Pathfinder instruments. By analogy to terrestrial flood basalts, any lava analyzed by Pathfinder is likely to be representative of the entire Elysium province.

  14. Gusev Rocks Solidified from Lava (3-D)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    In recent weeks, as NASA's Mars Exploration Rover Spirit has driven through the basin south of 'Husband Hill,' it has been traversing mainly sand and dune deposits. This week, though, Spirit has been maneuvering along the edge of an arc-shaped feature called 'Lorre Ridge' and has encountered some spectacular examples of basaltic rocks with striking textures. This panoramic camera (Pancam) image shows a group of boulders informally named 'FuYi.' These basaltic rocks were formed by volcanic processes and may be a primary constituent of Lorre Ridge and other interesting landforms in the basin.

    Spirit first encountered basalts at its landing site two years ago, on a vast plain covered with solidified lava that appeared to have flowed across Gusev Crater. Later, basaltic rocks became rare as Spirit climbed Husband Hill. The basaltic rocks that Spirit is now seeing are interesting because they exhibit many small holes or vesicles, similar to some kinds of volcanic rocks on Earth. Vesicular rocks form when gas bubbles are trapped in lava flows and the rock solidifies around the bubbles. When the gas escapes, it leaves holes in the rock. The quantity of gas bubbles in rocks on Husband Hill varies considerably; some rocks have none and some, such as several here at FuYi, are downright frothy.

    The change in textures and the location of the basalts may be signs that Spirit is driving along the edge of a lava flow. This lava may be the same as the basalt blanketing the plains of Spirit's landing site, or it may be different. The large size and frothy nature of the boulders around Lorre Ridge might indicate that eruptions once took place at the edge of the lava flow, where the lava interacted with the rocks of the basin floor. Scientists hope to learn more as Spirit continues to investigate these rocks.

    As Earth approaches the Chinese New Year (The Year of the Dog), the Athena science team decided to use nicknames representing Chinese culture and geography

  15. Gusev Rocks Solidified from Lava (False Color)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    In recent weeks, as NASA's Mars Exploration Rover Spirit has driven through the basin south of 'Husband Hill,' it has been traversing mainly sand and dune deposits. This week, though, Spirit has been maneuvering along the edge of an arc-shaped feature called 'Lorre Ridge' and has encountered some spectacular examples of basaltic rocks with striking textures. This panoramic camera (Pancam) image shows a group of boulders informally named 'FuYi.' These basaltic rocks were formed by volcanic processes and may be a primary constituent of Lorre Ridge and other interesting landforms in the basin.

    Spirit first encountered basalts at its landing site two years ago, on a vast plain covered with solidified lava that appeared to have flowed across Gusev Crater. Later, basaltic rocks became rare as Spirit climbed Husband Hill. The basaltic rocks that Spirit is now seeing are interesting because they exhibit many small holes or vesicles, similar to some kinds of volcanic rocks on Earth. Vesicular rocks form when gas bubbles are trapped in lava flows and the rock solidifies around the bubbles. When the gas escapes, it leaves holes in the rock. The quantity of gas bubbles in rocks on Husband Hill varies considerably; some rocks have none and some, such as several here at FuYi, are downright frothy.

    The change in textures and the location of the basalts may be signs that Spirit is driving along the edge of a lava flow. This lava may be the same as the basalt blanketing the plains of Spirit's landing site, or it may be different. The large size and frothy nature of the boulders around Lorre Ridge might indicate that eruptions once took place at the edge of the lava flow, where the lava interacted with the rocks of the basin floor. Scientists hope to learn more as Spirit continues to investigate these rocks.

    As Earth approaches the Chinese New Year (The Year of the Dog), the Athena science team decided to use nicknames representing Chinese culture and geography

  16. Magnetostratigraphy of cave sediments, Wyandotte Ridge, Crawford County, southern Indiana

    SciTech Connect

    Pease, P.P.; Gomez, B. . Dept. of Geography and Geology); Schmidt, V.A. . Dept. of Geology and Planetary Science)

    1992-01-01

    The field polarities of 42 sediment samples obtained from 21 sites in Wyandotte Cave, and five smaller satellite caves in Wyandotte Ridge, southern Indiana, have been determined and correlated with magnetostratigraphic data from Mammoth Cave, Kentucky. In Wyandotte Cave sediment samples obtained between 137 m and 162 m in elevation possessed a normal field polarity, while samples obtained between 168 m and 171 m exhibited a field reversal. The reversal was interpreted to represent the most recent polarity change, dating the sediment fill and the end of the active period of the upper level of Wyandotte Cave at ca 0.788 Ma. There is a temporal correlation between the active period of the upper level in Wyandotte Cave and the C-level in Mammoth Cave, which lies at a similar elevation. Such a correlation is most likely a consequence of the contemporaneous abandonment of passages in the two cave systems during the early Pleistocene reconstruction of the Ohio River system, which acts as the base level control in both caves. Samples from two caves near the top of Wyandotte Ridge, located between elevations of 236 m and 241 m, exhibited a normal polarity. These caves are located at a higher elevation than any of the sample sites in Mammoth Cave and their location suggests that the fill predates sediments from that system. It appears most likely that the fill in these caves is a minimum of ca 2.48 Ma. old and correlates with the residuum of the upper Mitchell Plain surface, not with the fill in the upper (A- or B-levels) in Mammoth Cave.

  17. Identifying hazards associated with lava deltas

    USGS Publications Warehouse

    Poland, Michael P.; Orr, Tim R.

    2014-01-01

    Lava deltas, formed where lava enters the ocean and builds a shelf of new land extending from the coastline, represent a significant local hazard, especially on populated ocean island volcanoes. Such structures are unstable and prone to collapse—events that are often accompanied by small explosions that can deposit boulders and cobbles hundreds of meters inland. Explosions that coincide with collapses of the East Lae ‘Apuki lava delta at Kīlauea Volcano, Hawai‘i, during 2005–2007 followed an evolutionary progression mirroring that of the delta itself. A collapse that occurred when the lava–ocean entry was active was associated with a blast of lithic blocks and dispersal of spatter and fine, glassy tephra. Shortly after delta growth ceased, a collapse exposed hot rock to cold ocean water, resulting in an explosion composed entirely of lithic blocks and lapilli. Further collapse of the delta after several months of inactivity, by which time it had cooled significantly, resulted in no recognizable explosion deposit. Seaward displacement and subsidence of the coastline immediately inland of the delta was measured by both satellite and ground-based sensors and occurred at rates of several centimeters per month even after the lava–ocean entry had ceased. The anomalous deformation ended only after complete collapse of the delta. Monitoring of ground deformation may therefore provide an indication of the potential for delta collapse, while the hazard associated with collapse can be inferred from the level of activity, or the time since the last activity, on the delta.

  18. Geochemical Stratigraphy of Southern Parana' Lava Piles

    NASA Astrophysics Data System (ADS)

    Marzoli, A.; De Min, A.; Marques, L. S.; Nardy, A.; Chiaradia, M.

    2015-12-01

    Basaltic lava flows of the Paranà Large Igneous Province exhibit significant regional and stratigraphic geochemical variations. While the most notable difference concerns the dominance of low-Ti (TiO2 < 2.0 wt.%) and high-Ti types in the southern and northern part of the province, respectively, detailed analyses of lava flow sequences sampled mostly in drill cores allowed definition of six main groups of chemically distinct flow units. The chemical and possible age differences among these units were then used to define the global time-related evolution of Paranà basaltic magmatism and involvement of distinct mantle-source components. Newly sampled outcropping lava flow sequences from the southern Paranà do however only partially support this picture. Our new major and trace element and Sr-Nd-Pb isotopic data show that high- and low-Ti basaltic flows are interlayered. In particular, Pitanga type high-Ti basalts are interlayered with Gramado and Esmeralda low-Ti basalts (these latter being present both towards the base and the top of the sequence) in Paranà State, while in Santa Caterina State Gramado flows are interlayered with Urubici-type high-Ti basalts. The interlayering of distinct basaltic magma type requires near-synchronous eruption of chemically strongly different magma types generated from clearly heterogeneous mantle sources and erupted through separated magma plumbing systems, without apparent interaction (mixing) among the distinct basalts. In conclusion, the relative timing of low- and high-Ti magma types seems to be much more complicated than previously thought, as for example Esmeralda or Pitanga basalts, previously considered as quite late and postdating Gramado basalts, are indeed synchronous with them.

  19. The Crystals Cave in a test tube

    NASA Astrophysics Data System (ADS)

    Puig, C.; Romero, M. L.

    2012-04-01

    It's quite easy to understand formation of crystals in Nature by evaporation of the solutions that contain minerals, but many times we have realised that our pupils hardly understand that precipitation is a process mostly caused by changing parameters in a solution, like pH, temperature, etc. and not necessarily depending on evaporation. We propose a hands-on activity using the context of the Cave of the Crystals in Naica's mine, Mexico. The Crystals Cave is a wonderful place where giant crystals of selenite (gypsum) have grown feeding from a supersaturated anhydrite solution1. Miners discovered the cave filled with hot water, and drained it to explore the gallery. The cave is now a giant laboratory where scientists are looking for the keys to understand geological processes. Teaching sequence (for students 15 years old) is as follows: DISCOVERING A MARVELLOUS PLACE: We showed our pupils several images and a short video of the Cave of the Crystals and ask them about the process that may have caused the phenomenon. Whole-class discussion. PRESENTING A CHALLENGE TO OUR STUDENTS: "COULD WE CREATE A CRYSTALS CAVE IN A TEST TUBE?" EXPERIMENTING TO IMITATE NATURE: Students tried to grow crystals simulating the same conditions as those in Naica's mine. We have chosen KNO3, a salt more soluble than gypsum. We added 85 g of salt to 200 ml of water (solubility of KNO3 at 25°C is 36 g per 100 gr of water) and heated it until it is dissolved. Afterwards, we poured the solution into some test tubes and other recipients and let them cool at room temperature. And they got a beautiful crystals cave!! THINKING A LITTLE MORE: we asked pupils some questions to make them think about the process and to predict what would happen in different situations. For example: a) What would happen with crystals if we heated the tubes again? or b) What would happen if we took the remaining solution from the tubes and keep it in the fridge? PROVING A NEW HYPOTHESIS: Pupils collected the remaining

  20. Intraformational deformation in the tuffs and lavas of Calico Hills exposed near Yucca Mountain, Nevada

    SciTech Connect

    Buesch, D.C. ); Dickerson, R.P. )

    1993-04-01

    The 12.9 Ma tuffs and lavas of Calico Hills (CH) records development of part of the Southwest Nevada Volcanic Field that formed during intermittent periods of extensional tectonism. Exposures of the CH in upper Paintbrush Canyon, 6 km northeast of Yucca Mountain, consists of five lava flows interstratified with pyroclastic flow and fallout deposits, and fluvially redeposited sediment. The lower part of the exposures (shown in cross section below) consists of a lava flow (L1), interbedded primary and redeposited tuffaceous deposits (R1a and R1b), massive breccia deposit (M1), lava flow (L2), massive breccia deposit (M2), and redeposited tuffaceous deposits (R2). Moderately developed stratification at the base of massive breccia deposit M1 and localized concentrations of lithic fragments throughout the deposit indicates probably deposition from a pyroclastic flow. Bedding in R1, R2, and the base of M1 (dashed line) parallels stratigraphic unit contacts. An intraformational unconformity between R1 subunits (solid line) is interpreted as a fluctuation in local base level, or minor folding prior to deposition of R1b. Northward thinning of post-R1 rocks indicate L1 and R1 were folded into a southeast plunging anticline that formed a topographic high; across which M1 was deposited and against which L2, M2, and R2 abutted. Because post-R2 CH deposits shown no significant intraformational deformation at this location, most deformation described here occurred early in the depositional history of the CH and resulted from localized compression synchronous with regional extension or localized tumescence associated with volcanism.

  1. Lava thicknesses: Implications for rheological and crustal development

    NASA Technical Reports Server (NTRS)

    Kilburn, C. R. J.; Lopes, R. M. C.

    1988-01-01

    The morphology of a lava flow is strongly influenced by its rheological structure. The rheological structure is, in turn, dependent on numerous factors including: (1) bulk composition, (2) crystallingity, (3) vesicularity, and (4) crustal development. Identifying which of the latter factors are most significant, and hence most readily investigated by remote-sensing techniques, is necessary to clarify short-term objectives and expectations from the study of Martian lava flows. Insights into the rheological controls on flow morphology are provided by variations in thickness of undrained lava streams on Etna and Vesuvius, Southern Italy. Both pahoehoe and aa lavas were studied.

  2. Lava tubes - Potential shelters for habitats. [on moon

    NASA Technical Reports Server (NTRS)

    Horz, F.

    1985-01-01

    Natural caverns occur on the moon in the form of 'lava tubes', which are the drained conduits of underground lava rivers. The inside dimensions of these tubes measure tens to hundreds of meters, and their roofs are expected to be thicker than 10 meters. Consequently, lava tube interiors offer an environment that is naturally protected from the hazards of radiation and meteorite impact. Further, constant, relatively benign temperatures of -20 C prevail. These are extremely favorable environmental conditions for human activities and industrial operations. Significant operational, technological, and economical benefits might result if a lunar base were constructed inside a lava tube.

  3. Determining the Compositions of Extraterrestrial Lava Flows

    NASA Technical Reports Server (NTRS)

    Fink, Jonathan H.

    2002-01-01

    The primary purpose of this research project has been to develop techniques that allow the emplacement conditions of volcanic landforms on other planets to be related to attributes that can be remotely detected with available instrumentation. The underlying assumption of our work is that the appearance of a volcano, lava flow, debris avalanche, or exhumed magmatic intrusion can provide clues about the conditions operating when that feature was first emplaced. Magma composition, amount of crustal heat flow, state of tectonic stress, and climatic conditions are among the important variables that can be inferred from the morphology and texture of an igneous body.

  4. Altered former alkalic carbonatite lava from Oldoinyo Lengai, Tanzania: Inferences for calcite carbonatite lavas

    NASA Astrophysics Data System (ADS)

    Dawson, J. B.; Garson, M. S.; Roberts, B.

    1987-08-01

    The active volcano Oldoinyo Lengai, Tanzania, is well known for its extrusions of alkalic carbonatite lava, first witnessed in 1960. An older carbonatite flow from the volcano was originally also rich in Na and K, but replacement of nyerereite by pirssonite as a result of leaching of these elements (together with soluble components such as SO3, Cl, and Rb) and addition of Ca has resulted in a rock intermediate in bulk composition between the unique 1960 Lengai lavas and calcite-rich carbonatite flows reported from other localities. Further replacement of Na by Ca could theoretically result in a pure calcite rock, and we suggest that the partially altered alkalic lava described here is the “missing link” between lavas that are now calcitic but which had a high alkali content when originally extruded. The suggested link between alkali carbonate precursors and present-day calcium carbonate “lavas” explains the apparent paradox between the existence of calcite-rich “flows” and the experimental evidence that denies the possibility of hot, liquid calcium carbonate.

  5. Topographic Attributes of Three Hawaiian Lava Flows: Implications for Evaluation of Lava Flow Emplacement on Mars

    NASA Astrophysics Data System (ADS)

    Zimbelman, J. R.

    2004-12-01

    Differential Global Positioning System surveys were carried out recently across portions of three lava flows on the Big Island of Hawaii. Transects crossed an entire flow in several cases, and in other cases provided detailed information about selected flow margins. The 1907 basalt (a'a) flow from the southwestern rift zone of Mauna Loa has easy access at several points via the Ocean View Estates road system; flow thickness ranges from about 1 m near the middle of the eastern flow lobe to more than 10 m toward the distal end of this flow. Several components of a benmoreite (alkali-rich basaltic andesite) flow complex from Mauna Kea were examined near the small community of Mana (with permission of the Parker Ranch management), on the western flank of the volcano. The flows are more than 14,000 years old and completely covered with soil more than a meter thick, but flow morphology at the decameter scale remains very evident in aerial photographs; some benmoreite flows have up to 30 m of relief along their middle reaches. A trachyte flow more than 100,000 years old extends down slope from Puu Waawaa, on the northern flank of Hualalai; Puu Anahulu represents a very advanced stage of magmatic differentiation that resulted in a flow complex with more than 120 m of relief at its southern margin. Width/thickness represents a good discriminator between these three Hawaiian lava flows. Unfortunately, width is often the most difficult parameter to measure remotely for flows on other planets. Recent imaging data from the Thermal Emission Imaging System on the Mars Odyssey spacecraft reveal important new details of lava flows in the Tharsis region of Mars, some of which can be combined with elevation information from the Mars Orbiter Laser Altimeter. The precise topographic characteristics of diverse Hawaiian lava flows provide a new tool for evaluating the potential emplacement conditions for some Martian lava flows, which appear to be more consistent with the basalt to

  6. Impacts of cave air ventilation and in-cave prior calcite precipitation on Golgotha Cave dripwater chemistry, southwest Australia

    NASA Astrophysics Data System (ADS)

    Treble, Pauline C.; Fairchild, Ian J.; Griffiths, Alan; Baker, Andy; Meredith, Karina T.; Wood, Anne; McGuire, Elizabeth

    2015-11-01

    Speleothem trace element chemistry is an important component of multi-proxy records of environmental change but a thorough understanding of hydrochemical processes is essential for its interpretation. We present a dripwater chemistry dataset (PCO2, alkalinity, Ca, SIcc, Mg and Sr) from an eight-year monitoring study from Golgotha Cave, building on a previous study of hydrology and dripwater oxygen isotopes (Treble et al., 2013). Golgotha Cave is developed in Quaternary aeolianite and located in a forested catchment in the Mediterranean-type climate of southwest Western Australia. All dripwaters from each of the five monitored sites become supersaturated with respect to calcite during most of the year when cave ventilation lowers PCO2 in cave air. In this winter ventilation mode, prior calcite precipitation (PCP) signals of increased Mg/Ca and Sr/Ca in dripwater are attributed to stalactite deposition. A fast-dripping site displays less-evolved carbonate chemistry, implying minimal stalactite growth, phenomena which are attributed to minimal degassing because of the short drip interval (30 s). We employ hydrochemical mass-balance modelling techniques to quantitatively investigate the impact of PCP and CO2 degassing on our dripwater. Initially, we reverse-modelled dripwater solutions to demonstrate that PCP is dominating the dripwater chemistry at our low-flow site and predict that PCP becomes enhanced in underlying stalagmites. Secondly, we forward-modelled the ranges of solution Mg/Ca variation that potentially can be caused by degassing and calcite precipitation to serve as a guide to interpreting the resulting stalagmite chemistry. We predict that stalagmite trace element data from our high-flow sites will reflect trends in original dripwater solutes, preserving information on biogeochemical fluxes within our system. By contrast, stalagmites from our low-flow sites will be dominated by PCP effects driven by cave ventilation. Our poorly karstified system allows us

  7. 43 CFR 37.11 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... administrative review or appeal under 43 CFR part 4. (h) If a cave is determined to be significant, its entire... significant caves. 37.11 Section 37.11 Public Lands: Interior Office of the Secretary of the Interior CAVE MANAGEMENT Cave Designation § 37.11 Nomination, evaluation, and designation of significant caves....

  8. Delineating recharge areas for Onondaga and Cathedral Caves using groundwater tracing techniques

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Onondaga Cave and Cathedral Cave are two large, significant cave systems with active streams located along the Meramec River in the Ozarks ecoregion of Missouri. Groundwater dye tracing has delineated recharge areas for both caves in order to aid in the management of the cave systems by Onondaga Cav...

  9. The transport of CO2 into central Texas caves (Invited)

    NASA Astrophysics Data System (ADS)

    Breecker, D.; Banner, J. L.; Larson, T.

    2013-12-01

    It is well established that CO2 is flushed out of caves by seasonal or synoptic temperature- and barometric pressure-driven ventilation. The mechanism by which CO2 is transported into caves is not as well studied and must be understood in order to quantify carbon (C) cycling through caves, soils and epikarst. Transport mechanisms into caves include gas and aqueous phase (i.e. drip-water) transport. We interpret δ13C values of cave-air CO2 and O2/Ar ratios of cave-air in order to distinguish between these transport mechanisms in three central Texas caves. Gas phase transport might allow cave-air to be used as a simple proxy for otherwise largely inaccessible epikarst air. Drip-water transport might allow measurements of individual drips to be scaled up to cave-integrated assessment of water flux, calcite precipitation, and degassing-related isotope fractionation using measurements of cave-air CO2. We start by assuming gas phase transport and then evaluate the consistency of the results. We apply to cave-air CO2 the theory for steady state soil CO2 transport, which involves mixing with atmospheric air and isotope fractionation by diffusion. This allows calculation of the C isotope composition of the reduced C source for cave-air CO2 (δ13Cr). Calculated cave-air δ13Cr values are consistent with observed soil δ13Cr values. For instance, where trees are evenly distributed at the surface, cave-air δ13Cr values (-24‰) remained within 1‰ of tree-dominated soil δ13Cr values and were 3.5 to 4.5 ‰ lower than grass-dominated soil δ13Cr values, suggesting that trees are the dominant C source. This internally consistent explanation suggests that CO2 diffuses and/or advects into these caves as a gas because aqueous transport into caves would likely result in different cave-air and soil δ13Cr values, as described next. The magnitude of the CO2(g) -HCO3-(aq) carbon isotope per mil fractionation factor is -8.4 ‰ at 20.5°C, the mean Inner Space Cavern drip

  10. Lava tube shatter rings and their correlation with lava flux increases at Kīlauea Volcano, Hawai`i

    NASA Astrophysics Data System (ADS)

    Orr, Tim R.

    2011-04-01

    Shatter rings are circular to elliptical volcanic features, typically tens of meters in diameter, which form over active lava tubes. They are typified by an upraised rim of blocky rubble and a central depression. Prior to this study, shatter rings had not been observed forming, and, thus, were interpreted in many ways. This paper describes the process of formation for shatter rings observed at Kīlauea Volcano during November 2005-July 2006. During this period, tilt data, time-lapse images, and field observations showed that episodic tilt changes at the nearby Pu`u `Ō`ō cone, the shallow magmatic source reservoir, were directly related to fluctuations in the level of lava in the active lava tube, with periods of deflation at Pu`u `Ō`ō correlating with increases in the level of the lava stream surface. Increases in lava level are interpreted as increases in lava flux, and were coincident with lava breakouts from shatter rings constructed over the lava tube. The repetitive behavior of the lava flux changes, inferred from the nearly continuous tilt oscillations, suggests that shatter rings form from the repeated rise and fall of a portion of a lava tube roof. The locations of shatter rings along the active lava tube suggest that they form where there is an abrupt decrease in flow velocity through the tube, e.g., large increase in tube width, abrupt decrease in tube slope, and (or) sudden change in tube direction. To conserve volume, this necessitates an abrupt increase in lava stream depth and causes over-pressurization of the tube. More than a hundred shatter rings have been identified on volcanoes on Hawai`i and Maui, and dozens have been reported from basaltic lava fields in Iceland, Australia, Italy, Samoa, and the mainland United States. A quick study of other basaltic lava fields worldwide, using freely available satellite imagery, suggests that they might be even more common than previously thought. If so, this confirms that episodic fluctuation in lava

  11. Lava tube shatter rings and their correlation with lava flux increases at Kīlauea Volcano, Hawai‘i

    USGS Publications Warehouse

    Orr, T.R.

    2011-01-01

    Shatter rings are circular to elliptical volcanic features, typically tens of meters in diameter, which form over active lava tubes. They are typified by an upraised rim of blocky rubble and a central depression. Prior to this study, shatter rings had not been observed forming, and, thus, were interpreted in many ways. This paper describes the process of formation for shatter rings observed at Kīlauea Volcano during November 2005–July 2006. During this period, tilt data, time-lapse images, and field observations showed that episodic tilt changes at the nearby Pu‘u ‘Ō‘ō cone, the shallow magmatic source reservoir, were directly related to fluctuations in the level of lava in the active lava tube, with periods of deflation at Pu‘u ‘Ō‘ō correlating with increases in the level of the lava stream surface. Increases in lava level are interpreted as increases in lava flux, and were coincident with lava breakouts from shatter rings constructed over the lava tube. The repetitive behavior of the lava flux changes, inferred from the nearly continuous tilt oscillations, suggests that shatter rings form from the repeated rise and fall of a portion of a lava tube roof. The locations of shatter rings along the active lava tube suggest that they form where there is an abrupt decrease in flow velocity through the tube, e.g., large increase in tube width, abrupt decrease in tube slope, and (or) sudden change in tube direction. To conserve volume, this necessitates an abrupt increase in lava stream depth and causes over-pressurization of the tube. More than a hundred shatter rings have been identified on volcanoes on Hawai‘i and Maui, and dozens have been reported from basaltic lava fields in Iceland, Australia, Italy, Samoa, and the mainland United States. A quick study of other basaltic lava fields worldwide, using freely available satellite imagery, suggests that they might be even more common than previously thought. If so, this confirms that episodic

  12. Bed Bugs FAQs

    MedlinePlus

    ... Tropical Diseases Laboratory Diagnostic Assistance [DPDx] Parasites Home Bed Bugs FAQs Recommend on Facebook Tweet Share Compartir On ... are bed bugs treated and prevented? What are bed bugs? Bed bugs ( Cimex lectularius ) are small, flat, parasitic ...

  13. Peralkaline silicate lavas at Oldoinyo Lengai, Tanzania

    NASA Astrophysics Data System (ADS)

    Klaudius, Jurgis; Keller, Jörg

    2006-10-01

    A detailed study of Oldoinyo Lengai has led to the recognition of two major cone-building stages. An early, predominantly phonolitic stage, Lengai I, forms the southern cone. The recent nephelinitic Lengai II developed following a major sector collapse event over Lengai I. Petrography of Lengai II lavas show that nephelinite is combeite- and wollastonite-bearing. All Oldoinyo Lengai lavas are peralkaline and highly evolved in terms of low Mg#, Ni and Cr values. Within the unique Lengai II combeite-wollastonite-nephelinite (CWN) peralkalinity increases with time to extreme values (Na + K)/Al = 2.36. Mineralogical expression of peralkalinity is the presence of combeite and Na-rich clinopyroxene. In addition, exceptionally high Fe 2O 3 (up to 10.28 wt.%) in nepheline is an indicator for alumina deficiency. Combeite also shows high Fe 3+. Phonolite and CWN of Lengai I and Lengai II show similarly enriched LILE and LREE values and generally parallel patterns in PM normalized and REE plots.

  14. Pressure Analysis for LAVA-OVEN

    NASA Technical Reports Server (NTRS)

    Cendana, Donna Q.

    2014-01-01

    The Lunar Advanced Volatiles Analysis (LAVA) and the Oxygen Volatiles Extraction Node (OVEN) are subsystems included in the Regolith Environment Science, and Oxygen Lunar Volatiles Extraction (RESOLVE) payload bound for the Moon in 2019. This Resource Prospector Mission (RPM) has the objective of landing on a shadowed region of the Moons South Pole to collect data and determine whether the resources could be effectively used for space exploration systems. The quantification of the resources will help understand if it can adequately minimize materials carried from Earth by: providing life support, propellants, construction materials or energy supply to the payload or crew. This paper outlines the procedures done for the pressure analysis of the LAVA-OVEN (LOVEN) Integration Testing. The pressure analysis quantifies how much gases and water are present in the sample tested during the Engineering Testing Unit (ETU) phase of instrument development. Ultimately the purpose of these tests is to improve the estimate of the amount of water in each Lunar sample and reduce the time necessary for this estimate. The governing principle that was used for the analysis is the Ideal Gas Law, PV=nRT where P stands for pressure, V for volume, n for number of moles, R being the gas constant and T for temperature. We also estimate the errors involved in these measured and derived quantities since a key objective of the mission is to estimate the quantity of volatiles present in the lunar samples introduced into OVEN.

  15. A flexible open-source toolkit for lava flow simulations

    NASA Astrophysics Data System (ADS)

    Mossoux, Sophie; Feltz, Adelin; Poppe, Sam; Canters, Frank; Kervyn, Matthieu

    2014-05-01

    Lava flow hazard modeling is a useful tool for scientists and stakeholders confronted with imminent or long term hazard from basaltic volcanoes. It can improve their understanding of the spatial distribution of volcanic hazard, influence their land use decisions and improve the city evacuation during a volcanic crisis. Although a range of empirical, stochastic and physically-based lava flow models exists, these models are rarely available or require a large amount of physical constraints. We present a GIS toolkit which models lava flow propagation from one or multiple eruptive vents, defined interactively on a Digital Elevation Model (DEM). It combines existing probabilistic (VORIS) and deterministic (FLOWGO) models in order to improve the simulation of lava flow spatial spread and terminal length. Not only is this toolkit open-source, running in Python, which allows users to adapt the code to their needs, but it also allows users to combine the models included in different ways. The lava flow paths are determined based on the probabilistic steepest slope (VORIS model - Felpeto et al., 2001) which can be constrained in order to favour concentrated or dispersed flow fields. Moreover, the toolkit allows including a corrective factor in order for the lava to overcome small topographical obstacles or pits. The lava flow terminal length can be constrained using a fixed length value, a Gaussian probability density function or can be calculated based on the thermo-rheological properties of the open-channel lava flow (FLOWGO model - Harris and Rowland, 2001). These slope-constrained properties allow estimating the velocity of the flow and its heat losses. The lava flow stops when its velocity is zero or the lava temperature reaches the solidus. Recent lava flows of Karthala volcano (Comoros islands) are here used to demonstrate the quality of lava flow simulations with the toolkit, using a quantitative assessment of the match of the simulation with the real lava flows. The

  16. Next generation phylogeography of cave and surface Astyanax mexicanus.

    PubMed

    Coghill, Lyndon M; Darrin Hulsey, C; Chaves-Campos, Johel; García de Leon, Francisco J; Johnson, Steven G

    2014-10-01

    The loss of traits is a commonly observed evolutionary pattern in cave organisms, but due to extensive morphological convergence, inferring relationships between cave and surface populations can be difficult. For instance, Astyanax mexicanus (the blind Mexican cavefish) is thought to have repeatedly lost its eyes following colonization of cave environments, but the number of evolutionarily independent invasions of this species into caves remains unclear. Because of these repeated losses, it has become a model organism for studying the genetic basis of phenotypic trait loss. Here we reconstruct a high-resolution phylogeography for A. mexicanus inferred from both mitochondrial DNA and several thousand single nucleotide polymorphisms. We provide novel insight into the origin of cave populations from the Sabinos and Río Subterráneo caves and present evidence that the Sabinos cave population is part of a unique cave lineage unrelated to other A. mexicanus cave populations. Our results indicate A. mexicanus cave populations have at least four independent origins. PMID:25014568

  17. Exploring caves: teaching packet for grades K-3

    USGS Publications Warehouse

    ,

    1998-01-01

    "Exploring Caves" is an interdisciplinary set of materials on caves for grades K-3. Caves entail at least five scientific disciplines: earth science, hydrology, mapping, biology, and anthropology. Each of these disciplines involves a unique content area as well as the development of particular intellectual skills. This unit aims at helping teachers to sort and organize the most important ideas in this rich scientific area. Detailed lesson plans serve as ways to pass these ideas on to very young students. Most American caves are big holes that form in limestone rock. The holes begin as cracks in limestone. The cracks get bigger and bigger. They grow into underground streams, rivers, and even lakes. When water drains away, the waterways turn into open cave tunnels, passages, and caverns. It takes 10,000 to 100,000 years to form a cave big enough for people to move around inside. Water drips constantly in caves. The drips dissolve limestone minerals in one part of the cave. As water dries out, the minerals build up in other places. In this way, beautiful cave rock formations and crystals grow over thousands of years. These rock formations change dark limestone caves into hidden fantasy lands.

  18. Book Review: Caves and Karst of the Yorkshire Dales

    NASA Astrophysics Data System (ADS)

    Westaway, Rob

    2015-10-01

    The British Cave Research Association (BCRA) is the research division of the British Caving Association (BCA), itself the principal society in Britain for those interested in caving, with activities including provision of training and safety certification for cavers and managing access to caves. Although some UK cave-related research is carried out by academics, this tends to be restricted to archaeological investigations of caves that have served as human habitations, and to be focused more on the occupants than the caves themselves. In contrast, most cave exploration is undertaken as a leisure activity, under the auspices of clubs affiliated to the BCA/BCRA, this being indeed virtually the only field of Earth science where amateur investigators can continue to make significant discoveries. Many cave explorers are also affiliated with academic researchers, such as managers of dating laboratories; the synergy between these two groups is highly productive, having resulted for instance in the discovery and exploration in recent years of the vast Ogof Draenen cave system in South Wales, which probably dates back to the Early Pleistocene (e.g., Farrant et al., 2014).

  19. Construction dynamics of a lava channel

    NASA Astrophysics Data System (ADS)

    Harris, Andrew J. L.; Favalli, Massimiliano; Mazzarini, Francesco; Hamilton, Christopher W.

    2009-05-01

    We use a kinematic GPS and laser range finder survey of a 200 m-long section of the Muliwai a Pele lava channel (Mauna Ulu, Kilauea) to examine the construction processes and flow dynamics responsible for the channel-levee structure. The levees comprise three packages. The basal package comprises an 80-150 m wide 'a'a flow in which a ˜2 m deep and ˜11 m wide channel became centred. This is capped by a second package of thin (<45 cm thick) sheets of pahoehoe extending no more than 50 m from the channel. The upper-most package comprises localised 'a'a overflows. The channel itself contains two blockages located 130 m apart and composed of levee chunks veneered with overflow lava. The channel was emplaced over 50 h, spanning 30 May-2 June, 1974, with the flow front arriving at our section (4.4 km from the vent) 8 h after the eruption began. The basal 'a'a flow thickness yields effusion rates of 35 m3 s-1 for the opening phase, with the initial flow advancing across the mapped section at ˜10 m/min. Short-lived overflows of fluid pahoehoe then built the levee cap, increasing the apparent channel depth to 4.8 m. There were at least six pulses at 90-420 m3 s-1, causing overflow of limited extent lasting no more than 5 min. Brim-full flow conditions were thus extremely short-lived. During a dominant period of below-bank flow, flow depth was ˜2 m with an effusion rate of ˜35 m3 s-1, consistent with the mean output rate (obtained from the total flow bulk volume) of 23-54 m3 s-1. During pulses, levee chunks were plucked and floated down channel to form blockages. In a final low effusion rate phase, lava ponded behind the lower blockage to form a syn-channel pond that fed 'a'a overflow. After the end of the eruption the roofed-over pond continued to drain through the lower blockage, causing the roof to founder. Drainage emplaced inflated flows on the channel floor below the lower blockage for a further ˜10 h. The complex processes involved in levee-channel construction

  20. The explosive origin of obsidian lava (Invited)

    NASA Astrophysics Data System (ADS)

    Castro, J. M.; Bindeman, I. N.; Tuffen, H.; Schipper, C.

    2013-12-01

    A long-standing challenge in volcanology has been to explain why explosive eruptions of rhyolite magma transition into outpourings of lava. Many studies suggest that lava is the product of non-explosive processes that allow magmatic vapour to escape in an open-system manner without wholesale fragmentation. Recent eruptions at Chaitén and Cordón Caulle volcanoes have shown that effusive rhyolites are anything but 'non-explosive' and may erupt simultaneously with vigourous pyroclastic fountains for months from a common vent. This behaviour implies that pyroclastic processes play a critical if not dominant role in degassing magma sufficiently such that it erupts effusively. Here we use H-isotope and bulk H2O measurements paired with textural evidence from the 2008 Chaitén and 2011 Cordón Caulle eruptions to demonstrate that effusion requires explosion(s)--lavas are the direct product of brittle deformation that fosters batched degassing into transient pyroclastic channels that repetitively and explosively vent from effusing lava. Evidence for cyclical brecciation and collapse of porous and permeable magmatic foams is abundant in the textures and structures of tuffisites--ash and lapilli-filled pyroclastic channels--found in volcanic bombs at both Chaitén and Cordón Caulle. We have used FTIR and a TCEA-MAT 253 system to precisely measure total water and D/H in erupted glass. Bulk H2O measurements on tuffisite and adjacent bomb obsidian indicate significantly lower H2O (~0.2-1.0 wt.%) in the tuffisite veins. These depletions imply effective local degassing and rapid advective transport of exsolved vapour through the veins. The H-isotopic signatures of tuffisites are also different from the hosting material insofar as being enriched in deuterium (up to -20‰). Such deuterium enrichments are inconsistent with isotope fractionation during both closed- and open-system degassing, but can be explained if an abundant and more primitive volatile phase from less degassed

  1. Actinobacterial Diversity in Volcanic Caves and Associated Geomicrobiological Interactions

    PubMed Central

    Riquelme, Cristina; Marshall Hathaway, Jennifer J.; Enes Dapkevicius, Maria de L. N.; Miller, Ana Z.; Kooser, Ara; Northup, Diana E.; Jurado, Valme; Fernandez, Octavio; Saiz-Jimenez, Cesareo; Cheeptham, Naowarat

    2015-01-01

    Volcanic caves are filled with colorful microbial mats on the walls and ceilings. These volcanic caves are found worldwide, and studies are finding vast bacteria diversity within these caves. One group of bacteria that can be abundant in volcanic caves, as well as other caves, is Actinobacteria. As Actinobacteria are valued for their ability to produce a variety of secondary metabolites, rare and novel Actinobacteria are being sought in underexplored environments. The abundance of novel Actinobacteria in volcanic caves makes this environment an excellent location to study these bacteria. Scanning electron microscopy (SEM) from several volcanic caves worldwide revealed diversity in the morphologies present. Spores, coccoid, and filamentous cells, many with hair-like or knobby extensions, were some of the microbial structures observed within the microbial mat samples. In addition, the SEM study pointed out that these features figure prominently in both constructive and destructive mineral processes. To further investigate this diversity, we conducted both Sanger sequencing and 454 pyrosequencing of the Actinobacteria in volcanic caves from four locations, two islands in the Azores, Portugal, and Hawai'i and New Mexico, USA. This comparison represents one of the largest sequencing efforts of Actinobacteria in volcanic caves to date. The diversity was shown to be dominated by Actinomycetales, but also included several newly described orders, such as Euzebyales, and Gaiellales. Sixty-two percent of the clones from the four locations shared less than 97% similarity to known sequences, and nearly 71% of the clones were singletons, supporting the commonly held belief that volcanic caves are an untapped resource for novel and rare Actinobacteria. The amplicon libraries depicted a wider view of the microbial diversity in Azorean volcanic caves revealing three additional orders, Rubrobacterales, Solirubrobacterales, and Coriobacteriales. Studies of microbial ecology in

  2. Actinobacterial Diversity in Volcanic Caves and Associated Geomicrobiological Interactions.

    PubMed

    Riquelme, Cristina; Marshall Hathaway, Jennifer J; Enes Dapkevicius, Maria de L N; Miller, Ana Z; Kooser, Ara; Northup, Diana E; Jurado, Valme; Fernandez, Octavio; Saiz-Jimenez, Cesareo; Cheeptham, Naowarat

    2015-01-01

    Volcanic caves are filled with colorful microbial mats on the walls and ceilings. These volcanic caves are found worldwide, and studies are finding vast bacteria diversity within these caves. One group of bacteria that can be abundant in volcanic caves, as well as other caves, is Actinobacteria. As Actinobacteria are valued for their ability to produce a variety of secondary metabolites, rare and novel Actinobacteria are being sought in underexplored environments. The abundance of novel Actinobacteria in volcanic caves makes this environment an excellent location to study these bacteria. Scanning electron microscopy (SEM) from several volcanic caves worldwide revealed diversity in the morphologies present. Spores, coccoid, and filamentous cells, many with hair-like or knobby extensions, were some of the microbial structures observed within the microbial mat samples. In addition, the SEM study pointed out that these features figure prominently in both constructive and destructive mineral processes. To further investigate this diversity, we conducted both Sanger sequencing and 454 pyrosequencing of the Actinobacteria in volcanic caves from four locations, two islands in the Azores, Portugal, and Hawai'i and New Mexico, USA. This comparison represents one of the largest sequencing efforts of Actinobacteria in volcanic caves to date. The diversity was shown to be dominated by Actinomycetales, but also included several newly described orders, such as Euzebyales, and Gaiellales. Sixty-two percent of the clones from the four locations shared less than 97% similarity to known sequences, and nearly 71% of the clones were singletons, supporting the commonly held belief that volcanic caves are an untapped resource for novel and rare Actinobacteria. The amplicon libraries depicted a wider view of the microbial diversity in Azorean volcanic caves revealing three additional orders, Rubrobacterales, Solirubrobacterales, and Coriobacteriales. Studies of microbial ecology in

  3. Predecessors of the 2004 Indian Ocean tsunami in a coastal cave, Aceh Province, Sumatra

    NASA Astrophysics Data System (ADS)

    Pilarczyk, J.; Rubin, C. M.; Sieh, K.; Horton, B.; Daly, P.; Majewski, J.; Ismail, N.

    2013-12-01

    Geological studies of coral reefs and coastal plains have uncovered short and incomplete records of predecessors for the 2004 Indian Ocean tsunami. Here we present a longer and more-complete mid- to late Holocene tsunami history from an extraordinary sedimentary deposit in northwestern Aceh Province, Sumatra. We exposed clastic sediment in six trenches up to 2 m deep within a sheltered limestone cave 200 m from the present coastline. The trim line of the 2004 tsunami is about 25 m above sea level and 15 m above the top of the 10-m high entrance to the cave. Within the cave, the deposits of 2004 comprise a 15 - 20 cm thick, laterally continuous sand sheet. Beneath this youngest tsunami sand is a <3-cm thick bed rich in guano dropped by insect feeding bats (Microchiroptera). Many similar couplets of sand and bat guano occur lower in the stratigraphic sequence. The sands have many diagnostic features of the 2004 deposit, namely a distinctly marine geochemical signature, high-diversity foraminiferal assemblages that include offshore species, normal grading, basal rip-up clasts, lenticular laminations, and articulated bivalves. Minor, local, non-tectonic normal and decollement faults that break the layers at several locations are likely due to strong ground shaking. Radiocarbon dating of charcoal and molluscs establish a mid- to late Holocene age range for the tsunami sands. Other than the 2004 deposit, layers younger than about 2,000 years are absent, because by about 2,000 years ago, accommodation space beneath the level of the rocky entrance to the cave had been filled. Pending analyses will reveal whether three clay layers within the sequence are of marine or of freshwater origin.

  4. Age and speleogenesis of epigenic gypsum caves in the northern Apennines (Italy)

    NASA Astrophysics Data System (ADS)

    Columbu, Andrea; Chiarini, Veronica; De Waele, Jo; Drysdale, Russell; Forti, Paolo; Hellstrom, John; Woodhead, Jon

    2016-04-01

    Triassic and Messinian gypsum beds host the majority of the caves in the eastern flank of the northern Apennines. To date, more than six hundreds voids have been mapped, including the longest known epigenic gypsum cave system in the world (Spipola-Acquafredda, ~11 km of tunnels) (De Waele et al., 2013). Superimposed caves are typically sub-horizontal (Klimchouk, 2000) and connected through vertical shafts, reflecting the palaeo base-level variations. When preserved, river terraces at the surface lie at the same palaeo altitude of the base level and horizontal cave passages. Notwithstanding the well-known geology of the area known (Vai and Martini, 2001), the age of these caves has been greatly underestimated in the past. Considering the rapid dissolution of the gypsum and uplifting of the area, the start of speleogenesis activity was considered to have occurred during the last glacial age. The age of karst voids can be only indirectly estimated by the dating of the infilling sediments. U-Th dating on carbonate speleothems provides high-precision and accurate ages (Hellstrom, 2003; Scholz and Hoffmann, 2008). We thus applied this methodology to 20 speleothems coming from 14 different caves belonging to the Monte Tondo, Spipola Acquafredda, Castelnuovo, Stella-Rio Basino and Brisighella systems. The results show that: i) caves were forming since at least ~300 ka; ii) the peak of speleogenesis was reached during relatively cold climate stages, when rivers formed terraces at the surface and aggradation caused paragenesis in the stable cave levels (Columbu et al., 2015). Besides the significant contribution to the understanding of the Apennines evaporite karst evolution, this study (and its further advancement) may also refine knowledge of the local vs regional uplifting rates and base-level variations since the late Pleistocene (Wegmann and Pazzaglia, 2009). References Columbu, A., De Waele, J., Forti, P., Montagna, P., Picotti, V., Pons-Branchu, E., Hellstrom, J

  5. Temperature as tracer of the hydraulic dynamic of an anchialine cave (coastal submerged cave) of Krka Estuary (Croatia)

    NASA Astrophysics Data System (ADS)

    Domínguez-Villar, David; Cukrov, Neven; Krklec, Kristina

    2016-04-01

    A series of temperature, conductivity and water level loggers were used to characterize the hydraulic dynamic of a submerged cave (anchialine cave) in Krka Estuary. Litno Cave is a sub-horizontal gallery, less than 5 m in diameter and one meter below sea level. Apart from some sections that contain occasional air pockets under the ceiling, the cave is completely flooded. Outflow discharge through the cave is continuous during the year (>30 l/s). During several months vertical temperature profiles were measured in three locations inside the cave at 20, 60 and 100 m from the cave entrance, whereas another vertical profile was set in the estuary in front of the cave. Thermometers from the estuary measured thermal gradients to characterize position and evolution of the thermocline up to a depth of 3.5 m. Tides measured in the estuary are synchronous to those recorded in the cave and their amplitudes (20 to 40 cm in the estuary) are the same or smaller depending on cave outflow discharge. Records of cave water temperature show a non-linear response to tides due to the vertical displacement of the thermocline. During neap tides the thermocline was located in the aquifer below the cave, whereas during spring tides only thermometers in the top meter of the cave were not affected by the thermocline vertical displacement. After the first significant rains of the hydrological year, the freshwater contribution increased the cave outflow discharge by one order of magnitude. Thus, conductivity decreased in response to rains from 16000 ±1000 μS/cm to <700 μS/cm at the bottom of the cave. Under these conditions variability of cave water temperature was less than 0.1 °C, although a 0.4 °C long-term variability was recorded. These data shows that the discharge of freshwater to the estuary determines the dynamic of this submerged cave, limiting the influence of estuarine water intrusion in the coastal aquifer and the impact of tides. This research shows that temperature is a

  6. Biomineralization and biosignatures of coralloid-type speleothems from lava tubes of Galapagos Islands: evidences on the fossil record of prokaryotes

    NASA Astrophysics Data System (ADS)

    Miller, Ana Z.; Garcia-Sanchez, Angela M.; Pereira, Manuel F. C.; Gazquez, Fernando; Calaforra, José M.; Forti, Paolo; Toulkeridis, Theofilos; Martínez-Frías, Jesús; Saiz-Jimenez, Cesareo

    2016-04-01

    Lava tubes have traditionally been considered of little interest from a mineralogical point of view. Recently, this type of volcanic caves has received particular attention because lava tubes have been described on Mars. Speleothems, or secondary mineral deposits in lava tubes are mainly composed of siliceous minerals. Coralloid-type speleothems are found either on basaltic cave walls or on the surface of other speleothems. Several authors attribute a microbially mediated origin to their formation. This type of speleothems was recorded within Royal Palm Cave of Santa Cruz Island in Galapagos Archipelago (Ecuador), a lava tube 600 m long, 5 to 15 m height and 2 to 10 m width. The Galapagos Islands are an archipelago of 19 volcanic islands located some 1500 km west of Ecuador, in the Pacific Ocean. These islands host one of the most biodiverse settings on Earth, studied by Charles Darwin. Beige and greyish small coralloids were collected in Royal Palm Cave and analysed by field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDS), X-ray micro-computed tomography (micro-CT) and mineralogical analyses for morphological, 3D microstructural and compositional characterization, as well as for assessing microbe-mineral interactions and biogenicity. In addition, 16S rRNA gene analyses were performed to identify microbial communities associated with the coralloid-type speleothems. The coralloids showed internal compositional zonation along the growth direction of the speleothems, according to micro-CT data. Internal layering was clearly discernable by the differences in opacity of the distinct mineralogical phases to X-rays, being dominated by alteration products of siliceous composition, whereas more opaque phases, usually Ca-rich minerals, were dominant in the outermost part of the speleothems. X-ray diffraction and infrared spectroscopy reinforced that the first stage of deposition is mainly composed of opal A and clay minerals

  7. Small domes on Venus: probable analogs of Icelandic lava shields

    USGS Publications Warehouse

    Garvin, James B.; Williams, Richard S.

    1990-01-01

    On the basis of observed shapes and volumetric estimates, we interpret small, dome-like features on radar images of Venus to be analogs of Icelandic lava-shield volcanoes. Using morphometric data for venusian domes in Aubele and Slyuta (in press), as well as our own measurements of representative dome volumes and areas from Tethus Regio, we demonstrate that the characteristic aspect ratios and flank slopes of these features are consistent with a subclass of low Icelandic lava-shield volcanoes (LILS ). LILS are slightly convex in cross-section with typical flank slopes of ∼3°. Plausible lava-shield-production rates for the venusian plains suggest formation of ∼53 million shields over the past 0.25 Ga. The cumulative global volume of lava that would be associated with this predicted number of lava shields is only a factor of 3–4 times that of a single oceanic composite shield volcano such as Mauna Loa. The global volume of all venusian lava shields in the 0.5–20-km size range would only contribute a meter of resurfacing over geologically significant time scales. Thus, venusian analogs to LILS may represent the most abundant landform on the globally dominant plains of Venus, but would be insignificant with regard to the global volume of lava extruded. As in Iceland, associated lavas from fissure eruptions probably dominate plains volcanism and should be evident on the higher resolution Magellan radar images.

  8. Lava Flows on Io: Modelling Cooling After Solidification

    NASA Technical Reports Server (NTRS)

    Davies, A. G.; Matson, D. L.; Veeder, G. J.; Johnson, T. V.; Blaney, D. L.

    2003-01-01

    We have modeled the cooling of lava bodies on Io after solidification of the lava, a process that has been little explored since Carr (1986). With recent estimates of lava flow thicknesses on Io ranging from 1 m to 10 m, the modeling of thermal emission from active volcanism must take into account the cooling behaviour after the solidification of the lava, which we model using a finite-element model. Once a lava body is fully solidified, the surface temperature decreases faster, as heat loss is no longer buffered by release of latent heat. This is significant as observed surface temperature is often the only clue available to determine lava surface age. We also find that cooling from the base of the lava is an important process that accelerates the solidification of a flow and therefore subsequent cooling. It is necessary to constrain the cooling process in order to better understand temperature-area relationships on Io's surface and to carry out stochastic modelling of lava flow emplacement.

  9. Measuring the Rate of Lava Effusion by InSAR

    NASA Astrophysics Data System (ADS)

    Wadge, G.

    2004-06-01

    The rate at which lava emerges from a volcano is a fundamental property of the dynamics of the eruption. Intensive field measurements can capture this. However, for many, often cloud-covered, volcanoes with long-lived eruptions, spaceborne InSAR provides a potentially useful source of information. Repeated DEM creation at intervals allows the changing thickness of the lava flow field to be measured and incremental changes to calculate the volumetric lava flux rate. ERS data from (i) an andesitic lava dome eruption at Soufri re Hills, Montserrat , and (ii) a basaltic andesite lava flow-field at Arenal volcano, Costa Rica illustrate the method. There are two main limitations. Firstly, flowing or otherwise thermo- mechanically unstable surfaces that are active between interferogram pair acquisitions leads to decorrelation. This effect is particularly difficult on lava domes where the surface is extremely dynamic. Compound lava flow-fields are more tractable. Secondly, very slight motions on flows that have "stopped" can be confused with topography in repeat-pass interferograms. The InSAR-measured rate of lava effusion at Arenal fits well with rates calculated by other methods over the last 30 years. Radar systems best suited to this task should be L-band, have short orbit repeat intervals and moderate perpendicular baselines.

  10. Extremely acidic, pendulous cave wall biofilms from the Frasassi cave system, Italy.

    PubMed

    Macalady, Jennifer L; Jones, Daniel S; Lyon, Ezra H

    2007-06-01

    The sulfide-rich Frasassi cave system hosts an aphotic, subsurface microbial ecosystem including extremely acidic (pH 0-1), viscous biofilms (snottites) hanging from the cave walls. We investigated the diversity and population structure of snottites from three locations in the cave system using full cycle rRNA methods and culturing. The snottites were composed primarily of bacteria related to Acidithiobacillus species. Other populations present in the snottites included Thermoplasmata group archaea, bacteria related to Sulfobacillus, Acidimicrobium, and the proposed bacterial lineage TM6, protists, and filamentous fungi. Based on fluorescence in situ hybridization population counts, Acidithiobacillus are key members of the snottite communities, accompanied in some cases by smaller numbers of archaea related to Ferroplasma and other Thermoplasmata. Diversity estimates show that the Frasassi snottites are among the lowest-diversity natural microbial communities known, with one to six prokaryotic phylotypes observed depending on the sample. This study represents the first in-depth molecular survey of cave snottite microbial diversity and population structure, and contributes to understanding of rapid limestone dissolution and cave formation by microbially mediated sulfuric acid speleogenesis.

  11. A Biosignature Suite from Cave Pool Precipitates, Cottonwood Cave, New Mexico

    NASA Astrophysics Data System (ADS)

    Melim, L. A.; Liescheidt, R.; Northup, D. E.; Spilde, M. N.; Boston, P. J.; Queen, J. M.

    2009-11-01

    Calcite cave pool precipitates often display a variety of potential biosignatures from the macroscopic to the submicroscopic. A fossil cave pool in Cottonwood Cave, New Mexico, exhibits older stalactites and stalagmites that are completely coated in brown, laminated calcitic crust that extends down as pool fingers and u-loops. The pool fingers and u-loops are mainly micrite to clotted micrite, some recrystallized to microspar, with some isopachous spar layers. Micrite, particularly clotted micrite, is usually interpreted by carbonate workers as microbial in origin. Scanning electron microscopy examination of etched pool fingers, u-loops, and the brown crust revealed abundant calcified microbial filaments and biofilm. Energy dispersive X-ray analysis showed that these features have excess carbon, above that found in pure calcite. Independent carbon analysis indicated that these same samples contain up to 0.2% organic carbon. Since pool fingers hang down but form underwater, we hypothesize they are biogenic with hanging microbial filaments or biofilm acting as nuclei for calcite precipitation. Because of the abundance of micrite and fossil filaments, we further hypothesize that these pendant features formed during a period of plentiful nutrients and active hydrological activity when the pool was literally dripping with microbial slime. Although each of these lines of evidence could be interpreted in other ways, their combined weight strongly suggests the cave pool precipitates in Cottonwood Cave are biogenic. These investigations can be used to help inform extraterrestrial life-detection studies.

  12. A biosignature suite from cave pool precipitates, Cottonwood Cave, New Mexico.

    PubMed

    Melim, L A; Liescheidt, R; Northup, D E; Spilde, M N; Boston, P J; Queen, J M

    2009-11-01

    Calcite cave pool precipitates often display a variety of potential biosignatures from the macroscopic to the submicroscopic. A fossil cave pool in Cottonwood Cave, New Mexico, exhibits older stalactites and stalagmites that are completely coated in brown, laminated calcitic crust that extends down as pool fingers and u-loops. The pool fingers and u-loops are mainly micrite to clotted micrite, some recrystallized to microspar, with some isopachous spar layers. Micrite, particularly clotted micrite, is usually interpreted by carbonate workers as microbial in origin. Scanning electron microscopy examination of etched pool fingers, u-loops, and the brown crust revealed abundant calcified microbial filaments and biofilm. Energy dispersive X-ray analysis showed that these features have excess carbon, above that found in pure calcite. Independent carbon analysis indicated that these same samples contain up to 0.2% organic carbon. Since pool fingers hang down but form underwater, we hypothesize they are biogenic with hanging microbial filaments or biofilm acting as nuclei for calcite precipitation. Because of the abundance of micrite and fossil filaments, we further hypothesize that these pendant features formed during a period of plentiful nutrients and active hydrological activity when the pool was literally dripping with microbial slime. Although each of these lines of evidence could be interpreted in other ways, their combined weight strongly suggests the cave pool precipitates in Cottonwood Cave are biogenic. These investigations can be used to help inform extraterrestrial life-detection studies.

  13. Analysis of inflated submarine and sub-lacustrine Pahoehoe lava flows using high-resolution bathymetric and lidar data (Invited)

    NASA Astrophysics Data System (ADS)

    Deschamps, A.; Van Vliet-Lanoe, B.; Soule, S. A.; Allemand, P.; Le Saout, M.; Delacourt, C.

    2013-12-01

    . For example, the Hells Half Acres Holocene lava flows, Idaho, display similar morphology as EPR flows, with sheet lavas, flow lobes 5-8 m high and approximately 100 m wide, and pressure ridges. Similar flows are observed in the ESRP: Craters of the Moon, Wapi, and Cerro Grande lava flows for example. In Oregon, Potholes, Devils Garden, Diamond Craters, Deschute River, Owyhee River, Jordan Crater flows are also strictly comparable. In Iceland, Lake Mytvan lava flows, for example, were emplaced in sublacustrine environments, and Budahraun flows in Snaefellness were emplaced at the coast below the sea level. The common point of these presently "aerial" lava flow is their emplacement in lakes, paleo-lakes and river beds, thus in "wet" environment, often controlled by rivers and their tributaries. A more efficient cooling of the lava lobes in wet environment probably triggers the development of strong and plastic margins due to cooling, which resists continued movement of the flow, whereas a thinner margin developing in aerial environment may favor lobe break out when internal pressure rises above the tensile strength of the crust. We propose a theoretical model for these lava flow emplacement on sub-horizontal basement.

  14. Analysis of inflated submarine and sub-lacustrine Pahoehoe lava flows using high-resolution bathymetric and lidar data

    NASA Astrophysics Data System (ADS)

    Deschamps, A.; Soule, S. A.; Le Saout, M.; Allemand, P.

    2012-12-01

    , the Hells Half Acres Holocene lava flows, Idaho, display similar morphology as EPR flows, with sheet lavas, flow lobes 5-8 m high and approximately 100 m wide, and pressure ridges. Similar flows are observed in the ESRP: Craters of the Moon, Wapi, and Cerro Grande lava flows for example. In Oregon, Potholes, Devils Garden, Diamond Craters, Deschute River, Owyhee River, Jordan Crater flows are also strictly comparable. In Iceland, Lake Mytvan lava flows, for example, were emplaced in sublacustrine environments, and Budahraun flows in Snaefellness were emplaced at the coast below the sea level. The common point of these presently "aerial" lava flow is their emplacement in lakes, paleo-lakes and river beds, thus in "wet" environment, often controlled by rivers and their tributaries. A more efficient cooling of the lava lobes in wet environment probably triggers the development of strong and plastic margins due to cooling, which resists continued movement of the flow, whereas a thinner margin developing in aerial environment may favor lobe break out when internal pressure rises above the tensile strength of the crust. We propose a theoretical model for these lava flow emplacement on sub-horizontal basement.

  15. 222Rn variations in Mystery Cave, Minnesota

    USGS Publications Warehouse

    Lively, R.S.; Krafthefer, B.C.

    1995-01-01

    222Rn concentrations and meteorological parameters were measured at 4- h intervals over a 2-y period in Mystery Cave, southeastern Minnesota. Continuous radon monitors and meteorological sensors connected to data loggers were installed at several locations along commercial tour routes. 222Rn concentrations ranged as high as 25 kBq m-3 in summer and 20 kBq m-3 in winter. Average winter concentrations were lower than summer by at least a factor of two. Seasonal radon variations were correlative with outside air temperatures. During the winter, radon concentrations were observed to fluctuate periodically by factors of 20 or more in under 24 h. Both the long- and short-term variations are correlative with temperature- induced mixing of cave air with surface air.

  16. 222Rn variations in Mystery Cave, Minnesota.

    PubMed

    Lively, R S; Krafthefer, B C

    1995-04-01

    222Rn concentrations and meteorological parameters were measured at 4-h intervals over a 2-y period in Mystery Cave, southeastern Minnesota. Continuous radon monitors and meteorological sensors connected to data loggers were installed at several locations along commercial tour routes. 222Rn concentrations ranged as high as 25 kBq m-3 in summer and 20 kBq m-3 in winter. Average winter concentrations were lower than summer by at least a factor of two. Seasonal radon variations were correlative with outside air temperatures. During the winter, radon concentrations were observed to fluctuate periodically by factors of 20 or more in under 24 h. Both the long- and short-term variations are correlative with temperature-induced mixing of cave air with surface air.

  17. Sensing Structures Inspired by Blind Cave Fish

    NASA Astrophysics Data System (ADS)

    McConney, Michael E.; Chen, Nannan; Lu, David; Anderson, Kyle D.; Hu, Huan; Liu, Chang; Tsukruk, Vladimir V.

    2009-03-01

    Blind cave fish, with degenerated non-functioning eyes, have evolved to ``see'' their hydrodynamic environment by using the flow receptors of the lateral line system. The hair-cell receptors are encapsulated in a hydrogel-like material, called a cupula, which increases the sensitivity of the hair-cell receptors by coupling their motion to the surrounding flowing media. We characterized the viscoelastic properties and of blind cave fish cupulae by using colloidal-probe spectroscopy in fluid. A photo-patternable hydrogel with similar properties was developed to mimic the fish receptor coupling structure. Flow-based measurements indicated that the hydrogels enhance drag through increased surface area, but also inherent material properties. These bio-inspired structures endowed micro-fabricated flow sensors with sensitivities rivaling that of fish.

  18. Shallow outgassing changes disrupt steady lava lake activity, Kilauea Volcano

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  19. Morphology and dynamics of inflated subaqueous basaltic lava flows

    NASA Astrophysics Data System (ADS)

    Deschamps, Anne; Grigné, Cécile; Le Saout, Morgane; Soule, Samuel Adam; Allemand, Pascal; Van Vliet-Lanoe, Brigitte; Floc'h, France

    2014-06-01

    eruptions onto low slopes, basaltic Pahoehoe lava can form thin lobes that progressively coalesce and inflate to many times their original thickness, due to a steady injection of magma beneath brittle and viscoelastic layers of cooled lava that develop sufficient strength to retain the flow. Inflated lava flows forming tumuli and pressure ridges have been reported in different kinds of environments, such as at contemporary subaerial Hawaiian-type volcanoes in Hawaii, La Réunion and Iceland, in continental environments (states of Oregon, Idaho, Washington), and in the deep sea at Juan de Fuca Ridge, the Galapagos spreading center, and at the East Pacific Rise (this study). These lava have all undergone inflation processes, yet they display highly contrasting morphologies that correlate with their depositional environment, the most striking difference being the presence of water. Lava that have inflated in subaerial environments display inflation structures with morphologies that significantly differ from subaqueous lava emplaced in the deep sea, lakes, and rivers. Their height is 2-3 times smaller and their length being 10-15 times shorter. Based on heat diffusion equation, we demonstrate that more efficient cooling of a lava flow in water leads to the rapid development of thicker (by 25%) cooled layer at the flow surface, which has greater yield strength to counteract its internal hydrostatic pressure than in subaerial environments, thus limiting lava breakouts to form new lobes, hence promoting inflation. Buoyancy also increases the ability of a lava to inflate by 60%. Together, these differences can account for the observed variations in the thickness and extent of subaerial and subaqueous inflated lava flows.

  20. Toxicity and Geochemistry of Missouri Cave Stream Sediments

    NASA Astrophysics Data System (ADS)

    Lawler, C. A.; Besser, J.; Wicks, C. M.

    2005-05-01

    Water and sediment quality are among the most important variables affecting the survival of stygobites. In Tumbling Creek Cave, Taney County Missouri the population of the endangered cave snail, Antrobia culveri, has declined significantly over the past decade. The cause of the population decline is unknown but could be related to the quality of streambed sediment in which the cave snail lives. The objective of this study was to determine the toxicity and concentrations of heavy metals in the sediment of Tumbling Creek Cave and five other caves in Missouri. These sediments were analyzed to assess possible point sources from within the recharge areas of the caves and to provide baseline geochemical data to which Tumbling Creek Cave sediments could be compared. Standard sediment toxicity tests and ICP-MS analysis for heavy metals were conducted. Survival and reproduction of the amphipod, Hyalella azteca, did not differ significantly between cave sediments and a control sediment. However the growth of amphipods differed significantly among sites and was significantly reduced in sediments from Tumbling Creek Cave relative to controls. Concentrations of several metals in sediments differed substantially among locations, with elevated levels of zinc and copper occurring in Tumbling Creek Cave. However, none of the measured metal concentrations exceeded sediment quality guidelines derived to predict probable effects on benthic organisms and correlations between sediment metal concentrations and toxicity endpoints were generally weak. While elevated metal levels may play a part in the cave snail's decline, other factors may be of equal or greater importance. Ongoing analyses of persistent organic contaminants and total organic carbon in cave sediments, along with continued water quality monitoring, may provide data that will allow us to better understand this complicated problem.

  1. An American scientist visits the Altamira cave in northern Spain

    SciTech Connect

    Wilkening, M.

    1981-12-01

    The Altamira Cave is internationally known for its remarkable Stone Age paintings. It is located in the brow of a hill overlooking the village of Santillana del Mar which is nestled among green rolling hills near the coast of northern Spain. This report gives a brief description of the Cave and its paintings, the nature of the deterioration that has resulted in the closing of the cave to tourists, and the scientific studies being undertaken to help preserve the paintings.

  2. Rheological analyses of lava flows on Mars

    NASA Technical Reports Server (NTRS)

    Moore, H. J.; Davis, P. A.

    1991-01-01

    Researchers obtained 183 profiles of lava flows on Mars using photoclinometry. These photoclinometric profiles were leveled by adjusting them until the levee crests or bases had the same elevations (depending on the situation). Here, researchers report some of the results of their analysis of 27 flows on the flanks of Alba Patera (3 flows), near the summit of Ascraeus Mons (6 flows), the flanks of Arsia Mons (3 flows), and the flanks of Olympus Mons (15 flows). Results suggest that the flows examined to date are not felsic or ultramafic; rather, they probably range from basalts to basaltic andesites. Thus, the suggestion that flows on Olympus Mons and elsewhere may be more silicic than Hawaiian basalts is supported by the researchers' results. These suggestions are testable with suitable measurements of silica contents of the flows.

  3. Venus - Complex Lava Flows at Sif Mons

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This is a full resolution mosaic centered at 25 degrees north latitude, 351 east longitude. The region is approximately 160 kilometers (100 miles) across. It shows a series of complex lava flows which emerge from the northern flank of Sif Mons, a large volcano just to the south. Several of the flows occupy narrow troughs formed by long fractures. A sequence of events that can be inferred from this image is the formation of the dark background plains by eruptions of extremely fluid volcanic material, and the formation of the small shield volcanoes on the plains surface that can be seen in the upper left part of the image. Next, the region was domed upward probably by heat from the interior of Venus that ultimately caused magmas to break out from the surface near the summit regions forming the Sif volcanic structure and its associated flank eruptions which can be seen in this image.

  4. Cave biosignature suites: microbes, minerals, and Mars.

    PubMed

    Boston, P J; Spilde, M N; Northup, D E; Melim, L A; Soroka, D S; Kleina, L G; Lavoie, K H; Hose, L D; Mallory, L M; Dahm, C N; Crossey, L J; Schelble, R T

    2001-01-01

    Earth's subsurface offers one of the best possible sites to search for microbial life and the characteristic lithologies that life leaves behind. The subterrain may be equally valuable for astrobiology. Where surface conditions are particularly hostile, like on Mars, the subsurface may offer the only habitat for extant lifeforms and access to recognizable biosignatures. We have identified numerous unequivocally biogenic macroscopic, microscopic, and chemical/geochemical cave biosignatures. However, to be especially useful for astrobiology, we are looking for suites of characteristics. Ideally, "biosignature suites" should be both macroscopically and microscopically detectable, independently verifiable by nonmorphological means, and as independent as possible of specific details of life chemistries--demanding (and sometimes conflicting) criteria. Working in fragile, legally protected environments, we developed noninvasive and minimal impact techniques for life and biosignature detection/characterization analogous to Planetary Protection Protocols. Our difficult field conditions have shared limitations common to extraterrestrial robotic and human missions. Thus, the cave/subsurface astrobiology model addresses the most important goals from both scientific and operational points of view. We present details of cave biosignature suites involving manganese and iron oxides, calcite, and sulfur minerals. Suites include morphological fossils, mineral-coated filaments, living microbial mats and preserved biofabrics, 13C and 34S values consistent with microbial metabolism, genetic data, unusual elemental abundances and ratios, and crystallographic mineral forms.

  5. The longevity of lava dome eruptions

    NASA Astrophysics Data System (ADS)

    Wolpert, Robert L.; Ogburn, Sarah E.; Calder, Eliza S.

    2016-02-01

    Understanding the duration of past, ongoing, and future volcanic eruptions is an important scientific goal and a key societal need. We present a new methodology for forecasting the duration of ongoing and future lava dome eruptions based on a database (DomeHaz) recently compiled by the authors. The database includes duration and composition for 177 such eruptions, with "eruption" defined as the period encompassing individual episodes of dome growth along with associated quiescent periods during which extrusion pauses but unrest continues. In a key finding, we show that probability distributions for dome eruption durations are both heavy tailed and composition dependent. We construct objective Bayesian statistical models featuring heavy-tailed Generalized Pareto distributions with composition-specific parameters to make forecasts about the durations of new and ongoing eruptions that depend on both eruption duration to date and composition. Our Bayesian predictive distributions reflect both uncertainty about model parameter values (epistemic uncertainty) and the natural variability of the geologic processes (aleatoric uncertainty). The results are illustrated by presenting likely trajectories for 14 dome-building eruptions ongoing in 2015. Full representation of the uncertainty is presented for two key eruptions, Soufriére Hills Volcano in Montserrat (10-139 years, median 35 years) and Sinabung, Indonesia (1-17 years, median 4 years). Uncertainties are high but, importantly, quantifiable. This work provides for the first time a quantitative and transferable method and rationale on which to base long-term planning decisions for lava dome-forming volcanoes, with wide potential use and transferability to forecasts of other types of eruptions and other adverse events across the geohazard spectrum.

  6. Correlation of the Deccan and Rajahmundry Trap lavas: Are these the longest and largest lava flows on Earth?

    USGS Publications Warehouse

    Self, S.; Jay, A.E.; Widdowson, M.; Keszthelyi, L.P.

    2008-01-01

    We propose that the Rajahmundry Trap lavas, found near the east coast of peninsular India, are remnants of the longest lava flows yet recognized on Earth (??? 1000??km long). These outlying Deccan-like lavas are shown to belong to the main Deccan Traps. Several previous studies have already suggested this correlation, but have not demonstrated it categorically. The exposed Rajahmundry lavas are interpreted to be the distal parts of two very-large-volume pa??hoehoe flow fields, one each from the Ambenali and Mahabaleshwar Formations of the Wai Sub-group in the Deccan Basalt Group. Eruptive conditions required to emplace such long flows are met by plausible values for cooling and eruption rates, and this is shown by applying a model for the formation of inflated pa??hoehoe sheet flow lobes. The model predicts flow lobe thicknesses similar to those observed in the Rajahmundry lavas. For the last 400??km of flow, the lava flows were confined to the pre-existing Krishna valley drainage system that existed in the basement beyond the edge of the gradually expanding Deccan lava field, allowing the flows to extend across the subcontinent to the eastern margin where they were emplaced into a littoral and/or shallow marine environment. These lavas and other individual flow fields in the Wai Sub-group may exceed eruptive volumes of 5000??km3, which would place them amongst the largest magnitude effusive eruptive units yet known. We suggest that the length of flood basalt lava flows on Earth is restricted mainly by the size of land masses and topography. In the case of the Rajahmundry lavas, the flows reached estuaries and the sea, where their advance was perhaps effectively terminated by cooling and/or disruption. However, it is only during large igneous province basaltic volcanism that such huge volumes of lava are erupted in single events, and when the magma supply rate is sufficiently high and maintained to allow the formation of very long lava flows. The Rajahmundry lava

  7. International comparison of cave radon concentrations identifying the potential alpha radiation risks to British cave users

    SciTech Connect

    Hyland, R.; Gunn, J.

    1994-08-01

    Elevated concentrations of {sup 222}Rn have been recorded in many limestone caves throughout the world. As prolonged exposure to high radon concentrations has been linked to cancer and tumors, particularly of the lung, a national survey of radon in British caves was undertaken. Passive radon detectors were exposed at 250 sites in 47 caves over four 7-d sampling periods. Mean concentrations ranging from 454-8,868 Bq m{sup {minus}3} were recorded. In one system, in the Peak District, radon concentrations of 155,000 Bq m{sup {minus}3} were recorded. The results indicate that the potential radiation dose from a single 4-h trip could exceed the national average annual background radiation dose (for the UK) from radon of 1.25 mSv. 18 refs., 3 tabs.

  8. Legal protection for caves in the United States

    NASA Astrophysics Data System (ADS)

    Huppert, G. N.

    1995-09-01

    This study reviews significant state and federal laws that can be used to protect karst, caves, and associated unique minerals and biota. The first state cave protection act was passed in Colorado in 1883; unfortunately it was repealed in 1971. From that modest beginning there are now a total of 22 states, Puerto Rico, and the Cherokee Nation that have specific cave protection acts. Most of these have been legislated during the last 20 years. There are a number of laws on the federal level that can be used for cave protection. The most important of these is the Federal Cave Resources Protection Act of 1988, which mandates cave conservation for many federal land management agencies. The Endangered Species Act of 1973 and the Federal Archaeological Resources Protection Act of 1976 can also be of significant use in the conservation of caves on federal land. The effects of these acts are variable. One factor is how important agency officials and law enforcement officers regard caves. It has not been unusual that little was done in the way of protection or prosecution even when the perpetrators have been apprehended. This attitude is changing rapidly primarily because those involved in enforcing the laws have been educated to the uniqueness and values of caves and their contents.

  9. 6. Photographic copy of historic photograph (from Wind Cave National ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Photographic copy of historic photograph (from Wind Cave National Park), photographer unknown, date unknown. Route 87, Pigtail Bridge, elevation. - Pigtail Bridge, Hot Springs, Fall River County, SD

  10. Interdisciplinary research produces results in the understanding of planetary caves

    NASA Astrophysics Data System (ADS)

    Titus, Timothy; Boston, Penelope J.

    2012-05-01

    First International Planetary Cave Research Workshop: Implications for Astrobiology, Climate, Detection, and Exploration; Carlsbad, New Mexico, 25-28 October 2011 With the advent of high-resolution spatial imaging, the idea of caves on other planets has moved from the pages of science fiction into the realm of hard-core science—complete with hypotheses, models, experiments, and observational data. Recently acquired data from spacecraft, together with terrestrial analogs and numerical models, are providing new insights into caves on Earth as well as caves on other terrestrial planetary bodies (e.g., Moon, Mars, and Titan).

  11. Pre-excavation studies of prehistoric cave sites by magnetic prospecting

    NASA Astrophysics Data System (ADS)

    Itkis., Sonia; Matskevich, Zinovii; Meshveliani, Tengiz

    2014-05-01

    Detailed magnetic survey was performed for caves study in Israel (1995-1996) within the framework of the Beit Shemesh Regional Project (Judean Shephelah). The experience accumulated in Israel we applied later (2010) in two Georgian prehistoric cave sites: Cherula and Kotias-Klde. The magnetic method is based on the contrast in magnetic properties between a target object (e.g., buried archaeological feature) and the host medium (i.e, the surrounding bedrock and soil). The feasibility of the magnetic method for cave revealing was evaluated by magnetic susceptibility (κ) measurements of surrounding soil and rocks, and archaeological features: stones making up the walls, ceramic fragments and cave fill. According to data obtained, the κ of soil within caves (cave fill) is higher than that of surrounding soil. The enhancement of cave fill κ occurs because processes associated with human habitation: repeated heating and accumulation of organic debris. Both these processes provide good conditions for the conversion of the iron oxide found within the soil to a strongly ferromagnetic form (Mullins, 1977; Maher, 1986; Dalan and Banerjee, 1998, Itkis and Eppelbaum, 1999; Itkis, 2003) The presence of highly magnetic ceramics in caves also enhances magnetic contrast between practically non-magnetic bed rock (chalk in Ramat Beit Shemesh Site (Israel) and limestone (Georgian sites) and the cave fill, increasing the potential of the magnetic method to reveal caves (Itkis, 2011). Based on magnetic survey results, an excavation revealed a cave with a large amount of well preserved pottery and finds typical of the Early Bronze Age. Both studied cave sites in Georgia were located in Chiatura region of Imeretia province. Cherula site is a karstic rockshelter with a single chamber, ca 100 sq. m. The site was briefly tested in 1970s'. The area excavated in 2010 went to the depth of 60 cm below the present day surface; the limestone bedrock was not reached. The excavation revealed

  12. Some deep caves in Biokovo Mountain (Croatia)

    NASA Astrophysics Data System (ADS)

    Garasic, Mladen; Garasic, Davor

    2014-05-01

    The investigation of 3 caves explored more than 1000 meters in depth in the Dinaric karst area in Croatia, has been in progress for a considerable period of time. These are complex speleological features situated in the longest mountain range of the Dinaric karst, i.e. at the Northern Velebit mountain range. In fact, these caves have been studied for over two decades now. The first one is a cave system of Lukina jama (Luke's Cave) - Trojama cave, which has been investigated until the depth of 1421 meters (Jalžić, 2007; Šmida, 1993). Its total length is 3731 meters and a new expedition will soon continue to investigate this pit through speleodiving in siphons. The second greatest cave by depth is Slovačka jama (Slovak Cave), 1320 meters in depth, with cave chanals measuring 5677 meters in total length. The third greatest cave by depth is the Cave system of Velebita, reaching down to 1026 m in depth, with the chanal length of 3176 meters (Bakšić, 2006a; 2006b). However, another 3 speleological sites, which can rightly be added to those deeper than 1000 m, have recently been discovered. These are three caverns that were discovered during construction of the Sveti Ilija Tunnel that passes through Mt. Biokovo, in the Dinaric karst area. These caverns undoubtedly point to the link with the ground surface, while the rock overburden above the tunnel in the zone where the caverns were discovered ranges from 1250 and 1350 meters. Bats from the ground surface were found in the caverns and, according to measurements, they are situated in the depth from 200 and 300 meters below the tunnel level. This would mean that the depth of these newly found caves ranges from 1450 and 1650 m, when observed from the ground surface. There are several hundreds of known caves in Biokovo, and the deepest ones discovered so far are Jama Mokre noge (Wet Feet Cave) 831 m in depth, and Jama Amfora (Amphora Cave) 788 m in depth (Bockovac, 1999; Bakšić & all, 2002; Lacković & all, 2001

  13. Pre-excavation studies of prehistoric cave sites by magnetic prospecting

    NASA Astrophysics Data System (ADS)

    Itkis., Sonia; Matskevich, Zinovii; Meshveliani, Tengiz

    2014-05-01

    Detailed magnetic survey was performed for caves study in Israel (1995-1996) within the framework of the Beit Shemesh Regional Project (Judean Shephelah). The experience accumulated in Israel we applied later (2010) in two Georgian prehistoric cave sites: Cherula and Kotias-Klde. The magnetic method is based on the contrast in magnetic properties between a target object (e.g., buried archaeological feature) and the host medium (i.e, the surrounding bedrock and soil). The feasibility of the magnetic method for cave revealing was evaluated by magnetic susceptibility (κ) measurements of surrounding soil and rocks, and archaeological features: stones making up the walls, ceramic fragments and cave fill. According to data obtained, the κ of soil within caves (cave fill) is higher than that of surrounding soil. The enhancement of cave fill κ occurs because processes associated with human habitation: repeated heating and accumulation of organic debris. Both these processes provide good conditions for the conversion of the iron oxide found within the soil to a strongly ferromagnetic form (Mullins, 1977; Maher, 1986; Dalan and Banerjee, 1998, Itkis and Eppelbaum, 1999; Itkis, 2003) The presence of highly magnetic ceramics in caves also enhances magnetic contrast between practically non-magnetic bed rock (chalk in Ramat Beit Shemesh Site (Israel) and limestone (Georgian sites) and the cave fill, increasing the potential of the magnetic method to reveal caves (Itkis, 2011). Based on magnetic survey results, an excavation revealed a cave with a large amount of well preserved pottery and finds typical of the Early Bronze Age. Both studied cave sites in Georgia were located in Chiatura region of Imeretia province. Cherula site is a karstic rockshelter with a single chamber, ca 100 sq. m. The site was briefly tested in 1970s'. The area excavated in 2010 went to the depth of 60 cm below the present day surface; the limestone bedrock was not reached. The excavation revealed

  14. Similarities in basalt and rhyolite lava flow emplacement processes

    NASA Astrophysics Data System (ADS)

    Magnall, Nathan; James, Mike; Tuffen, Hugh; Vye-Brown, Charlotte

    2016-04-01

    Here we use field observations of rhyolite and basalt lava flows to show similarities in flow processes that span compositionally diverse lava flows. The eruption, and subsequent emplacement, of rhyolite lava flows is currently poorly understood due to the infrequency with which rhyolite eruptions occur. In contrast, the emplacement of basaltic lava flows are much better understood due to very frequent eruptions at locations such as Mt Etna and Hawaii. The 2011-2012 eruption of Cordón Caulle in Chile enabled the first scientific observations of the emplacement of an extensive rhyolite lava flow. The 30 to 100 m thick flow infilled a topographic depression with a negligible slope angle (0 - 7°). The flow split into two main channels; the southern flow advanced 4 km while the northern flow advanced 3 km before stalling. Once the flow stalled the channels inflated and secondary flows or breakouts formed from the flow front and margins. This cooling rather than volume-limited flow behaviour is common in basaltic lava flows but had never been observed in rhyolite lava flows. We draw on fieldwork conducted at Cordón Caulle and at Mt Etna to compare the emplacement of rhyolite and basaltic flows. The fieldwork identified emplacement features that are present in both lavas, such as inflation, breakouts from the flow font and margins, and squeeze-ups on the flow surfaces. In the case of Cordón Caulle, upon extrusion of a breakout it inflates due to a combination of continued lava supply and vesicle growth. This growth leads to fracturing and breakup of the breakout surface, and in some cases a large central fracture tens of metres deep forms. In contrast, breakouts from basaltic lava flows have a greater range of morphologies depending on the properties of the material in the flows core. In the case of Mt Etna, a range of breakout morphologies are observed including: toothpaste breakouts, flows topped with bladed lava as well as breakouts of pahoehoe or a'a lava. This

  15. Lost Jim Lava Flow, Seward Peninsula, Alaska as an analog for lava-ice interactions on Mars

    NASA Astrophysics Data System (ADS)

    Marcucci, E.; Hamilton, C.; Herrick, R. R.

    2015-12-01

    On Mars, volcanism within Elysium Planitia may have occurred as recently as ~10 million years ago, which associated lava flows being emplaced with ice-bearing permafrost. On Earth, there are few active volcanic regions that are cold enough to support permafrost, but the Seward Peninsula in Alaska is a prime location to study recent volcano-ice interactions. In the early 2000s, J.E. Beget and J.S. Kargel explored two areas in Alaska that exhibit features characteristic of explosive volcanism that may be the result of lava-ice interaction. These locations include the Lost Jim Lava Flow (65°29'N, 163°17'W) and several large maars (66°23'N, 164°29'W). The work presented here focuses on the Lost Jim Lava Flow, emanating from Lost Jim Cone and flowing West and North. The flow was erupted 1000-2000 years ago, covers ~225 km2, and ranges 3-30 m in thickness. Previous fieldwork identified pits along the margins of the flow that were interpreted to be collapse features (i.e., thermokarst) that formed as ground-ice beneath the lava melted due to heat transfer from the overlaying lava flow. This investigation utilizes stereo photogrammetry to generate high-resolution digital terrain models (DTMs) of these flow features to assess if these pits are indeed the products of thermokarstification, or if they are lava-rise pits formed by lava flow inflation. The DTMs were generated from ALOS PRISM data and DigitalGlobe Worldview 1 and 2 panchromatic satellite images taken as stereo-pairs or -triplets. With these new models the extent and morphology of the flow and pits will be categorized across the entire flow. These results are also compared to young lava flows on Mars, which may have experienced lava-ice interactions. Understanding the expression of such interactions on Earth may aid in the identification and interpretation of analogous eruptions on Mars.

  16. Sedimentologic, stratigraphic, and paleoenvironmental study of Paleocene Fort Union Formation in South Cave Hills of Harding County, South Dakota

    SciTech Connect

    Best, W.A.; Rich, F.J.

    1986-08-01

    The Paleocene Fort Union Formation consists of the Ludlow, Cannonball, and Tongue River Members and forms prominent buttes in the Cave Hills, north-central Harding County, South Dakota. Investigations in the North Cave Hills show that cliff-forming Tongue River sandstones are actually the marine Cannonball Member. Field/laboratory studies indicate a similar reinterpretation for the cliff-forming sandstones in the South Cave Hills. These strata include fine to very fine-grained silty/clayey quartz sandstone. Textural analyses indicate the sand grains are subangular to rounded, polished, and of low to moderate sphericity. Sedimentary/biogenic structures indicate a high-energy, mainland beach/nearshore marine depositional environment. The transgressive sequence includes foreshore or littoral, shoreface, and subshoreface or estuarine environments. Foreshore/littoral sediments consist of fine to very fine-grained, moderately well to well-sorted, low-angle wedge planar and wedge trough cross-bedded sandstone. Trace fossils are dominated by Skolithos-like burrows. Marine vertebrate remains include Elasmobrachii sp., Myliobatis sp., and Myledaphus sp. Shoreface deposits are similar to those of the foreshore. Sedimentary structures are dominantly low- and high-angle wedge trough cross-beds. Ophiomorpha burrows occur near the upper contact. Shoreface deposits are separated from the subshoreface deposits by extensively burrowed silty sandstone or an erosional surface. The subshoreface environment produced very fine-grained sandstone interbedded with clay-claystone and clay shale that is very thin to thin bedded with minor amounts of ripple lamination and low-angle cross-stratification. Pseudo-symmetrical and composite ripples; flaser, wavy, and lenticular bedding; and sand-filled trails and burrows are present.

  17. Initial excavation and dating of Ngalue Cave: a Middle Stone Age site along the Niassa Rift, Mozambique.

    PubMed

    Mercader, Julio; Asmerom, Yemane; Bennett, Tim; Raja, Mussa; Skinner, Anne

    2009-07-01

    Direct evidence for a systematic occupation of the African tropics during the early late Pleistocene is lacking. Here, we report a record of human occupation between 105-42ka, based on results from a radiometrically-dated cave section from the Mozambican segment of the Niassa (Malawi/Nyasa) Rift called Ngalue. The sedimentary sequence from bottom to top has five units. We concentrate on the so-called "Middle Beds," which contain a Middle Stone Age industry characterized by the use of the discoidal reduction technique. A significant typological feature is the presence of formal types such as points, scrapers, awls, and microliths. Special objects consist of grinders/core-axes covered by ochre. Ngalue is one of the few directly-dated Pleistocene sites located along the biogeographical corridor for modern human dispersals that links east, central, and southern Africa, and, with further study, may shed new light on hominin cave habitats during the late Pleistocene.

  18. Benchmarking computational fluid dynamics models for lava flow simulation

    NASA Astrophysics Data System (ADS)

    Dietterich, Hannah; Lev, Einat; Chen, Jiangzhi

    2016-04-01

    Numerical simulations of lava flow emplacement are valuable for assessing lava flow hazards, forecasting active flows, interpreting past eruptions, and understanding the controls on lava flow behavior. Existing lava flow models vary in simplifying assumptions, physics, dimensionality, and the degree to which they have been validated against analytical solutions, experiments, and natural observations. In order to assess existing models and guide the development of new codes, we conduct a benchmarking study of computational fluid dynamics models for lava flow emplacement, including VolcFlow, OpenFOAM, FLOW-3D, and COMSOL. Using the new benchmark scenarios defined in Cordonnier et al. (Geol Soc SP, 2015) as a guide, we model viscous, cooling, and solidifying flows over horizontal and sloping surfaces, topographic obstacles, and digital elevation models of natural topography. We compare model results to analytical theory, analogue and molten basalt experiments, and measurements from natural lava flows. Overall, the models accurately simulate viscous flow with some variability in flow thickness where flows intersect obstacles. OpenFOAM, COMSOL, and FLOW-3D can each reproduce experimental measurements of cooling viscous flows, and FLOW-3D simulations with temperature-dependent rheology match results from molten basalt experiments. We can apply these models to reconstruct past lava flows in Hawai'i and Saudi Arabia using parameters assembled from morphology, textural analysis, and eruption observations as natural test cases. Our study highlights the strengths and weaknesses of each code, including accuracy and computational costs, and provides insights regarding code selection.

  19. A comparative Study of Circulation Patterns at Active Lava Lakes

    NASA Astrophysics Data System (ADS)

    Lev, Einat; Oppenheimer, Clive; Spampinato, Letizia; Hernandez, Pedro; Unglert, Kathi

    2016-04-01

    Lava lakes present a rare opportunity to study magma dynamics in a large scaled-up "crucible" and provide a unique natural laboratory to ground-truth dynamic models of magma circulation. The persistence of lava lakes allows for long-term observations of flow dynamics and of lava properties, especially compared to surface lava flows. There are currently five persistent lava lakes in the world: Halemaumau in Kilauea (Hawaii, USA), Erta Ale (Ethiopia), Nyiragongo (Congo), Erebus (Antarctica), and Villarica (Chile). Marum and Benbow craters of Ambrym volcano (Vanuatu) and Masaya (Nicaragua) have often hosted lava lakes as well. We use visible-light and thermal infrared time-lapse and video footage collected at all above lakes (except Villarica, where the lake is difficult to observe), and compare the circulation patterns recorded. We calculate lake surface motion from the footage using the optical flow method (Lev et al., 2012) to produce 2D velocity fields. We mined both the surface temperature field and the surface velocity field for patterns using machine learning techniques such as "self-organizing maps (SOMs)" and "principle component analysis (PCA)". We use automatic detection technique to study the configuration of crustal plates at the lakes' surface. We find striking differences among the lakes, in flow direction, flow speed, frequency of changes in flow direction and speed, location and consistency of upwelling and downwelling, and crustal plate configuration. We relate the differences to lake size, shallow conduit geometry, lava viscosity, crystal and gas content, and crust integrity.

  20. Improvement of a 2D numerical model of lava flows

    NASA Astrophysics Data System (ADS)

    Ishimine, Y.

    2013-12-01

    I propose an improved procedure that reduces an improper dependence of lava flow directions on the orientation of Digital Elevation Model (DEM) in two-dimensional simulations based on Ishihara et al. (in Lava Flows and Domes, Fink, JH eds., 1990). The numerical model for lava flow simulations proposed by Ishihara et al. (1990) is based on two-dimensional shallow water model combined with a constitutive equation for a Bingham fluid. It is simple but useful because it properly reproduces distributions of actual lava flows. Thus, it has been regarded as one of pioneer work of numerical simulations of lava flows and it is still now widely used in practical hazard prediction map for civil defense officials in Japan. However, the model include an improper dependence of lava flow directions on the orientation of DEM because the model separately assigns the condition for the lava flow to stop due to yield stress for each of two orthogonal axes of rectangular calculating grid based on DEM. This procedure brings a diamond-shaped distribution as shown in Fig. 1 when calculating a lava flow supplied from a point source on a virtual flat plane although the distribution should be circle-shaped. To improve the drawback, I proposed a modified procedure that uses the absolute value of yield stress derived from both components of two orthogonal directions of the slope steepness to assign the condition for lava flows to stop. This brings a better result as shown in Fig. 2. Fig. 1. (a) Contour plots calculated with the original model of Ishihara et al. (1990). (b) Contour plots calculated with a proposed model.

  1. Lava flow dynamics driven by temperature-dependent viscosity variations

    NASA Astrophysics Data System (ADS)

    Diniega, S.; Smrekar, S. E.; Anderson, S. W.; Stofan, E. R.

    2011-12-01

    As lava viscosity can change 1-2 orders of magnitude due to small changes in temperature, several studies have predicted the formation of low-viscosity/high-temperature "fingers" (similar to a Saffman-Taylor type instability) within an initially near-uniform flow. We examine the onset and evolution of such fingers within a uniform lava sheet flow due to an influx of lava with slightly-variable temperature. We assume Hele-shaw-type geometry (depth << other dimensions), Newtonian and laminar fluid flow, a simple Nahme's exponential law relating temperature and viscosity, and radiative heat-loss through the flow's upper surface. Through the use of numerical simulation and steady-state analysis of model equations, we identify solutions that provide pahoehoe lava flows with a natural mechanism for the formation of lava channels/tubes within a sheet flow. Preliminary results indicate that flow-focusing occurs rapidly due to the thermo-viscosity relation, but zones of hotter flow commonly settle into a new steady-state and it is difficult to create perpetually-lengthening hot-fingers of lava (which seem more physically similar to developing lava tubes). This suggests that additional and/or discontinuous physical processes (such as decreasing radiative rates due to thickening of the surface crust or crystallization abruptly retarding flow within lower-temperature regions) may play important roles in the continued growth of preferred flow zones. We also derive qualitative and quantitative estimates of environmental controls on finger size, spacing, and location. This work has application to Earth and planetary volcanology studies as pahoehoe flows dominate terrestrial basaltic lavas and the eruption/emplacement mechanics that yield long lava flows on the Earth and Mars are not yet well understood.

  2. Compound Lava Flow Fields on Planetary Surfaces: Hawaiian Analogue Studies

    NASA Astrophysics Data System (ADS)

    Crown, D. A.; Byrnes, J. M.; Ramsey, M. S.

    2002-12-01

    Quantitative, process-oriented analyses of planetary volcanism have primarily been based on analogue studies of single-lobed lava flows emplaced as discrete units. Comparative analyses of compound lava flow fields on the Earth and terrestrial planets are being conducted in order to include volcanic styles characterized by complex distributary systems, stratigraphic relationships, and emplacement histories. Field observations, differential Global Positioning Systems (dGPS) measurements, and visible, thermal, and radar remote sensing are being used to characterize Hawaiian lava flow fields and develop techniques for analyses of planetary flow fields using datasets with high spatial and/or spectral resolution, such as MOC and THEMIS. These terrestrial studies allow flow field surface morphology, topography, and lava textures as well as detailed maps of distributary networks to be used to examine flow field growth and development. Information on flow field evolution is provided by delineating relationships between remote sensing signatures, surface morphology, and lava transport processes and by identifying input parameters for flowfield emplacement models. Investigations of the Mauna Ulu (1969-1974) and Puu Oo (1983-present) flow fields (Kilauea Volcano, HI) have focused on understanding the nature of distributary networks at various scales in order to determine spatial and temporal variations in lava transport. Initial work at Mauna Ulu has included analyses of 1) the distribution, network morphometry, and volumetric significance of lava channels in the medial zone of the flow field, and 2) the distribution, lava texture, and volumetric significance of breakouts from surface conduits and subsurface storage. Analyses of the temporal evolution of individual conduit systems provide the basis for interpretation of complex patterns of overlapping surface units that characterize local flow stratigraphy. Reconstruction of lava transport networks and relationships to surface

  3. Monitoring of Radon in Tourist Part of Skocjan Caves

    NASA Astrophysics Data System (ADS)

    Debevec Gerjevic, Vanja; Jovanovic, Peter

    2010-05-01

    Due to their exceptional significance for cultural and natural heritage, the Škocjan Caves were entered on UNESCO's list of natural and cultural world heritage sites in 1986. Park Škocjan Caves is located in South Eastern part of Slovenia. It was established with aim of conserving and protecting exceptional geomorphological, geological and hydrological outstanding features, rare and endangered plant and animal species, paleontological and archaeological sites, ethnological and architectural characteristics and cultural landscape and for the purpose of ensuring opportunities for suitable development, by the National Assembly of the Republic of Slovenia in 1996. Park Škocjan Caves established monitoring that includes caves microclimate parameters: humidity, CO2, wind flow and radon concentration and daughter products. The approach in managing the working place with natural background radiation is complex. Monitoring of Radon has been functioning for more than ten years now. Presentation will show the yearly dynamic observed in the different parts of the caves, related to radon daughter products and other microclimatic data, beside the most convenient measuring technique. Implementing the Slovene legislation in the field of radiation protection, we are obligated to perform special measurements in the caves and also having our guides and workers in the caves regularly examined according to established procedure. The medical exams are performed at Institution of Occupational Safety, Ljubljana in order to monitor the influence of Radon to the workers in the cave. The equivalent dose for each employed person is also established on regular basis and it is part of medical survey of workers in the caves. The survey will be described along with education of the staff working in the caves in the field of radiation protection. An overview of Slovene legislation with practical example on implementation will be demonstrated in the case of Škocjan Caves where the managing

  4. Map Showing Lava Inundation Zones for Mauna Loa, Hawaii

    USGS Publications Warehouse

    Trusdell, F.A.; Graves, P.; Tincher, C.R.

    2002-01-01

    Introduction The Island of Hawaii is composed of five coalesced basaltic volcanoes. Lava flows constitute the greatest volcanic hazard from these volcanoes. This report is concerned with lava flow hazards on Mauna Loa, the largest of the island shield volcanoes. Hilo lies 58 km from the summit of Mauna Loa, the Kona coast 33 km, and the southernmost point of the island 61 km. Hawaiian volcanoes erupt two morphologically distinct types of lava, aa and pahoehoe. The surfaces of pahoehoe flows are rather smooth and undulating. Pahoehoe flows are commonly fed by lava tubes, which are well insulated, lava-filled conduits contained within the flows. The surfaces of aa flows are extremely rough and composed of lava fragments. Aa flows usually form lava channels rather than lava tubes. In Hawaii, lava flows are known to reach distances of 50 km or more. The flows usually advance slowly enough that people can escape from their paths. Anything overwhelmed by a flow will be damaged or destroyed by burial, crushing, or ignition. Mauna Loa makes up 51 percent of the surface area of the Island of Hawaii. Geologic mapping shows that lava flows have covered more than 40 percent of the surface every 1,000 years. Since written descriptions of its activity began in A.D. 1832, Mauna Loa has erupted 33 times. Some eruptions begin with only brief seismic unrest, whereas others start several months to a year following increased seismic activity. Once underway, the eruptions can produce lava flows that reach the sea in less than 24 hours, severing roads and utilities. For example, the 1950 flows from the southwest rift zone reached the ocean in approximately three hours. The two longest flows of Mauna Loa are pahoehoe flows from the 50-kilometer-long 1859 and the 48-kilometer-long 1880-81 eruptions. Mauna Loa will undoubtedly erupt again. When it does, the first critical question that must be answered is: Which areas are threatened with inundation? Once the threatened areas are

  5. Modelling the thermal effects of spherulite growth in rhyolitic lava

    NASA Astrophysics Data System (ADS)

    Tuffen, H.; Cordonnier, B.; Castro, J. M.

    2012-12-01

    Rhyolitic lava flows, sills and dykes commonly comprise a spherulitic interior enveloped by a glassy carapace. Spherulite crystallisation has long been assumed to be a "passive" process that occurs during cooling of the lava around and below its glass transition temperature (~600-700 °C). It has also been suggested to be self-limiting due to diffusion controlled growth, creating only a small proportion of spherulites embedded in glass (snowflake obsidian). However, textures in rhyolitic lava bodies at Hrafntinnuhryggur, Krafla, Iceland indicate that near-complete spherulite crystallisation can occur, and suggest that parts of the lava spatially associated with zones of spherulite and lithophysae growth may be significantly heated. Evidence for heating includes melting of parts of the glassy lava carapace by lower-viscosity, invading melt of identical composition. Additionally, spherulitic crystal morphologies have been grown experimentally at undercoolings of only 100 °C. As the liquidus temperature of dry rhyolite may approach 1200 °C, this means that spherulites could continue to grow in degassed magma at temperatures of >900 °C, well above the initial magma temperature. We use new constraints on spherulite growth rates to model the thermal effects of spherulite growth within rhyolitic lava bodies, using three growth laws (size- and temperature-dependent, diffusion controlled and linear) and a variety of initial temperatures, nucleation densities and seed nuclei sizes. Models consider both latent heat release due to crystallisation and conductive cooling. Model results indicate that, when lava bodies are sufficiently large, spherulite growth can cause considerable heating (possibly >150 °C), enabling parts of lava bodies to heat to above the initial eruption temperature. This heating can lead to a viscosity reduction of orders of magnitude and trigger vesiculation. Model results indicate that cooling rates of between 10-3 to 10-5 °C/s ought to mark the

  6. Comparative analysis between Payen and Daedalia Planum lava fields

    NASA Astrophysics Data System (ADS)

    Giacomini, Lorenza; Massironi, Matteo; Pasquarè, Giorgio; Carli, Cristian; Martellato, Elena; Frigeri, Alessandro; Cremonese, Gabriele; Bistacchi, Andrea; Federico, Costanzo

    The Payen volcanic complex is a large Quaternary fissural structure belonging to the back-arc extensional area of the Andes in the Mendoza Province (Argentina). From the eastern portion of this volcanic structure huge pahoehoe lava flows were emitted, extending more than 180 km from the feeding vents. These huge flows propagated over the nearly flat surface of the Pampean foreland (ca 0.3° slope). The very low viscosity of the olivine basalt lavas, coupled with the inflation process are the most probable explanation for their considerable length. In an inflation process a thin viscoelastic crust, produced at an early stage, is later inflated by the underlying fluid core, which remains hot and fluid thanks to the thermal-shield effect of the crust. The inflation shows some typical morphological fingerprints like tumuli, lava lobes, lava rises and lava ridges. In order to compare the morphology of the Argentinean Payen flows with lava flows on Mars, MOLA, THEMIS, MOC, MRO/HIRISE, and MEX/OMEGA data have been analysed, providing a multi-scale characterisation of Martian flows. Mars Global Surveyor/MOLA data were used to investigate the topographic environment over which flows propagated on Mars in order to detect very low angle slopes where possibly inflation processes could have developed. Then Mars Odyssey/THEMIS and Mars Global Surveyor's MOC data were used to detect Martian lava flows with inflation "fingerprints", whereas OMEGA data were used to obtain some inferences about their composition. Finally the MRO/HIRISE images recently acquired, can provide further details and constraints on surface morphologies and lava fronts. All these data were used to analyze Daedalia Planum lava field, at about 300 km southwest of Arsia Mons, and clear morphological similarities with the longest flows of the Payen lava fields were found. These striking morphological analogies suggest that inflation process is quite common also for the Daedalia field. This is also supported by

  7. Monitoring of cave air temperature and humidity in the Niedźwiedzia Cave system (Sudetes, Poland) - a key to understanding tourists activity impact to cave environment

    NASA Astrophysics Data System (ADS)

    Gasiorowski, M.; Hercman, H.

    2012-04-01

    The Niedźwiedzia Cave is located in Śnieżnik Massif (the Easter Sudetes, SW Poland) at 800 m a.s.l. The length of known passages is ~3000 m and denivelation is 69 m. The system is composed of 3 levels of passages and chambers. It is a show cave with ~80,000 visitors every year. In 2010 we started monitoring program of cave air temperature and humidity, drip rate, stable isotopes and Uranium and Polonium content in water in selected sites inside the cave and in its vicinity. Changes in dropping rate in upper level are well correlated with precipitation. However, a response of dripping to rainfall depends on former precipitation frequency and intensity - during the humid period the dripping reacts immediately and after long dry period dripping responses with two-weeks delay. There is not so direct correlation between precipitation and dripping in lower level of the system. Air temperature inside the cave is almost stable in lower level (mean annual ~5.3 °C, and annual variation up to 0.7 °C) and more dynamic in the middle level (mean annual ~6.4 °C, and mean annual amplitude up to 4 °C). Daily and weekly measured changes of cave air temperature demonstrate extremely well correlation with number of visitors. In show cave passages (the middle level of the system) temperature increase 0.1-0.2 °C during every day when the cave is open for tourists and such changes is not observed during days without visitors and in lower level of the system closed for tourists. But even short visits of 3-4 cavers are recorded by temperature sensors exposed in the lower level (~0.02 °C increase). It proves very high sensitivity of cave environment to human activity. This study is funded by the National Science Centre and Higher Education grant no. N N306 131038.

  8. Numerical and Experimental Approaches Toward Understanding Lava Flow Heat Transfer

    NASA Astrophysics Data System (ADS)

    Rumpf, M.; Fagents, S. A.; Hamilton, C.; Crawford, I. A.

    2013-12-01

    We have performed numerical modeling and experimental studies to quantify the heat transfer from a lava flow into an underlying particulate substrate. This project was initially motivated by a desire to understand the transfer of heat from a lava flow into the lunar regolith. Ancient regolith deposits that have been protected by a lava flow may contain ancient solar wind, solar flare, and galactic cosmic ray products that can give insight into the history of our solar system, provided the records were not heated and destroyed by the overlying lava flow. In addition, lava-substrate interaction is an important aspect of lava fluid dynamics that requires consideration in lava emplacement models Our numerical model determines the depth to which the heat pulse will penetrate beneath a lava flow into the underlying substrate. Rigorous treatment of the temperature dependence of lava and substrate thermal conductivity and specific heat capacity, density, and latent heat release are imperative to an accurate model. Experiments were conducted to verify the numerical model. Experimental containers with interior dimensions of 20 x 20 x 25 cm were constructed from 1 inch thick calcium silicate sheeting. For initial experiments, boxes were packed with lunar regolith simulant (GSC-1) to a depth of 15 cm with thermocouples embedded at regular intervals. Basalt collected at Kilauea Volcano, HI, was melted in a gas forge and poured directly onto the simulant. Initial lava temperatures ranged from ~1200 to 1300 °C. The system was allowed to cool while internal temperatures were monitored by a thermocouple array and external temperatures were monitored by a Forward Looking Infrared (FLIR) video camera. Numerical simulations of the experiments elucidate the details of lava latent heat release and constrain the temperature-dependence of the thermal conductivity of the particulate substrate. The temperature-dependence of thermal conductivity of particulate material is not well known

  9. Identifying and Describing a Seismogenic Zone in a Sublevel Caving Mine

    NASA Astrophysics Data System (ADS)

    Abolfazlzadeh, Yousef; Hudyma, Marty

    2016-09-01

    Analysis of caving-induced seismicity can aid in the understanding of rock mass behaviour in the different stages of the caving process. A detailed analysis of caving-induced seismicity at the Telfer sublevel caving mine was undertaken. Interpretation of seismic data in the Telfer mine showed the influence of the major geological features on cave behaviour and helped to identify the phases of cave evolution. Two geological zones with unique seismic characteristics (the M50 and M30 stiff reefs) and four key caving phases (initial undercut blasting, cave initiation, cave propagation and breakthrough) were defined through seismic data analysis. Movement of the seismogenic zone was significantly affected by the stiff reefs within the cave column. Seismic source parameter analysis was used to investigate caving mechanisms at Telfer.

  10. Hardened Lava Meets Wind on Mars

    NASA Technical Reports Server (NTRS)

    2006-01-01

    NASA's Mars Exploration Rover Spirit used its microscopic imager to capture this spectacular, jagged mini-landscape on a rock called 'GongGong.' Measuring only 3 centimeters (1.2 inches) across, this surface records two of the most important and violent forces in the history of Mars -- volcanoes and wind.

    GongGong formed billions of years ago in a seething, stirring mass of molten rock. It captured bubbles of gases that were trapped at great depth but had separated from the main body of lava as it rose to the surface. Like taffy being stretched and tumbled, the molten rock was deformed as it moved across an ancient Martian landscape. The tiny bubbles of gas were deformed as well, becoming elongated. When the molten lava solidified, the rock looked like a frozen sponge.

    Far from finished with its life, the rock then withstood billions of years of pelting by small sand grains carried by Martian dust storms that sometimes blanketed the planet. The sand wore away the surface until, little by little, the delicate strands that enclosed the bubbles of gas were breached and the spiny texture we see today emerged.

    Even now, wind continues to deposit sand and dust in the holes and crevices of the rock.

    Similar rocks can be found on Earth where the same complex interplay of volcanoes and weathering occur, whether it be the pelting of rocks by sand grains in the Mojave desert or by ice crystals in the frigid Antarctic.

    GongGong is one of a group of rocks studied by Spirit and informally named by the Athena Science Team to honor the Chinese New Year (the Year of the Dog). In Chinese mythology, GongGong was the god-king of water in the North Land. When he sacrificed his life to knock down Mount BuZhou, he defeated the bad Emperor in Heaven, freed the sun, moon and stars to go from east to west, and caused all the rivers in China to flow from west to east.

    Spirit's microscopic imager took this image during on the rover's 736th day, or sol, of

  11. A geochronological approach for cave evolution in the Cantabrian Coast (Pindal Cave, NW Spain)

    USGS Publications Warehouse

    Jimenez-Sanchez, M.; Bischoff, J.L.; Stoll, H.; Aranburu, A.

    2006-01-01

    Some of the oldest speleothems in the North Cantabrian Coast (Spain) are reported for the first time in this work. Pindal Cave is developed at 24 m above sea level, in a karstic massif reaching its highest surface in a marine terrace (rasa) located at 50-64 m above the present sea level. Several phases of evolution were previously recognized into the cave, including block collapse of the roof, episodic flooding and detrital sedimentation, and chemical precipitation of at least four speleothem generations over both alluvial and collapse deposits. Three of these speleothem generations have been dated by U/Th. The first generation yielded ages from 124,2 ?? 1, 5 ka BP to 73,1 ?? 0,9 ka BP, giving a minimum age for the main detritic sediments in the cave. The second one is not dated. The third generation gives an age of 3,71 ?? 0,4 ka BP (mathematically corrected to 2.7 ?? 0.5 ka BP), while for the youngest generation, with actively growing stalagmites in the cave, basal ages of 200 years BP are estimated by counting annual laminae. The data suggest a tentative maximum elevation rate close to 0, 2 mm/yr for the Cantabrian Margin in this area, although further chronological studies will be needed to check this hypothesis. ?? 2006 Gebru??der Borntraeger.

  12. Rhyolite lava fracturing and degassing induced spherulitic growth of Sawajiriwan and Sanukayama lavas in Kozushima Island, Japan

    NASA Astrophysics Data System (ADS)

    Furukawa, K.; Uno, K.; Kanamaru, T.

    2015-12-01

    Sawajiriwan and Sanukayama rhyolite lavas are distributed along west and east coasts of Kozushima Island, Japan, respectively (Taniguchi, 1977). They were erupted in about 40,000-50,000 years ago (Yokoyama et al., 2004). The both lavas are characterized by alignment of spherulites as well as previous works (Seaman et al., 2009; Clay et al., 2013). Seaman et al. (2009) attributed the spherulite alignment to the contrasting water concentration and concluded that the heterogeneity of water contents has already achieved within the magma chamber. In this study, we propose that development of the spherulite alignment is significantly related to the fracturing within the lavas. In Sawajiriwan lava, the distal part is well exposed and shows ramp structure and reverse faults with ductile-deformed fault planes. The both structures were formed within consistent compressional stress deduced from their geometry. Discrepancy of the structure would be attributed to the strain rate variation within the advancing lava. The spherulite alignment is characteristically developed along the planes. This indicates that the fractures acted as degassing pathway, and the part achieved large undercooling. The fault planes would be healed and deformed after decreasing strain rate, and spherulites were eventually grown along the planes. In Sanukayama lava, the ductile-deformed cataclastic faults are often developed as well as Sawajiriwan lava. The cataclasite is composed of porphyroclasts and nano- and micro-scale fine particles such as microlite and crystalline fragments. Microscopic observation clearly showed that the fine particles are released from the fault margin into the surrounding melt and are aligned along the flow line. Spherulites typically nucleated on the aligned fine particles, and consequently spherulite alignment was developed. We concluded from the lavas that development of the spherulite alignment is significantly related to the fracturing within the lavas.

  13. THE MID-LATITUDE BIODIVERSITY RIDGE IN TERRESTRIAL CAVE FAUNA

    EPA Science Inventory

    The world's obligate cave-dwelling fauna holds considerable promise for biogeographic analysis because it represents a large number of independent evolutionary experiments in isolation in caves and adaptation to subterranean life. We focus on seven north temperate regions of at l...

  14. Evolution and development in cave animals: from fish to crustaceans

    PubMed Central

    Protas, Meredith; Jeffery, William R.

    2013-01-01

    Cave animals are excellent models to study the general principles of evolution as well as the mechanisms of adaptation to a novel environment: the perpetual darkness of caves. In this article, two of the major model systems used to study the evolution and development (evo–devo) of cave animals are described: the teleost fish Astyanax mexicanus and the isopod crustacean Asellus aquaticus. The ways in which these animals match the major attributes expected of an evo–devo cave animal model system are described. For both species, we enumerate the regressive and constructive troglomorphic traits that have evolved during their adaptation to cave life, the developmental and genetic basis of these traits, the possible evolutionary forces responsible for them, and potential new areas in which these model systems could be used for further exploration of the evolution of cave animals. Furthermore, we compare the two model cave animals to investigate the mechanisms of troglomorphic evolution. Finally, we propose a few other cave animal systems that would be suitable for development as additional models to obtain a more comprehensive understanding of the developmental and genetic mechanisms involved in troglomorphic evolution. PMID:23580903

  15. 36 CFR 7.36 - Mammoth Cave National Park.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Mammoth Cave National Park. 7.36 Section 7.36 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.36 Mammoth Cave National Park. (a)...

  16. 36 CFR 7.36 - Mammoth Cave National Park.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Mammoth Cave National Park. 7.36 Section 7.36 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.36 Mammoth Cave National Park. (a)...

  17. Guanophilic fungi in three caves of southwestern Puerto Rico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fifty species of guanophilic (bat guano-loving) fungi were isolated from field-collected samples within three caves in south-western Puerto Rico; most were mitosporic fungi (23 species). The caves studied were Cueva La Tuna (Cabo Rojo), Cueva de Malano (Sistema de Los Chorros, San Germán), and Cuev...

  18. 36 CFR 7.68 - Russell Cave National Monument.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.68 Russell Cave National Monument. (a) Caves—(1) Closed Areas. Entering, exploring, or remaining within any cave area other than the public archeological exhibit without prior written permission of the Superintendent is prohibited. (2) Permits....

  19. A burial cave in the western Aleutian Islands, Alaska.

    PubMed

    West, Dixie; Lefèvre, Christine; Corbett, Debra; Crockford, Susan

    2003-01-01

    During the 1998 field season, the Western Aleutians Archaeological and Paleobiological Project (WAAPP) team located a cave in the Near Islands, Alaska. Near the entrance of the cave, the team identified work areas and sleeping/sitting areas surrounded by cultural debris and animal bones. Human burials were found in the cave interior. In 2000, with permission from The Aleut Corporation, archaeologists revisited the site. Current research suggests three distinct occupations or uses for this cave. Aleuts buried their dead in shallow graves at the rear of the cave circa 1,200 to 800 years ago. Aleuts used the front of the cave as a temporary hunting camp as early as 390 years ago. Finally, Japanese and American military debris and graffiti reveal that the cave was visited during and after World War II. Russian trappers may have also taken shelter there 150 to 200 years ago. This is the first report of Aleut cave burials west of the Delarof Islands in the central Aleutians.

  20. The Oldest Cave Art: An Essay on Giftedness and Excellence.

    ERIC Educational Resources Information Center

    Breen, Maureen; White, David A.

    1996-01-01

    This essay examines issues of giftedness and excellence, beginning with classical references to human striving toward the "good," the attraction of gifted children to quality, and the recent discovery of the oldest known cave art with its manifest excellence. Classroom activities related to cave art and language arts, social studies, sciences,…

  1. 36 CFR 7.36 - Mammoth Cave National Park.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Mammoth Cave National Park. 7.36 Section 7.36 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.36 Mammoth Cave National Park. (a)...

  2. 43 CFR 37.12 - Confidentiality of cave location information.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... individual or organization assisting the land managing agency with cave management activities. To request... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Confidentiality of cave location information. 37.12 Section 37.12 Public Lands: Interior Office of the Secretary of the Interior...

  3. Lava and Life: New investigations into the Carson Volcanics, lower Kimberley Basin, north Western Australia

    NASA Astrophysics Data System (ADS)

    Orth, Karin; Phillips, Chris; Hollis, Julie

    2014-05-01

    The Carson Volcanics are the only volcanic unit in the Paleoproterozoic Kimberley Basin and are part of a poorly studied Large Igneous Province (LIP) that was active at 1790 Ma. New work focussing on this LIP in 2012 and 2013 involved helicopter-supported traverses and sampling of the Carson Volcanics in remote areas near Kalumburu in far north Western Australia's Kimberley region. The succession is widespread and flat lying to gently dipping. It consists of three to six basalt units with intercalated sandstone and siltstone. The basalts are 20-40 m thick, but can be traced up to 60 km along strike. The basalt can be massive or amygdaloidal and commonly display polygonal to subhorizontal and rare vertical columnar jointing. Features of the basalt include ropy lava tops and basal pipe vesicles consistent with pahoehoe lavas. The intercalated cross-bedded quartzofeldspathic sandstone and siltstone vary in thickness up to 40 m and can be traced up to 40 km along strike. Peperite is common and indicates interaction between wet, unconsolidated sediment and hot lava. Stromatolitic chert at the top of the formation represents the oldest life found within the Kimberley region. Mud cracks evident in the sedimentary rocks, and stromatolites suggest an emergent broad tidal flat environment. The volcanics were extruded onto a wide marginal margin setting subject to frequent flooding events. Thickening of the volcanic succession south and the palaeocurrents in the underlying King Leopold Sandstone and the overlying Warton Sandstone suggest that this shelf sloped to the south. The type of basalt and the basalt morphology indicate a low slope gradient of about 1°.

  4. Packed Bed Reactor Experiment

    NASA Video Gallery

    The purpose of the Packed Bed Reactor Experiment in low gravity is to determine how a mixture of gas and liquid flows through a packed bed in reduced gravity. A packed bed consists of a metal pipe ...

  5. Detail of redwood tank on lava rock platform. Trestle and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of redwood tank on lava rock platform. Trestle and steel tanks can be see in right background. - Hawaii Volcanoes National Park Water Collection System, Hawaii Volcanoes National Park, Volcano, Hawaii County, HI

  6. Athabasca Valles, Mars: A lava-draped channel system

    USGS Publications Warehouse

    Jaeger, W.L.; Keszthelyi, L.P.; McEwen, A.S.; Dundas, C.M.; Russell, P.S.

    2007-01-01

    Athabasca Valles is a young outflow channel system on Mars that may have been carved by catastrophic water floods. However, images acquired by the High-Resolution Imaging Science Experiment camera onboard the Mars Reconnaissance Orbiter spacecraft reveal that Athabasca Valles is now entirely draped by a thin layer of solidified lava - the remnant of a once-swollen river of molten rock. The lava erupted from a fissure, inundated the channels, and drained downstream in geologically recent times. Purported ice features in Athabasca Valles and its distal basin, Cerberus Palus, are actually composed of this lava. Similar volcanic processes may have operated in other ostensibly fluvial channels, which could explain in part why the landers sent to investigate sites of ancient flooding on Mars have predominantly found lava at the surface instead.

  7. Athabasca Valles, Mars: a lava-draped channel system.

    PubMed

    Jaeger, W L; Keszthelyi, L P; McEwen, A S; Dundas, C M; Russell, P S

    2007-09-21

    Athabasca Valles is a young outflow channel system on Mars that may have been carved by catastrophic water floods. However, images acquired by the High-Resolution Imaging Science Experiment camera onboard the Mars Reconnaissance Orbiter spacecraft reveal that Athabasca Valles is now entirely draped by a thin layer of solidified lava-the remnant of a once-swollen river of molten rock. The lava erupted from a fissure, inundated the channels, and drained downstream in geologically recent times. Purported ice features in Athabasca Valles and its distal basin, Cerberus Palus, are actually composed of this lava. Similar volcanic processes may have operated in other ostensibly fluvial channels, which could explain in part why the landers sent to investigate sites of ancient flooding on Mars have predominantly found lava at the surface instead.

  8. Simulation of inflated pahoehoe lava flows

    NASA Astrophysics Data System (ADS)

    Glaze, Lori S.; Baloga, Stephen M.

    2013-04-01

    A new stochastic model simulates late-stage pahoehoe lobes where random processes dominate emplacement. The model prescribes probabilistic rules for determining where and when parcels of lava move within the lobe. Unlike a classical Brownian motion random walk, the model allows individual parcels to remain dormant, but fluid, for multiple time steps. The randomness of parcel volume transfers within the lobe interior as well as at the margins qualitatively reflects inflation processes observed in the field. The fraction of inflated volume to total volume increases with the total volume, with greater than 75% of the lobe volume contributed through inflation for typical lobes. The influence on planform shape and topographic cross-sectional profiles of total volume, source area and shape, topographic confinement, and sequential breakouts at the lobe margins, are all explored with the stochastic model. Each of these factors influences the overall lobe thickness and width. The model provides a means for assessing the relative importance of these processes through comparisons with field data. For the first time, Gaussian and parabolic functions are quantitatively fit to field measurements of pahoehoe lobes. Both functional forms provide adequate description of the cross-sectional flow shapes. When comparing simulated lobes to field data, sequential breakouts at the lobe margins are found to be an important process controlling the final topographic distribution of observed pahoehoe lobes.

  9. THEMIS observes possible cave skylights on Mars

    USGS Publications Warehouse

    Cushing, G.E.; Titus, T.N.; Wynne, J.J.; Christensen, P.R.

    2007-01-01

    Seven possible skylight entrances into Martian caves were observed on and around the flanks of Arsia Mons by the Mars Odyssey Thermal Emission Imaging System (THEMIS). Distinct from impact craters, collapse pits or any other surface feature on Mars, these candidates appear to be deep dark holes at visible wavelengths while infrared observations show their thermal behaviors to be consistent with subsurface materials. Diameters range from 100 m to 225 m, and derived minimum depths range between 68 m and 130 m. Most candidates seem directly related to pitcraters, and may have formed in a similar manner with overhanging ceilings that remain intact. Copyright 2007 by the American Geophysical Union.

  10. Clinker formation in basaltic and trachybasaltic lava flows

    NASA Astrophysics Data System (ADS)

    Loock, Sébastien; van Wyk de Vries, Benjamin; Hénot, Jean-Marc

    2010-09-01

    Clinker is a term used to describe massive or scoriaceous fragments commonly associated with ‘a‘ā lava flows. Clinker is generally considered to form by fragmentation of an upper vesiculated crust, due to an increase in apparent viscosity and/or to an increase in shear strain rate. Surface clinker is considered to be transported to the flow front and incorporated at the base by caterpillar motion. Clinker that we have observed on a variety of lava flows has very variable textures, which suggests several different mechanisms of formation. In order to study clinker formation, we examined several lava flows from the Chaîne des Puys Central France, where good sections, surface morphology and surface textures are widespread and clearly visible. We observed basal and surface ‘a‘ā clinker that has fragmentation textures similar to those observed in ash formed in eruptions under dry conditions. In two pāhoehoe flows we have observed basal clinker that formed in-situ. Two other flows display clinker features identical to those commonly observed in phreatomagmatic ash, such as adhering particles, blocky shapes, spherical glass and attached microphenocrysts. Another pāhoehoe flow has a flakey, angular basal breccia, with microfaulted and abraded clasts. These were probably formed at a cooled lava base by large amounts of simple shear and consequent intra-lava brittle faulting. Using these observations we propose three different ways of fragmentation. (1) Clinker can form at the surface and eventually produce roll-over basal breccia. (2) Water/lava interactions can form basal clinker by phreatomagmatic fragmentation. Water/lava ratio variations may produce different clinker structures, in a manner similar to observed textural changes in phreatomagmatic eruptions. (3) Clinker can be formed by brittle brecciation during basal simple shear. The different clinker can provide information about the mechanisms and environmental conditions during lava flow emplacement.

  11. Small domes on Venus - Probable analogs of Icelandic lava shields

    NASA Technical Reports Server (NTRS)

    Garvin, James B.; Williams, Richard S., Jr.

    1990-01-01

    On the basis of observed shapes and volumetric estimates, small, dome-like features on radar images of Venus are interpreted to be analogs of Icelandic lava-shield volcanoes. Morphometric data for Venusian domes in Aubele and Slyuta as well as measurements of representative dome volumes and areas from Tethus Regio are used to demonstrate that the characteristic aspect ratios and flank slopes of these features are consistent with a subclass of low Icelandic lava-shield volcanoes (LILS).

  12. Validating Cellular Automata Lava Flow Emplacement Algorithms with Standard Benchmarks

    NASA Astrophysics Data System (ADS)

    Richardson, J. A.; Connor, L.; Charbonnier, S. J.; Connor, C.; Gallant, E.

    2015-12-01

    A major existing need in assessing lava flow simulators is a common set of validation benchmark tests. We propose three levels of benchmarks which test model output against increasingly complex standards. First, imulated lava flows should be morphologically identical, given changes in parameter space that should be inconsequential, such as slope direction. Second, lava flows simulated in simple parameter spaces can be tested against analytical solutions or empirical relationships seen in Bingham fluids. For instance, a lava flow simulated on a flat surface should produce a circular outline. Third, lava flows simulated over real world topography can be compared to recent real world lava flows, such as those at Tolbachik, Russia, and Fogo, Cape Verde. Success or failure of emplacement algorithms in these validation benchmarks can be determined using a Bayesian approach, which directly tests the ability of an emplacement algorithm to correctly forecast lava inundation. Here we focus on two posterior metrics, P(A|B) and P(¬A|¬B), which describe the positive and negative predictive value of flow algorithms. This is an improvement on less direct statistics such as model sensitivity and the Jaccard fitness coefficient. We have performed these validation benchmarks on a new, modular lava flow emplacement simulator that we have developed. This simulator, which we call MOLASSES, follows a Cellular Automata (CA) method. The code is developed in several interchangeable modules, which enables quick modification of the distribution algorithm from cell locations to their neighbors. By assessing several different distribution schemes with the benchmark tests, we have improved the performance of MOLASSES to correctly match early stages of the 2012-3 Tolbachik Flow, Kamchakta Russia, to 80%. We also can evaluate model performance given uncertain input parameters using a Monte Carlo setup. This illuminates sensitivity to model uncertainty.

  13. Field constraints for modeling the emplacement of the 2010 Gigjökull lava flow, southern Iceland: interplay between subaqueous, ice contact and subaerial lava emplacement

    NASA Astrophysics Data System (ADS)

    Edwards, B.; Oddsson, B.; Gudmundsson, M. T.; Rossi, R.

    2012-04-01

    One of the least accessible products of the 2010 Eyjafjallajokull eruption is the trachyandesite lava that flowed north from the summit eruption site down through Gigjökull glacier. Based on numerous overflights during 2010, syn-eruption satellite imagery and two on-site investigations in 2011, we have developed a preliminary model to illustrate the progressive movement of the complex lava flow down through Gigjökull. Previous workers have documented the events surrounding the explosive summit eruptions, including the flow path for the majority of the water derived from melting ~0.1 cubic km of summit ice, which moved over, through and beneath Gigjökull producing a series of jokulhlaups during April and May 2010. Overflights in 2010 and 2011 show that most of the upper parts of the lava flow are surfaced by oxidized, blocky lava that appears very similar to what would be expected from an entirely subaerial lava flow. However, exposures at the lowest end of the flow preserve a record documenting lava emplacement in water and through ice tunnels. We describe 8 different components visible in this northernmost, lowest part of the lava flow, including: (1) upper subaerial levee-bounded lava flow, (2) subaerial blocky lava bench, (3) subaqueous/ice contact lava mounds, (4) subaqueous/ice contact sheet lava complex, (5) ponded, glaciolacustrine sediments, (6) subaerial slabby lava flow, (7) subaqueous pillow lava lobes, and (8) ice-tunnel confined lava flows. In combination these 8 components are consistent a model for lava emplacement through a valley glacier. We propose that the lava flow, which appears to have started moving down the glacier from a tephra cone immediately north of the main summit craters after the largest of the jokulhlaups, exploited newly formed and/or pre-existing sub-ice drainage systems along the base of Gigjökull. Initial meltwater from the eruption site created/enhanced basal ice drainage systems. Lava flows exploited these drainage systems

  14. Stochastic modeling of a lava-flow aquifer system

    USGS Publications Warehouse

    Cronkite-Ratcliff, Collin; Phelps, Geoffrey A.

    2014-01-01

    This report describes preliminary three-dimensional geostatistical modeling of a lava-flow aquifer system using a multiple-point geostatistical model. The purpose of this study is to provide a proof-of-concept for this modeling approach. An example of the method is demonstrated using a subset of borehole geologic data and aquifer test data from a portion of the Calico Hills Formation, a lava-flow aquifer system that partially underlies Pahute Mesa, Nevada. Groundwater movement in this aquifer system is assumed to be controlled by the spatial distribution of two geologic units—rhyolite lava flows and zeolitized tuffs. The configuration of subsurface lava flows and tuffs is largely unknown because of limited data. The spatial configuration of the lava flows and tuffs is modeled by using a multiple-point geostatistical simulation algorithm that generates a large number of alternative realizations, each honoring the available geologic data and drawn from a geologic conceptual model of the lava-flow aquifer system as represented by a training image. In order to demonstrate how results from the geostatistical model could be analyzed in terms of available hydrologic data, a numerical simulation of part of an aquifer test was applied to the realizations of the geostatistical model.

  15. Fracturing as a Quantitative Indicator of Lava Flow Dynamics

    NASA Astrophysics Data System (ADS)

    Kilburn, C. R.; Solana, C.

    2005-12-01

    The traditional classification of lava flows into pahoehoe and aa varieties reflects differences in how a flow can fracture its surface during advance. Both types of lava have a low strength upon eruption and require surface cooling to produce a crust that can fracture. Among pahoehoe lavas, applied stresses are small enough to allow the growth of a continuous crust, which is broken intermittently as the flow advances by propagating a collection of lava tongues. Among aa lavas, in contrast, applied stresses are large enough to maintain persistent crustal failure. The differences in fracturing characteristics has been used to quantify the transition between flow regimes and suggests that shear fracture may dominate tensile failure. Applied to Lanzarote, the model confirms the inference from incomplete eye-witness accounts of the 1730-36 Timanfaya eruption that pahoehoe flows were able to advance about an order of magnitude more quickly than would have been expected by analogy with Hawaiian pahoehoe flow-fields of similar dimensions. Surface texture and morphology, therefore, are insufficient guides for constraining the rate and style of pahoehoe emplacement. Applications include improved hazard assessments during effusive eruptions and new evaluations of the emplacement conditions for very large-volume pahoehoe lava flows.

  16. Studies of vesicle distribution patterns in Hawaiian lavas

    NASA Technical Reports Server (NTRS)

    Walker, George P. L.

    1987-01-01

    Basaltic lava flows are generally vesicular, and the broader facts relating to vesicle distribution have long been established; few studies have yet been made with a view to determining how and when vesicles form in the cooling history of the lava, explaining vesicle shape and size distribution, and gaining enough understanding to employ vesicles as a geological tool. Various avenues of approach exist by which one may seek to gain a better understanding of these ubiquitous structures and make a start towards developing a general theory, and three such avenues have recently been explored. One avenue involves the study of pipe vesicles; these are a well known feature of lava flows and are narrow pipes which occur near the base of many pahoehoe flow units. Another avenue of approach is that presented by the distinctive spongy pahoehoe facies of lava that is common in distal locations on Hawaiian volcanoes. A third avenue of approach is that of the study of gas blisters in lava. Gas blisters are voids, which can be as much as tens of meters wide, where the lava split along a vesicle-rich layer and the roof up-arched by gas pressure. These three avenues are briefly discussed.

  17. Lamprophyric lavas in the Colima graben, SW Mexico

    NASA Astrophysics Data System (ADS)

    Allan, J. F.; Carmichael, I. S. E.

    1984-12-01

    The Colima graben, located in SW Mexico, is one of three grabens which intersect about 50 km SSW of Guadalajara, forming a triple junction. The 90 km long, 20 60 km wide Colima graben represents a N-S rift of the E-W trending Mexican Volcanic Belt. Since the Early Pliocene, the Colima graben has served as a locus for the eruption of alkaline lavas, the most recent of which are basanites and minettes erupted from Late Pleistocene cinder cones (Luhr and Carmichael 1981). In this paper, we report on older alkaline lavas which crop out in the graben's walls. These rocks include phlogopite- and hornblende-bearing lamprophyres, a phlogopite-kalsilite-ankaratrite, and high-K andesites. These lavas crop out throughout the Colima graben area, and are intimately associated with calc-alkaline lavas in the field. Compared to these, the alkaline rocks are strikingly enriched in the incompatible elements, particularly Ba, Sr, P, and the LREE. Unlike the younger Late Pleistocene alkaline cinder cone lavas, most of the graben wall lamprophyres and the high-K andesites represent magmas that appear to have undergone significant evolution since their generation, including fractionation, crustal contamination, and possible magma mixing. Least-squares modeling indicates that the cinder cone minettes represent reasonable parental magmas for the graben lamprophyres. The occurrence of these alkaline lavas in an active calc-alkaline volcanic arc is unusual, and we suggest that they are a manifestation of the rifting processes which produced the Colima graben.

  18. Fossil invertebrates records in cave sediments and paleoenvironmental assessments: a study of four cave sites from Romanian Carpathians

    NASA Astrophysics Data System (ADS)

    Moldovan, O. T.; Constantin, S.; Panaiotu, C.; Roban, R. D.; Frenzel, P.; Miko, L.

    2015-06-01

    Fossil invertebrates from cave sediments have been recently described as a potential new proxy for paleoenvironment and used in cross-correlations with alternate proxy records from cave deposits. Here we present the results of a fossil invertebrates study in four caves from two climatically different regions of the Romanian Carpathians, to complement paleoenvironmental data previously reported. Oribatid mites and ostracods are the most common invertebrates in the studied cave sediments. Some of the identified taxa are new for science, and most of them are indicative for either warm/cold stages or dry/wetter oscillations. In two caves the fossil invertebrates records indicate rapid climate oscillations during times known for a relatively stable climate. By corroborating the fossil invertebrates' record with the information given by magnetic properties and sediment structures, complementary data on past vegetation, temperatures, and hydraulic regimes could be gathered. This paper analyses the potential of fossil invertebrate records as a paleoenvironmental proxy, potential problems and pitfalls.

  19. Under the volcano: phylogeography and evolution of the cave-dwelling Palmorchestia hypogaea (Amphipoda, Crustacea) at La Palma (Canary Islands)

    PubMed Central

    Villacorta, Carlos; Jaume, Damià; Oromí, Pedro; Juan, Carlos

    2008-01-01

    Background The amphipod crustacean Palmorchestia hypogaea occurs only in La Palma (Canary Islands) and is one of the few terrestrial amphipods in the world that have adapted to a strictly troglobitic life in volcanic cave habitats. A surface-dwelling closely related species (Palmorchestia epigaea) lives in the humid laurel forest on the same island. Previous studies have suggested that an ancestral littoral Orchestia species colonized the humid forests of La Palma and that subsequent drought episodes in the Canaries reduced the distribution of P. epigaea favouring the colonization of lava tubes through an adaptive shift. This was followed by dispersal via the hypogean crevicular system. Results P. hypogaea and P. epigaea did not form reciprocally monophyletic mitochondrial DNA clades. They showed geographically highly structured and genetically divergent populations with current gene flow limited to geographically close surface locations. Coalescence times using Bayesian estimations assuming a non-correlated relaxed clock with a normal prior distribution of the age of La Palma, together with the lack of association of habitat type with ancestral and recent haplotypes, suggest that their adaptation to cave life is relatively ancient. Conclusion The data gathered here provide evidence for multiple invasions of the volcanic cave systems that have acted as refuges. A re-evaluation of the taxonomic status of the extant species of Palmorchestia is needed, as the division of the two species by habitat and ecology is unnatural. The information obtained here, and that from previous studies on hypogean fauna, shows the importance of factors such as the uncoupling of morphological and genetic evolution, the role of climatic change and regressive evolution as key processes in leading to subterranean biodiversity. PMID:18234125

  20. Soft-bottom crustacean assemblages in Mediterranean marine caves: the cave of Cerro Gordo (Granada, Spain) as case study

    NASA Astrophysics Data System (ADS)

    Navarro-Barranco, C.; Guerra-García, J. M.; Sánchez-Tocino, L.; García-Gómez, J. C.

    2012-12-01

    Although marine caves are priority conservation areas according to the Directive 92/43/CEE of the European Community, there is a lack of studies dealing with their soft-bottom communities. For a case study, we selected the Cerro Gordo cave at 15 m depth. Three different zones were defined: a semi-dark 25-m long entrance area, a dark intermediate area of 35 m, and the final zone at 90 m from the entrance. Sediment samples were taken from these zones as well as from outside the cave (control) by SCUBA diving. Six rectangular cores of 10 × 250 cm2 were collected in each site for macrofaunal study, and three more replicates were taken to analyze physico-chemical parameters. The granulometry showed a clear gradient from medium sands outside the cave to silt and clay in the inner zone. Measurements of the crustacean assemblages showed that the number of species and abundance were significantly higher outside the cave (30-40 species, >4,000 ind m-2) than inside (5-10 species, <1,000 ind m-2). Multivariate analyses showed a clear difference in species composition between outside and inside the cave. Caprellids, tanaids, cumaceans, and decapods were only found outside the cave, while gammarids and isopods were present both outside and inside the cave. The gammarid Siphonoecetes sabatieri and the tanaid Apseudes latreilli were the dominant species outside the cave, while the gammarids Harpinia pectinata, Harpinia crenulata, and Harpinia ala were dominant inside. The present study represents an increase in depth range and geographic distribution for Kupellonura mediterranea and Monoculodes packardi. This is the first description of soft-bottom crustacean communities from submarine caves of southern Spain.

  1. Seven Possible Cave Skylights on Mars

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Figure 1

    Seven very dark holes on the north slope of a Martian volcano have been proposed as possible cave skylights, based on day-night temperature patterns suggesting they are openings to subsurface spaces. These six excerpts of images taken in visible-wavelength light by the Thermal Emission Imaging System camera on NASA's Mars Odyssey orbiter show the seven openings. Solar illumination comes from the left in each frame. The volcano is Arsia Mons, at 9 degrees south latitude, 239 degrees east longitude.

    The features have been given informal names to aid comparative discussion (see figure 1). They range in diameter from about 100 meters (328 feet) to about 225 meters (738 feet). The candidate cave skylights are (A) 'Dena,' (B) 'Chloe,' (C) 'Wendy,' (D) 'Annie,' (E) 'Abby' (left) and 'Nikki,' and (F) 'Jeanne.' Arrows signify north and the direction of illumination.

    Mars Odyssey is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The orbiter's Thermal Emission Imaging System was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing, Santa Barbara, Calif., and is operated by Arizona State University.

  2. Studies of Cave Sediments: Physical and Chemical Records of Paleoclimate (Revised Edition)

    NASA Astrophysics Data System (ADS)

    Baker, Andy

    2007-10-01

    Caves have long fascinated humankind, from prehistory to present-day tourism. Caves are also a subject for a range of scientific investigations, including cave biology, archaeology, paleoclimatology, geology, hydrology, and geomorphology. One of the benefits caves provide is their role as a repository of material that might not otherwise survive on the Earth's surface, due to caves' interiors being protected from physical erosion by nature of their underground locations. Studies of Cave Sediments focuses on this role as a repository, in particular on Quaternary (historic to 1.8 million years old) paleoclimate information preserved in cave sediments.

  3. Geochemical characteristics of Cocos Plate seamount lavas

    NASA Astrophysics Data System (ADS)

    Allan, James F.; Batiza, Rodey; Sack, Richard O.

    1994-03-01

    A wide compositional continuum of basalts has been erupted from near-ridge seamounts constructed on the Cocos Plate between the Clipperton and Orozco Francture Zones. They range from highly evolved to moderately primitive (3.0 7.8% MgO), LREE-enriched alkali basalts, to moderately evolved to near-primary (5.2 9.5% MgO) tholeiites indistinguishable from N-type MORB. The data set of 159 quench glass analyses exhibits a remarkably consistent variation in both major and trace element composition that is keyed to variations in (La/Sm). Modeling of potential liquid lines of descent at pressures ranging from 1 bar to 8 kbar shows that this covariation is partially due to systematic differences in liquid lines of descent, where the alkaline lavas have undergone substantially more high pressure clinopyroxene fractionation and substantially less low pressure plagioclase fractionation than the tholeiites. In addition, systematic variation in the composition of the more primitive glasses indicates that they were derived from mixing of discrete enriched and depleted melts in the heterogenous seamount mantle source at pressures of 8 10 kbar and greater, and that clinopyroxene may be a residual phase during partial melting. These results show that porous media flow in the seamount mantle source is minor and that melt transport is accomplished primarily through cracking and diking. This study supports suggestions that the general homogeneity of basalt along the EPR is due to mixing in sub-axial magma chambers and mush zones, with additional mixing during partial mantle melting and melt segregation.

  4. The dynamics of a channel-fed lava flow on Pico Partido volcano, Lanzarote

    NASA Astrophysics Data System (ADS)

    Woodcock, Duncan; Harris, Andrew

    2006-09-01

    A short length of channel on Pico Partido volcano, Lanzarote, provides us the opportunity to examine the dynamics of lava flowing in a channel that extends over a sudden break in slope. The 1 2-m-wide, 0.5 2-m-deep channel was built during the 1730 1736 eruptions on Lanzarote and exhibits a sinuous, well-formed channel over a steep (11° slope) 100-m-long proximal section. Over-flow units comprising smooth pahoehoe sheet flow, as well as evidence on the inner channel walls for multiple (at least 11) flow levels, attest to unsteady flow in the channel. In addition, superelevation is apparent at each of the six bends along the proximal channel section. Superelevation results from banking of the lava as it moves around the bend thus causing preferential construction of the outer bank. As a result, the channel profile at each bend is asymmetric with an outer bank that is higher than the inner bank. Analysis of superelevation indicates flow velocities of ~8 m s 1. Our analysis of the superelevation features is based on an inertia-gravity balance, which we show is appropriate, even though the down-channel flow is in laminar flow. We use a viscosity-gravity balance model, together with the velocities calculated from superelevation, to obtain viscosities in the range 25 60 Pa s (assuming that the lava behaved as a Newtonian liquid). Estimated volume fluxes are in the range 7 12 m3 s 1. An apparent down-flow increase in derived volume flux may have resulted from variable supply or bulking up of the flow due to vesiculation. Where the channel moves over a sharp break in slope and onto slopes of ~6°, the channel becomes less well defined and widens considerably. At the break of slope, an elongate ridge extends across the channel. We speculate that this ridge was formed as a result of a reduction in velocity immediately below the break of slope to allow deposition of entrained material or accretion of lava to the channel bed as a result of a change in flow regime or depth.

  5. Vision-mediated interaction with the Nottingham caves

    NASA Astrophysics Data System (ADS)

    Ghali, Ahmed; Bayomi, Sahar; Green, Jonathan; Pridmore, Tony; Benford, Steve

    2003-05-01

    The English city of Nottingham is widely known for its rich history and compelling folklore. A key attraction is the extensive system of caves to be found beneath Nottingham Castle. Regular guided tours are made of the Nottingham caves, during which castle staff tell stories and explain historical events to small groups of visitors while pointing out relevant cave locations and features. The work reported here is part of a project aimed at enhancing the experience of cave visitors, and providing flexible storytelling tools to their guides, by developing machine vision systems capable of identifying specific actions of guides and/or visitors and triggering audio and/or video presentations as a result. Attention is currently focused on triggering audio material by directing the beam of a standard domestic flashlight towards features of interest on the cave wall. Cameras attached to the walls or roof provide image sequences within which torch light and cave features are detected and their relative positions estimated. When a target feature is illuminated the corresponding audio response is generated. We describe the architecture of the system, its implementation within the caves and the results of initial evaluations carried out with castle guides and members of the public.

  6. An outbreak and review of cave-associated histoplasmosis capsulati.

    PubMed

    Sacks, J J; Ajello, L; Crockett, L K

    1986-08-01

    Three male college students from Florida developed acute onsets of fever, chills, shortness of breath, and cough within one day of each other, and all were eventually hospitalized for four to 29 days. All chest x-ray films showed diffuse reticulonodularities in both lung fields. Laboratory studies confirmed the diagnosis of histoplasmosis. The three students had been 'spelunking' (cave exploring) 6 to 7 days before their onset of symptoms. One of four soil samples collected in the caves was positive for Histoplasma capsulatum by the indirect mouse inoculation procedure. Of three investigators who entered the implicated caves, two developed acute febrile illness within 15-21 days. One investigator was hospitalized for 18 days with a confirmed diagnosis of histoplasmosis. Investigation identified an additional case (the person had entered the caves 6 months before this episode), but was not reported to health authorities. Spelunkers should be aware of the potential risk of histoplasmosis and how to avoid infection. Physicians should be cognizant of cave-associated histoplasmosis, inquire about spelunking in persons who develop febrile respiratory illnesses with diffuse nodularities on chest x-ray films, and report such cases to their health department. A review of 42 reported outbreaks of cave-associated histoplasmosis and the approach to environmental control of infected caves are included.

  7. The fungal colonisation of rock-art caves: experimental evidence

    NASA Astrophysics Data System (ADS)

    Jurado, Valme; Fernandez-Cortes, Angel; Cuezva, Soledad; Laiz, Leonila; Cañaveras, Juan Carlos; Sanchez-Moral, Sergio; Saiz-Jimenez, Cesareo

    2009-09-01

    The conservation of rock-art paintings in European caves is a matter of increasing interest. This derives from the bacterial colonisation of Altamira Cave, Spain and the recent fungal outbreak of Lascaux Cave, France—both included in the UNESCO World Heritage List. Here, we show direct evidence of a fungal colonisation of rock tablets in a testing system exposed in Altamira Cave. After 2 months, the tablets, previously sterilised, were heavily colonised by fungi and bacteria. Most fungi isolated were labelled as entomopathogens, while the bacteria were those regularly identified in the cave. Rock colonisation was probably promoted by the dissolved organic carbon supplied with the dripping and condensation waters and favoured by the displacement of aerosols towards the interior of the cave, which contributed to the dissemination of microorganisms. The role of arthropods in the dispersal of spores may also help in understanding fungal colonisation. This study evidences the fragility of rock-art caves and demonstrates that microorganisms can easily colonise bare rocks and materials introduced into the cavity.

  8. Discrimination, correlation, and provenance of Bed I tephrostratigraphic markers, Olduvai Gorge, Tanzania, based on multivariate analyses of phenocryst compositions

    NASA Astrophysics Data System (ADS)

    Habermann, Jörg M.; McHenry, Lindsay J.; Stollhofen, Harald; Tolosana-Delgado, Raimon; Stanistreet, Ian G.; Deino, Alan L.

    2016-06-01

    The chronology of Pleistocene flora and fauna, including hominin remains and associated Oldowan industries in Bed I, Olduvai Gorge, Tanzania, is primarily based on 40Ar/39Ar dating of intercalated tuffs and lavas, combined with detailed tephrostratigraphic correlations within the basin. Although a high-resolution chronostratigraphic framework has been established for the eastern part of the Olduvai Basin, the western subbasin is less well known due in part to major lateral facies changes within Bed I combined with discontinuous exposure. We address these correlation difficulties using the discriminative power of the chemical composition of the major juvenile mineral phases (augite, anorthoclase, plagioclase) from tuffs, volcaniclastic sandstones, siliciclastic units, and lavas. We statistically evaluate these compositions, obtained from electron probe micro-analysis, applying principal component analysis and discriminant analysis to develop discriminant models that successfully classify most Bed I volcanic units. The correlations, resulting from integrated analyses of all target minerals, provide a basin-wide Bed I chemostratigraphic framework at high lateral and vertical resolution, consistent with the known geological context, that expands and refines the geochemical databases currently available. Correlation of proximal ignimbrites at the First Fault with medial and distal Lower Bed I successions of the western basin enables assessment of lateral facies and thickness trends that confirm Ngorongoro Volcano as the primary source for Lower Bed I, whereas Upper Bed I sediment supply is mainly from Olmoti Volcano. Compositional similarity between Tuff IA, Bed I lava, and Mafic Tuffs II and III single-grain fingerprints, together with north- and northwestward thinning of Bed I lava, suggests a common Ngorongoro source for these units. The techniques applied herein improve upon previous work by evaluating compositional affinities with statistical rigor rather than

  9. The evolution of cave systems from the surface to subsurface

    SciTech Connect

    Loucks, R.G.; Handford, C.R.

    1996-12-31

    Many carbonate reservoirs are the result of cave-forming processes. The origin and recognition of fractures, breccias, and sediment fills associated with paleocaves were determined through the study of modern and paleocaves systems. Cave formation and destruction are the products of near-surface processes. Near-surface processes include solutional excavation, clastic and chemical sedimentation, and collapse of cave walls and ceilings. Cave sediment is derived from inside and/or outside the system. Depositional mechanisms include suspension, tractional, mass-flow and rock-fall. Collapse of ceilings and walls from chaotic breakdown breccias. These piles can be tens of meters thick and contain large voids and variable amounts of matrix. Cave-roof crackle breccia forms from stress-and tension-related fractures in cave-roof strata. As the cave-bearing strata subside into the subsurface, mechanical compaction increases and restructures the existing breccias and remaining cavities. Fracture porosity increases and breccia and vug porosity decreases. Large cavities collapse forming burial chaotic breakdown breccias. Differentially compacted strata over the collapsed chamber fracture and form burial cave-roof crackle breccias. Continued burial leads to more extensive mechanical compaction causing previously formed clasts to fracture and pack closer together. The resulting product is a rebrecciated chaotic breakdown breccia composed predominantly of small clasts. Rebrecciated blocks are often overprinted by crackling. Subsurface paleocave systems commonly have a complex history with several episodes of fracturing and brecciation. The resulting collapsed-paleocave reservoir targets are not single collapsed passages of tens of feet across, but are homogenized collapsed-cave systems hundreds to several thousand feet across.

  10. The evolution of cave systems from the surface to subsurface

    SciTech Connect

    Loucks, R.G. ); Handford, C.R. )

    1996-01-01

    Many carbonate reservoirs are the result of cave-forming processes. The origin and recognition of fractures, breccias, and sediment fills associated with paleocaves were determined through the study of modern and paleocaves systems. Cave formation and destruction are the products of near-surface processes. Near-surface processes include solutional excavation, clastic and chemical sedimentation, and collapse of cave walls and ceilings. Cave sediment is derived from inside and/or outside the system. Depositional mechanisms include suspension, tractional, mass-flow and rock-fall. Collapse of ceilings and walls from chaotic breakdown breccias. These piles can be tens of meters thick and contain large voids and variable amounts of matrix. Cave-roof crackle breccia forms from stress-and tension-related fractures in cave-roof strata. As the cave-bearing strata subside into the subsurface, mechanical compaction increases and restructures the existing breccias and remaining cavities. Fracture porosity increases and breccia and vug porosity decreases. Large cavities collapse forming burial chaotic breakdown breccias. Differentially compacted strata over the collapsed chamber fracture and form burial cave-roof crackle breccias. Continued burial leads to more extensive mechanical compaction causing previously formed clasts to fracture and pack closer together. The resulting product is a rebrecciated chaotic breakdown breccia composed predominantly of small clasts. Rebrecciated blocks are often overprinted by crackling. Subsurface paleocave systems commonly have a complex history with several episodes of fracturing and brecciation. The resulting collapsed-paleocave reservoir targets are not single collapsed passages of tens of feet across, but are homogenized collapsed-cave systems hundreds to several thousand feet across.

  11. Rheology of lava flows on Mercury: An analog experimental study

    NASA Astrophysics Data System (ADS)

    Sehlke, A.; Whittington, A. G.

    2015-11-01

    We experimentally determined the rheological evolution of three basaltic analog compositions appropriate to Mercury's surface, during cooling, and crystallization. Investigated compositions are an enstatite basalt, and two magnesian basalts representing the compositional end-members of the northern volcanic plains with 0.19 wt % (NVP) and 6.26 wt % Na2O (NVP-Na). The viscosity-strain rate dependence of lava was quantified using concentric cylinder viscometry. We measured the viscosities of the crystal-free liquids from 1600°C down to the first detection of crystals. Liquidus temperatures of the three compositions studied are around 1360°C, and all three compositions are more viscous than Hawaiian basalt at the same temperature. The onset of pseudoplastic behavior was observed at crystal fractions ~0.05 to 0.10, which is consistent with previous studies on mafic lavas. We show that all lavas develop detectable yield strengths at crystal fractions around 0.20, beyond which the two-phase suspensions are better described as Herschel-Bulkley fluids. By analogy with the viscosity-strain rate conditions at which the pahoehoe to `a`a transition occurs in Kilauea basalt, this transition is predicted to occur at ~1260 ± 10°C for the enstatite basalt, at ~1285 ± 20°C for the NVP, and at ~1240 ± 40°C for the NVP-Na lavas. Our results indicate that Mercury lavas are broadly similar to terrestrial ones, which suggests that the extensive smooth lava plains of Mercury could be due to large effusion rates (flood basalts) and not to unusually fluid lavas.

  12. The Influence of Topographic Obstacles on Basaltic Lava Flow Morphologies

    NASA Astrophysics Data System (ADS)

    von Meerscheidt, H. C.; Brand, B. D.; deWet, A. P.; Bleacher, J. E.; Hamilton, C. W.; Samuels, R.

    2014-12-01

    Smooth pāhoehoe and jagged ´áā represent two end-members of a textural spectrum that reflects the emplacement characteristics of basaltic lava flows. However, many additional textures (e.g., rubbly and slabby pāhoehoe) reflect a range of different process due to lava flow dynamics or interaction with topography. Unfortunately the influence of topography on the distribution of textures in basaltic lava flows is not well-understood. The 18 ± 1.0 ka Twin Craters lava flow in the Zuni-Bandera field (New Mexico, USA) provides an excellent site to study the morphological changes of a lava flow that encountered topographic obstacles. The flow field is 0.2-3.8 km wide with a prominent central tube system that intersects and wraps around a 1000 m long ridge, oriented perpendicular to flow. Upstream of the ridge, the flow has low-relief inflation features extending out and around the ridge. This area includes mildly to heavily disrupted pāhoehoe with interdispersed agglutinated masses, irregularly shaped rubble and lava balls. Breakouts of ´áā and collapse features are also common. These observations suggest crustal disruption due to flow-thickening upstream from the ridge and the movement of lava out and around the obstacle. While the ridge influenced the path of the tube, which wraps around the southern end of the ridge, the series of collapse features and breakouts of ´áā along the tube system are more likely a result of changes in flux throughout the tube system because these features are found both upstream and downstream of the obstacle. This work demonstrates that topography can significantly influence the formation history and surface disruption of a flow field, and in some cases the influence of topography can be separated from the influences of changes in flux along a tube system.

  13. Fractal analysis: A new remote sensing tool for lava flows

    NASA Technical Reports Server (NTRS)

    Bruno, B. C.; Taylor, G. J.; Rowland, S. K.; Lucey, P. G.; Self, S.

    1992-01-01

    Many important quantitative parameters have been developed that relate to the rheology and eruption and emplacement mechanics of lavas. This research centers on developing additional, unique parameters, namely the fractal properties of lava flows, to add to this matrix of properties. There are several methods of calculating the fractal dimension of a lava flow margin. We use the 'structured walk' or 'divider' method. In this method, we measure the length of a given lava flow margin by walking rods of different lengths along the margin. Since smaller rod lengths transverse more smaller-scaled features in the flow margin, the apparent length of the flow outline will increase as the length of the measuring rod decreases. By plotting the apparent length of the flow outline as a function of the length of the measuring rod on a log-log plot, fractal behavior can be determined. A linear trend on a log-log plot indicates that the data are fractal. The fractal dimension can then be calculated from the slope of the linear least squares fit line to the data. We use this 'structured walk' method to calculate the fractal dimension of many lava flows using a wide range of rod lengths, from 1/8 to 16 meters, in field studies of the Hawaiian islands. We also use this method to calculate fractal dimensions from aerial photographs of lava flows, using lengths ranging from 20 meters to over 2 kilometers. Finally, we applied this method to orbital images of extraterrestrial lava flows on Venus, Mars, and the Moon, using rod lengths up to 60 kilometers.

  14. Hidden Outgassing Dynamics at Kilauea (Hawaii) Lava Lake

    NASA Astrophysics Data System (ADS)

    Del Bello, E.; Taddeucci, J.; Orr, T. R.; Houghton, B. F.; Scarlato, P.; Patrick, M. R.

    2014-12-01

    Lava lakes offer unique opportunities for understanding how magmatic volatiles physically escape from low-viscosity, vesicular magma in open-vent conditions, a process often referred to as magma outgassing. Large-scale lava convection movements and meter-scale bubble explosions, sometimes triggered by rock falls, are acknowledged outgassing processes but may not be the only ones. In 2013 we used high-frequency (50-500 Hz) thermal and visible imaging to investigate the short-timescale dynamics of the currently active Halema`uma`u lava lake. At that time, besides the dominant release of large bubbles, three types of peculiar outgassing features were observed on the lava lake surface. The first, diffusely observed throughout the observation experiment, consisted of prolonged (up to seconds) gas venting from 'spot vents'. These vents appeared to open and close without the ejection of material or bubble bursting, and were the site of hot gas emission. Spot vents were located both between and inside cooling plates, and followed the general circulation pattern together with the rest of the lava lake surface. The second feature, observed only once, consisted of the transient wobbling of the whole lava lake surface. This wobbling, with a wavelength of meters to tens of meters, was not related to any external trigger, and dampened soon without apparent consequences on the other lake dynamics. Finally, we observed large (meters) doming areas of the lake surface randomly fluctuating over seconds to minutes. These areas were either stationary or moved independently of the general lake surface circulation, and usually were not affected by other lake surface features (e.g., cooling plate boundaries). These three features, though trivial for the overall lake outgassing, testify that the lava lake has a complex shallow subsurface architecture, in which permeable channels and gas pockets act independently of the more common bubble bursts.

  15. Lunar Lava Tubes - The Promise of New Orbital Data

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.

    2009-01-01

    The basaltic plains of the Moon contain lava channels on scales of tens of meters to hundreds of kilometers. Many of these channels are segmented, strongly suggesting that some portions include covered lava tubes. Lunar lava tubes are expected to provide unique environments below the harsh lunar surface, maintaining near-isothermal conditions and substantial shielding from solar and galactic radiation. A lava tube has often been suggested as natural shelter for a future human outpost. Previous searches for lunar lava tubes have been limited by a combination of image resolution and completeness of coverage. The five robotic Lunar Orbiter spacecraft combined to photograph essentially the entire lunar surface with a resolution of 60 m, and covered selected sites with resolutions as high as 2 m. The highest-resolution Apollo images, from the mapping and panoramic cameras, covered swaths totaling 16% of the lunar surface, at resolutions of approximately 5 m. The Lunar Reconnaissance Orbiter -- launched in June 2009 to a polar orbit -- carries a suite of instruments that will revolutionize lunar remote sensing, including the identification and characterization of lava tubes. The Lunar Reconnaissance Orbiter Camera (LROC) system includes a multi-spectral wide-angle camera with a resolution of 70 m, allowing a comprehensive survey of the entire lunar surface. The LROC narrow-angle camera is providing targeted images at resolutions of 0.5 - 2 m, including stereo coverage, which should allow detection of tube entrances and breakdown structures. The Lunar Orbiter Laser Altimeter is producing a global topographic map with a vertical resolution of 1 m and a horizontal resolution of 50 m. These data will be critical to understanding lava dynamics and tube emplacement.

  16. Spectral and Morphological Analysis of Daedalia Planum Lava Field

    NASA Astrophysics Data System (ADS)

    Giacomini, L.; Massironi, M.; Carli, C.; Martellato, E.; Pasquarè, G.; Pompilio, L.; Cremonese, G.

    2008-12-01

    Daedalia Planum is one of the Tharsis volcanic plains and is located southwest of the Arsia Mons. According to MOLA data, the flanks of Arsia have an average slope < 5°, while the surrounding regions, including Daedalia Planum, have slopes < 0.5° and commonly < 0.1°. MOC and THEMIS images show a plain covered by a huge number of lava flows. Older and larger lava flows on the field have a length greater than 1500, even if determining their absolute length is difficult as subsequent lava flows have buried the source vents. MEX/OMEGA data reveal that Daedalia Planum lavas have a spectral shapes comparable to those observed in laboratory for rock slabs of Earth's basalts. Moreover most of the Daedalia flows are associated to wrinkly and ropy surfaces, typical of pahoehoe lavas. The Daedalia Planum flow surfaces show several morphological features that remember the inflation fingerprints. This suggests that also Daedalia Planum could have been interested by inflation. However these features appear dissimilar to inflation forms on Elysium Planitia flows. Different degrees of erosion could explain such dissimilarities. In particular Daedalia Planum flow surfaces appear heavily modelled by wind erosion whereas the Elysium Planitia features seem fresher. The different age between the two areas support this hypothesis. Our crater counting dated the most recent Daedalia Planum flows to about 230 Myr , by contrast the Elysium Planitia lava flows range from 100 to 10 My. In conclusion, the inflation process on Martian flows could be more frequent than previously supposed and, consequently, effusion rates and rheological properties of Martian lavas more variable.

  17. Magma rheology from 3D geometry of martian lava flows

    NASA Astrophysics Data System (ADS)

    Allemand, P.; Deschamps, A.; Lesaout, M.; Delacourt, C.; Quantin, C.; Clenet, H.

    2012-04-01

    Volcanism is an important geologic agent which has been recently active at the surface of Mars. The composition of individual lava flows is difficult to infer from spectroscopic data because of the absence of crystallized minerals and the possible cover of the flows by dust. The 3D geometry of lava flows provides an interesting alternative to infer the chemical composition of lavas and effusion rates. Indeed, chemical composition exerts a strong control on the viscosity and yield strength of the magma and global geometry of lava flow reflects its emplacement rate. Until recently, these studies where realized from 2D data. The third dimension, which is a key parameter, was deduced or supposed from local shadow measurements on MGS Themis IR images with an uncertainty of more than 500%. Recent CTX data (MRO mission) allow to compute Digital Elevation Model at a resolution of 1 or 2 pixels (5 to 10 m) with the help of Isis and the Ames Stereo Pipeline pipe line. The CTX images are first transformed in format readable by Isis. The external geometric parameters of the CTX camera are computed and added to the image header with Isis. During a correlation phase, the homologous pixels are searched on the pair of stereo images. Finally, the DEM is computed from the position of the homologous pixels and the geometrical parameters of the CTX camera. Twenty DEM have been computed from stereo images showing lava flows of various ages on the region of Cerberus, Elyseum, Daedalia and Amazonis planitia. The 3D parameters of the lava flows have been measured on the DEMs and tested against shadows measurement. These 3D parameters have been inverted to estimate the viscosity and the yield strength of the flow. The effusion rate has also been estimated. These parameters have been compared to those of similar lava flows of the East Pacific rise.

  18. Monitoring of Bunker Cave (NW Germany): Assessing the complexity of cave environmental parameters

    NASA Astrophysics Data System (ADS)

    Riechelmann, Dana Fc; Schröder-Ritzrau, Andrea; Scholz, Denis; Spötl, Christoph; Richter, Detlev K.; Mangini, Augusto

    2010-05-01

    Bunker Cave (N 51° 22'03', E 7° 39'53') is located in the Rhenish Slate Mountains in the western part of Germany and is part of a giant cave system in the area of Iserlohn (Hammerschmidt et al., 1995).As part of the DAPHNE (Dated Speleothems - archives of the paleoenvironment) project Bunker Cave is being monitored since the end of 2006. The ongoing monitoring program is performed on a monthly base. Surface climate parameters are measured and samples of rain water, cave air, drip water at eight different drip sites and modern calcite precipitates from watch glasses placed beneath drip sites are collected. Data sets include temperature, precipitation, calculated infiltration, drip rates, electric conductivity, pH, alkalinity, cations, anions and stable isotopes. Bunker Cave shows a constant temperature throughout the year. Active calcite precipitation is higher in winter than in summer, which is due to lower cave pCO2 in winter. The generally low pCO2 values, however, support almost continuous calcite precipitation throughout the whole year. Drip water δ18O values reflect the mean annual isotopic composition of the rainfall in this area with no or less contribution of the summer rain. The slope of the MWL for local precipitation is close to the slope of both the global MWL and the local MWL at the nearby station Bad Salzuflen. The karst aquifer is well mixed as shown by the uniform drip water δ18O values. Hence, the site is well suited to detect multi-annual climate trends using stalagmite stable isotope records. In order to test the potential influence of kinetic isotope fractionation on the stable isotope signals at Bunker Cave, stable isotope data of modern calcite precipitated on watch glasses were compared to predicted values. Comparison of the δ18O values of in situ modern calcite precipitates with the δ18O values expected from equilibrium isotope fractionation suggests a small kinetic influence, which is probably related to the variability in drip rate

  19. IDENTIFICATION OF BAT ECTOPARASITE LEPTOCIMEX INORDINATUS FROM BAT-DWELLING CAVE, KANCHANABURI PROVINCE, THAILAND.

    PubMed

    Potiwat, Rutcharin; Sungvornyothin, Sungsit; Samung, Yudthana; Payakkapol, Anon; Apiwathnasorn, Chamnarn

    2016-01-01

    Bat bugs are blood-feeding insects of bats or warm blooded animals and humans. Since 2011, Leptocimex spp (Heteroptera: Cimicidae) has been reported in Thailand. However, microscopic examination of Leptocimex spp is complicated, especially when the entire body of the specimen is not available. To confirm the phenotypic identification of L. inordinatus from a limestone bat cave in Thailand, partial fragments of mitochondrial cytochrome c oxidase subunit 1 (COI) gene and 16S mitochondrial ribosomal DNA were PCR amplified and sequenced, which revealed 97% sequence identity with Cimicidae family members, being most similar to Cacodminae gen. sp. and C. vicinus, both bat bugs. Phylogenetic tree construction showed that L. inordinatus has a separate genetic lineage from that of with human bed bugs (Cimex hemipterus or C. lectularius), swallow bugs and other tick species. The presence of L. inordinatus in a bat-dwelling cave frequented by humans presents a potential public health problem requiring attention in particular regarding the possibility of zoonotic transmission of pathogens. PMID:27086421

  20. Degassing processes during lava dome growth: Insights from Santiaguito lava dome, Guatemala

    NASA Astrophysics Data System (ADS)

    Holland, A. S. Peter; Watson, I. Matthew; Phillips, Jeremy C.; Caricchi, Luca; Dalton, Marika P.

    2011-04-01

    Eruptions of intermediate magma may be explosive or effusive. The development of open system degassing has been proposed as a pre-requisite for effusion of intermediate magma, however processes leading to open system degassing are poorly understood. To better understand degassing processes during lava dome extrusion we report high temporal-resolution SO 2 emission rate measurements collected with an ultra violet imaging camera at Santiaguito, Guatemala. Santiaguito is an ideal case study as the dome lava is compositionally very similar to products of the 1902 Plinian eruption of the parental Santa María volcano. We find that degassing is weak (0.4-1 kg s - 1 ) but continuous, and explosions are associated with small increases in emission rates (up to 2-3 kg s - 1 ). Continuous repose degassing occurs through a shallow cap rock which likely represents a proto-crust on the block lava flow which is extruded from the same vent. The continual permeability of the upper conduit argues against a mechanism of explosion triggering in which gas pressure builds beneath a viscous cap rock or plug. Rather, we consider degassing data better consistent with a model of shear-fracturing at the conduit margins. Using field constraints, we model the viscosity of Santiaguito magma as a function of depth and show that conditions for shear-fracturing are met from 150-600 m to the surface. This is in line with independent estimates of explosion initiation depth. We show that repose timescales are orders of magnitude longer than the timescale for shear fracture, and suggest that explosions are triggered when a continuous network of smaller-scale fractures develops, at which point decompression occurs and an explosion is triggered. Fracture healing occurs by viscous relaxation however near to the surface where viscosity is highest, an unconsolidated gouge layer may develop. Our model implies that the observed explosions are a by-product of extrusion. Shear-fracturing can drive open system

  1. Do cave features affect underground habitat exploitation by non-troglobite species?

    NASA Astrophysics Data System (ADS)

    Lunghi, Enrico; Manenti, Raoul; Ficetola, Gentile Francesco

    2014-02-01

    Many biospeleological studies focus on organisms that are exclusive inhabitants of the subterranean realm, but organisms that are not obligate cave-dwellers are frequent in caves, and may account for a substantial portion of biomass. Moreover, several taxa that are usually epigeous are regularly found inside caves, but for most of them it is unknown whether they accidentally enter them, or whether they actively select caves for specific environmental features. In this study we analysed the community of non-strict cave-dwelling organisms (amphibians, gastropods, spiders and orthopterans) in 33 caves from Central Italy, to assess how environmental factors determine community structure. Cave features strongly affected the distribution of the taxa considered. The combined effect of cave morphology and microclimate explained nearly 50% of the variation of community structure. Most of community variation occurred along a gradient from deep, dark and humid caves, to dry caves with wider entrances and extended photic areas. Most of species were associated with humid, deep and dark caves. Most of the non-troglobiont amphibians and invertebrates did not occur randomly in caves, but were associated to caves with specific environmental features. Analysing relationships between cave-dwelling species and environmental variables can allow a more ecological and objective classification of cave-dwelling organisms.

  2. Calcite Farming at Hollow Ridge Cave: Calibrating Net Rainfall and Cave Microclimate to Dripwater and Calcite Chemical Variability

    NASA Astrophysics Data System (ADS)

    Tremaine, D. M.; Kilgore, B. P.; Froelich, P. N.

    2012-04-01

    Stable isotope (δ18O and δ13C) and trace element records in cave speleothems are often interpreted as climate changes in rainfall amount or source, cave air temperature, overlying vegetation and atmospheric pCO2. However, these records are difficult to verify without in situ calibration of changes in cave microclimate (e.g., net rainfall, interior ventilation changes) to contemporaneous variations in dripwater and speleothem chemistry. In this study at Hollow Ridge Cave (HRC) in Marianna, Florida (USA), cave dripwater, bedrock, and modern calcite (farmed in situ) were collected in conjunction with continuous cave air pCO2, temperature, barometric pressure, relative humidity, radon-222 activity, airflow velocity and direction, rainfall amount, and drip rate data [1]. We analyzed rain and dripwater δD and δ18O, dripwater Ca2+, pH, δ13C and TCO2, cave air pCO2 and δ13C, and farmed calcite δ18O and δ13C to examine the relationships among rainwater isotopic composition, cave air ventilation, cave air temperature, calcite growth rate and seasonal timing, and calcite isotopic composition. Farmed calcite δ13C decreases linearly with distance from the front entrance to the interior of the cave during all seasons, with a maximum entrance-to-interior gradient of Δδ13C = -7‰ . A whole-cave "Hendy test" at distributed contemporaneous farming sites reveals that ventilation induces a +1.9 ± 0.96‰ δ13C offset between calcite precipitated in a ventilation flow path and out of flow paths. Farmed calcite δ18O exhibits a +0.82 ± 0.24‰ offset from values predicted by both theoretical calcite-water calculations and by laboratory-grown calcite [2]. Unlike calcite δ13C, oxygen isotopes show no ventilation effects and are a function only of temperature. Combining our data with other speleothem studies, we find a new empirical relationship for cave-specific water-calcite oxygen isotope fractionation across a range of temperatures and cave environments: 1000 ln α = 16

  3. Spatial organization and connectivity of caves

    NASA Astrophysics Data System (ADS)

    Jouves, Johan; Viseur, Sophie; Guglielmi, Yves; Camus, Hubert

    2015-04-01

    The main particularity of karst systems is their hierarchical organization as three-dimensional network of conduits behaving as drain. They are recognized as having a major influence on fluid flow at reservoir scale. However, a karstic network is generally hardly continuously observable and their great intrinsic heterogeneity makes their characterization very complex. This media can be only observed by speleological investigation, conditioned to human possibilities. As a result, only few parts can be observed and therefore it is required to model the non-observable parts for reservoir characterizations. To provide realistic 3D models, non-observable karstic features will be generated using parameters extracted from observed ones. Morphometric analysis of the three-dimensional karstic network provides quantitative measures that can (i) give information on speleogenesis processes, (ii) be used to compare different karst systems, (iii) be correlated with hydrogeological behavior and (iii) control the simulation of realistic karst networks. Recent work done on the subject characterize the karstic network as a whole, without genetic a-priori. However, most of observable caves appears to have a polygenic history due to modifications in boundary conditions and some different karst features can be observed in a same cavity. To study the geometrical organization of caves, we propose to analyze 3D speleological topographies for which speleogenetic context is known. This way, it is possible to characterize karst features according to speleogenetic processes. Several morphometric descriptors have been calculated on three-dimensional topographies provided by speleological works. Some parameters describe the existence of preferential direction of karstification and preferential flow paths, other parameters describe the complexity, geometry and connectivity of the three-dimensional karstic networks. Through the study of fifteen different caves, 150km of 3D data have been analyzed

  4. Late Holocene lava flow morphotypes of the northern Harrat Rahat, Kingdom of Saudi Arabia: implications for the description of continental lava fields

    NASA Astrophysics Data System (ADS)

    Murcia, H. F.; Nemeth, K.; Moufti, R.; Lindsay, J. M.; El-Masry, N.; Cronin, S. J.; Qaddah, A.; Smith, I. E.

    2013-12-01

    Lava morphotype refers to the surface morphology of a lava flow after solidification. In Saudi Arabia, young and well-preserved mafic lava fields (Harrats) display a wide range of these morphotypes. This study examines those exhibited by four of the post-4500 yrs. BP lava fields in the northern Harrat Rahat (<10 Ma) and describes these lava fields from general characteristics to detailed lava structures. This study also discusses the relationship between rheology and morphotypes, and proposes a preliminary correlation with whole-rock chemical composition. The Harrat Rahat lava fields include one or more lobes that may extend over 20 km from the source, with thicknesses varying between 1-2 m up to 12 m. Each lava flow episode covered areas between ~32 and ~61 km2, with individual volumes estimated between ~0.085 and ~0.29 km3. The whole-rock chemical compositions of these lavas lie between 44.3 to 48.4% SiO2, 9.01-4.28% MgO and 3.13-6.19% NaO+K2O. Seven different morphotypes with several lava structures are documented: Shelly, Slabby, Rubbly-pahoehoe, Platy, Cauliflower, Rubbly-a'a, and Blocky. These may be related to the shear strain and/or apparent viscosity of the lava flows formed from typical pahoehoe (pure or Hawaiian-pahoehoe, or sheet-pahoehoe). The well-preserved lava fields in Harrat Rahat allow the development of a more expanded classification scheme than has been traditionally applied. In addition to the whole-rock composition, these morphotypes may be indicators of other properties such as vesicularity, crystallization, effusion mechanism, as well as significant along-flow variations in topography and lava thickness and temperature that modify the rheology. The linearity of transitions between morphotypes observed in the lava fields suggest that real time forecasting of the evolution of lava flows might be possible.

  5. Annual Thermal Amplitudes and Thermal Detection of Southwestern U.S. Caves: Additional Insights for Remote Sensing of Caves on Earth and Mars

    NASA Astrophysics Data System (ADS)

    Wynne, J. J.; Titus, T. N.; Drost, C. A.; Toomey, R. S.; Peterson, K.

    2008-03-01

    We analyzed temperature data of nine SW U.S. caves using Fourier analysis to characterize thermal behavior, and line graphs to identify optimal times of detection in the thermal infrared. This work furthered our understanding of cave thermal behavior.

  6. Analogue experiments as benchmarks for models of lava flow emplacement

    NASA Astrophysics Data System (ADS)

    Garel, F.; Kaminski, E. C.; Tait, S.; Limare, A.

    2013-12-01

    During an effusive volcanic eruption, the crisis management is mainly based on the prediction of lava flow advance and its velocity. The spreading of a lava flow, seen as a gravity current, depends on its "effective rheology" and on the effusion rate. Fast-computing models have arisen in the past decade in order to predict in near real time lava flow path and rate of advance. This type of model, crucial to mitigate volcanic hazards and organize potential evacuation, has been mainly compared a posteriori to real cases of emplaced lava flows. The input parameters of such simulations applied to natural eruptions, especially effusion rate and topography, are often not known precisely, and are difficult to evaluate after the eruption. It is therefore not straightforward to identify the causes of discrepancies between model outputs and observed lava emplacement, whereas the comparison of models with controlled laboratory experiments appears easier. The challenge for numerical simulations of lava flow emplacement is to model the simultaneous advance and thermal structure of viscous lava flows. To provide original constraints later to be used in benchmark numerical simulations, we have performed lab-scale experiments investigating the cooling of isoviscous gravity currents. The simplest experimental set-up is as follows: silicone oil, whose viscosity, around 5 Pa.s, varies less than a factor of 2 in the temperature range studied, is injected from a point source onto a horizontal plate and spreads axisymmetrically. The oil is injected hot, and progressively cools down to ambient temperature away from the source. Once the flow is developed, it presents a stationary radial thermal structure whose characteristics depend on the input flow rate. In addition to the experimental observations, we have developed in Garel et al., JGR, 2012 a theoretical model confirming the relationship between supply rate, flow advance and stationary surface thermal structure. We also provide

  7. Lava flow risk maps at Mount Cameroon volcano

    NASA Astrophysics Data System (ADS)

    Favalli, M.; Fornaciai, A.; Papale, P.; Tarquini, S.

    2009-04-01

    Mount Cameroon, in the southwest Cameroon, is one of the most active volcanoes in Africa. Rising 4095 m asl, it has erupted nine times since the beginning of the past century, more recently in 1999 and 2000. Mount Cameroon documented eruptions are represented by moderate explosive and effusive eruptions occurred from both summit and flank vents. A 1922 SW-flank eruption produced a lava flow that reached the Atlantic coast near the village of Biboundi, and a lava flow from a 1999 south-flank eruption stopped only 200 m from the sea, threatening the villages of Bakingili and Dibunscha. More than 450,000 people live or work around the volcano, making the risk from lava flow invasion a great concern. In this work we propose both conventional hazard and risk maps and novel quantitative risk maps which relate vent locations to the expected total damage on existing buildings. These maps are based on lava flow simulations starting from 70,000 different vent locations, a probability distribution of vent opening, a law for the maximum length of lava flows, and a database of buildings. The simulations were run over the SRTM Digital Elevation Model (DEM) using DOWNFLOW, a fast DEM-driven model that is able to compute detailed invasion areas of lava flows from each vent. We present three different types of risk maps (90-m-pixel) for buildings around Mount Cameroon volcano: (1) a conventional risk map that assigns a probability of devastation by lava flows to each pixel representing buildings; (2) a reversed risk map where each pixel expresses the total damage expected as a consequence of vent opening in that pixel (the damage is expressed as the total surface of urbanized areas invaded); (3) maps of the lava catchments of the main towns around the volcano, within every catchment the pixels are classified according to the expected impact they might produce on the relative town in the case of a vent opening in that pixel. Maps of type (1) and (3) are useful for long term planning

  8. Comparison of 3D point clouds produced by LIDAR and UAV photoscan in the Rochefort cave (Belgium)

    NASA Astrophysics Data System (ADS)

    Watlet, Arnaud; Triantafyllou, Antoine; Kaufmann, Olivier; Le Mouelic, Stéphane

    2016-04-01

    Amongst today's techniques that are able to produce 3D point clouds, LIDAR and UAV (Unmanned Aerial Vehicle) photogrammetry are probably the most commonly used. Both methods have their own advantages and limitations. LIDAR scans create high resolution and high precision 3D point clouds, but such methods are generally costly, especially for sporadic surveys. Compared to LIDAR, UAV (e.g. drones) are cheap and flexible to use in different kind of environments. Moreover, the photogrammetric processing workflow of digital images taken with UAV becomes easier with the rise of many affordable software packages (e.g. Agisoft, PhotoModeler3D, VisualSFM). We present here a challenging study made at the Rochefort Cave Laboratory (South Belgium) comprising surface and underground surveys. The site is located in the Belgian Variscan fold-and-thrust belt, a region that shows many karstic networks within Devonian limestone units. A LIDAR scan has been acquired in the main chamber of the cave (~ 15000 m³) to spatialize 3D point cloud of its inner walls and infer geological beds and structures. Even if the use of LIDAR instrument was not really comfortable in such caving environment, the collected data showed a remarkable precision according to few control points geometry. We also decided to perform another challenging survey of the same cave chamber by modelling a 3D point cloud using photogrammetry of a set of DSLR camera pictures taken from the ground and UAV pictures. The aim was to compare both techniques in terms of (i) implementation of data acquisition and processing, (ii) quality of resulting 3D points clouds (points density, field vs cloud recovery and points precision), (iii) their application for geological purposes. Through Rochefort case study, main conclusions are that LIDAR technique provides higher density point clouds with slightly higher precision than photogrammetry method. However, 3D data modeled by photogrammetry provide visible light spectral information

  9. Rheology of a long lava flow at Pavonis Mons, Mars

    NASA Astrophysics Data System (ADS)

    Baloga, S. M.; Mouginis-Mark, P. J.; Glaze, L. S.

    2003-07-01

    Dimensions of lava flows can be used to unravel the relative roles of viscosity changes and concurrent formation of levees, stationary margins, and stagnant zones. This approach is applied to data derived from the Mars Orbiter Laser Altimeter (MOLA) experiment for a long lava flow on the plains north of Pavonis Mons, Mars. We obtain a formula for the relative change in viscosity on the basis of a steady state Newtonian flow rate. Our approach features a new length scale that describes the transfer of lava from the active advancing component to passive components. This length scale can be determined from planetary image and topographic data by estimating the volume fraction of lava contained in flow margins relative to the total flow volume. We find only modest changes in viscosity over the distal 175 km of the Pavonis flow. Allowing the flow to also lose volume through degassing (resulting in a density increase) does little to affect the overall viscosity change. Thickening and widening of the flow with distance are as expected for a single coherent, isothermal, viscous flow. This dynamic regime features a balance between the formation of an outer skin and shedding of lava into stationary zones. Requirements for attaining such a regime include a thick flow, shallow slopes over extended distances, and preexisting surface roughness that is small compared to flow thickness. This style of emplacement may explain why many of the long, thick sheet-like flows on the plains of Mars often exhibit an unexpected lack of thickening with distance.

  10. The Influence of Slope Breaks on Lava Flow Surface Disruption

    NASA Technical Reports Server (NTRS)

    Glaze, Lori S.; Baloga, Stephen M.; Fagents, Sarah A.; Wright, Robert

    2014-01-01

    Changes in the underlying slope of a lava flow impart a significant fraction of rotational energy beyond the slope break. The eddies, circulation and vortices caused by this rotational energy can disrupt the flow surface, having a significant impact on heat loss and thus the distance the flow can travel. A basic mechanics model is used to compute the rotational energy caused by a slope change. The gain in rotational energy is deposited into an eddy of radius R whose energy is dissipated as it travels downstream. A model of eddy friction with the ambient lava is used to compute the time-rate of energy dissipation. The key parameter of the dissipation rate is shown to be rho R(sup 2/)mu, where ? is the lava density and mu is the viscosity, which can vary by orders of magnitude for different flows. The potential spatial disruption of the lava flow surface is investigated by introducing steady-state models for the main flow beyond the steepening slope break. One model applies to slow-moving flows with both gravity and pressure as the driving forces. The other model applies to fast-moving, low-viscosity, turbulent flows. These models provide the flow velocity that establishes the downstream transport distance of disrupting eddies before they dissipate. The potential influence of slope breaks is discussed in connection with field studies of lava flows from the 1801 Hualalai and 1823 Keaiwa Kilauea, Hawaii, and 2004 Etna eruptions.

  11. ComputerApplications and Virtual Environments (CAVE)

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. The Marshall Space Flight Centerr (MSFC) in Huntsville, Alabama began to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models were used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup was to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability provided general visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC). The X-34 program was cancelled in 2001.

  12. Computer Applications and Virtual Environments (CAVE)

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. Marshall SPace Flight Center (MSFC) is begirning to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models are used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup is to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability provides general visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC).

  13. ComputerApplications and Virtual Environments (CAVE)

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. The Marshall Space Flight Center (MSFC) in Huntsville, Alabama began to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models were used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup was to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability providedgeneral visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC). The X-34 program was cancelled in 2001.

  14. 7 CFR 2902.15 - Bedding, bed linens, and towels.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Bedding, bed linens, and towels. 2902.15 Section 2902... PROCUREMENT Designated Items § 2902.15 Bedding, bed linens, and towels. (a) Definition. (1) Bedding is that group of woven cloth products used as coverings on a bed. Bedding includes products such as...

  15. Contemporary flowstone development links early hominin bearing cave deposits in South Africa

    NASA Astrophysics Data System (ADS)

    Pickering, Robyn; Kramers, Jan D.; Hancox, Philip John; de Ruiter, Darryl J.; Woodhead, Jon D.

    2011-06-01

    The Cradle of Humankind cave sites in South Africa preserve fossil evidence of four early hominin taxa: Australopithecus africanus, Australopithecus sediba, Paranthropus robustus and early Homo. In order to integrate this record into a pan-African scenario of human evolutionary history it is critical to have reliable dates and temporal ranges for the southern African hominins. In the past a lack of precise and accurate chronological data has prevented the evaluation of the temporal relationships between the various sites. Here we report new uranium-lead (U-Pb) radiometric ages obtained from sheets of calcium carbonate flowstone inter-bedded between clastic cave sediments at the site of Swartkrans, providing bracketing ages for the fossiliferous deposits. The fossil bearing units of Swartkrans, specifically the Hanging Remnant and Lower Bank of Member 1, are underlain by flowstone layers dated to 2.25 ± 0.05 Ma and 2.25 ± 0.08 Ma and capped by layers of 1.8 ± 0.01 Ma and 1.7 ± 0.07 Ma. The age bracket of the Member 1 deposits is therefore between 2.31 and 1.64 Ma. However, by combining the U-Pb with biostratigraphic data we suggest that this can be narrowed down to between 1.9 and 1.8 Ma. These data can be compared with other recently dated sites and a radiometrically dated U-Pb age sequence formed: Sterkfontein Member 4, Swartkrans Member 1, Malapa, and Cooper's D. From this new U-Pb dataset, a pattern of contemporary flowstone development emerges, with different caves recording the same flowstone-forming event. Specifically overlapping flowstone formation takes place at Swartkrans and Sterkfontein at ~ 2.29 Ma and ~ 1.77 Ma, and at Sterkfontein and Malapa at ˜ 2.02 Ma. This suggests a regional control over the nature and timing of speleothem development in cave deposits and these flowstone layers could assist in future correlation, both internal to specific deposits and regionally between sites.

  16. Isotopic dating of Lava Creek B tephra in terrace deposits along the Wind River, Wyoming--Implications for post 0. 6 Ma uplift of the Yellowstone hotspot

    SciTech Connect

    Izett, G.A.; Pierce, K.L.; Naeser, N.D. ); Jaworowski, C. . Dept. of Geology and Geophysics)

    1992-01-01

    Along the Wind River near Kinnear (Pavillon quadrangle), a meter-thick tephra layer occurs near the middle of a main-stem gravel deposit about 100 m above the river. On Muddy Ridge 25 km east of Kinnear, a Lava Creek B tephra layer occurs at the base of a terrace deposit about 100 m above Muddy Creek. Another Lava Creek B tephra site 67 km northwest and upstream from Kinnear occurs within main-stem gravels of a terrace deposit 145 m above the river. This upstream increase of 45 m of the tephra horizon raises the concern that the two tephra layers might not be of the same age. All three tephras contain the same assemblage of phenocrysts as that in the Lava Creek Tuff, Member B in Yellowstone National Park and the Lava Creek B volcanic ash bed of the Western U.S., and therefore they are arguably correlatives. The authors confirmed this petrographic correlation by isotopic dating of sanidine crystals recovered from cm-size pumice lapilli in the Kinnear tephra and from coarse-grained tephra at the Muddy Creek site. Laser total-fusion Ar-40-Ar-39 ages of sanidine from the two sites are coeval, 0.66[plus minus]0.01 Ma and 0.67[plus minus]0.01 Ma at Muddy Creek. Conventional K-Ar dating of sanidine from the tephra at the Cl453 site resulted in an age of 0.60[plus minus]0.02 Ma. Glass-mantled zircon crystals from the Cl453 site yielded a fission-track age of 0.67[plus minus]0.16 Ma. These isotopic ages are compatible with conventional K-Ar, Ar-40-Ar-39, and fission-track ages of the Lava Creek Tuff, Member B in Yellowstone National Park and other occurrences of Lava Creek B ash beds. The authors suggest that the terrace deposit that contains the Lava Creek B tephra rises from the Kinnear site northwest up the Wind River as a result of Quaternary uplift in the area of the Yellowstone hotspot.

  17. Clumped isotope thermometry of cryogenic cave carbonates

    NASA Astrophysics Data System (ADS)

    Kluge, Tobias; Affek, Hagit P.; Zhang, Yi Ge; Dublyansky, Yuri; Spötl, Christoph; Immenhauser, Adrian; Richter, Detlev K.

    2014-02-01

    Freezing of cave pool water that is increasingly oversaturated with dissolved carbonate leads to precipitation of a very specific type of speleothems known as cryogenic cave carbonates (CCC). At present, two different environments for their formation have been proposed, based on their characteristic carbon and oxygen isotope ratios. Rapidly freezing thin water films result in the fast precipitation of fine-grained carbonate powder (CCCfine). This leads to rapid physicochemical changes including CO2 degassing and CaCO3 precipitation, resulting in significantly 13C-enriched carbonates. Alternatively, slow carbonate precipitation in ice-covered cave pools results in coarse crystalline CCC (CCCcoarse) yielding strongly 18O-depleted carbonate. This is due to the formation of relatively 18O-enriched ice causing the gradual depletion of 18O in the water from which the CCC precipitates. Cryogenic carbonates from Central European caves were found to have been formed primarily during the last glacial period, specifically during times of permafrost thawing, based on the oxygen isotope ratios and U-Th dating. Information about the precise conditions of CCCcoarse formation, i.e. whether these crystals formed under equilibrium or disequilibrium conditions with the parent fluid, however, is lacking. An improved understanding of CCCcoarse formation will increase the predictive value of this paleo-permafrost archive. Here we apply clumped isotopes to investigate the formation conditions of cryogenic carbonates using well-studied CCCcoarse from five different cave systems in western Germany. Carbonate clumped isotope measurements yielded apparent temperatures between 3 and 18 °C and thus exhibit clear evidence of isotopic disequilibrium. Although the very negative carbonate δ18O values can only be explained by gradual freezing of pool water accompanied by preferential incorporation of 18O into the ice, clumped isotope-derived temperatures significantly above expected freezing

  18. Ancient photosynthetic eukaryote biofilms in an Atacama Desert coastal cave

    USGS Publications Warehouse

    Azua-Bustos, A.; Gonzalez-Silva, C.; Mancilla, R.A.; Salas, L.; Palma, R.E.; Wynne, J.J.; McKay, C.P.; Vicuna, R.

    2009-01-01

    Caves offer a stable and protected environment from harsh and changing outside prevailing conditions. Hence, they represent an interesting habitat for studying life in extreme environments. Here, we report the presence of a member of the ancient eukaryote red algae Cyanidium group in a coastal cave of the hyperarid Atacama Desert. This microorganism was found to form a seemingly monospecific biofilm growing under extremely low photon flux levels. Our work suggests that this species, Cyanidium sp. Atacama, is a new member of a recently proposed novel monophyletic lineage of mesophilic "cave" Cyanidium sp., distinct from the remaining three other lineages which are all thermo-acidophilic. The cave described in this work may represent an evolutionary island for life in the midst of the Atacama Desert. ?? Springer Science + Business Media, LLC 2009.

  19. Further constraints on the Chauvet cave artwork elaboration.

    PubMed

    Sadier, Benjamin; Delannoy, Jean-Jacques; Benedetti, Lucilla; Bourlès, Didier L; Jaillet, Stéphane; Geneste, Jean-Michel; Lebatard, Anne-Elisabeth; Arnold, Maurice

    2012-05-22

    Since its discovery, the Chauvet cave elaborate artwork called into question our understanding of Palaeolithic art evolution and challenged traditional chronological benchmarks [Valladas H et al. (2001) Nature 413:419-479]. Chronological approaches revealing human presences in the cavity during the Aurignacian and the Gravettian are indeed still debated on the basis of stylistic criteria [Pettitt P (2008) J Hum Evol 55:908-917]. The presented (36)Cl Cosmic Ray Exposure ages demonstrate that the cliff overhanging the Chauvet cave has collapsed several times since 29 ka until the sealing of the cavity entrance prohibited access to the cave at least 21 ka ago. Remarkably agreeing with the radiocarbon dates of the human and animal occupancy, this study confirms that the Chauvet cave paintings are the oldest and the most elaborate ever discovered, challenging our current knowledge of human cognitive evolution.

  20. 12. Deck view of bridge near Alum Cave parking area ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Deck view of bridge near Alum Cave parking area looking S. - Great Smoky Mountains National Park Roads & Bridges, Newfound Gap Road, Between Gatlinburg, TN & Cherokee, NC, Gatlinburg, Sevier County, TN

  1. Cave Holography - Out of the lab and under the ground

    NASA Astrophysics Data System (ADS)

    Klayer, J.

    2013-02-01

    This paper describes the combination of my hobbies, caving and holography. Most traditional holography involves bringing the objects to a lab with all the necessary holography equipment mounted on a stable table. I instead bring all the equipment assembled as a portable unit to the natural formations in a cave with the cave itself being the stable table. The first successes were Denisyuks made with a HeNe or laser diode and spatial filter mounted on a tripod. For greater depth, transmission holograms were made with a DPSS laser in several configurations sometimes using fiber optics to route the reference beam and sometimes a spatial filter and mirrors. The cave environment presents unique obstacles that have been overcome as evidenced by the beautiful holograms made.

  2. The biogeochemistry of anchialine caves: Progress and possibilities

    USGS Publications Warehouse

    Pohlman, John W.

    2011-01-01

    Recent investigations of anchialine caves and sinkholes have identified complex food webs dependent on detrital and, in some cases, chemosynthetically produced organic matter. Chemosynthetic microbes in anchialine systems obtain energy from reduced compounds produced during organic matter degradation (e.g., sulfide, ammonium, and methane), similar to what occurs in deep ocean cold seeps and mud volcanoes, but distinct from dominant processes operating at hydrothermal vents and sulfurous mineral caves where the primary energy source is mantle derived. This review includes case studies from both anchialine and non-anchialine habitats, where evidence for in situ chemosynthetic production of organic matter and its subsequent transfer to higher trophic level metazoans is documented. The energy sources and pathways identified are synthesized to develop conceptual models for elemental cycles and energy cascades that occur within oligotrophic and eutrophic anchialine caves. Strategies and techniques for testing the hypothesis of chemosynthesis as an active process in anchialine caves are also suggested.

  3. Further constraints on the Chauvet cave artwork elaboration

    PubMed Central

    Sadier, Benjamin; Delannoy, Jean-Jacques; Benedetti, Lucilla; Bourlès, Didier L.; Jaillet, Stéphane; Geneste, Jean-Michel; Lebatard, Anne-Elisabeth; Arnold, Maurice

    2012-01-01

    Since its discovery, the Chauvet cave elaborate artwork called into question our understanding of Palaeolithic art evolution and challenged traditional chronological benchmarks [Valladas H et al. (2001) Nature 413:419–479]. Chronological approaches revealing human presences in the cavity during the Aurignacian and the Gravettian are indeed still debated on the basis of stylistic criteria [Pettitt P (2008) J Hum Evol 55:908–917]. The presented 36Cl Cosmic Ray Exposure ages demonstrate that the cliff overhanging the Chauvet cave has collapsed several times since 29 ka until the sealing of the cavity entrance prohibited access to the cave at least 21 ka ago. Remarkably agreeing with the radiocarbon dates of the human and animal occupancy, this study confirms that the Chauvet cave paintings are the oldest and the most elaborate ever discovered, challenging our current knowledge of human cognitive evolution. PMID:22566649

  4. Unexplored diversity and conservation potential of neotropical hot caves.

    PubMed

    Ladle, Richard J; Firmino, João V L; Malhado, Ana C M; Rodríguez-Durán, Armando

    2012-12-01

    The term hot cave is used to describe some subterranean chambers in the Neotropics that are characterized by constantly high ambient temperatures generated by the body heat of high densities of certain bat species. Many of these species have limited geographic ranges, and some occur only in the hot-cave environment. In addition to the bats, the stable microclimate and abundant bat guano provides refuge and food for a high diversity of invertebrates. Hot caves have so far been described in the Caribbean and in a few isolated locations from Mexico to Brazil, although there is some evidence that similar caves may be present throughout the tropics. The existing literature suggests these poorly known ecosystems, with their unique combination of geomorphology and bat-generated microclimate, are particularly sensitive to disturbance and face multiple threats from urbanization, agricultural development, mining, and tourism. PMID:23003344

  5. Further constraints on the Chauvet cave artwork elaboration

    NASA Astrophysics Data System (ADS)

    Sadier, Benjamin; Delannoy, Jean-Jacques; Benedetti, Lucilla; Bourlès, Didier L.; Jaillet, Stéphane; Geneste, Jean-Michel; Lebatard, Anne-Elisabeth; Arnold, Maurice

    2012-05-01

    Since its discovery, the Chauvet cave elaborate artwork called into question our understanding of Palaeolithic art evolution and challenged traditional chronological benchmarks [Valladas H et al. (2001) Nature 413:419-479]. Chronological approaches revealing human presences in the cavity during the Aurignacian and the Gravettian are indeed still debated on the basis of stylistic criteria [Pettitt P (2008) J Hum Evol 55:908-917]. The presented 36Cl Cosmic Ray Exposure ages demonstrate that the cliff overhanging the Chauvet cave has collapsed several times since 29 ka until the sealing of the cavity entrance prohibited access to the cave at least 21 ka ago. Remarkably agreeing with the radiocarbon dates of the human and animal occupancy, this study confirms that the Chauvet cave paintings are the oldest and the most elaborate ever discovered, challenging our current knowledge of human cognitive evolution.

  6. Dated rock engravings from Wonderwerk Cave, South Africa

    SciTech Connect

    Thackeray, A.I.; Thackeray, J.F.; Beaumont, P.B.; Vogel, J.C.

    1981-10-02

    Radiocarbon dates associated with engraved stones from sealed archeological deposits at Wonderwerk Cave in the northern Cape Province indicate that rock engraving in South Africa is at least 10,000 years old.

  7. Ancient photosynthetic eukaryote biofilms in an Atacama Desert coastal cave.

    PubMed

    Azúa-Bustos, A; González-Silva, C; Mancilla, R A; Salas, L; Palma, R E; Wynne, J J; McKay, C P; Vicuña, R

    2009-10-01

    Caves offer a stable and protected environment from harsh and changing outside prevailing conditions. Hence, they represent an interesting habitat for studying life in extreme environments. Here, we report the presence of a member of the ancient eukaryote red algae Cyanidium group in a coastal cave of the hyperarid Atacama Desert. This microorganism was found to form a seemingly monospecific biofilm growing under extremely low photon flux levels. Our work suggests that this species, Cyanidium sp. Atacama, is a new member of a recently proposed novel monophyletic lineage of mesophilic "cave" Cyanidium sp., distinct from the remaining three other lineages which are all thermo-acidophilic. The cave described in this work may represent an evolutionary island for life in the midst of the Atacama Desert.

  8. 5. Photographic copy of historic photograph (from Wind Cave National ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Photographic copy of historic photograph (from Wind Cave National Park), photographer unknown, date unknown. Route 87, Beaver Creek Bridge, elevation. - Beaver Creek Bridge, Hot Springs, Fall River County, SD

  9. Organochlorine residues in bat guano from nine Mexican caves, 1991

    USGS Publications Warehouse

    Clark, D.R.; Moreno-Valdez, A.; Mora, M.A.

    1995-01-01

    Samples of bat guano, primarily from Mexican free-tailed bats (Tadarida brasiliensis), were collected at nine bat roosts in caves in northern and eastern Mexico and analysed for organochlorine residues. DDE, the most abundant residue found in each cave, was highest (0.99 p.p.m. dry weight) at Ojuela Cave, Durango. Other studies of DDE in bat guano indicate that this concentration is too low to reflect harmful concentrations in the bats themselves. The DDE at Ojuela may represent either lingering residues from use of DDT years ago in the Ojuela area of perhaps depuration loss from migrant bats with summer maternity roost(s) in a DDE-contaminated area such as Carlsbad Cavern, New Mexico. Presence of o,p-DDT at Tio Bartolo Cave, Nuevo Leon, indicates recent use of DDT, but the concentration of this contaminant was low. Possible impacts on bat colonies of the organophosphorus and carbamate insecticides now in extensive use are unknown.

  10. Organochlorine residues in bat guano from nine Mexican caves, 1991

    USGS Publications Warehouse

    Clark, D.R.; Moreno-Valdez, A.; Mora, M.A.

    1995-01-01

    Samples of bat guano, primarily from Mexican free-tailed bats (Tadarida brasiliensis), were collected at nine bat roosts in caves in northern and eastern Mexico and analysed for organochlorine residues. DDE, the most abundant residue found in each cave, was highest (0.99 p.p.m. dry weight) at Ojuela Cave, Durango. Other studies of DDE in bat guano indicate that this concentration is too low to reflect harmful concentrations in the bats themselves. The DDE at Ojuela may represent either lingering resides from use of DDT years ago in the Ojuela area or perhaps depuration loss from migrant bats with summer maternity roost(s) in a DDE-contaminated area such as Carlsbad Cavern, New Mexico. Presence of o,p'-DDT at Tio Bartolo Cave, Nuevo Leon, indicates recent use of DDT, but the concentration of this contaminant was low. Possible impacts on bat colonies of the organophosphorus and carbonate insecticides now in extensive use are unknown.

  11. Using Lava Inflation Structures to Estimate Eruption Duration in Fossil Lava Fields: the Helgafell Eruption 5900 BP

    NASA Astrophysics Data System (ADS)

    Mattsson, H.; Höskuldsson, A.

    2002-12-01

    Lava inflation structures, such as tumuli and pressure ridges, are common features in subarial pahoehoe flow fields but has also been reported from submarine lava flows. Tumuli form by clogging of individual lava tubes inside a flow field or when the lava supply rate exceeds the flow front displacement, which causes inflation of previously formed crust and formation of the characteristic whale-back shape of tumuli. Axial and radial clefts cut the tumuli ("inflation-clefts"). Measurements on active lava flows has shown that the time (during which inflation occur) correlates posetively with the square of the measured inflation-cleft depth, and can therefore be used to calculating active time of inflation by measuring cleft depths in fossil flows. Over threehundred measurements of inflation cleft depths were collected from tumuli and pressure ridges located in the Helgafell lava field, Vestmannaeyjar, South Iceland. The Helgafell eruption occurred approximately 5900 BP, and emplaced the largest lava flow on the island covering 6.5 km2 (~ 0.6 km3 DRE). The erupted lava are plagioclase-phyric alkali basalt, exhibiting considerable variation (7.0 wt% MgO to 4.4 wt% MgO) due to flow fractionation and incorporation of large (< 7 cm) plagioclase xenocrysts. Measurements of inflation cleft depths show that a minimum crustal thickness of 0.3 m is required to initiate tumulus growth. The deepest clefts are located furthest away from the vent, which coinsides with the largest elevation difference between tumuli and source (e.g. uppermost point of lava tube). The cleft measurements where combined with careful stratigraphic mapping in order to estimate the total duration of the Helgafell eruption. It is important to keep in mind that tumuli are surface features and only reflect inflation of the uppermost flows. The maximum time calculated for active inflation must therefore correspond to a minimum eruption duration. By doing these calculations, and adding measurements of tumuli

  12. Radon Dose Determination for Cave Guides in Czech Republic

    SciTech Connect

    Thinova, Lenka; Rovenska, Katerina

    2008-08-07

    According to recommended approach there are six (from total of twelve) open-to-public caves in Czech Republic, reaching near to an effective lung-dose of 6mSv/year. A conservative approach for estimating the potential effective lung-dose in caves (or underground) is based on two season's measurements, using solid state alpha track detector (Kodak in plastic diffusion chamber). The obtained dataset is converted into an annual effective dose, in agreement with the ICRP65 recommendation, using the 'cave factor' 1.5. The value of 'cave factor' which depends on the spectrum of aerosol particles, or on the proportional representation of the unattached/attached ratio (6.5 : 93.5 for residential places, 13.6 : 86.4 for caves due to lower concentration of free aerosols) and on the equilibrium factor. Thus conversion factor is 1.5 times higher in comparison with ICRP 65. Is this correct? Because a more precisely determined dose value would have a significant impact on radon remedies, or on restricting the time workers stay underground, a series of measurement was initiated in 2003 with the aim to specify input data, computation and errors in effective dose assessment in each one of the evaluated caves separately. The enhancement of personal dosimetry for underground work places includes a study of the given questions, from the following points of view in each cave: continual radon measurement; regular measurements of radon and its daughters to estimate the equilibrium factor and the presence of free {sup 218}Po; regular indoor air flow measurements to study the location of the radon supply and its transfer among individual areas of the cave; natural radioactive element content evaluation in subsoil and in water inside/outside, a study of the radon sources in the cave; determination of the free fraction from continual unattached and attached fraction measurement (grid and filter); thoron measurement. Air flow measurements provide very interesting information about the origin

  13. High-Resolution Isotopic Monitoring of Cave Air CO2

    NASA Astrophysics Data System (ADS)

    Töchterle, Paul; Dublyansky, Yuri; Mandic, Magda; Stöbener, Nils; Jost, Hj; Spötl, Christoph

    2016-04-01

    This study aims at characterising the ventilation patterns in Spannagel Cave, a high-alpine cave system in the Zillertal Alps, Austria. A Thermo Scientific Delta Ray Isotope Ratio Infrared Spectrometer was installed in a chamber ca. 100 m behind the cave entrance to monitor pCO2 and δ13C and δ18O of CO2 at high temporal resolution (up to 1 s). The air temperature was independently monitored inside and outside the cave. This study aims at characterising the ventilation patterns in Spannagel Cave, a high-alpine cave system in the Zillertal Alps, Austria. A Thermo Scientific Delta Ray Isotope Ratio Infrared Spectrometer was installed in a chamber ca. 100 m behind the cave entrance to monitor pCO2 and δ13C and δ18O of CO2 at high temporal resolution (up to 1s). The air temperature was independently monitored inside and outside the cave. The data show two distinct patterns in terms of CO2 concentration and its isotopic composition, which are closely coupled with the temperature difference between the cave interior and the outside atmosphere. This gradient controls the direction of air flow in the cave on a seasonal to synoptic timescale (chimney-type ventilation). The summer circulation is characterised by CO2 closely resembling atmospheric values (pCO2 = 399 ± 12 ppm, δ13C = -8.5 ± 0.7 permil, δ18O = 8.1 ± 2.5 permil). The winter circulation mode features generally higher CO2 concentrations and lower isotopic compositions (pCO2 = 409 ± 14 ppm, δ13C = -10.1 ± 0.7 permil, δ18O = 2.3 ± 1.5 permil). The high temporal resolution of stable isotope data allows tracking cave air ventilation changes, including transient and short-lived ones. Moreover, the data make it possible to address concomitant geochemical processes, such as the input of atmospheric CO2 and the degassing of CO2 from seepage water. These processes would not be possible to quantify without the new generation of laser-based isotope ratio instruments represented by the Delta Ray.

  14. Radon Dose Determination for Cave Guides in Czech Republic

    NASA Astrophysics Data System (ADS)

    Thinova, Lenka; Rovenska, Katerina

    2008-08-01

    According to recommended approach there are six (from total of twelve) open-to-public caves in Czech Republic, reaching near to an effective lung-dose of 6mSv/year. A conservative approach for estimating the potential effective lung-dose in caves (or underground) is based on two season's measurements, using solid state alpha track detector (Kodak in plastic diffusion chamber). The obtained dataset is converted into an annual effective dose, in agreement with the ICRP65 recommendation, using the "cave factor" 1.5. The value of "cave factor" which depends on the spectrum of aerosol particles, or on the proportional representation of the unattached/attached ratio (6.5 : 93.5 for residential places, 13.6 : 86.4 for caves due to lower concentration of free aerosols) and on the equilibrium factor. Thus conversion factor is 1.5 times higher in comparison with ICRP 65. Is this correct? Because a more precisely determined dose value would have a significant impact on radon remedies, or on restricting the time workers stay underground, a series of measurement was initiated in 2003 with the aim to specify input data, computation and errors in effective dose assessment in each one of the evaluated caves separately. The enhancement of personal dosimetry for underground work places includes a study of the given questions, from the following points of view in each cave: continual radon measurement; regular measurements of radon and its daughters to estimate the equilibrium factor and the presence of free 218Po; regular indoor air flow measurements to study the location of the radon supply and its transfer among individual areas of the cave; natural radioactive element content evaluation in subsoil and in water inside/outside, a study of the radon sources in the cave; determination of the free fraction from continual unattached and attached fraction measurement (grid and filter); thoron measurement. Air flow measurements provide very interesting information about the origin of

  15. Insights into the dynamics of the Nyiragongo lava lake level

    NASA Astrophysics Data System (ADS)

    Smets, Benoît; d'Oreye, Nicolas; Geirsson, Halldor; Kervyn, Matthieu; Kervyn, François

    2016-04-01

    Nyiragongo volcano, in North Kivu, Democratic Republic of Congo, is among the most active volcanoes in Africa and on Earth. Since the first European observations in the late 19th Century, its eruptive activity mostly concentrated into its main crater, with the presence of a persistent lava lake from at least 1928 to 1977 and since 2002. The size, shape and elevation of this lava lake have evolved through time, modifying the topography of the main crater. In January 1977 and 2002, the uppermost magmatic system of Nyiragongo, including the lava lake, was drained during flank eruptions. These flank events caused major disasters, mostly due to the exceptionally fast-moving lava flows and the presence of a dense population living at foot of this volcano. Despite a large scientific interest and societal concern, the study of the eruptive activity of Nyiragongo remains limited by climate and vegetation conditions that, most of the time, limit use of satellite remote sensing techniques, and recurrent armed conflicts in the Kivu region, which sometimes prevent field access to the main crater. Here we focus on the dynamics of the Nyiragongo lava lake level and its relationship with the volcanic plumbing system by describing the historical and recent lava lake activity and presenting new quantitative observations using close-range photogrammetry, a Stereographic Time-Lapse Camera (STLC) system and high-resolution satellite SAR and InSAR remote sensing. Results highlight that, contrary to the interpretation found in some recent publications, the lava lake drainages appear to be the consequence and not the cause of the 1977 and 2002 flank eruptions. Two types of short-term lava lake level variations are observed. The first one corresponds to cyclic metre-scale variations attributed to gas piston activity. The STLC data recorded in September 2011 show hour-scale gas piston cycles reaching up to 3.8 m, which are interpreted to be related to gas accumulation and release in the

  16. Gigantic self-confined pahoehoe inflated lava flows in Argentina

    NASA Astrophysics Data System (ADS)

    Pasquare', G.; Bistacchi, A.

    2007-05-01

    The largest lava flows on Earth are pahoehoe basalts emplaced by inflation, a process which can change lava lobes initially a few decimetres thick into large lava sheets several metres thick. Inflation involves the initial formation of a thin, solidified, viscoelastic crust, under which liquid lava is continually added. This thermally efficient endogenous growth process explains the spread of huge volumes of lava over large, almost flat areas, as in the sheet flows which characterise the distal portions of Hawaiian volcanoes or some continental flood basalt provinces. Long, narrow, inflated pahoehoe flows have occasionally been described, either emplaced along pre-existing river channels or confined within topographic barriers. In this contribution we present previously unknown inflated pahoehoe lava flows following very long, narrow pathways over an almost flat surface, with no topographic confinement. Lava, which erupted in Late Quaternary times from the eastern tip of a 60 km long volcanic fissure in Argentina, formed several discrete flows extending as far as 180 km from the source. This fissure was characterized by a long-lasting and complex activity. Alkali-basaltic lava flows were emitted at the two extremities of the fissure system. In the intermediate section of the fissure, the Payun Matru, a great trachitic composite volcano, developed, giving rise to a large caldera which produced large pyroclastic flows. Alkali-basalts predate and postdate the trachitic activity, in fact at the end of the trachitic activity, new basaltic lava flows (mainly aa) were emitted from both ends of the fissure. We studied in details the youngest of the gigantic flows (Pampas Onduladas lava flow), which progressively develops through differing thermally-efficient flow mechanisms. The flow created a large shield volcanic structure at the eastern tip of the E-W fissure and spread to the E forming a very large and thick inflated pahoehoe sheet flow. Leaving the flanks of the

  17. Morphology and growth of the 2009 Redoubt Volcano lava dome

    NASA Astrophysics Data System (ADS)

    Bull, K. F.; Anderson, S. W.; Diefenbach, A. K.; Wessels, R. L.

    2010-12-01

    Redoubt Volcano began to extrude the third and final lava dome of the 2009 eruption on April 4. By July 1 the dome had filled the summit crater and ceased to grow, reaching a volume of 70M m3. The first 12 days of growth (4/4-16) produced blocky lava of unknown vesicularity that effused at a rate of 35 m3sec-1. Lava formed a round dome, and began to flow northward down a steep, glacial gorge. The effusion rate from 4/16-5/4 decreased to 4 m3sec-1. At that time, while blocky lava continued to be exposed on the margins and south side of the dome, more finely fragmented lava began to appear at the top of the dome directly above the vent. This material, more scoriaceous than the blocky lava was tracked by webcam images, and sampled in August, 2010. Dome growth continued for the next two months in the form of inflation and steep, north-directed flow. The effusion rate increased 5/4-16 to an average of 18 m3sec-1 and the surface area comprising fragmented, scoriaceous lava increased from 10 to 30%. This time period includes 2 days (5/14-16) of high effusion rate (27 m3sec-1) and an increase in the surface area of scoriaceous lava by 15%/day. Effusion rates decreased steadily to 2 m3sec-1 shortly before growth ceased around July 1. Fragmental, scoriaceous lava, however, continued to increase in area over the dome surface, spreading as a relatively cool carapace over the top of the dome. By 7/1 the fragmental carapace covered ~40% of the total dome area. Lava along the southern half, lower margins and northern toe of the dome appeared relatively dense and blocky. The hottest areas on the dome (~200-300°C) were found in blocky areas and along radial cracks that originate at the top of the dome, overlying the vent. We can gain insights regarding degassing processes by comparing similarities and differences in surface morphology of Redoubt’s dome with the 1980-86 Mount St. Helens (MSH) dome. The 1980-86 MSH dome displayed lobes with a predominantly scoriaceous carapace

  18. Bubbled lava from the floor of the Sea of Okhotsk

    NASA Astrophysics Data System (ADS)

    Baturin, G. N.; Dubinchuk, V. T.; Rashidov, V. A.

    2014-05-01

    A sample of bubbled lava raised from a submarine volcano in the Sea of Okhotsk was analyzed by means of electron microscopy and the ICP-MS technique. The outside of the sample is flecked with rounded micro- and macrocavities, and the inner part is characterized by a liquation structure. Along with this, the unstructured mass of the rock contains globular particles of nearly the same diameters as the cavities. The lava is close to andesites and volcanic ashes of Kamchatka Peninsula in the macro- and microelemental composition but different in the somewhat increased content of barium, strontium, lithium, niobium, tungsten, uranium, and thorium. It is suggested that the cavities were formed during the eruption of the submarine volcano owing to contact of the boiling gas-saturated lava with seawater accompanied by the ejection of ash, which was spread by marine currents over long distances.

  19. Chasing lava: a geologist's adventures at the Hawaiian Volcano Observatory

    USGS Publications Warehouse

    Duffield, Wendell A.

    2003-01-01

    A lively account of the three years (1969-1972) spent by geologist Wendell Duffield working at the Hawaiian Volcano Observatory at Kilauea, one of the world's more active volcanoes. Abundantly illustrated in b&w and color, with line drawings and maps, as well. Volcanologists and general readers alike will enjoy author Wendell Duffield's report from Kilauea--home of Pele, the goddess of fire and volcanoes. Duffield's narrative encompasses everything from the scientific (his discovery that the movements of cooled lava on a lava lake mimic the movements of the earth's crust, providing an accessible model for understanding plate tectonics) to the humorous (his dog's discovery of a snake on the supposedly snake-free island) to the life-threatening (a colleague's plunge into molten lava). This charming account of living and working at Kilauea, one of the world's most active volcanoes, is sure to be a delight.

  20. Influence of cooling on lava-flow dynamics

    NASA Astrophysics Data System (ADS)

    Stasiuk, Mark V.; Jaupart, Claude; Stephen, R.; Sparks, J.

    1993-04-01

    Experiments have been carried out to determine the effects of cooling on the flow of fluids with strongly temperature dependent viscosity. Radial viscous-gravity currents of warm glucose syrup were erupted at constant rate into a flat tank filled with a cold aqueous solution. Cold, viscous fluid accumulates at the leading edge, altering the flow shape and thickness and slowing the spreading. The flows attain constant internal temperature distributions and bulk viscosities. The value of the bulk viscosity depends on the Péclet number, which reflects the advective and diffusive heat transport properties of the flow, the flow skin viscosity, which reflects cooling, and the eruption viscosity. Our results explain why most lava flows have bulk viscosities much higher than the lava eruption viscosity. The results can be applied to understanding dynamic lava features such as flow-front thickening, front avalanches, and welded basal breccias.

  1. Lava Flow Hazard Assessment for the Idaho National Laboratory: A Probabilistic Approach to Modeling Lava Flow Inundation with MOLASSES

    NASA Astrophysics Data System (ADS)

    Gallant, E.; Connor, C.; Richardson, J. A.; Wetmore, P. H.; Connor, L.

    2015-12-01

    We present the results of a lava flow hazard assessment for the Idaho National Laboratory (INL) using a new lava flow code, MOLASSES (MOdular LAva Simulation Software for Earth Science). INL is a nuclear research and development facility located on the eastern Snake River Plain with the potential for lava flow inundation from both monogenetic and polygenetic basaltic eruptions. Previously published inventories of observed surface vents and vents that are buried by younger lava flows and inferred from interpretation of borehole stratigraphy were used to created spatial density maps of vents within the INL region. Monte carlo simulations were run using the MOLASSES code to compare the difference between events initiated using only surface vents and events initiated using both the surface and the buried vents. We find that the inclusion of the buried vent locations drastically increases the number of site inundations and events initiating within INL boundaries. This highlights the need to seek out a more complete eruption record in an area of heavy prehistoric activity to better assess future hazard and associated risk.

  2. Hybrid fluidized bed combuster

    DOEpatents

    Kantesaria, Prabhudas P.; Matthews, Francis T.

    1982-01-01

    A first atmospheric bubbling fluidized bed furnace is combined with a second turbulent, circulating fluidized bed furnace to produce heat efficiently from crushed solid fuel. The bed of the second furnace receives the smaller sizes of crushed solid fuel, unreacted limestone from the first bed, and elutriated solids extracted from the flu gases of the first bed. The two-stage combustion of crushed solid fuel provides a system with an efficiency greater than available with use of a single furnace of a fluidized bed.

  3. Geologic history of the Black Hills caves, South Dakota

    USGS Publications Warehouse

    Palmer, Arthur N.; Palmer, Margaret; Paces, James B.

    2016-01-01

    The caves reveal four phases of calcite deposition: eogenetic ferroan calcite (Mississippian replacement of sulfates); white scalenohedra in paleovoids deposited during deep post-Mississippian burial; palisade crusts formed during blockage of springs by Oligocene–Miocene continental sediments; and laminated crusts from late Pleistocene water-table fluctuations. The caves reveal more than 300 m.y. of geologic history and a close relationship to regional geologic events.

  4. Some Caves in tunnels in Dinaric karst of Croatia

    NASA Astrophysics Data System (ADS)

    Garasic, Mladen; Garasic, Davor

    2016-04-01

    In the last 50 years during the construction of almost all the tunnels in the Croatian Dinaric Karst thousands of caves have been encountered that represented the major problems during the construction works. Geological features (fissures, folding, faults, etc.) are described in this contribution, together with the hydrogeological conditions (rapid changes in groundwater levels). Special engineering geological exploration and survey of each cave, together with the stabilization of the tunnel ceiling, and groundwater protection actions according to basic engineering geological parameters are also presented. In karst tunneling in Croatia over 150 caves longer than 500 m have been investigated. Several caves are over 300 m deep (St. Ilija tunnel in Biokovo Mt), and 10 are longer than 1000 m (St.Rok tunnel, HE Senj and HE Velebit tunnels in Velebit Mt, Ucka tunnel in Ucka Mt, Mala kapela tunnel in Kapela Mt, caverns in HE Plat tunnel etc). Different solutions were chosen to cross the caves depending on the size and purpose of the tunnels (road, rail, pedestrian tunnel, or hydrotechnical tunnels). This is presentations of interesting examples of ceiling stabilization in big cave chambers, construction of bridges inside tunnels, deviations of tunnels, filling caves, grouting, etc. A complex type of karstification has been found in the cavern at the contact between the Palaeozoic clastic impervious formations and the Mesozoic complex of dolomitic limestones in the Vrata Tunnel and at the contact with flysch in the Učka Tunnel. However, karstification advancing in all directions at a similar rate is quite rare. The need to have the roadway and/or tunnel above water from a spring is the biggest possible engineering-geological, hydrogeological and civil engineering challenge. Significant examples are those above the Jadro spring (Mravinci tunnel) in flysch materials or above the Zvir spring in Rijeka (Katarina tunnel), and in fractured Mesozoic carbonates. Today in Croatian

  5. Birth of a lava lake: Nyamulagira volcano 2011-2015

    NASA Astrophysics Data System (ADS)

    Coppola, D.; Campion, R.; Laiolo, M.; Cuoco, E.; Balagizi, C.; Ripepe, M.; Cigolini, C.; Tedesco, D.

    2016-03-01

    Since 1938, Nyamulagira volcano (Democratic Republic of Congo) has operated as a classic pressurized basaltic closed system, characterized by frequent dike-fed flank eruptions. However, on June 24, 2014, an active lava lake was observed in its summit, after a period of 76 years. The small lava lake is now exposed at the bottom of a pit-crater and is rising and growing. Based on satellite-derived infrared (IR) data, SO2 fluxes and periodic field surveys, we provide evidence that the development of the lava lake was gradual and occurred more than 2 years before it was first observed in the field. Notably, this process followed the voluminous 2011-2012 distal flank eruption and was coeval with weakening of the central rock column below the summit. Hence, the opening and development of the pit-crater favoured the continuous rise of fresh magma through the central conduit and promoted the gradual "re-birth" of the Nyamulagira lava lake. Budgeted volumes of magma erupted, and magma degassed at depth indicate that the formation of the lava lake is due to the draining and refilling of a shallow plumbing system (1-2 km depth), probably in response to the rift-parallel 2011-2012 distal eruption. We thus suggest that the transition from lateral to central activity did not result from a substantial change in the magma supply rate but, more likely, from the perturbation of the plumbing system (and related stress field) associated with the distal eruption. The processes observed at Nyamulagira are not unique and suggest that rift-fissure eruptions, in addition to triggering caldera collapses or lava lake drainages, may also induce a progressive resumption of central vent activity. Current activity at Nyamulagira represents a tangible and major hazard for the population living at the base of its southern flank.

  6. Numerical simulation of formation and preservation of Ningwu ice cave, Shanxi, China

    NASA Astrophysics Data System (ADS)

    Yang, S.; Shi, Y.

    2015-04-01

    Ice caves exist in locations where annual average temperature in higher than 0 °C. An example is Ningwu ice cave, Shanxi Province, the largest ice cave in China. In order to quantitatively explain the mechanism of formation and preservation of the ice cave, we use Finite Element Method to simulate the heat transfer process at this ice cave. There are two major control factors. First, there is the seasonal asymmetric heat transfer. Heat is transferred into the ice cave from outside, very inefficiently by conduction in spring, summer and fall. In winter, thermal convection occurs that transfers heat very efficiently out of the ice cave, thus cooling it down. Secondly, ice-water phase change provides a heat barrier for heat transfer into the cave in summer. The calculation also helps to evaluate effects of global warming, tourists, etc. for sustainable development of ice cave as tourism resource. In some other ice caves in China, managers installed air-tight doors at these ice caves entrance intending to "protect" these caves, but this prevent cooling down these caves in winters and these cave ices will entirely melt within tens of years.

  7. Evaluating genetic viability of pronghorn in Wind Cave National Park

    USGS Publications Warehouse

    Jenks, Jonathan A.; Jacques, Christopher N.; Sievers, Jaret D.; Klaver, Robert W.; Bowyer, R. Terry; Roddy, Daniel E.

    2006-01-01

    The pronghorn (Antilocapra americana) was reintroduced into Wind Cave National Park, South Dakota, in 1914 and thus, has inhabited the Park for almost a century. A decline in the population has raised concern for the continued existence of pronghorn inside Wind Cave National Park. Historically, pronghorn numbers reached greater than 300 individuals in the 1960’s but declined to about 30 individuals by 2002. The primary objective of our study was to evaluate genetic characteristics of pronghorn to determine if reduced heterozygosity contributed to the decline of pronghorn in Wind Cave National Park. Microsatellite DNA was collected from 75 pronghorn inhabiting Wind Cave National Park in western South Dakota (n = 11), northwestern South Dakota (n = 33), and southwestern South Dakota (n = 31). Pronghorn in Wind Cave National Park had similar levels of observed heterozygosity (0.473 to 0.594) and low inbreeding coefficients (-0.168 to 0.037) when compared with other populations in western South Dakota. Furthermore, indices of population structure indicated no differentiation occurred among pronghorn populations. Results indicated that genetic variability was not a primary factor in the decline of pronghorn in Wind Cave National Park.

  8. Late-stage flood lavas in the Elysium region, Mars

    NASA Technical Reports Server (NTRS)

    Plescia, J. B.

    1987-01-01

    In the southeastern part of the Elysium region is a unit that exhibits little texture and a generally low albedo and that has a very low crater frequency. This unit has been mapped as smooth plains material and previously interpreted as an eolian deposit on the basis of Mariner 9 images. More recently, the unit was mapped as material deposited during a channeling episode. The author interprets the smooth plains unit as being a volcanic deposit composed of low viscosity lava flows: both flood lavas and individual flows. The reasons for these conclusions are given and briefly discussed.

  9. Fractal dimension analyses of lava surfaces and flow boundaries

    NASA Technical Reports Server (NTRS)

    Cleghorn, Timothy F.

    1993-01-01

    An improved method of estimating fractal surface dimensions has been developed. The accuracy of this method is illustrated using artificially generated fractal surfaces. A slightly different from usual concept of linear dimension is developed, allowing a direct link between that and the corresponding surface dimension estimate. These methods are applied to a series of images of lava flows, representing a variety of physical and chemical conditions. These include lavas from California, Idaho, and Hawaii, as well as some extraterrestrial flows. The fractal surface dimension estimations are presented, as well as the fractal line dimensions where appropriate.

  10. Thermo-Rheological Feedbacks in Silicic Lavas and Ignimbrites

    NASA Astrophysics Data System (ADS)

    Whittington, A. G.; Robert, G.; Andrews, G. D.; Avard, G.; Romine, W. L.; Ye, J.

    2012-12-01

    The rheology of lava is highly dependent on temperature, both directly (via non-Arrhenian temperature dependence of melt viscosity) and indirectly (via increasing crystal content). Rheology feeds back to temperature, because rapidly sheared melts can undergo viscous heating (heat production = viscosity × [strain rate]2), and rapid disequilibrium crystallization can cause heating due to latent heat release (ΔHxt). The heat budget of partially crystalline lava balances these gains with conductive losses controlled by thermal diffusivity (D) and conductivity (k = DρCP, where ρ is density and CP is heat capacity). We measured the apparent viscosity of several crystalline dacitic lavas from Santiaguito, Guatemala and Bezymianny, Kamchatka. At conditions appropriate to lava flows (shear stress ~0.1 to 0.4 MPa, strain rate ~10-8 to 10-5s-1), apparent viscosity is best modeled as a power-law with no yield strength. Viscosity of the flow core, at ~850°C, is estimated ~5×1010 Pa.s. There is no evidence for significant crystallization during flow emplacement at Santiaguito, but viscous heating may be significant ongoing heat source within these flows (~100Wm-3 if most shearing is restricted to a ~1m wide zone), enabling highly viscous lava to travel long distances (~4 km in ~2 yrs for Santiaguito). Extremely high-grade, lava-like welded ignimbrites are deposited by many of the largest explosive eruptions in Earth history with volumes typically ranging between 10 to 1000 km3 and volcanic explosivity indices of 8 to 9. The lava-like and rheomorphic Grey's Landing ignimbrite, Idaho, provides abundant field evidence supporting the upward-migration of a transient, 1 - 2 m thick, sub-horizontal ductile shear zone at the interface between the pyroclastic density current and deposit, through which all of the deposit passed. We test the syn-depositional shear zone model through a combination of rheological experiments and thermo-mechanical modeling. Our results demonstrate that

  11. Field Measurements of the 1983 Royal Gardens Lava Flows, Kilauea Volcano, and 1984 Mauna Loa Lava Flow, Hawaii

    NASA Technical Reports Server (NTRS)

    Fink, J.; Zimbelman, J.

    1985-01-01

    Theoretical models used in the remote determination of lava flow rheology and compositions rely on estimates of such geometric and flow parameters as volume flow rates, levee heights, and channel dimensions, as well as morphologic and structural patterns on the flow surfaces. Quantitative measures of these variables are difficult to obtain, even under optimum conditions. Detailed topographic profiles across several Hawaiian lava flows that were carefully monitored by the U.S. Geological Survey during their emplacement in 1983 were surveyed in order to test various flow emplacement models. Twenty two accurate channel cross sections were constructed by combining these profiles with digitized pre-flow topographic measurements. Levee heights, shear zone widths, and flow depths could then be read directly from the cross sections and input into the models. The profiles were also compared with ones constructed for some Martian lava flows.

  12. Field measurements of the 1983 Royal Gardens lava flows, Kilauea Volcano, and 1984 Mauna Loa lava flows, Hawaii

    NASA Astrophysics Data System (ADS)

    Fink, J.; Zimbelman, J.

    1985-04-01

    Theoretical models used in the remote determination of lava flow rheology and compositions rely on estimates of such geometric and flow parameters as volume flow rates, levee heights, and channel dimensions, as well as morphologic and structural patterns on the flow surfaces. Quantitative measures of these variables are difficult to obtain, even under optimum conditions. Detailed topographic profiles across several Hawaiian lava flows that were carefully monitored by the U.S. Geological Survey during their emplacement in 1983 were surveyed in order to test various flow emplacement models. Twenty two accurate channel cross sections were constructed by combining these profiles with digitized pre-flow topographic measurements. Levee heights, shear zone widths, and flow depths could then be read directly from the cross sections and input into the models. The profiles were also compared with ones constructed for some Martian lava flows.

  13. Practice Hospital Bed Safety

    MedlinePlus

    ... Bed? Todd says that there is no standard definition for hospital beds, a fact that consumers shopping ... in retail stores that don’t meet the definition of medical devices under the law, but which ...

  14. Enuresis (Bed-Wetting)

    MedlinePlus

    ... their development. Bed-wetting is more common among boys than girls. What causes bed-wetting? A number of things ... valves in boys or in the ureter in girls or boys Abnormalities in the spinal cord A small bladder ...

  15. Morphometry and distribution of isolated caves as a guide for phreatic and confined paleohydrological conditions

    NASA Astrophysics Data System (ADS)

    Frumkin, Amos; Fischhendler, Itay

    2005-04-01

    Isolated caves are a special cave type common in most karst terrains, formed by prolonged slow water flow where aggressivity is locally boosted. The morphometry and distribution of isolated caves are used here to reconstruct the paleohydrology of a karstic mountain range. Within a homogenous karstic rock sequence, two main types of isolated caves are distinguished, and each is associated with a special hydrogeologic setting: maze caves form by rising water in the confined zone of the aquifer, under the Mt. Scopus Group (Israel) confinement, while chamber caves are formed in phreatic conditions, apparently by lateral flow mixing with a vadose input from above.

  16. Cave clastic sediments and implications for speleogenesis: New insights from the Mugnano Cave (Montagnola Senese, Northern Apennines, Italy)

    NASA Astrophysics Data System (ADS)

    Martini, Ivan

    2011-11-01

    The study of cave clastic sediments has been considered one of the hottest topics during the last years because of their importance in paleoclimatic reconstructions and archaeological surveys. This paper focuses on clastic deposits of the Mugnano Cave, a small cave located in the Siena district (Northern Apennines, Italy), showing unique features regarding the sedimentary fill, mostly made of grey-blue dolomitic silts. The sedimentary succession was investigated through a detailed sedimentological analysis aimed at a better understanding of sedimentary processes active during the deposition. The entire succession was subsequently reinterpreted through an allostratigraphic approach: the recognition of an important erosional surface, associated with a significant change in sedimentation, allowed the distinguishing of two main allounits labelled MG1 and MG2. Furthermore, the different kinds of sediments collected in the cave were analysed using the XRF and XRD techniques, in order to establish their chemical and mineralogical compositions. The integration of lithological, sedimentological, allostratigraphic and mineralogical data permits formulation of an interesting hypothesis about speleogenetic processes that influenced the cave, with particular reference to the processes capable of generating the underground space. In this context, most of the current available space results from a complex interplay between different processes: disintegration of a particular lithofacies of the bedrock, consequent production of sediments and deposition into a subterranean lake. These sediments were removed from the cave during some non-depositional and erosive phases, which led to a positive balance in the available space.

  17. Experiments on Natural-Scale Basaltic Lava Flows: Scope and First Results of the Syracuse University Lava Project

    NASA Astrophysics Data System (ADS)

    Karson, J.; Wysocki, R.; Kissane, M. T.; Smith, C.; Spencer, S.

    2012-12-01

    The Syracuse University Lava Project creates natural-scale basaltic lava flows for scientific investigations, educational opportunities and artistic projects. Modified furnaces designed for melting and pouring metals are used to create individual basaltic lava flow lobes of up to 450 kg (10-2m2) with the potential to generate much larger flow fields under controlled conditions. At present, the starting material used in 1.1 Ga Keewenan basalt from the Mid-Continent Rift in NW Wisconsin, a relatively uniform, well-characterized tholeiitic-alkalic basalt. Other compositions (andesite, komatiite, carbonatite) are planned for future experiments. Basaltic gravel is heated to 1100° to 1300°C in a crucible resulting in homogeneous, convecting basaltic magma. Lava is poured over a variety of surfaces including rock slabs, wet or dry sand, H2O or CO2 ice, rough or smooth material, and confined or unconfined channels. Resulting lava flows can be dissected for mapping details of morphological and textural variations. Video from various perspectives is used to document flow behavior and evolution. Infrared images constrain flow temperatures. Textural features of flows such as vesicles and plagioclase microlites have vertical and lateral variations similar to those of natural flows. Differing experimental set-ups provide analogs for a wide range of terrestrial, marine, and extraterrestrial lava flows. In an initial series of experiments, basaltic lava flows (50-200 kg) were poured over dry sand at near constant effusion rates (~10-4m3s-1). Flow temperature and slope were varied to produce a range of different flow morphologies. The results show systematic behavior consistent with observations of natural lava flows and analog experiments. At relatively high T (>1200°C) and steeper slopes (>15°) thin, narrow, leveed flows form. At intermediate T and slope, sheet-like, ropey, pahoehoe forms develop. Flows at the lowest T (1100°C) and gentlest slopes (<10°) investigated

  18. Can subterranean cave systems affect soil CO2 fluxes?

    NASA Astrophysics Data System (ADS)

    Krajnc, Bor; Ferlan, Mitja; Ogrinc, Nives

    2015-04-01

    Main factors affecting soil CO2 fluxes in most ecosystems are soil temperature and soil moisture. Nevertheless occasionally high soil CO2 fluxes were observed at carst areas, which could result from ventilation of subterranean cavities (Ferlan et al., 2011). The aim of this work was to determine the influence of cave ventilation to soil CO2 fluxes. Research was done in a dead-end passage of Postojna cave (Pisani rov) and on the surface area above the passage (Velika Jeršanova dolina) in south-western Slovenia. Inside the cave we measured CO2 concentrations, its carbon (13C) stable isotope composition, 222Rn activity concentrations, temperatures and air pressure. At the surface we had chosen two sampling plots; test plot above the cave and control. At both plots we measured soil CO2 fluxes with automatic chambers, CO2 concentrations, temperatures and carbon stable isotope composition of soil air at three different depths (0.2 m, 0.5 m and 0.8 m) and different meteorological parameters such as: air temperature, air pressure, wind speed an precipitation. To detect the cave influence, we compared two surface CO2 flux measurements with air temperatures and changes of CO2 concentrations in the cave atmosphere. Our results on CO2 concentrations in the gallery of the cave indicated that the ventilation of this particular gallery also depends on outside air temperatures. Outside temperature increased and corresponded to higher CO2 concentrations, whereas at lower temperatures (T < 9 oC) cave started to ventilate and exhaled CO2 reach air through unknown fissures and cracks. At the control plot the soil CO2 fluxes were in a good correlation with soil temperatures (r = 0.789, p =0.01), where greater soil temperatures correspond to greater soil CO2 fluxes. Soil CO2 fluxes at the plot above the cave did not show statistically significant correlations with soil temperatures or soil moisture indicating that other factors possibly cave ventilation could influence it. References

  19. Study of radiocarbon dynamics of Baradla Cave, Hungary

    NASA Astrophysics Data System (ADS)

    Molnár, Mihály; Dezsö, Zoltán; Futo, Istvan; Siklósy, Zoltan; Jull, A. J. Timothy; Koltai, Gabriella

    2016-04-01

    Carbon isotope composition of speleothems and their parent drip water reflects the isotope composition of the atmospheric CO2, the soil and the host rock and can sometimes be influenced even by the cave atmosphere. Owing to the fact that 14C in the bedrock has long decayed, the bedrock derived carbon content of the seepage water can be considered as inactive or "dead carbon". The initial dead carbon proportion (dcp) of a stalagmite or tufa layer, caused by the incorporation of the inactive carbon, can be calculated with the help of the C-14 level differences between the contemporary atmosphere and the formed stone carbonate. The revolutionary technological advances of 14C (AMS) have brought the possibility of analysing 14C dynamics of karst systems due to the small amount of demanded material. The Baradla-Domica Cave is the largest cave of Gömör-Torna Karst, a karst area situated in the northeast of Hungary, and located on the Slovakian-Hungarian borderland. The approximately 26 km long cave is a typical example of multi-level speleogenesis. As a case study we have investigated several recent (age < 50 years) and older (age about 10-11 kyrs) stalagmites and recent drip water, some freshwater tufa samples and the recent cave air carbon-dioxide of the Baradla-cave to study the carbon dynamics and dead carbon level there. According four modern stalagmites (formed 1991-2004) the current dcp is very small in Baradla Cave (3-7%). Stalagmites deposited in Holocene (U/Th dated) were also characterized by very small dead carbon contents (1-11% dcp). Outside the cave a dpc about 20-25% was found in a freshwater tufa sample. This relatively low dead carbon content might be either explained by the thinness of the limestone bedrock above (56-80 m) or the relatively fast infiltration conditions, or their combined effect. Cave air is enriched in CO2 (2-5 times higher than in natural air, not homogenous) but the source of this surplus CO2 is not the limestone according its

  20. Making a Bed

    ERIC Educational Resources Information Center

    Wexler, Anthony; Stein, Sherman

    2005-01-01

    The origins of this paper lay in making beds by putting pieces of plywood on a frame: If beds need to be 4 feet 6 inches by 6 feet 3 inches, and plywood comes in 4-foot by 8-foot sheets, how should one cut the plywood to minimize waste (and have stable beds)? The problem is of course generalized.

  1. Morphology and evolution of sulphuric acid caves in South Italy

    NASA Astrophysics Data System (ADS)

    D'Angeli, Ilenia M.; De Waele, Jo; Galdenzi, Sandro; Madonia, Giuliana; Parise, Mario; Vattano, Marco

    2016-04-01

    Sulphuric acid speleogenesis (SAS) related to the upwelling of acid water enriched in H2S and CO2 represents an unusual way of cave development. Since meteoric infiltration waters are not necessarily involved in speleogenesis, caves can form without the typical associated karst expressions (i.e. dolines) at the surface. The main mechanism of sulphuric acid dissolution is the oxidation of H2S (Jones et al., 2015) which can be amplified by bacterial mediation (Engel et al., 2004). In these conditions, carbonate dissolution associated with gypsum replacement, is generally believed to be faster than the normal epigenic one (De Waele et al., 2016). In Italy several SAS caves have been identified, but only few systems have been studied in detail: Frasassi and Acquasanta Terme (Marche)(Galdenzi et al., 2010), Monte Cucco (Umbria) (Galdenzi & Menichetti, 1995), and Montecchio (Tuscany) (Piccini et al., 2015). Other preliminary studies have been carried out in Calabria (Galdenzi, 2007) and Sicily (De Waele et al., 2016). Several less studied SAS cave systems located in South Italy, and in particular in Apulia (Santa Cesarea Terme), Sicily (Acqua Fitusa, Acqua Mintina) and Calabria (Mt. Sellaro and Cassano allo Ionio) have been selected in the framework of a PhD thesis on SAS caves and their speleogenesis. Using both limestone tablet weight loss (Galdenzi et al., 2012) and micro erosion meter (MEM) (Furlani et al., 2010) methods the dissolution rate above and under water in the caves will be quantified. Geomorphological observations, landscape analysis using GIS tools, and the analysis of gypsum and other secondary minerals (alunite and jarosite) (stable isotopes and dating) will help to reconstruct the speleogenetic stages of cave formation. Preliminary microbiological analysis will determine the microbial diversity and ecology in the biofilms. References Engel S.A., Stern L.A., Bennett P.C., 2004 - Microbial contributions to cave formation: New insight into sulfuric acid

  2. Where lava meets the sea; Kilauea Volcano, Hawaii

    USGS Publications Warehouse

    Mattox, T.N.

    1993-01-01

    Seaside explosions of the type and magnitude of the event on November 24, 1992, are infrequent. the observation of this event represents a rare opportunity to enhance our understanding of the birth of littoral cones and the nature of explosive activity when lava enters the ocean. 

  3. An assemblage of lava flow features on Mercury

    NASA Astrophysics Data System (ADS)

    Byrne, Paul K.; Klimczak, Christian; Williams, David A.; Hurwitz, Debra M.; Solomon, Sean C.; Head, James W.; Preusker, Frank; Oberst, Jürgen

    2013-06-01

    contrast to other terrestrial planets, Mercury does not possess a great variety of volcanic features, its history of volcanism instead largely manifest by expansive smooth plains. However, a set of landforms at high northern latitudes on Mercury resembles surface flow features documented on Earth, the Moon, Mars, and Venus. The most striking of such landforms are broad channels that host streamlined islands and that cut through the surrounding intercrater plains. Together with narrower, more sinuous channels, coalesced depressions, evidence for local flooding of intercrater plains by lavas, and a first-order analysis of lava flow rates, the broad channels define an assemblage of flow features formed by the overland flow of, and erosion by, voluminous, high-temperature, low-viscosity lavas. This interpretation is consistent with compositional data suggesting that substantial portions of Mercury's crust are composed of magnesian, iron-poor lithologies. Moreover, the proximity of this partially flooded assemblage to extensive volcanic plains raises the possibility that the formation of these flow features may preface total inundation of an area by lavas emplaced in a flood mode and that they escaped complete burial only due to a waning magmatic supply. Finally, that these broad channels on Mercury are volcanic in nature yet resemble outflow channels on Mars, which are commonly attributed to catastrophic water floods, implies that aqueous activity is not a prerequisite for the formation of such distinctive landforms on any planetary body.

  4. Removal of methylene blue by lava adsorption and catalysis oxidation.

    PubMed

    Ma, Jianfeng; Zhang, Jinbao; Li, Dinglong

    2010-03-01

    Adsorption has been found to be effective for the removal of dyes from effluent; however, the contaminant will cause secondary pollution if it is not properly treated. In this paper, the ability of lava as a low-cost adsorbent and catalyst for the removal of a commercial dye, Methylene Blue (MB), from aqueous solution has been investigated under various experimental conditions. It was found that lava had a high efficiency (more than 98%) for MB removal by adsorption. The adsorption equilibrium data can be fitted well by the Langmuir adsorption isotherm model. The adsorption kinetics was shown to be pseudo-second-order. After adsorption the contaminant could be catalysis oxidized by lava with the aids of H2O2 and ultrasound. The result showed that 95% of the MB could be decomposed in 100 min with the aid of ultrasound at 85 W/cm2. Overall, this study demonstrates lava as a promising material for wastewater treatment to remove and decompose dyes in a single treatment step.

  5. Lava Lakes on Io: New Perspectives from Modeling

    NASA Technical Reports Server (NTRS)

    Gregg, Tracy K. P.; Lopes, Rosaly M.

    2004-01-01

    Ionian paterae are a class of volcanic feature that are characterized by irregular craters with steep walls, flat floors, and arcuate margins that may or may not exhibit nesting. Loki (310 W, 12 N) is Io's largest patera at approx.200 km in diameter (Figure 1), and may account for 15% of Io's total heat flow. Earth-based infrared data, as well as information collected using the Galileo Near-Infrared Mapping Spectrometer (NIMS) and the Photopolarimeter Radiometer (PPR) have been used to interpret Loki s eruption style. Debate continues over whether Loki s occasional (periodic or not) temperature increases are due to an overturning lava lake within the patera, or to an eruption of surface flows on the patera floor. Interpretation of model results and comparisons with active terrestrial lava lakes suggest that Loki behaves quite differently from active lava lakes on Earth, and that surface flows (rather than an overturning lava lake) are a more likely explanation of Loki's thermal brightening.

  6. OVEN & LAVA Subsystems in the RESOLVE Payload for Resource Prospector

    NASA Technical Reports Server (NTRS)

    Captain, Janine E.

    2015-01-01

    A short briefing in Power Point of the status of the OVEN subsystem and the LAVA subsystems of the RESOLVE payload being developed under the Resource Prospector mission. The purpose of the mission is to sample and analyze volatile ices embedded in the lunar soil at the poles of the Moon and is expected to be conducted in the 2020 time frame.

  7. Oblique view of the northeast side, note the lava rock ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Oblique view of the northeast side, note the lava rock stem wall below the windows of the shed-roof addition, view facing west - U.S. Marine Corps Base Hawaii, Kaneohe Bay, Golf Course Equipment & Repair Shop, Reeves & Moffett Roads, Kaneohe, Honolulu County, HI

  8. Spotted hyena and steppe lion predation behaviours on cave bears of Europe - ?Late Quaternary cave bear extinction as result of predator stress

    NASA Astrophysics Data System (ADS)

    Diedrich, Cajus G.

    2010-05-01

    Cave bears hibernated in caves all over Eurasia (e.g. Rabeder et al., 2000) including alpine regions using mainly larger caves for this purpose. Late Quaternary spotted hyenas Crocuta crocuta spelaea instead occupied mainly areas close to the cave entrances as their dens (Diedrich and Žák 2006, Diedrich 2010). The largest predator, the steppe lion Panthera leo spelaea was only a sporadic cave dweller (Diedrich 2007b, 2009b). His presence and its remains from caves all over Europe can be recently explained best as result of imported carcasses after killing by their largest antagonists, the Late Quaternary spotted hyenas. In some cases the kill might have happened in the hyena den cave itself during the theft of prey remains by lions (Diedrich 2009a). Another reason of their remains in caves of Europe is the hunting onto the herbivorous cave bears, especially during hibernation times, when megafauna prey was less available in the open environments (Diedrich 2009c). These lion remains from caves of Europe, nearly all of which were from adult animals, provide evidence of active predation by lions onto cave bears even in medium high alpine regions (Diedrich 2009b, in review). Lion skeletons in European cave bear dens were therefore often found amongst originally articulated cave bear skeletons or scattered cave bear remains and even close to their hibernation nests (Diedrich et al. 2009c, in review). Not only lions fed on cave bears documented mainly by the large quantities of chewed, punctured and crushed cave bear long-bones; even damaged skulls reveal that hyenas scavenged primarily on cave bear carcasses which were mainly responsible for the destruction of their carcasses and bones (Diedrich 2005, 2009d). Predation and scavenging on cave bears by the two largest Late Quaternary predators C. c. spelaea and P. l. spelaea explains well the large quantity of fragmented cave bear bones over all European caves in low to medium high mountainous elevations, whereas in

  9. Carbon dioxide seasonality in dynamically ventilated caves: the role of advective fluxes

    NASA Astrophysics Data System (ADS)

    Lang, Marek; Faimon, Jiří; Godissart, Jean; Ek, Camille

    2016-07-01

    The seasonality in cave CO2 levels was studied based on (1) a new data set from the dynamically ventilated Comblain-au-Pont Cave (Dinant Karst Basin, Belgium), (2) archive data from Moravian Karst caves, and (3) published data from caves worldwide. A simplified dynamic model was proposed for testing the effect of all conceivable CO2 fluxes on cave CO2 levels. Considering generally accepted fluxes, i.e., the direct diffusive flux from soils/epikarst, the indirect flux derived from dripwater degassing, and the input/output fluxes linked to cave ventilation, gives the cave CO2 level maxima of 1.9 × 10-2 mol m-3 (i.e., ˜ 440 ppmv), which only slightly exceed external values. This indicates that an additional input CO2 flux is necessary for reaching usual cave CO2 level maxima. The modeling indicates that the additional flux could be a convective advective CO2 flux from soil/epikarst driven by airflow (cave ventilation) and enhanced soil/epikarstic CO2 concentrations. Such flux reaching up to 170 mol s-1 is capable of providing the cave CO2 level maxima up to 3 × 10-2 mol m-3 (70,000 ppmv). This value corresponds to the maxima known from caves worldwide. Based on cave geometry, three types of dynamic caves were distinguished: (1) the caves with the advective CO2 flux from soil/epikarst at downward airflow ventilation mode, (2) the caves with the advective soil/epikarstic flux at upward airflow ventilation mode, and (3) the caves without any soil/epikarstic advective flux. In addition to CO2 seasonality, the model explains both the short-term and seasonal variations in δ13C in cave air CO2.

  10. Numerical simulation of formation and preservation of Ningwu ice cave, Shanxi, China

    NASA Astrophysics Data System (ADS)

    Yang, S.; Shi, Y.

    2015-10-01

    Ice caves exist in locations where annual average air temperature is higher than 0 °C. An example is Ningwu ice cave, Shanxi Province, the largest ice cave in China. In order to quantitatively investigate the mechanism of formation and preservation of the ice cave, we use the finite-element method to simulate the heat transfer process at this ice cave. There are two major control factors. First, there is the seasonal asymmetric heat transfer. Heat is transferred into the ice cave from outside very inefficiently by conduction in spring, summer and fall. In winter, thermal convection occurs that transfers heat very efficiently out of the ice cave, thus cooling it down. Secondly, ice-water phase change provides a heat barrier for heat transfer into the cave in summer. The calculation also helps to evaluate effects of global warming, tourists, colored lights, climatic conditions, etc. for sustainable development of the ice cave as a tourism resource. In some other ice caves in China, managers have installed airtight doors at these ice caves' entrances with the intention of "protecting" these caves, but this in fact prevents cooling in winter and these cave ices will entirely melt within tens of years.

  11. Heterogenous nucleation in a cave with an apex and iso-curvature lateral surface

    NASA Astrophysics Data System (ADS)

    Li, Xiang-Ming; Liu, Qing-Hui

    2015-09-01

    A cave surface for heterogeneous nucleation is always assumed as a concave spherical or conical substrate. Nucleation in such assumed geometries has been well understood. However, a cave or a groove always has some cusps and certain lateral surface curvature. These geometries of a cave will have important effects on heterogenous nucleation. Here the nucleation in a cave with iso-curvature lateral surface and one apex was investigated in the scope of classical nucleation theory. Nucleation in a cave was described by comparing with nucleation on spherical and conical substrates. Results show that when the contact angle is the acute angle, nucleation in a cave with the convex or concave lateral surface is easier than nucleation on the corresponding spherical surfaces. Furthermore, nucleation in a cave with the concave surface is the easiest and nucleation on the convex surface of a cave is the most difficult, while nucleation in a conical cavity is always in between. However, whether a nucleus is more easily formed in a cave is dependent on the sizes of the cave geometry for the contact angle being the obtuse angle. As the apex angle is close to zero, nucleation in a conical cavity is easier than in a cave with the concave surface but more difficult than in a cave with the convex surface for the contact angle being the obtuse angle. The effect degree of the surface curvature of a cave on nucleation is dependent on the apex angle and the contact angle.

  12. Internal cave gating for protection of colonies of the endangered gray bat (Myotis grisescens)

    USGS Publications Warehouse

    Martin, K.W.; Leslie, David M.; Payton, M.E.; Puckette, William L.; Hensley, S.L.

    2003-01-01

    Persistent human disturbance is a major cause for the decline in populations of many cave-dwelling bats and other sensitive cave-obligate organisms. Cave gating has been used to climinate human disturbance, but few studies have assessed directly the impact of such management activities on resident bats. In northeastern Oklahoma, USA, 25 entrances of caves inhabited by two endangered species and one endangered subspecies of bats are protected from human entry with internal gates. Because cave gates may impede ingress and egress of bats at caves, we evaluated the impacts of internal gates before and after their construction at six colonies of endangered gray bats (Myotis grisescens) from 1981 to 2001. No caves were abandoned by gray bats after the construction of internal gates; in fact, total numbers of gray bats using the six caves increased from 60,130 in 1981 to 70,640 in 2001. Two caves harbored more gray bats after gating, and three caves had no change in gray bat numbers after gating. We also compared initiations of emergences at three gated and three open-passage caves in June and July 1999-2000. No differences in timing of initiation of emergence were found between colonies in gated versus open-passage caves. Our results support the use of internal gates to protect and thereby enhance recovery of colonies of endangered gray bats. Additional research is encouraged to confirm that our observations on gray bats are generally applicable to other species of cave-dwelling bats.

  13. Rheology of lava flows on Mercury: an experimental study

    NASA Astrophysics Data System (ADS)

    Sehlke, A.; Whittington, A. G.

    2014-12-01

    The morphology of lava flows is controlled by the physical properties of the lava and its effusion rates, as well as environmental influences such as surface medium, slope and ambient temperature and pressure conditions. The important rheological properties of lavas include viscosity (η) and yield strength (σy), strongly dependent on temperature (T), composition (X), crystal fraction (φc) and vesicularity (φb). The crystal fraction typically increases as temperature decreases, and also influences the residual liquid composition. The rheological behavior of multi-phase lava flows is expressed as different flow morphologies, for example basalt flows transition from smooth pahoehoe to blocky `a`a at higher viscosities and/or strain rates. We have previously quantified the rheological conditions of this transition for Hawaiian basalts, but lavas on Mercury are very different in composition and expected crystallization history. Here we determine experimentally the temperature and rheological conditions of the pahoehoe-`a`a transition for two likely Mercury lava compositions using concentric cylinder viscometry. We detect first crystals at 1302 ºC for an enstatite basalt and 1317 ºC for a basaltic komatiite composition representative of the northern volcanic plains (NVP). In both cases, we observe a transition from Newtonian to pseudo-plastic response at crystal fractions > 10 vol%. Between 30 to 40 vol%, a yield strength (τ0) around 26±6 and 110±6 Pa develops, classifying the two-phase suspensions as Herschel-Bulkley fluids. The measured increase in apparent viscosity (ηapp) ranges from 10 Pa s to 104 Pa s. This change in rheological properties occurs only in a temperature range up to 100 ºC below the liquidus. By analogy with the rheological conditions of the pahoehoe-`a`a transition for Hawaiian basalts, we can relate the data for Mercury to lava flow surface morphology as shown in Figure 1, where the onset of the transition threshold zone (TTZ) for the

  14. Fire and Ice: Lavas on Io, Cryolavas on Titan

    NASA Astrophysics Data System (ADS)

    Lopes, R. M.; Gregg, T. K.; Spencer, J. R.; Mitchell, K. L.; Williams, D. A.

    2007-12-01

    Volcanic flows in our solar system are remarkably varied. Io and Titan are particularly good examples of relatively large bodies that have erupted a variety of flows, ranging from basaltic and possibly sulfur and ultramafic lavas on Io to mixtures of water and possibly ammonia and methanol on Titan. These exotic extraterrestrial flows can be much different from the examples we see on Earth, but the similarities are also striking. Understanding their eruption mechanisms is important for better constraining how effusive eruptions behave on Earth under present and past conditions. Io has exceptionally long lava flows, but these are rare compared to the most common form of Ionian volcanism; lava lakes and lava flows that are confined within calderas [Lopes et al., 2004, Icarus; Gregg and Lopes, Icarus, in press]. The largest lava flows on Io can be considered analogues to continental flood basalts on Earth, being hundreds of km long and containing many different flow units. The composition of these flows on Io is thought to be either basaltic or ultramafic. Galileo results showed the largest active flow in the Solar System at Amirani [300 km long; Kezthelyi et al., 2001, JGR 106] and recent observations by the New Horizons spacecraft showed a new flow at Masubi that is about 200 km long. Ionian flows at volcanoes such as Masubi, Maui, and Prometheus generate persistently active plumes and the movement of the Prometheus plume has been related to the growth of the lava flow [Kieffer et al. 2000, Science 288]. Sulfur flows are thought to exist on Io, but are largely a by-product of silicic volcanism. On Earth, sulfur flows are rare but have formed from melting hydrothermal sulfur deposits. Flows around Emakong on Io are thought to be sulfur flows [Williams et al., 2001, JGR 106], but to date there are no measurements that can confirm their composition. Ra Patera's flows at the time of the Voyager encounter was thought to be a site of sulfur volcanism [Pieri et al., 1984

  15. Radon in Ingleborough / Clapham Cave, North Yorkshire, UK.

    NASA Astrophysics Data System (ADS)

    Gillmore, Gavin

    2015-04-01

    Atmospheric radon concentration was measured at Ingleborough Cave, North Yorkshire during the summer of 2004, and the autumn / winter of 2004/5. Significantly, Ingleborough Cave forms part of a larger system which includes the world famous Gaping Gill pothole. This plunges 105 m (334 ft), contains the tallest unbroken waterfall in England and one of the largest known underground chambers in the UK. Measurements were taken to assess the effects of seasonal and spatial variation, elevation and ventilation on radon concentration in Ingleborough. In this study personal dose exposures for three groups of cave user were identified, and the performance of a variety of radon detection systems evaluated. Summer radon concentrations inside the cave peaked at around 7,000 Bq m-3, although average concentrations were less than 5,000 Bq m-3. During the winter measurement period, average concentrations were around 100 Bq m-3, and a winter / summer ration therefore of 47,4. The average annual radon concentration exceeded the legislative limitations for the workplace of 400 Bq m-3 due in part to a failed fan in the ventilation system. When the fan was running we noted an 80% reduction in radon concentrations although reliability of the fan was problematic due to extensive but relatively rare flooding of the cave system. The radon dose experienced by cave workers and guides in this study exceeded the Ionisation Radiation Regulations limit of 5 mSv/annum, and highlighted that for health and safety reasons the ventilation system should be fully operational during the high radon concentration summer months. Keywords: Radon, Cave, Ingleborough, Detection methods

  16. Flow Classification and Cave Discharge Characteristics in Unsaturated Karst Formation

    NASA Astrophysics Data System (ADS)

    Mariethoz, G.; Mahmud, K.; Baker, A.; Treble, P. C.

    2015-12-01

    In this study we utilize the spatial array of automated cave drip monitoring in two large chambers of the Golgotha Cave, SW Australia, developed in Quaternary aeolianite (dune limestone), with the aim of understanding infiltration water movement via the relationships between infiltration, stalactite morphology and groundwater recharge. Mahmud et al. (2015) used the Terrestrial LiDAR measurements to analyze stalactite morphology and to characterize possible flow locations in this cave. Here we identify the stalactites feeding the drip loggers and classify each as matrix (soda straw or icicle), fracture or combined-flow. These morphology-based classifications are compared with flow characteristics from the drip logger time series and the discharge from each stalactite is calculated. The total estimated discharge from each area is compared with infiltration estimates to better understand flow from the surface to the cave ceilings of the studied areas. The drip discharge data agrees with the morphology-based flow classification in terms of flow and geometrical characteristics of cave ceiling stalactites. No significant relationships were observed between the drip logger discharge, skewness and coefficient of variation with overburden thickness, due to the possibility of potential vadose-zone storage volume and increasing complexity of the karst architecture. However, these properties can be used to characterize different flow categories. A correlation matrix demonstrates that similar flow categories are positively correlated, implying significant influence of spatial distribution. The infiltration water comes from a larger surface area, suggesting that infiltration is being focused to the studied ceiling areas of each chamber. Most of the ceiling in the cave site is dry, suggesting the possibility of capillary effects with water moving around the cave rather than passing through it. Reference:Mahmud et al. (2015), Terrestrial Lidar Survey and Morphological Analysis to

  17. Non-Newtonian and Viscoelastic Properties of Lava Flows

    NASA Astrophysics Data System (ADS)

    Bagdassarov, N. S.

    2004-12-01

    Lava flow models require an in-depth knowledge of the rheological properties of lava. Previous measurements have shown that, at typical eruption temperatures, lavas are non-Newtonian. The reasons for this include the formation and destruction of crystal networks and bubble deformation during shear. The effects of bubbles are investigated experimentally in this contribution using analogue fluids with bubble concentrations <20%. The shear-thinning behaviour of bubbly liquids noted by previous workers is shown to be dependent on the previous shearing history of the fluid. This thixotropic behaviour, which was investigated using a rotational vane viscometer, is caused by delayed bubble deformation and recovery when subjected to changes in shear stress. A rotational vane viscometer and torsional deformation apparatus were used to investigate the rheological properties of bubbly liquids and foams in order to determine a viscoelastic transition. These experiments have shown that the foams tested are viscoelastic power law fluids with a yield strength. Non-Newtonian properties and yield strength of foams are shown to be a probable cause of accelerating flow fragmentation in tube flow experiments on expanding foams. The flow of a bubbly fluid through a narrowing conduit may cause a pulsating regime of a flow due to periodic slip and slip-free boundary conditions near the walls of a conduit. Slip boundary conditions can lead to instability in viscoelastic shear flow causing short wavelength fluctuations at high shear rates. This mechanism may also take place during explosive volcanic eruptions. The frequency and amplitude of oscillation shear affect the structure of lavas which are thixotropic non-Newtonian liquids. The frequency dependent structure of lavas can be identified via frequency hysteresis and time-evolution of internal friction and viscosity. The rheological properties of basaltic lavas from Etna, Hawai'i and Vesuvius have been investigated at temperatures

  18. Getting Rid of Bed Bugs

    MedlinePlus

    ... Bed Bugs — Do-it-yourself Bed Bug Control — Pesticides to Control Bed Bugs Bed Bug Information Clearinghouse ... Greener Living Health and Safety Land and Cleanup Pesticides Waste Water Science & Technology Air Climate Change Ecosystems ...

  19. Paleo-watertable definition using cave ferromanganese stromatolites and associated cave-wall notches (Sierra de Arnero, Spain)

    NASA Astrophysics Data System (ADS)

    Rossi, Carlos; Villalaín, Juan J.; Lozano, Rafael P.; Hellstrom, John

    2016-05-01

    The steeply-dipping-dolostone-hosted caves of the Sierra de Arnero (N Spain) contain low-gradient relict canyons with up to ten mapped levels of ferromanganese stromatolites and associated wall notches over a vertical range of 85 m, the highest occurring ~ 460 m above base level. Despite a plausible speleogenetic contribution by pyrite oxidation, and the irregular cave-wall mesomorphologies suggestive of hypogenic speleogenesis, the Arnero relict caves are dominantly epigenic, as indicated by the conduit pattern and the abundant allogenic sediments. Allogenic input declined over time due to a piracy-related decrease in the drainage area of allogenic streams, explaining the large size of the relict Arnero caves relative to the limited present-day outcrop area of the karstified carbonates. Allogenic-sediment input also explains the observed change from watertable canyons to phreatic conduits in the paleo-downstream direction. Stromatolites and notches arguably formed in cave-stream passages at the watertable. The best-defined paleo-watertables show an overall slope of 1.7°, consistent with the present-day relief of the watertable, with higher-slope segments caused by barriers related to sulfide mineralization. The formation of watertable stromatolites favored wall notching by the combined effect of enhanced acidity by Mn-Fe oxidation and shielding of cave floors against erosion. Abrasive bedload further contributed to notch formation by promoting lateral mechanical erosion and protecting passage floors. The irregular wallrock erosional forms of Arnero caves are related partly to paragenesis and partly to the porous nature of the host dolostones, which favored irregular dissolution near passage walls, generating friable halos. Subsequent mechanical erosion contributed to generate spongework patterns. The dolostone porosity also contributes to explain the paradox that virtually all Arnero caves are developed in dolostone despite being less soluble than adjacent

  20. Origin of lead in andean calc-alkaline lavas, southern peru.

    PubMed

    Tilton, G R; Barreiro, B A

    1980-12-12

    Lead isotope data from Quaternary andesitic lavas of the Arequipa and Barroso groups of southern Peru and from regional Precambrian granulitic gneisses reveal a lead component in the lavas from the gneisses. The lava leads can be accounted for by two-component mixtures of lead from mantle and lower crustal sources, although the mixing process need not have occurred in the lower crust.

  1. A roadmap to cave dwelling on the Moon and Mars

    NASA Astrophysics Data System (ADS)

    Blamont, Jacques

    2014-11-01

    Habitat in lava tubes recently discovered on the Moon and Mars, should become a unifying concept for occupancy. Basic motivations and specifications for such a habitat are briefly reviewed. The first step is to obtain a consensus from Agencies on the validity of the concept. Afterwards, two types of research programs should be implemented: Search for lava tubes by dedicated polar orbiters.Mapping, classification and choice of site should be achieved before 2020. Development of specific technology to begin by the end of the 2020s: Bulldozers, elevators, and cranes for access. Inflatable cylindrical structures of large dimension for housing. Since apprenticeship is needed for Mars habitat, Moon lava tubes would be used as a first step. Use of lava tubes provides therefore a unifying concept for exploration. A roadmap is proposed.

  2. Transitional lava flows as potential analogues for lunar impact melts

    NASA Astrophysics Data System (ADS)

    Neish, Catherine; Hughes, Scott; Hamilton, Christopher; Kobs Nawotniak, Shannon; Garry, William Brent; Skok, John Roma; Elphic, Richard; Carter, Lynn; Bandfield, Joshua; Osinski, Gordon; Lim, Darlene; Heldmann, Jennifer

    2015-11-01

    Lunar impact melt deposits are among the roughest surface materials on the Moon at the decimeter scale, even though they appear smooth at the meter scale. These characteristics distinguish them from well-studied terrestrial analogues, such as Hawaiian pāhoehoe and ´a´ā lava flows. The morphology of impact melt deposits can be related to their emplacement conditions, so understanding the origin of these unique surface properties will inform us as to the circumstances under which they were formed. Although there is no perfect archetype for lunar impact melts on Earth, certain terrestrial environments lend themselves as functional analogues. Specifically, a variety of transitional lava flow types develop if the surface of a pāhoehoe-like flow is disrupted, producing ‘slabby’ or ‘rubbly’ flows that are extremely rough at the decimeter scale. We investigated the surface roughness of transitional lava flows at Craters of the Moon (COTM) National Monument, comparing radar imagery and high-resolution topographic profiles to similar data sets acquired by the Lunar Reconnaissance Orbiter for impact melt deposits on the Moon. Results suggest that the lava flows at COTM have similar radar properties to lunar impact melt deposits, but the terrestrial flows are considerably rougher at the meter scale. It may be that lunar impact melts represent a unique lava type not observed on Earth, whose surface texture is influenced by their high emplacement temperatures and/or cooling in a vacuum. Information about the surface properties of lunar impact melt deposits will be critical for future landed missions that wish to sample these materials.

  3. Pleistocene cave art from Sulawesi, Indonesia.

    PubMed

    Aubert, M; Brumm, A; Ramli, M; Sutikna, T; Saptomo, E W; Hakim, B; Morwood, M J; van den Bergh, G D; Kinsley, L; Dosseto, A

    2014-10-01

    Archaeologists have long been puzzled by the appearance in Europe ∼40-35 thousand years (kyr) ago of a rich corpus of sophisticated artworks, including parietal art (that is, paintings, drawings and engravings on immobile rock surfaces) and portable art (for example, carved figurines), and the absence or scarcity of equivalent, well-dated evidence elsewhere, especially along early human migration routes in South Asia and the Far East, including Wallacea and Australia, where modern humans (Homo sapiens) were established by 50 kyr ago. Here, using uranium-series dating of coralloid speleothems directly associated with 12 human hand stencils and two figurative animal depictions from seven cave sites in the Maros karsts of Sulawesi, we show that rock art traditions on this Indonesian island are at least compatible in age with the oldest European art. The earliest dated image from Maros, with a minimum age of 39.9 kyr, is now the oldest known hand stencil in the world. In addition, a painting of a babirusa ('pig-deer') made at least 35.4 kyr ago is among the earliest dated figurative depictions worldwide, if not the earliest one. Among the implications, it can now be demonstrated that humans were producing rock art by ∼40 kyr ago at opposite ends of the Pleistocene Eurasian world. PMID:25297435

  4. Pleistocene cave art from Sulawesi, Indonesia.

    PubMed

    Aubert, M; Brumm, A; Ramli, M; Sutikna, T; Saptomo, E W; Hakim, B; Morwood, M J; van den Bergh, G D; Kinsley, L; Dosseto, A

    2014-10-01

    Archaeologists have long been puzzled by the appearance in Europe ∼40-35 thousand years (kyr) ago of a rich corpus of sophisticated artworks, including parietal art (that is, paintings, drawings and engravings on immobile rock surfaces) and portable art (for example, carved figurines), and the absence or scarcity of equivalent, well-dated evidence elsewhere, especially along early human migration routes in South Asia and the Far East, including Wallacea and Australia, where modern humans (Homo sapiens) were established by 50 kyr ago. Here, using uranium-series dating of coralloid speleothems directly associated with 12 human hand stencils and two figurative animal depictions from seven cave sites in the Maros karsts of Sulawesi, we show that rock art traditions on this Indonesian island are at least compatible in age with the oldest European art. The earliest dated image from Maros, with a minimum age of 39.9 kyr, is now the oldest known hand stencil in the world. In addition, a painting of a babirusa ('pig-deer') made at least 35.4 kyr ago is among the earliest dated figurative depictions worldwide, if not the earliest one. Among the implications, it can now be demonstrated that humans were producing rock art by ∼40 kyr ago at opposite ends of the Pleistocene Eurasian world.

  5. Field test of a calcite dissolution rate law: Fort's Funnel Cave, Mammoth Cave National Park

    SciTech Connect

    Slunder, J.S. ); Groves, C.G. . Center for Cave and Karst Studies)

    1994-03-01

    The laboratory-derived calcite dissolution rate law of Plummer et al. (1978) is the most widely used and mechanistically detailed expression currently available for predicting dissolution rates as a function of water chemistry. Such rate expressions are of great use in understanding timescales associated with limestone karst development. Little work has gone into the field testing of the rate law under natural conditions. This work measured dissolution rates by a crystal weight loss experiment in Buffalo Creek within Fort's funnel Cave, which lies within a pristine, forested catchment of Mammoth Cave National Park. Continuous water chemistry sampling over the same period allowed a time-integrated prediction of the dissolution based on the Plummer et al. (1978) expression. Results indicate that the rate law overpredicted dissolution by a factor of about ten. This concurs with earlier laboratory work suggesting that the law tends to overpredict rates in solutions close to equilibrium with respect to calcite, as were the waters within this part of the groundwater flow system.

  6. A prototype mass spectrometer for in situ analysis of cave atmospheres

    NASA Astrophysics Data System (ADS)

    Patrick, Edward L.; Mandt, Kathleen E.; Mitchell, Evelynn J.; Mitchell, Joseph N.; Younkin, Kerri N.; Seifert, Clarissa M.; Williams, Gregg C.

    2012-10-01

    Research in cave environments has many applications: studying local hydrogeologic activity, paleoclimate studies, analyzing white nose syndrome in bat populations, analogs for underground atmospheres in mining facilities, carbon sequestration efforts, and terrestrial analogs for planetary caves. The atmospheres of many caves contain tracers of current geological and biological activity, but up to this point, in situ studies have been limited to sensors that monitor individual components of the cave atmosphere. A prototype cave mass spectrometer system was assembled from commercial off-the-shelf parts to conduct surveys of atmospheric compositions inside four local Texas caves and to perform atmospheric analysis of two aquifer wellheads to a depth of 60 m. We found increased levels of CO2 in all caves and, surprisingly, increased levels of O2 in Bracken Bat Cave. Aquifer wellhead measurements showed indications of methane, other hydrocarbons, and other constituents not anticipated.

  7. Geomicrobiology of Phreatic Caves Associated With Central Florida Springs

    NASA Astrophysics Data System (ADS)

    Giannotti, A. L.; Tysall, T. N.; Franklin, R. B.; Mills, A. L.

    2005-05-01

    Phreatic (underwater) limestone caves are common in Florida in association with the numerous springs that issue from the karst landscape. Extensive microbial mats and diverse communities of invertebrates have been observed by cave divers, but, as ecosystems, the caves are not well studied. Four aphotic aquatic caves were identified in which to investigate relationships between microbial communities and their geochemical surroundings, and to evaluate the potential for chemolithoautotrophic microbial activity to support higher-order consumers. The caves were associated with the discharge sites of four different second-magnitude springs (flow: 0.3 to 3 m3 s-1) in central Florida in which communities containing microbial mats, isopods, amphiphods, and cave crayfish have been observed. Samples of bulk water and microbial mat were collected along the flow path in each cave; depths ranged from 0.5 to 15 m below the ground surface, and penetration distance extended up to 250 m from each cave entrance. Microscopic examination of the mats revealed the presence of sulfur-granule-containing, filamentous morphologies consistent with Thiothrix and Beggiatoa and an unidentified filamentous iron bacteria. The bacteria were found in all four springs, but H2S was detected in water samples from only one of the caves. In many cases, the morphology of the organisms changed along the flow path within an individual spring, although there was little change in the associated water chemistry (pH, dissolved oxygen, conductivity, total Fe, NH4+, NO3-, HS-, SO42-, PO4-, Cl-, Fl-, Ca2+, Na+, and Mg2+). The overall water chemistry of the four caves/springs was distinct (principal components analysis), and the major differences were due to Ca2+, K+, and Cl- concentrations, pH (range: 7.3 to 8.4), and sulfur and iron availability. Efforts to culture the dominant organisms in each set of mats (using media prepared with cave or spring water) and community-level genetic analyses (T-RFLP) demonstrated

  8. Tamarugite from Diana Cave (SW Romania) -first true karst occurrence

    NASA Astrophysics Data System (ADS)

    Pušcaš, C. M.; Onac, B. P.; Effenberger, H. S.; Povarǎ, I.

    2012-04-01

    Diana Cave is located within the town limits of Baile Herculane (SW Romania) and develops as a 14 m long, westward oriented, unique passage guided by the Diana fault [1]. At the far end of the cave, the thermo-mineral Diana Spring wells forth. In the early 1970s a mine gallery that intersected the cave was created to drain the water into a pumping station and the original cave passage was somewhat altered and reinforced with concrete. Today the concrete and the silty limestone cave walls are heavily corroded by H2SO4 outgassing from the hot water (ca. 50°C) and display abundant gypsum crusts, soggy aggregates of native S, and a variety of more exotic sulfates. Among them, a mineral that has been previously identified in caves only in connection to volcanic activity, either as thermal springs or fumaroles [2]: tamarugite [NaAl(SO4)26H2O]. It was [3] that first mentioned the occurrence of this Na and Al sulfate in Diana Cave, our research aiming to give a detailed description of this mineral, its paragenesis, and mechanisms of precipitation. Recently, tamarugite has also been identified in a sulfuric acid cave from Greece [4]. Along with powder X-ray diffractions coupled with Rietveld refinement, scanning electron microscope, and electron probe micro-analysis, δ18O and δ34S compositions of the sulfate mineral as well as precipitates from the water were analyzed to identify and better constrain the genesis of this rare sulfate. Regrettably, the crystal size of our specimens is inappropriate for identification by means of single crystal X-ray diffraction. Physical and chemical parameters of Diana Spring were as well measured on several occasions. Geochemical analysis suggests that the minute, white tamarugite flakes precipitated in Diana Cave as a result of the interactions between the thermo-mineral water or water vapor and the original limestone bedrock and concrete that blankets the mine gallery. [1] Povara, I., Diaconu, G., Goran, C. (1972). Observations pr

  9. The CAVE (TM) automatic virtual environment: Characteristics and applications

    NASA Technical Reports Server (NTRS)

    Kenyon, Robert V.

    1995-01-01

    Virtual reality may best be defined as the wide-field presentation of computer-generated, multi-sensory information that tracks a user in real time. In addition to the more well-known modes of virtual reality -- head-mounted displays and boom-mounted displays -- the Electronic Visualization Laboratory at the University of Illinois at Chicago recently introduced a third mode: a room constructed from large screens on which the graphics are projected on to three walls and the floor. The CAVE is a multi-person, room sized, high resolution, 3D video and audio environment. Graphics are rear projected in stereo onto three walls and the floor, and viewed with stereo glasses. As a viewer wearing a location sensor moves within its display boundaries, the correct perspective and stereo projections of the environment are updated, and the image moves with and surrounds the viewer. The other viewers in the CAVE are like passengers in a bus, along for the ride. 'CAVE,' the name selected for the virtual reality theater, is both a recursive acronym (Cave Automatic Virtual Environment) and a reference to 'The Simile of the Cave' found in Plato's 'Republic,' in which the philosopher explores the ideas of perception, reality, and illusion. Plato used the analogy of a person facing the back of a cave alive with shadows that are his/her only basis for ideas of what real objects are. Rather than having evolved from video games or flight simulation, the CAVE has its motivation rooted in scientific visualization and the SIGGRAPH 92 Showcase effort. The CAVE was designed to be a useful tool for scientific visualization. The Showcase event was an experiment; the Showcase chair and committee advocated an environment for computational scientists to interactively present their research at a major professional conference in a one-to-many format on high-end workstations attached to large projection screens. The CAVE was developed as a 'virtual reality theater' with scientific content and

  10. The setting of the Mt. Carmel caves reassessed

    NASA Astrophysics Data System (ADS)

    Vita-Finzi, Claudio; Stringer, Chris

    2007-02-01

    Four caves on the SW flank of Mt. Carmel, es Skhul, el Wad, el Jaml and et Tabun, were first excavated in the 1930s by a team led by Dorothy Garrod. They yielded human remains whose age and evolutionary status remain controversial partly because the complexity of the cave deposits invites conflicting interpretations. The abrasion of artefacts and pebbles in el Wad and es Skhul, which was originally ascribed to spring flow within the caves, is explained here by wave action, with the implication that during part of the Middle Palaeolithic the caves were on the shoreline rather than being separated from it—as they now are—by several kilometres of coastal plain and a height difference of some 45 m. U-series, thermoluminescence (TL) and electron spin resonance (ESR) dating suggests that this occurred about 120,000 years ago, when sea level in the eastern Mediterranean stood 5-6 m above its present position. It follows that Mt. Carmel has subsequently undergone some 40 m of uplift. During the period of maximum submergence, the coastal route between Africa and the northern Mediterranean would have been partly blocked, but the loss of the coastal plain for transit and as a source of animal food was offset by easier access from the caves to marine resources.

  11. Constraints on Lava Flow Emplacement Derived From Precision Topographic Measurements

    NASA Astrophysics Data System (ADS)

    Zimbelman, J. R.; Bjonnes, E. E.

    2005-12-01

    Precision topography obtained with a Differential Global Positioning System (DGPS) was used to derive constraints on the physical properties of two lava flows on the Big Island of Hawaii. We used a Trimble 4800 DGPS to collect positional information across the lava flows with < 2 cm horizontal and < 4 cm vertical precision (but field tests show that points are usually repeatable to < 1 cm both horizontally and vertically). The DGPS data were overlaid on georeferenced aerial and satellite imaging data, allowing us to correlate the measured topographic points to field notes and photographs, as well as to the local setting evident in the vertical images. We combined field and imaging data for the eastern lobe of the 1907 basalt flow from the southwestern rift zone of Mauna Loa volcano, east of the Ocean View Estates subdivision, and for portions of a grass-covered Pleistocene benmoreite flow near Mana on the western flank of Mauna Kea volcano. Measured physical dimensions of the Hawaiian lava flows obtained from the DGPS data were then used to calculate the yield strength, average effusion rate, and effective viscosity of the lavas using published relationships derived from diverse theories of fluid flow. Yield strengths obtained from three different expressions ranged from 5800 to 56000 Pa for the Mauna Loa basalt flow and from 13000 to 28000 Pa for the Mauna Kea benmoreite flow. Total flow length could not be determined for the Mauna Kea flow, but the entire surface portion of the 1907 flow is well exposed; this allowed us to calculate an average effusion rate of 29 m/s and effective viscosities ranging from 17000 to 280000 Pa-s for this flow, broadly consistent with values published for the 1984 basalt flow from the eastern rift zone of Mauna Loa. These results improve our confidence in being able to derive similar constraints on the likely emplacement conditions of lava flows on other planets, such as the enormous lava flows commonly found on the martian, venusian

  12. 36 CFR 290.3 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... designation of significant caves. 290.3 Section 290.3 Parks, Forests, and Public Property FOREST SERVICE... significant caves. (a) Nominations for initial and subsequent listings. The authorized officer will give... subsequent listings. The evaluation of the nominations for significant caves will be carried out...

  13. Atacama Desert Caves as Analog Models of Habitability for Microbial Life on the Surface of Mars

    NASA Astrophysics Data System (ADS)

    Azúa-Bustos, A.; González-Silva, C.; Salas, L.; Wynne, J. J.; McKay, C. P.; Palma, R. E.; Vicuña, R.

    2010-04-01

    On Mars, caves have been recently confirmed. They are important in the search for life since they offer protection from harsh outside conditions. Here we report our latest findings in two Atacama Desert caves that could be considered analog models for martian caves.

  14. Ancient DNA reveals differences in behaviour and sociality between brown bears and extinct cave bears.

    PubMed

    Fortes, Gloria G; Grandal-d'Anglade, Aurora; Kolbe, Ben; Fernandes, Daniel; Meleg, Ioana N; García-Vázquez, Ana; Pinto-Llona, Ana C; Constantin, Silviu; de Torres, Trino J; Ortiz, Jose E; Frischauf, Christine; Rabeder, Gernot; Hofreiter, Michael; Barlow, Axel

    2016-10-01

    Ancient DNA studies have revolutionized the study of extinct species and populations, providing insights on phylogeny, phylogeography, admixture and demographic history. However, inferences on behaviour and sociality have been far less frequent. Here, we investigate the complete mitochondrial genomes of extinct Late Pleistocene cave bears and middle Holocene brown bears that each inhabited multiple geographically proximate caves in northern Spain. In cave bears, we find that, although most caves were occupied simultaneously, each cave almost exclusively contains a unique lineage of closely related haplotypes. This remarkable pattern suggests extreme fidelity to their birth site in cave bears, best described as homing behaviour, and that cave bears formed stable maternal social groups at least for hibernation. In contrast, brown bears do not show any strong association of mitochondrial lineage and cave, suggesting that these two closely related species differed in aspects of their behaviour and sociality. This difference is likely to have contributed to cave bear extinction, which occurred at a time in which competition for caves between bears and humans was likely intense and the ability to rapidly colonize new hibernation sites would have been crucial for the survival of a species so dependent on caves for hibernation as cave bears. Our study demonstrates the potential of ancient DNA to uncover patterns of behaviour and sociality in ancient species and populations, even those that went extinct many tens of thousands of years ago. PMID:27506329

  15. Identifying Source Mixing and Examining Water Chemistry Variations: The Carroll Cave - Toronto Springs System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Located in the Missouri Ozarks, Carroll Cave is a dendritic stream cave system, formed in Ordivician Gasconade dolomite. In 2002, a new survey effort was launched under the auspices of the Carroll Cave Conservancy to provide a comprehensive map of the system. Since that time, 29.89 km of estimated p...

  16. Project C.A.V.E.S.: High School Spelunking in Arkansas.

    ERIC Educational Resources Information Center

    Reese, Rachel

    1989-01-01

    Project CAVES (Creative Adventures and Valuable Experiences through Spelunking) is a summer residential program for gifted high-school students, involving lectures, surveying and mapping simulated caves, and exploring and surveying actual caves in Arkansas. The project's development and learning activities are described. (JDD)

  17. 36 CFR 290.3 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... designation of significant caves. 290.3 Section 290.3 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE CAVE RESOURCES MANAGEMENT § 290.3 Nomination, evaluation, and designation of significant caves. (a) Nominations for initial and subsequent listings. The authorized officer will...

  18. 36 CFR 290.3 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... designation of significant caves. 290.3 Section 290.3 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE CAVE RESOURCES MANAGEMENT § 290.3 Nomination, evaluation, and designation of significant caves. (a) Nominations for initial and subsequent listings. The authorized officer will...

  19. 36 CFR 290.3 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... designation of significant caves. 290.3 Section 290.3 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE CAVE RESOURCES MANAGEMENT § 290.3 Nomination, evaluation, and designation of significant caves. (a) Nominations for initial and subsequent listings. The authorized officer will...

  20. Evidence of palaeoseismicity in a flowstone of the Observatoire cave (Monaco)

    NASA Astrophysics Data System (ADS)

    Gilli, E.

    1999-05-01

    Monaco is a medium seismicity zone. The Observatoire cave, a well decorated show cave, is a good place for palaeoseismicity studies. On the floor of the cave it is possible to observe a great number of collapsed sodastraws. The breakages are attributed to the 1887 Ligurian earthquake. A borehole in a flowstone shows several levels of collapses that may indicate ancient earthquakes.

  1. 43 CFR 37.11 - Nomination, evaluation, and designation of significant caves.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Paleontologic resources with potential to contribute useful educational and scientific information. (4... the public, including those who utilize caves for scientific, educational, and recreational purposes... where the cave is located as new cave discoveries are made or as new information becomes...

  2. Ancient DNA reveals differences in behaviour and sociality between brown bears and extinct cave bears.

    PubMed

    Fortes, Gloria G; Grandal-d'Anglade, Aurora; Kolbe, Ben; Fernandes, Daniel; Meleg, Ioana N; García-Vázquez, Ana; Pinto-Llona, Ana C; Constantin, Silviu; de Torres, Trino J; Ortiz, Jose E; Frischauf, Christine; Rabeder, Gernot; Hofreiter, Michael; Barlow, Axel

    2016-10-01

    Ancient DNA studies have revolutionized the study of extinct species and populations, providing insights on phylogeny, phylogeography, admixture and demographic history. However, inferences on behaviour and sociality have been far less frequent. Here, we investigate the complete mitochondrial genomes of extinct Late Pleistocene cave bears and middle Holocene brown bears that each inhabited multiple geographically proximate caves in northern Spain. In cave bears, we find that, although most caves were occupied simultaneously, each cave almost exclusively contains a unique lineage of closely related haplotypes. This remarkable pattern suggests extreme fidelity to their birth site in cave bears, best described as homing behaviour, and that cave bears formed stable maternal social groups at least for hibernation. In contrast, brown bears do not show any strong association of mitochondrial lineage and cave, suggesting that these two closely related species differed in aspects of their behaviour and sociality. This difference is likely to have contributed to cave bear extinction, which occurred at a time in which competition for caves between bears and humans was likely intense and the ability to rapidly colonize new hibernation sites would have been crucial for the survival of a species so dependent on caves for hibernation as cave bears. Our study demonstrates the potential of ancient DNA to uncover patterns of behaviour and sociality in ancient species and populations, even those that went extinct many tens of thousands of years ago.

  3. Fossil invertebrates records in cave sediments and paleoenvironmental assessments - a study of four cave sites from Romanian Carpathians

    NASA Astrophysics Data System (ADS)

    Moldovan, O. T.; Constantin, S.; Panaiotu, C.; Roban, R. D.; Frenzel, P.; Miko, L.

    2016-01-01

    Fossil invertebrates from cave sediments have been recently described as a potential new proxy for paleoenvironment and used in cross-correlations with alternate proxy records from cave deposits. Here we present the results of a fossil invertebrates study in four caves from two climatically different regions of the Romanian Carpathians, to complement paleoenvironmental data previously reported. Oribatid mites and ostracods are the most common invertebrates in the studied cave sediments. Some of the identified taxa are new to science, and most of them are indicative for either warm and/or cold stages or dry and/or wetter oscillations. In two caves the fossil invertebrates records indicate rapid climate oscillations during times known for a relatively stable climate. By corroborating the fossil invertebrates' record with the information given by magnetic properties and sediment structures, complementary data on past vegetation, temperatures and hydraulic regimes could be gathered. This paper analyzes the potential of fossil invertebrate records as a paleoenvironmental proxy, potential problems and pitfalls.

  4. Dry cave deposits and their palaeoenvironmental significance during the last 115 ka, Sodmein Cave, Red Sea Mountains, Egypt

    NASA Astrophysics Data System (ADS)

    Moeyersons, J.; Vermeersch, P. M.; Van Peer, P.

    2002-03-01

    The Sodmein cliff foot cave is the present-day remnant of an ancient cavity, probably of karstic origin. Physical breakdown of the limestone bedrock, rather than solution, has governed its subsequent evolution. Long before 115 ka BP an estimated 8000 m 3 of debris came off the weathered roof and mixed with contemporaneous cliff rockfall. Over 4 m of sediments have since accumulated. Wet conditions outside the cave during isotopic stage 5e are documented by sedimentary properties of the J-complex and by its detailed botanical and faunal content. These wet conditions were of regional significance. Shortly after 115 ka BP further subsidence of the roof of the ancient cave led to the present-day cave form. The cave interior has remained dry up to the present, but the deposits indicate an increase of animal passage and plant growth around 25 ka BP and during the Holocene interglacial. The latter period was rather arid in absolute terms, receiving less precipitation under a less regular pluvial regime, compared with the interglacial during isotopic stage 5e.

  5. Submarine lava flow direction revealed by neutron diffraction analysis in mineral lattice orientation

    NASA Astrophysics Data System (ADS)

    Zucali, M.; Fontana, E.; Panseri, M.; Tartarotti, P.; Capelli, S.; Ouladdiaf, B.

    2014-03-01

    ocean crust is formed by the rising of magma from mid-ocean ridges and voluminous (1-30 km3) flows of lava away from ridge axes. However, our understanding of the emplacement kinematics of submarine lava is often limited to plan view geometries of near-axis lava. Drilled cores provide in situ access to the intact internal structure of submarine lavas. We used neutron diffraction to study off-axis lava flows drilled into the uppermost crust of ODP/IODP-Site 1256 (Cocos Plate). We provide quantitative insights into submarine lava microstructures and strong evidence for a secondary lava injection into the interior of a solidifying flow of lava along the NW-SE direction parallel to the paleo-ridge axis of the East Pacific Rise. The dynamics of lava inflow are controlled by crystal abundance and the temperature of the lava-crystal mixture rather than by local seafloor topography. We provide a description of an in situ shear within submarine lavas revealed by composite shape and lattice preferred orientations, accounting for a dominant laminar nonuniform-type flow.

  6. Chromatic perception of non-invasive lighting of cave paintings

    NASA Astrophysics Data System (ADS)

    Zoido, Jesús; Vazquez, Daniel; Álvarez, Antonio; Bernabeu, Eusebio; García, Ángel; Herraez, Juán A.; del Egido, Marian

    2009-08-01

    This work is intended to deal with the problems which arise when illuminanting Paleolithic cave paintings. We have carried out the spectral and colorimetric characterization of some paintings located in the Murcielagos (bats) cave (Zuheros, Córdoba, Spain). From this characterization, the chromatic changes produced under different lighting conditions are analysed. The damage function is also computed for the different illuminants used. From the results obtained, it is proposed an illuminant whose spectral distribution diminishes the damage by minimizing the absorption of radiation and optimises the color perception of the paintings in this cave. The procedure followed in this study can be applied to optimise the lighting systems used when illuminating any other art work

  7. Molecular Characterization of Aquatic Bacterial Communities in Dinaric Range Caves.

    PubMed

    Pleše, Bruna; Pojskić, Naris; Ozimec, Roman; Mazija, Mirna; Ćetković, Helena; Lukić-Bilela, Lada

    2016-07-01

    Dinaric limestone cave systems, recognized as a hotspot of subterranean biodiversity, inhabit composite microbial communities whose structure, function and importance to ecosystems was poorly considered until the last few years. Filamentous microbial biofilms from three caves in Dinaric karst were assessed using 16S rRNA-based phylogenetic approach combined with universally protein coding genes/proteins. Studied clone libraries shared divisions but phylogenetic distribution of the obtained phylotypes differed: in Veternica and Vjetrenica clone libraries, Nitrospirae prevailed with 36% and 60% respectively, while in Izvor Bistrac the most abundant were Alphaproteobacteria (41%) followed by Firmicutes (32%). Moreover, three phylotypes were associated with novel uncultured candidate divisions OP3, WS5 and OD1 revealing the diversity and uniqueness of the microbial world in caves. Deeply understanding subterranean habitats could elucidate many new aspects in phylogeny and evolution of microorganisms as well as animal taxa, adjacent to their energy suppliers in microbial communities and biofilms. PMID:27329058

  8. Medical illustration: from caves to cyberspace.

    PubMed

    Tsafrir, J; Ohry, A

    2001-06-01

    The human body has been depicted in ancient cave-paintings, in primitively sculpted figures, and through all the ages in various forms of artistic expression. The earliest medical texts were descriptive but not illustrated. Later, as it became clear that knowledge of the human body and all its systems was essential to the practice of healing, texts were accompanied by illustrations which became an integral part of the teaching process. The illustrators included artists, whose interest was primarily artistic, but who were sometimes employed by surgeons or physicians to illustrate their texts. Occasionally, the physicians or scientists accompanied their texts with their own illustrations, and in the last century, medical illustration, in its infinite variety of techniques, has been developed as a profession in its own right. As knowledge was extended, permitted by social and cultural change, as well as by technological advances, the types of illustrations have ranged from gross anatomy through dissections showing the various organ systems, histological preparations, and radiological images, right up to the computerized digital imagery that is available today, which allows both static and dynamic two- and three-dimensional representations to be transmitted electronically across the world in a matter of seconds. The techniques used to represent medical knowledge pictorially have been as varied as the illustrators themselves, involving drawing, engraving, printing, photography, cinematography and digital processing. Each new technique has built on previous experience to broaden medical knowledge and make it accessible to an ever-widening audience. This vast accumulation of pictorial material has posed considerable problems of storage, cataloguing, retrieval, display and dissemination of the information, as well as questions of ethics, validity, manipulation and reliability. This paper traces these developments, illustrating them with representative examples drawn from

  9. Fluidized bed combustor modeling

    NASA Technical Reports Server (NTRS)

    Horio, M.; Rengarajan, P.; Krishnan, R.; Wen, C. Y.

    1977-01-01

    A general mathematical model for the prediction of performance of a fluidized bed coal combustor (FBC) is developed. The basic elements of the model consist of: (1) hydrodynamics of gas and solids in the combustor; (2) description of gas and solids contacting pattern; (3) kinetics of combustion; and (4) absorption of SO2 by limestone in the bed. The model is capable of calculating the combustion efficiency, axial bed temperature profile, carbon hold-up in the bed, oxygen and SO2 concentrations in the bubble and emulsion phases, sulfur retention efficiency and particulate carry over by elutriation. The effects of bed geometry, excess air, location of heat transfer coils in the bed, calcium to sulfur ratio in the feeds, etc. are examined. The calculated results are compared with experimental data. Agreement between the calculated results and the observed data are satisfactory in most cases. Recommendations to enhance the accuracy of prediction of the model are suggested.

  10. Fluidized bed combustion

    SciTech Connect

    Sowards, N.K.; Murphy, M.L.

    1991-10-29

    This patent describes a vessel. It comprises a fluid bed for continuously incinerating fuel comprising tire segments and the like which comprise metallic wire tramp and for concurrently removing tramp and bed materials at a bottom effluent exit means of the vessel, the vessel further comprising static air distributor means at the periphery of the bed comprising a substantially centrally unobstructed relatively large central region in which the fluid bed and fuel only are disposed and through which bed material and tramp migrate without obstruction to and through the effluent exit means, downwardly and inwardly stepped lower vessel wall means and a plurality of peripherally located centrally directed vertically and horizontally offset spaced air influent means surrounding the central region and associated with the stepped lower vessel wall means by which the bed is supported and fluidized.

  11. Holocene glacier history from alpine speleothems, Milchbach cave, Switzerland

    NASA Astrophysics Data System (ADS)

    Luetscher, M.; Hoffmann, D. L.; Frisia, S.; Spötl, C.

    2011-02-01

    Mountain glaciers and their sediments are prominent witnesses of climate change, responding sensitively to even small modifications in meteorological parameters. Even in such a classical and thoroughly studied area as the European Alps the record of Holocene glacier mass-balance is only incompletely known. Here we explore a novel and continuous archive of glacier fluctuations in a cave system adjacent to the Upper Grindelwald Glacier in the Swiss Alps. Milchbach cave became partly ice-free only recently and hosts Holocene speleothems. Four coeval stalagmites show consistent petrographic and stable isotopic changes between 9.2 and 2.0 ka which can be tied to abrupt modifications in the cave environment as a result of the closing and opening of multiple cave entrances by the waxing and waning of the nearby glacier. During periods of Holocene glacier advances, columnar calcite fabric is characterized by δ18O values of about -8.0‰ indicative of speleothem growth under quasi-equilibrium conditions, i.e. little affected by kinetic effect related to forced degassing or biological processes. In contrast, fabrics formed during periods of glacier minima are typical of bacterially mediated calcite precipitation within caves overlain by an alpine soil cover. Moreover, δ18O values of the bacterially mediated calcite fabrics are consistent with a ventilated cave system fostering kinetic fractionation. These data suggest that glacier retreats occurred repeatedly before 5.8 ka, and that the amplitudes of glacier retreats became substantially smaller afterwards. Our reconstruction of the Upper Grindelwald Glacier fluctuations agrees well with paleoglaciological studies from other sites in the Alps and provides a higher temporal resolution compared to traditional analyses of peat and wood remains found in glacier forefields.

  12. Vermiculation patterns in Coiba Mare cave, Bihor Mountains, Romania

    NASA Astrophysics Data System (ADS)

    Bojar, Ana-Voica; Guja, Ovidiu; Stefanescu, Daniel

    2014-05-01

    Vermiculation patterns developing on cave surfaces are certainly a spectacular feature. Sometimes vermiculation cover hundreds of square meters, like for example in Coiba Mare cave, which is situated in the Bihor Mountains, Romania. The Coiba Mare Cave is located at 1020 m altitude, on the Gardisoara Valley, not far from the Casa de Piatra Hamlet, in the Apuseni Natural Park (Bihor Mountains) situated in the western part of Romania. The first written document concerning the cave dates back to 1929, when R. Jeannel and E. Racovitza presented a brief description. Speleological investigations, which were started by I. Viehmann, D. Coman and M. Bleahu in 1953, were continued by several speleological clubs during 1975-1976. In this study, we are investigating the mineralogy, stable isotope distribution and patterns of vermiculations in the Coiba Mare cave. Material from the vermiculations developed on cave wall was analysed using Powder X-ray diffraction (PXRD), Fourier transformed infrared (FTIR) and energy dispersive analyses (EDS). The material consists mainly of calcite with traces of quartz, muscovite, chlinochlore, kaolinite, potassium feldspar and organic material. In Coiba Mare, the general look of the vermiculation pattern is that of a "pelli de leopardo" (Leopard's spots), a term used by Bini et al. (1978) for large vermiculations composed of clay. In the light of previous literature and according, to the own field and laboratory data a mechanism responsible for the formation of vermiculations is proposed. Evaporation and water film rupture cause the concentration of the loose particles. Evaporation is also associated with the formation of calcite microcrystals at the water-air interface. Concentration of the particle in vermiculations patterns and crystallisation is the result of evaporation and shrinking water spots.

  13. An Overview of Recent Observations on Lava-H2Ointeractions

    NASA Astrophysics Data System (ADS)

    Edwards, B. R.

    2014-12-01

    Lava flows can be sensitive recorders of their environments of formation (e.g., pillow lava). However, while deposits formed during interactions between lava and frozen water are increasing critical for constraining paleoclimate reconstructions on Earth and Mars, those interactions are subtle and complex. Fortunately, recent observations made during eruptions (2010 Fimmvorduhals/Eyjafjallajokull, Iceland; 2012-13 Tolbachik, Russia; 2013 Veniaminof, Alaska), during large-scale experiments (Syracuse Lava Lab), and on ancient deposits are shedding new light on these complexities. To understand these observations, it is critical to constrain the nature (porosity, permeability, ability to deform) of the boundary between the lava and the substrate. When lava travels directly on top of non-permeable ice, meltwater is produced rapidly enough to significantly accelerate lava movement (e.g., 'hydroplaning' or 'Leidenfrost effect'). The lack of surface permeability also facilitates ingestion of steam into the base of the lava for several minutes on the scale of experiments (dm); anomalously large gas cavities are also present in modern and ancient lava flow deposits inferred to have formed in water/ice-rich environments. When lava is emplaced directly on snow, the permeability of the substrate controls meltwater accumulation, which can facilitate/hinder heat transfer but can also weaken the substrate. Finally, the presence of basal lava flow breccia ('a'a flows) or an earlier erupted tephra blanket at the lava-H2O boundary acts to significantly slow heat transfer. The speed of lava emplacement may also be important. The lavas emplaced during most of the eruptions above were not able to cover a large enough area to quickly generate significant volumes of meltwater. However, at the high discharge rates for the first few days of the Tolbachik eruption (~400 m3 s-1), effusion onto a less permeable surface (e.g., ice instead of snow) could generate significant volumes of meltwater.

  14. Lava-seawater vapor interaction at the mid-ocean ridge crest: an important volcanic process to explain lava transport and flow morphology on the deep sea floor

    NASA Astrophysics Data System (ADS)

    Ridley, W. I.; Perfit, M.; Fornari, D.; Cann, J.; Smith, D.

    2003-12-01

    Eruption of lava from seafloor vents at the mid-ocean ridge (MOR) crest remains a poorly understood phenomena, despite the fact that it is the dominant volcanic process on earth. During the last decade only a handful of MOR eruptions have been documented using either NOAA-PMEL hydrophone detected events or serendipity, and observations of seafloor manifestations of those effusive events did not capture the actual interaction between erupted lava and near-freezing ambient seawater. Because of the great physical and technological obstacles to actually observing volcanic eruption processes in the deep sea, we must rely on the physical and chemical evidence left behind in the cooled seafloor lava flows to deduce the likely processes that occurred. Based on observations and sampling of numerous lava flows from slow to fast-spreading MORs we find a plethora of delicate macroscopic features preserved on the crusts of lava flows and in lava pillars that suggest intense and extensive interactions between hot magma and seawater during seafloor eruptions resulting in a briny vapor phase. Undersides of many lobate and sheet lava crusts have glassy drips (lava stalactites) and flanges (relict bubble walls) that could only have formed in cavities initially filled with a hot vapor at magmatic temperatures as lava was transported across the seafloor. Detailed petrologic observations of the surfaces of drips and flanges, including the presence of molten salt, exotic Cl- and S-bearing secondary silicates, secondary sulfates and almost pure forsterite, suggest that the vapor phase was flashed seawater. This vapor phase is a key to understanding delicate drip structures formed on lava crusts and the mechanisms by which lava is distributed far from eruptive fissures on the deep sea floor. We suggest that vaporized seawater is incorporated at the flow front as lava moves over the seafloor. The vapor rises as streams of bubbles through the lava behind the flow front and then collects

  15. Bed rest in pregnancy.

    PubMed

    Bigelow, Catherine; Stone, Joanne

    2011-01-01

    The use of bed rest in medicine dates back to Hippocrates, who first recommended bed rest as a restorative measure for pain. With the formalization of prenatal care in the early 1900s, maternal bed rest became a standard of care, especially toward the end of pregnancy. Antepartum bed rest is a common obstetric management tool, with up to 95% of obstetricians utilizing maternal activity restriction in some way in their practice. Bed rest is prescribed for a variety of complications of pregnancy, from threatened abortion and multiple gestations to preeclampsia and preterm labor. Although the use of bed rest is pervasive, there is a paucity of data to support its use. Additionally, many well-documented adverse physical, psychological, familial, societal, and financial effects have been discussed in the literature. There have been no complications of pregnancy for which the literature consistently demonstrates a benefit to antepartum bed rest. Given the well-documented adverse effects of bed rest, disruption of social relationships, and financial implications of this intervention, there is a real need for scientific investigation to establish whether this is an appropriate therapeutic modality. Well-designed randomized, controlled trials of bed rest versus normal activity for various complications of pregnancy are required to lay this debate to rest once and for all. PMID:21425272

  16. Secondary sulfate minerals from Alum Cave Bluff: Microscopy and microanalysis

    SciTech Connect

    Lauf, R.J.

    1997-07-01

    Microcrystals of secondary sulfate minerals from Alum Cave Bluff, Great Smoky Mountains National Park, were examined by scanning electron microscopy and identified by X-ray fluorescence (XRF) in the SEM. Among the samples the author discovered three new rare-earth sulfates: coskrenite-(Ce), levinsonite-(Y), and zugshunstite-(Ce). Other minerals illustrated in this report include sulfur, tschermigite, gypsum, epsomite, melanterite, halotrichite, apjohnite, jarosite, slavikite, magnesiocopiapite, and diadochite. Additional specimens whose identification is more tentative include pickeringite, aluminite, basaluminite, and botryogen. Alum Cave is a ``Dana locality`` for apjohnite and potash alum, and is the first documented North American occurrence of slavikite.

  17. Radiative temperature measurements at Kupaianaha lava lake, Kilauea Volcano, Hawaii

    NASA Astrophysics Data System (ADS)

    Flynn, Luke P.; Mouginis-Mark, Peter J.; Gradie, Jonathan C.; Lucey, Paul G.

    1993-04-01

    The radiative temperature of the surface of Kupaianaha lava lake is computed using field spectroradiometer data. Observations were made during periods of active overturning. The lake surface exhibits three stages of activity. Magma fountaining and overturning events characterize stage 1, which exhibits the hottest crustal temperatures and the largest fractional hot areas. Rifting events between plates of crust mark stage 2; crustal temperatures in this stage are between 100 C and 340 C, and fractional hot areas are at least an order of magnitude smaller than those in stage 1. Stage 3 is characterized by quiescent periods when the lake is covered by a thick crust. This stage dominates the activity of the lake more than 90 percent of the time. The results of this study are relevant for satellite and airborne measurement of the thermal characteristics of active volcanoes, and indicate that the thermal output of a lava lake varies on a time scale of seconds to minutes.

  18. Predicting the impact of lava flows at Mount Etna, Italy

    NASA Astrophysics Data System (ADS)

    Crisci, Gino M.; Avolio, Maria V.; Behncke, Boris; D'Ambrosio, Donato; di Gregorio, Salvatore; Lupiano, Valeria; Neri, Marco; Rongo, Rocco; Spataro, William

    2010-04-01

    Forecasting the time, nature, and impact of future eruptions is difficult at volcanoes such as Mount Etna, in Italy, where eruptions occur from the summit and on the flanks, affecting areas distant from each other. Nonetheless, the identification and quantification of areas at risk from new eruptions are fundamental for mitigating potential human casualties and material damage. Here, we present new results from the application of a methodology to define flexible high-resolution lava invasion susceptibility maps based on a reliable computational model for simulating lava flows at Etna and on a validation procedure for assessing the correctness of susceptibility mapping in the study area. Furthermore, specific scenarios can be extracted at any time from the simulation database, for land use and civil defense planning in the long term, to quantify, in real time, the impact of an imminent eruption, and to assess the efficiency of protective measures.

  19. Scientists Engage With the Public During Lava Flow Threat

    NASA Astrophysics Data System (ADS)

    McCarter, Tricia

    2014-11-01

    On 27 June, lava from Kīlauea, an active volcano on the island of Hawai`i, began flowing to the northeast, threatening the residents in Pāhoa, a community in the District of Puna, as well as the only highway accessible to this area. Scientists from the U.S. Geological Survey's Hawaiian Volcano Observatory (HVO) and the Hawai`i County Civil Defense have been monitoring the volcano's lava flow and communicating with affected residents through public meetings since 24 August. Eos recently spoke with Michael Poland, a geophysicist at HVO and a member of the Eos Editorial Advisory Board, to discuss how he and his colleagues communicated this threat to the public.

  20. Acute renal toxicity after ingestion of Lava light liquid.

    PubMed

    Erickson, T B; Aks, S E; Zabaneh, R; Reid, R

    1996-06-01

    A 65-year-old man with a history of alcohol abuse and seizure disorder presented to the emergency department with altered mental status, increased anion gap acidosis, phenytoin toxicity, and acute kidney failure. The patient had ingested the liquid contents of a Lava light, which contained chlorinated paraffin, polyethylene glycol (molecular weight 200), kerosene, and micro-crystalline wax. Gas chromatography-mass spectrophotometry of the patient's blood produced results consistent with the same analysis of the Lava light contents. After 3 days of declining mental status and worsening kidney function, the patient required hemodialysis. After a prolonged hospitalization, the patient was discharged home with residual renal insufficiency. Although multifactorial, the associated renal toxicity was most probably related to the low molecular weight polyethylene glycol content of the lamp's liquid contents. PMID:8644972

  1. Microscopic and macroscopic assessment of the emplacement of obsidian lavas

    NASA Astrophysics Data System (ADS)

    Befus, K. S.; Williams, M.; Gardner, J. E.

    2013-12-01

    Rhyolitic obsidian lavas are common in silicic volcanic systems, but quantitative data related to the emplacement of such lavas is rare. To assess the emplacement dynamics of rhyolitic obsidian lavas we measured the 3D orientation of microlites in samples collected systematically across five of the Central Plateau Member lavas of Yellowstone. Eruption volumes and maximum flow distances of targeted lava flows range from 0.01-70 km3 and 0.13-22 km, respectively. The dataset allows us to examine how deformation during emplacement varies with eruption size. Oriented thin sections were prepared from samples thought to be in place (i.e., not rotated by autobrecciation or erosion). In each sample, we petrographically measured the trend and plunge of >130 acicular Fe-Ti oxide microlites. The 3D microlite orientation can be used in two ways to understand the kinematics of emplacement. First, microlite orientations can be used to infer the dominant directions of fluid stretching because microlite long axes align in the direction of local extension. Second, the degree of alignment of a microlite population (i.e., standard deviation of trend and plunge), irrespective of preferred orientation, is dependent on the strain microlites experience during emplacement. We found that microlites are strongly aligned in all samples from all flows. Microlites are aligned roughly parallel to the direction of flow in samples collected near the flow front. Conversely, microlites are generally aligned orthogonal to the flow direction in samples collected from interior portions of the flows. In individual flows, the degree of alignment shows no correlation with distance travelled, instead it has slight random variations. Large- and small-volume flows display indistinguishable degrees of microlite alignment. Microlites provide a indicator of flow direction near flow fronts where strain is imparted by simple shear. In the interior portions of flows, strain is induced by pure shear via flattening

  2. Subglacial lava propagation, ice melting and heat transfer during emplacement of an intermediate lava flow in the 2010 Eyjafjallajökull eruption

    NASA Astrophysics Data System (ADS)

    Oddsson, Björn; Gudmundsson, Magnús T.; Edwards, Benjamin R.; Thordarson, Thorvaldur; Magnússon, Eyjólfur; Sigurðsson, Gunnar

    2016-07-01

    During the 2010 Eyjafjallajökull eruption in South Iceland, a 3.2-km-long benmoreite lava flow was emplaced subglacially during a 17-day effusive-explosive phase from April 18 to May 4. The lava flowed to the north out of the ice-filled summit caldera down the outlet glacier Gígjökull. The flow has a vertical drop of about 700 m, an area of ca. 0.55 km2, the total lava volume is ca. 2.5·107 m3 and it is estimated to have melted 10-13·107 m3 of ice. During the first 8 days, the lava advanced slowly (<100 m day-1), building up to a thickness of 80-100 m under ice that was initially 150-200 m thick. Faster advance (up to 500 m day-1) formed a thinner (10-20 m) lava flow on the slopes outside the caldera where the ice was 60-100 m thick. This subglacial lava flow was emplaced along meltwater tunnels under ice for the entire 3.2 km of the flow field length and constitutes 90 % of the total lava volume. The remaining 10 % belong to subaerial lava that was emplaced on top of the subglacial lava flow in an ice-free environment at the end of effusive activity, forming a 2.7 km long a'a lava field. About 45 % of the thermal energy of the subglacial lava was used for ice melting; 4 % was lost with hot water; about 1 % was released to the atmosphere as steam. Heat was mostly released by forced convection of fast-flowing meltwater with heat fluxes of 125-310 kWm-2.

  3. Fractal geometry of some Martian lava flow margins: Alba Patera

    NASA Technical Reports Server (NTRS)

    Kauhanen, K.

    1993-01-01

    Fractal dimension for a few lava flow margins on the gently sloping flanks of Alba Patera were measured using the structured walk method. Fractal behavior was observed at scales ranging from 20 to 100 pixels. The upper limit of the linear part of log(margin length) vs. log(scale) profile correlated well to the margin length. The lower limit depended on resolution and flow properties.

  4. Lava effusion rate definition and measurement--A review

    USGS Publications Warehouse

    Calvari, Sonia; Dehn, Jonathan; Harris, A.

    2007-01-01

    Measurement of effusion rate is a primary objective for studies that model lava flow and magma system dynamics, as well as for monitoring efforts during on-going eruptions. However, its exact definition remains a source of confusion, and problems occur when comparing volume flux values that are averaged over different time periods or spatial scales, or measured using different approaches. Thus our aims are to: (1) define effusion rate terminology; and (2) assess the various measurement methods and their results. We first distinguish between instantaneous effusion rate, and time-averaged discharge rate. Eruption rate is next defined as the total volume of lava emplaced since the beginning of the eruption divided by the time since the eruption began. The ultimate extension of this is mean output rate, this being the final volume of erupted lava divided by total eruption duration. Whether these values are total values, i.e. the flux feeding all flow units across the entire flow field, or local, i.e. the flux feeding a single active unit within a flow field across which many units are active, also needs to be specified. No approach is without its problems, and all can have large error (up to ∼50%). However, good agreement between diverse approaches shows that reliable estimates can be made if each approach is applied carefully and takes into account the caveats we detail here. There are three important factors to consider and state when measuring, giving or using an effusion rate. First, the time-period over which the value was averaged; second, whether the measurement applies to the entire active flow field, or a single lava flow within that field; and third, the measurement technique and its accompanying assumptions.

  5. Topographic and Stochastic Influences on Pahoehoe Lava Lobe Emplacement

    NASA Technical Reports Server (NTRS)

    Hamilton, Christopher W.; Glaze, Lori S.; James, Mike R.; Baloga, Stephen M.

    2013-01-01

    A detailed understanding of pahoehoe emplacement is necessary for developing accurate models of flow field development, assessing hazards, and interpreting the significance of lava morphology on Earth and other planetary surfaces. Active pahoehoe lobes on Kilauea Volcano, Hawaii, were examined on 21-26 February 2006 using oblique time-series stereo-photogrammetry and differential global positioning system (DGPS) measurements. During this time, the local discharge rate for peripheral lava lobes was generally constant at 0.0061 +/- 0.0019 m3/s, but the areal coverage rate of the lobes exhibited a periodic increase every 4.13 +/- 0.64 minutes. This periodicity is attributed to the time required for the pressure within the liquid lava core to exceed the cooling induced strength of its margins. The pahoehoe flow advanced through a series of down slope and cross-slope breakouts, which began as approximately 0.2 m-thick units (i.e., toes) that coalesced and inflated to become approximately meter-thick lobes. The lobes were thickest above the lowest points of the initial topography and above shallow to reverse facing slopes, defined relative to the local flow direction. The flow path was typically controlled by high-standing topography, with the zone directly adjacent to the final lobe margin having an average relief that was a few centimeters higher than the lava inundated region. This suggests that toe-scale topography can, at least temporarily, exert strong controls on pahoehoe flow paths by impeding the lateral spreading of the lobe. Observed cycles of enhanced areal spreading and inflated lobe morphology are also explored using a model that considers the statistical likelihood of sequential breakouts from active flow margins and the effects of topographic barriers.

  6. Preferential Weathering of Carbonatite Lava at Ol Doinyo Lengai, Tanzania

    NASA Astrophysics Data System (ADS)

    Robertson, C. H.; Harpp, K. S.; Geist, D.; Bosselait, M.

    2014-12-01

    Although carbonatites have been produced since the Archean and are preserved in the geologic record, the East African Rift is home to the only active carbonatite volcano, at Ol Doinyo Lengai. It has long been known that the natrocarbonatites become strongly weathered the first time they are exposed to rain. We studied the weathering patterns in the field and have determined the mineralogical transformations via petrography and XRD. Mass transport is assessed by XRF and ICP-MS analyses. Water preferentially dissolves specific minerals in the pristine lava, permeating through earlier layers of flow to form stalactites, which have differing mineralogical composition. These hang both from the host flow and from the bottom of underlying earlier flows. The weathering product is characterized by trona, a hydrated carbonate mineral, as well as the sodium sulfate mineral aphthitalite. Data from XRD analysis of the carbonatite lava confirm transformation of its original minerals, nyerereite and gregoryite, into secondary hydrated carbonate minerals gaylussite and pirssonite (e.g., Zaitsev and Keller, 2006). This transformation is attributed to the instability of the erupted minerals at atmospheric conditions. Data from XRF analysis indicate a 4-fold increase in the amount of sodium present in the stalactite as well as a 8-fold increase in potassium. Trace element analysis by ICP-MS indicates significantly elevated levels of vanadium, copper, and rubidium in the weathering product, whereas strontium, barium, lanthanum, and cesium are left behind in high concentrations in the carbonatite lava. Our results provide further evidence supporting the proposal by Dawson et al. (1987) that calcium carbonate dominated lava flows result from extensive weathering of sodic carbonatite flows.

  7. An analogue experimental model of depth fluctuations in lava lakes

    NASA Astrophysics Data System (ADS)

    Witham, Fred; Woods, Andrew W.; Gladstone, Charlotte

    2006-07-01

    Lava lakes, consisting of molten degassing lava in summit craters of active basaltic volcanoes, sometimes exhibit complex cycles of filling and emptying on time-scales of hours to weeks such as recorded at Pu’u’O’o in Hawaii and Oldoinyo Lengai in Tanzania. Here we report on a new series of analogue laboratory experiments of two-phase flow in a reservoir-conduit-lava lake system which spontaneously generates oscillations in the depth of liquid within the lake. During the recharge phase, gas supplied from a subsurface reservoir of degassing magma drives liquid magma up the conduit, causing the lake to fill. As the magmastatic pressure in the lake increases, the upward supply of magma, driven by the gas bubbles, falls. Eventually the upflow becomes unstable, and liquid drains downwards from the lake, driven by the magmastatic pressure of the overlying lake, suppressing the ascent of any more bubbles from the chamber. At a later stage, once the lake has drained sufficiently, the descent speed of liquid through the conduit decreases below the ascent speed of the bubbles, and the recharge cycle resumes. Application of a quantitative model of the experiments to the natural system is broadly consistent with field data.

  8. The formation of vesicular cylinders in pahoehoe lava flows

    NASA Astrophysics Data System (ADS)

    Fowler, A. C.; Rust, Alison C.; Vynnycky, M.

    2015-01-01

    Vertical cylinders of bubble-enriched, chemically evolved volcanic rock are found in many inflated pahoehoe lava flows. We provide a putative theoretical explanation for their formation, based on a description of a crystallising three-phase (liquid, solid, gas) crystal pile in which the water-saturated silicate melt exsolves steam and becomes more silica-rich as it crystallises anhydrous minerals. These cylinders resemble pipes that form in solidifying binary alloys as a result of sufficiently vigorous porous medium convection within the mush. A convection model with the addition of gas bubbles that provide the buoyancy source indicates that the effective Rayleigh number is too low for convection to occur in the mush of a basalt lava flow. However, the formation of gas bubbles during crystallisation means that the base state includes fluid migration up through the crystal mush even without convection. Stability considerations suggest that it is plausible to form a positive feedback where increased local porosity causes increased upwards fluid flow, which brings more silicic melt up and lowers the liquidus temperature, promoting locally higher porosity. Numerical solutions show that there are steady solutions in which cylinders form, and we conclude that this model provides a viable explanation for vesicular cylinder formation in inflated basalt lava flows.

  9. Transitional Lava Flows As Potential Analogues for Lunar Impact Melts

    NASA Astrophysics Data System (ADS)

    Neish, C.

    2014-12-01

    Lunar impact melts appear to be some of the roughest materials on the Moon at the centimeter scale, even though they appear smooth at the meter scale. These characteristics are unlike any terrestrial analogues yet studied, such as Hawaiian pahoehoe and a'a lava flows. The morphology of impact melt flows can be related to their emplacement conditions and melt properties through thermo-rheological models, so understanding the origin of these unique surface properties will inform us as to the conditions at which they were emplaced. In collaboration with the SSERVI FINESSE team, I am investigating the surface properties of several transitional lava types (e.g., rubbly pahoehoe) at Craters of the Moon National Monument in Idaho. I compare AIRSAR radar images of a range of lava flows to ground-based and high-resolution aerial imagery, for comparison to Mini-RF and Lunar Reconnaissance Orbiter Narrow Angle Camera (NAC) images of impact melts on the Moon. In the process, I will identify appropriate terrestrial analogues for these unusual materials, helping us to understand their emplacement conditions. Information about the surface properties of impact melt will also be critical for any future landed missions that wish to sample these materials on terrestrial planets.

  10. Assessing Lava Flow Hazards from Mauna Loa: A Natural Laboratory

    NASA Astrophysics Data System (ADS)

    Trusdell, F. A.

    2007-12-01

    The primary goal of the U.S. Geological Survey's Hawaiian Volcano Observatory is to provide scientific information that can be used to reduce risks from volcanic activity. With detailed geologic mapping, we are using GIS to assess lava flow hazards for Mauna Loa. Mauna Loa makes up 51 percent of the surface area of the island of Hawai"i. Its lava flows extend 50 km or more from source vents and have reached the sea in less than 24 hours. Mauna Loa has been showing signs of inflation and will undoubtedly erupt again. Anything in the path of a flow will be buried, crushed, or ignited. Emergency managers need to know the areas threatened with inundation, the frequency of inundation, and the people, property, and facilities at risk. We have prepared several different types of analyses: topographic, inundation, economic, and recurrence, to assess the potential hazards that lava flows present to communities on the island of Hawaii. GIS has greatly facilitated our ability to provide hazards analysis which should serve as a guide for planning by emergency managers and the public. It has enabled us to quantify volcanic risk on Mauna Loa in ways never before attempted for any volcano.

  11. Palæomagnetism of Hawaiian lava flows

    USGS Publications Warehouse

    Doell, Richard R.; Cox, Allan

    1961-01-01

    PALÆOMAGNETIC investigations of volcanic rocks extruded in various parts of the world during the past several million years have generally revealed a younger sequence of lava flows magnetized nearly parallel to the field of a theoretical geocentric axial dipole, underlain by a sequence of older flows with exactly the opposite direction of remanent magnetization. A 180-degree reversal of the geomagnetic field, occurring near the middle of the Pleistocene epoch, has been inferred by many workers from such results1–3. This is a preliminary report of an investigation of 755 oriented samples collected from 152 lava flows on the island of Hawaii, selected to represent as many stratigraphic horizons as possible. (Sampling details are indicated in Table 1.) This work was undertaken because Hawaii's numerous thick sequences of lava flows, previously mapped as Pliocene to Historic by Stearns and Macdonald4, and afterwards assigned ages ranging from later Tertiary to Recent, by Macdonald and Davis5, appeared to offer an ideal opportunity to examine the most recent reversal of Earth's field.

  12. Map showing lava-flow hazard zones, Island of Hawaii

    USGS Publications Warehouse

    Wright, Thomas L.; Chun, Jon Y.F.; Exposo, Jean; Heliker, Christina; Hodge, Jon; Lockwood, John P.; Vogt, Susan M.

    1992-01-01

    This map shows lava-flow hazard zones for the five volcanoes on the Island of Hawaii. Volcano boundaries are shown as heavy, dark bands, reflecting the overlapping of lava flows from adjacent volcanoes along their common boundary. Hazard-zone boundaries are drawn as double lines because of the geologic uncertainty in their placement. Most boundaries are gradational, and the change In the degree of hazard can be found over a distance of a mile or more. The general principles used to place hazard-zone boundaries are discussed by Mullineaux and others (1987) and Heliker (1990). The differences between the boundaries presented here and in Heliker (1990) reflect new data used in the compilation of a geologic map for the Island of Hawaii (E.W. Wolfe and Jean Morris, unpub. data, 1989). The primary source of information for volcano boundaries and generalized ages of lava flows for all five volcanoes on the Island of Hawaii is the geologic map of Hawaii (E.W. Wolfe and Jean Morris, unpub. data, 1989). More detailed information is available for the three active volcanoes. For Hualalai, see Moore and others (1987) and Moore and Clague (1991); for Mauna Loa, see Lockwood and Lipman (1987); and for Kilauea, see Holcomb (1987) and Moore and Trusdell (1991).

  13. Paleomagnetism of some Precambrian basaltic flows and red beds, Eastern Grand Canyon, Arizona

    USGS Publications Warehouse

    Elston, D.P.; Robert, Scott G.

    1973-01-01

    Lava flows and red sandstone beds near the middle of the Upper Precambrian Grand Canyon Series exhibit stable remanent magnetization. The beds are about 1000 m stratigraphically above rocks of the Grand Canyon Series for which paleomagnetic poles have been reported. All specimens were subjected to stepwise thermal (200??-700??C) or alternating field (25-5000 Oe) demagnetization for the determination of characteristic magnetization. The pole for two flows and an intercalated sandstone bed of the Cardenas Lavas of Ford, Breed and Mitchell (upper Unkar Group), is at 174.6W, 0.4N (N = 10, K = 50, ??95 = 6.9??). The pole for a weathered zone developed across the Cardenas Lavas is at 167.8W, 49.4N (N = 5, K = 79, ??95 = 8.6??). The pole for directly overlying sandstone of the Nankoweap Formation of Maxson is at 174.4E, 12.5N (N = 6, K = 105, ??95 = 6.6??). These poles lie on or near, and appear to follow, part of an apparent polar wandering path recently proposed for the Precambrian of North America by Spall. If the fit is not accidental, little or no rotation has occurred between north-central Arizona and parts of the North American continent used to define the proposed path. ?? 1973.

  14. Detrital cave sediments as recorders of environmental changes, the Seso Cave System (Huesca, Spain)

    NASA Astrophysics Data System (ADS)

    Oliva-Urcia, Belén; Bartolomé, Miguel; Moreno, Ana; Gil-Romera, Graciela; Sancho, Carlos; Muñoz, Arsenio; Osácar, Cinta

    2014-05-01

    The sedimentological study of a waterlaid detrital sequence of ~ 240 cm thick within the Seso Cave System (West-Central Pyrenees) reveals two types of sedimentary environments, the lower part (first 100 cm) is made of autochthonous (piping detached material from the Eocene marls host rock inside of the cavity) and the upper part, which is mixed with the pond deposits from 100 to 190 cm, is made of allochthonous (stream transported sediments from the outside) sediments. In these sediments, seven charcoal samples were dated using 14C AMS ranging from 2080 to 650 cal yr BP (130 BC-1300 AD). Two levels of human occupation of the cave have been recognized by ceramics associated to the Iberian Period and to the Roman Period, respectively. The autochthonous material is made up of fine grain laminated sediments (lutites and marls) and corresponds to pond facies, whereas the allochthonous material is lutites and sands and corresponds to stream facies. The increase in sedimentation rate towards the end of the sequence points to an intensification of the alluvial activity as a possible consequence of a more arid climate during the Medieval Climate Anomaly. In addition to the sedimentological and chronological studies, magnetic analyses were performed in 44 standard samples taken along the profile. The magnetic signature of the samples confirm the difference in the provenance of the studied sequence, with lower values in the natural remanent magnetization and magnetic susceptibility in the pond facies than in the stream facies due to the lower quantity of ferromagnetic minerals in the former. The rock magnetic analyses reveal that the ferromagnetic mineral is a soft coercive mineral with Curie temperatures of 580ºC, i.e., magnetite. In addition, the direction of the paleomagnetic record of the sediments is modified by the two human settlements.

  15. Bacterial Diversity and Composition in Oylat Cave (Turkey) with Combined Sanger/Pyrosequencing Approach.

    PubMed

    Gulecal-Pektas, Yasemin

    2016-01-01

    The microbiology of caves is an important topic for better understanding subsurface biosphere diversity. The diversity and taxonomic composition of bacterial communities associated with cave walls of the Oylat Cave was studied first time by molecular cloning based on Sanger/pyrosequencing approach. Results showed an average of 1,822 operational taxonomic units per sample. Clones analyzed from Oylat Cave were found to belong to 10 common phyla within the domain Bacteria. Proteobacteria dominated the phyla, followed by Actinobacteria, Acidobacteria and Nitrospirae. Shannon diversity index was between to 3.76 and 5.35. The robust analysis conducted for this study demonstrated high bacterial diversity on cave rock wall surfaces.

  16. Effects of lava-dome growth on the crater glacier of Mount St. Helens, Washington: Chapter 13 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Walder, Joseph S.; Schilling, Steve P.; Vallance, James W.; LaHusen, Richard G.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    The process of lava-dome emplacement through a glacier was observed for the first time as the 2004-6 eruption of Mount St. Helens proceeded. The glacier that had grown in the crater since the cataclysmic 1980 eruption was split in two by the new lava dome. The two parts of the glacier were successively squeezed against the crater wall. Photography, photogrammetry, and geodetic measurements document glacier deformation of an extreme variety, with strain rates of extraordinary magnitude as compared to normal temperate alpine glaciers. Unlike such glaciers, the Mount St. Helens crater glacier shows no evidence of either speed-up at the beginning of the ablation season or diurnal speed fluctuations during the ablation season. Thus there is evidently no slip of the glacier over its bed. The most reasonable explanation for this anomaly is that meltwater penetrating the glacier is captured by a thick layer of coarse rubble at the bed and then enters the volcano’s groundwater system rather than flowing through a drainage network along the bed. Mechanical consideration of the glacier-squeeze process also leads to an estimate for the driving pressure applied by the growing lava dome.

  17. A second species of Euscorpiops Vachon from caves in Vietnam (Scorpiones, Euscorpiidae, Scorpiopinae). Cave Euscorpiops scorpion from Vietnam.

    PubMed

    Lourenço, Wilson R; Pham, Dinh-Sac

    2014-09-01

    Euscorpiops dakrong sp. n., belonging to the family Euscorpiidae Laurie, is described on the basis of one male and one female collected in the Dakrong Nature Reserve cave system, Dakrong District, Quang Tri Province, Vietnam. The new species presents most features exhibited by scorpions of the genus Euscorpiops, but it is characterized by a slender body and elongated pedipalps. This new scorpion taxon represents the second species of Scorpiopinae discovered in a cave system and may be yet another endemic element in the fauna of Vietnam. Some taxonomic propositions on the generic position of Scorpiops oligotrichus Fage, 1933 are also suggested.

  18. Observations of obsidian lava flow emplacement at Puyehue-Cordón Caulle, Chile

    NASA Astrophysics Data System (ADS)

    Tuffen, H.; Castro, J. M.; Schipper, C. I.; James, M. R.

    2012-04-01

    The dynamics of obsidian lava flow emplacement remain poorly understood as active obsidian lavas are seldom seen. In contrast with well-documented basaltic lavas, we lack observational data on obsidian flow advance and temporal evolution. The ongoing silicic eruption at Puyehue-Cordón Caulle volcanic complex (PCCVC), southern Chile provides an unprecedented opportunity to witness and study obsidian lava on the move. The eruption, which started explosively on June 4th 2011, has since June 20 generated an active obsidian flow field that remains active at the time of writing (January 2012), with an area of ~6 km2, and estimated volume of ~0.18 km3. We report on observations, imaging and sampling of the north-western lava flow field on January 4th and 10th 2012, when vent activity was characterised by near-continuous ash venting and Vulcanian explosions (Schipper et al, this session) and was simultaneously feeding the advancing obsidian flow (Castro et al, this session). On January 4th the north-western lava flow front was characterised by two dominant facies: predominant rubbly lava approximately 30-40 m thick and mantled by unstable talus aprons, and smoother, thinner lobes of more continuous lava ~50 m in length that extended roughly perpendicular to the overall flow direction, forming lobes that protrude from the flow margin, and lacked talus aprons. The latter lava facies closely resembled squeeze-up structures in basaltic lava flows[1] and appeared to originate from and overlie the talus apron of the rubbly lava. Its upper surface consisted of smooth, gently folded lava domains cut by crevasse-like tension gashes. During ~2 hours of observation the squeeze-up lava lobe was the most frequent location of small-volume rockfalls, which occurred at ~1-10 minute intervals from the flow front and indicated a locus of lava advance. On January 10th the squeeze-up lava lobes had evolved significantly, with disruption and breakage of smooth continuous lava surfaces to form

  19. Key variables influencing patterns of lava dome growth and collapse

    NASA Astrophysics Data System (ADS)

    Husain, T.; Elsworth, D.; Voight, B.; Mattioli, G. S.; Jansma, P. E.

    2013-12-01

    Lava domes are conical structures that grow by the infusion of viscous silicic or intermediate composition magma from a central volcanic conduit. Dome growth can be characterized by repeated cycles of growth punctuated by collapse, as the structure becomes oversized for its composite strength. Within these cycles, deformation ranges from slow long term deformation to sudden deep-seated collapses. Collapses may range from small raveling failures to voluminous and fast-moving pyroclastic flows with rapid and long-downslope-reach from the edifice. Infusion rate and magma rheology together with crystallization temperature and volatile content govern the spatial distribution of strength in the structure. Solidification, driven by degassing-induced crystallization of magma leads to the formation of a continuously evolving frictional talus as a hard outer shell. This shell encapsulates the cohesion-dominated soft ductile core. Here we explore the mechanics of lava dome growth and failure using a two-dimensional particle-dynamics model. This meshless model follows the natural evolution of a brittle carapace formed by loss of volatiles and rheological stiffening and avoids difficulties of hour-glassing and mesh-entangelment typical in meshed models. We test the fidelity of the model against existing experimental and observational models of lava dome growth. The particle-dynamics model follows the natural development of dome growth and collapse which is infeasible using simple analytical models. The model provides insight into the triggers that lead to the transition in collapse mechasnism from shallow flank collapse to deep seated sector collapse. Increase in material stiffness due to decrease in infusion rate results in the transition of growth pattern from endogenous to exogenous. The material stiffness and strength are strongly controlled by the magma infusion rate. Increase in infusion rate decreases the time available for degassing induced crystallization leading to a

  20. Profiling bacterial diversity in a limestone cave of the western Loess Plateau of China

    PubMed Central

    Wu, Yucheng; Tan, Liangcheng; Liu, Wuxing; Wang, Baozhan; Wang, Jianjun; Cai, Yanjun; Lin, Xiangui

    2015-01-01

    Bacteria and archaea sustain subsurface cave ecosystems by dominating primary production and fueling biogeochemical cyclings, despite the permanent darkness and shortage of nutrients. However, the heterogeneity and underlying mechanism of microbial diversity in caves, in particular those well connect to surface environment are largely unexplored. In this study, we examined the bacterial abundance and composition in Jinjia Cave, a small and shallow limestone cave located on the western Loess Plateau of China, by enumerating and pyrosequencing small subunit rRNA genes. The results clearly reveal the contrasting bacterial community compositions in relation to cave habitat types, i.e., rock wall deposit, aquatic sediment, and sinkhole soil, which are differentially connected to the surface environment. The deposits on the cave walls were dominated by putative cave-specific bacterial lineages within the γ-Proteobacteria or Actinobacteria that are routinely found on cave rocks around the world. In addition, sequence identity with known functional groups suggests enrichments of chemolithotrophic bacteria potentially involved in autotrophic C fixation and inorganic N transformation on rock surfaces. By contrast, bacterial communities in aquatic sediments were more closely related to those in the overlying soils. This is consistent with the similarity in elemental composition between the cave sediment and the overlying soil, implicating the influence of mineral chemistry on cave microhabitat and bacterial composition. These findings provide compelling molecular evidence of the bacterial community heterogeneity in an East Asian cave, which might be controlled by both subsurface and surface environments. PMID:25870592

  1. Sulfur Cycling and Microbial Community Structure in Cave Environment: some geomicrobiological aspects

    NASA Astrophysics Data System (ADS)

    Gulecal, Y.; Temel, M.

    2013-12-01

    In the last decade, cave microbiology has emerged as a growing interdisciplinary field. Because of caves provides a unique subsurface environment for the exploration of microbial life and their roles on biogeochemical cycling under extreme condition. Sulfidic caves form in carbonate rocks where sulfide-rich waters interact with oxygen at the water table or at subterranean springs (1). Terrestrial sulfidic caves and springs are abundant and diverse, as assessed by efforts to characterize cave microbial ecosystems and to understand large scale geochemical processes (2). In this study we examined the geochemical features, microbial community and capacity of sulfur cycling in sulfidic cave ( Kaklik Cave, Turkey ) and its two hot springs. Pyrosequencing were used to understand bacterial diversity and community structure in this study area with contrasting hydrochemial and geological properties. Environmental nucleic acids were extracted, and PCR-directed screens reveal the presence or absence of functional genes, indicating genetic capacity for sulfur cycling. The microbial community displayed a high level of microbial diversity, representing 22 phylum of the Bacteria and 5 phylum of the Archaea. Our results provide a comparative view of the microbial communities and processes involved in sulfur cycling in sulfidic cave environments. 1- Macalady et al. (2007) Extremely acidic, pendulous cave wall biofilms from the Frasassi cave system, Italy. Env.Mic. 9(6), 1402-1414 2- Rossmassler et al. Drivers of epsilonproteobacterial community composition in sulfidic caves and springs.

  2. Study of aerosols collected in a speleotherapeutic cave situated below Budapest, Hungary

    NASA Astrophysics Data System (ADS)

    Kertész, Zs.; Borbély-Kiss, I.; Hunyadi, I.

    1999-04-01

    The Szemlőhegy-cave is one of the well-known hydrothermal caves of the Rózsadomb area of Budapest, which have been used for speleotherapy of respiratory diseases for years. It is known from the periodically changing airborne radon activity concentration data, that airflow of seasonally reversed direction are formed along the cave passages and fissures due to the temperature difference between the surface and cave air. This means that an intensive interaction takes place between the cave and its environment. The pollution of nearby waters and the urban atmospheric air represents a real danger for these caves below Buda, which recently became the part of the UNESCO World Heritage. The study of cave aerosols should be very important from the point of view of either the control possibilities of the environmental impact or speleotherapy, and probably helps in getting acquainted with the cave-forming processes. In this work we applied our standard aerosol sampling method to the high-humidity environment of the caves, and we studied the elemental composition, size fractionation as well as the spatial distribution and the seasonal variation of cave aerosols. Thanks to the sensitivity of PIXE traces of anthropogenic pollution of the Budapest air are shown in the Szemlőhegy-cave. Measured elemental concentrations remained less than one-tenth the air quality standard valid for the increasingly protected areas.

  3. Fluidized bed calciner apparatus

    DOEpatents

    Owen, Thomas J.; Klem, Jr., Michael J.; Cash, Robert J.

    1988-01-01

    An apparatus for remotely calcining a slurry or solution feed stream of toxic or hazardous material, such as ammonium diurante slurry or uranyl nitrate solution, is disclosed. The calcining apparatus includes a vertical substantially cylindrical inner shell disposed in a vertical substantially cylindrical outer shell, in which inner shell is disposed a fluidized bed comprising the feed stream material to be calcined and spherical beads to aid in heat transfer. Extending through the outer and inner shells is a feed nozzle for delivering feed material or a cleaning chemical to the beads. Disposed in and extending across the lower portion of the inner shell and upstream of the fluidized bed is a support member for supporting the fluidized bed, the support member having uniform slots for directing uniform gas flow to the fluidized bed from a fluidizing gas orifice disposed upstream of the support member. Disposed in the lower portion of the inner shell are a plurality of internal electric resistance heaters for heating the fluidized bed. Disposed circumferentially about the outside length of the inner shell are a plurality of external heaters for heating the inner shell thereby heating the fluidized bed. Further, connected to the internal and external heaters is a means for maintaining the fluidized bed temperature to within plus or minus approximately 25.degree. C. of a predetermined bed temperature. Disposed about the external heaters is the outer shell for providing radiative heat reflection back to the inner shell.

  4. Spotted hyena and steppe lion predation behaviours on cave bears of Europe - ?Late Quaternary cave bear extinction as result of predator stress

    NASA Astrophysics Data System (ADS)

    Diedrich, Cajus G.

    2010-05-01

    Cave bears hibernated in caves all over Eurasia (e.g. Rabeder et al., 2000) including alpine regions using mainly larger caves for this purpose. Late Quaternary spotted hyenas Crocuta crocuta spelaea instead occupied mainly areas close to the cave entrances as their dens (Diedrich and Žák 2006, Diedrich 2010). The largest predator, the steppe lion Panthera leo spelaea was only a sporadic cave dweller (Diedrich 2007b, 2009b). His presence and its remains from caves all over Europe can be recently explained best as result of imported carcasses after killing by their largest antagonists, the Late Quaternary spotted hyenas. In some cases the kill might have happened in the hyena den cave itself during the theft of prey remains by lions (Diedrich 2009a). Another reason of their remains in caves of Europe is the hunting onto the herbivorous cave bears, especially during hibernation times, when megafauna prey was less available in the open environments (Diedrich 2009c). These lion remains from caves of Europe, nearly all of which were from adult animals, provide evidence of active predation by lions onto cave bears even in medium high alpine regions (Diedrich 2009b, in review). Lion skeletons in European cave bear dens were therefore often found amongst originally articulated cave bear skeletons or scattered cave bear remains and even close to their hibernation nests (Diedrich et al. 2009c, in review). Not only lions fed on cave bears documented mainly by the large quantities of chewed, punctured and crushed cave bear long-bones; even damaged skulls reveal that hyenas scavenged primarily on cave bear carcasses which were mainly responsible for the destruction of their carcasses and bones (Diedrich 2005, 2009d). Predation and scavenging on cave bears by the two largest Late Quaternary predators C. c. spelaea and P. l. spelaea explains well the large quantity of fragmented cave bear bones over all European caves in low to medium high mountainous elevations, whereas in

  5. Study of a cave's air exchange pattern based on radon concentration and the time dependence of radon concentration in Pál-völgy Cave (Budapest, Hungary)

    NASA Astrophysics Data System (ADS)

    Nagy, H. E.; Horvath, A.; Jordan, Gy.; Szabo, Cs.; Kiss, A.

    2012-04-01

    A long-term (one year and a half), high resolution, with an integration time of one hour, radon concentration monitoring was carried out in Pál-völgy Cave (Budapest, Hungary). Our major goal was to determine the time dependence of radon concentration in the cave and to understand the exchange pattern of the cave air with the outdoor air based on radon concentrations, and to determine the factors that affect the radon concentration in the cave air. Pál-völgy Cave is situated in the Buda Hills, which is the NE part of the Transdanubian Central Range. The wall rock of the cave is dominantly Eocene Szépvölgy Limestone Formation. Above the limestone Eocene Buda Marl and Oligocene Tard Clay are deposited. A huge multiphase hydrothermal cave system developed in the Szépvölgy Limestone and partially in the Buda Marl resulted in a long-term complex paleokarstic evolution from the Late Eocene to the Quaternary. The radon concentration in the cave air was measured continuously by an AlphaGuard radon monitor, and meteorological parameters outside the cave were also collected simultaneously. The arithmetic mean of the annual radon concentration was 1.9 kBq/m3 and the radon concentration varied between 104-7,776 Bq/m3. In addition, the results indicate a clear seasonal variability of radon concentration in the cave air: in winter the radon concentration fluctuates around a low mean value of 253 Bq/m3, in summer it oscillates around a high mean value of 5,504 Bq/m3, whereas in spring and autumn the radon level varies between the winter and summer values. The summer to winter radon concentration ratio (radon concentration in summer/radon concentration in winter) was high, 21.8. The outside air temperature showed the strongest correlation with the radon concentration in the cave, Pierson's linear correlation coefficient is 0.76. If the outdoor air temperature is lower than the cave air temperature (12 °C), especially in autumn and winter the air flows from outside into the

  6. Assessment of the dose from radon and its decay products in the Bozkov dolomite cave.

    PubMed

    Rovenská, K; Thinová, L; Zdímal, V

    2008-01-01

    The dose from radon and its progeny remains a frequently discussed problem. ICRP 65 provides a commonly used methodology to calculate the dose from radon. Our work focuses on a cave environment and on assessing the doses in public open caves. The differences in conditions (aerosol size distribution, humidity, radon and its progeny ratio, etc.) are described by the so-called cave factor j. The cave factor is used to correct the dose for workers which is calculated using the ICRP 65 recommendation. In this work, the authors have brought together measured data of aerosol size distribution, unattached and attached fraction activity, and have calculated the so-called cave factor for the Bozkov dolomite cave environment. The dose conversion factors based on measured data and used for evaluating the cave factor were calculated by LUDEP software, which implements HRTM ICRP66.

  7. The occurrence of coliform bacteria in the cave waters of Slovak Karst, Slovakia.

    PubMed

    Seman, Milan; Gaálová, Barbora; Cíchová, Marianna; Prokšová, Miloslava; Haviarová, Dagmar; Fľaková, Renáta

    2015-05-01

    The diversity and abundance of coliform bacteria (taxonomically enterobacterias), an important quality water indicator, were determined for four representative caves in Slovak Karst: Domica Cave, Gombasecká Cave, Milada Cave and Krásnohorská Cave. Three hundred and fifty-two enterobacterial isolates were successfully identified by biochemical testing (commercial ENTEROtest 24) and selected isolates confirmed by molecular techniques (PCR, 16S rDNA sequence analysis). A total of 39 enterobacterial species were isolated from cave waters, with predominance of Escherichia coli, Serratia spp. and Enterobacter spp. PCR amplification of lacZ gene is not specific enough to provide a reliable detection of coliform bacteria isolated from the environment. Sequence analysis of 16S rDNA confirmed that all of the selected isolates belong to the family Enterobacteriaceae. In general, physical and chemical parameters of cave waters in Slovak Karst corresponded to national drinking water quality standards.

  8. Time variations of 222Rn concentration and air exchange rates in a Hungarian cave.

    PubMed

    Nagy, Hedvig Éva; Szabó, Zsuzsanna; Jordán, Gyozo; Szabó, Csaba; Horváth, Akos; Kiss, Attila

    2012-09-01

    A long-term radon concentration monitoring was carried out in the Pál-völgy cave, Budapest, Hungary, for 1.5 years. Our major goal was to determine the time dependence of the radon concentration in the cave to characterise the air exchange and define the most important environmental parameters that influence the radon concentration inside the cave. The radon concentration in the cave air was measured continuously by an AlphaGuard radon monitor, and meteorological parameters outside the cave were collected simultaneously. The air's radon concentration in the cave varied between 104 and 7776 Bq m(-3), the annual average value was 1884±85 Bq m(-3). The summer to winter radon concentration ratio was as high as 21.8. The outside air temperature showed the strongest correlation with the radon concentration in the cave, the correlation coefficient (R) was 0.76. PMID:22462600

  9. Lava flow hazard modeling during the 2014-2015 Fogo eruption, Cape Verde

    NASA Astrophysics Data System (ADS)

    Cappello, Annalisa; Ganci, Gaetana; Calvari, Sonia; Pérez, Nemesio M.; Hernández, Pedro A.; Silva, Sónia V.; Cabral, Jeremias; Del Negro, Ciro

    2016-04-01

    Satellite remote sensing techniques and lava flow forecasting models have been combined to enable a rapid response during effusive crises at poorly monitored volcanoes. Here we used the HOTSAT satellite thermal monitoring system and the MAGFLOW lava flow emplacement model to forecast lava flow hazards during the 2014-2015 Fogo eruption. In many ways this was one of the major effusive eruption crises of recent years, since the lava flows actually invaded populated areas. Combining satellite data and modeling allowed mapping of the probable evolution of lava flow fields while the eruption was ongoing and rapidly gaining as much relevant information as possible. HOTSAT was used to promptly analyze MODIS and SEVIRI data to output hot spot location, lava thermal flux, and effusion rate estimation. This output was used to drive the MAGFLOW simulations of lava flow paths and to continuously update flow simulations. We also show how Landsat 8 OLI and EO-1 ALI images complement the field observations for tracking the flow front position through time and adding considerable data on lava flow advancement to validate the results of numerical simulations. The integration of satellite data and modeling offers great promise in providing a unified and efficient system for global assessment and real-time response to effusive eruptions, including (i) the current state of the effusive activity, (ii) the probable evolution of the lava flow field, and (iii) the potential impact of lava flows.

  10. Discriminating lava flows of different age within Nyamuragira's volcanic field using spectral mixture analysis

    NASA Astrophysics Data System (ADS)

    Li, Long; Canters, Frank; Solana, Carmen; Ma, Weiwei; Chen, Longqian; Kervyn, Matthieu

    2015-08-01

    In this study, linear spectral mixture analysis (LSMA) is used to characterize the spectral heterogeneity of lava flows from Nyamuragira volcano, Democratic Republic of Congo, where vegetation and lava are the two main land covers. In order to estimate fractions of vegetation and lava through satellite remote sensing, we made use of 30 m resolution Landsat Enhanced Thematic Mapper Plus (ETM+) and Advanced Land Imager (ALI) imagery. 2 m Pleiades data was used for validation. From the results, we conclude that (1) LSMA is capable of characterizing volcanic fields and discriminating between different types of lava surfaces; (2) three lava endmembers can be identified as lava of old, intermediate and young age, corresponding to different stages in lichen growth and chemical weathering; (3) a strong relationship is observed between vegetation fraction and lava age, where vegetation at Nyamuragira starts to significantly colonize lava flows ∼15 years after eruption and occupies over 50% of the lava surfaces ∼40 years after eruption. Our study demonstrates the capability of spectral unmixing to characterize lava surfaces and vegetation colonization over time, which is particularly useful for poorly known volcanoes or those not accessible for physical or political reasons.

  11. Disruption of tephra fall deposits caused by lava flows during basaltic eruptions

    NASA Astrophysics Data System (ADS)

    Brown, R. J.; Thordarson, T.; Self, S.; Blake, S.

    2015-10-01

    Observations in the USA, Iceland and Tenerife, Canary Islands reveal how processes occurring during basaltic eruptions can result in complex physical and stratigraphic relationships between lava and proximal tephra fall deposits around vents. Observations illustrate how basaltic lavas can disrupt, dissect (spatially and temporally) and alter sheet-form fall deposits. Complexity arises through synchronous and alternating effusive and explosive activity that results in intercalated lavas and tephra deposits. Tephra deposits can become disrupted into mounds and ridges by lateral and vertical displacement caused by movement (including inflation) of underlying pāhoehoe lavas and clastogenic lavas. Mounds of tephra can be rafted away over distances of 100 s to 1,000 s m from proximal pyroclastic constructs on top of lava flows. Draping of irregular topography by fall deposits and subsequent partial burial of topographic depressions by later lavas can result in apparent complexity of tephra layers. These processes, deduced from field relationships, have resulted in considerable stratigraphic complexity in the studied proximal regions where fallout was synchronous or alternated with inflation of subjacent lava sheets. These mechanisms may lead to diachronous contact relationships between fall deposits and lava flows. Such complexities may remain cryptic due to textural and geochemical quasi-homogeneity within sequences of interbedded basaltic fall deposits and lavas. The net effect of these processes may be to reduce the usefulness of data collected from proximal fall deposits for reconstructing basaltic eruption dynamics.

  12. Rootless shield and perched lava pond collapses at Kīlauea Volcano, Hawai'i

    USGS Publications Warehouse

    Patrick, Matthew R.; Orr, Tim R.

    2012-01-01

    Effusion rate is a primary measurement used to judge the expected advance rate, length, and hazard potential of lava flows. At basaltic volcanoes, the rapid draining of lava stored in rootless shields and perched ponds can produce lava flows with much higher local effusion rates and advance velocities than would be expected based on the effusion rate at the vent. For several months in 2007–2008, lava stored in a series of perched ponds and rootless shields on Kīlauea Volcano, Hawai'i, was released episodically to produce fast-moving 'a'ā lava flows. Several of these lava flows approached Royal Gardens subdivision and threatened the safety of remaining residents. Using time-lapse image measurements, we show that the initial time-averaged discharge rate for one collapse-triggered lava flow was approximately eight times greater than the effusion rate at the vent. Though short-lived, the collapse-triggered 'a'ā lava flows had average advance rates approximately 45 times greater than that of the pāhoehoe flow field from which they were sourced. The high advance rates of the collapse-triggered lava flows demonstrates that recognition of lava accumulating in ponds and shields, which may be stored in a cryptic manner, is vital for accurately assessing short-term hazards at basaltic volcanoes.

  13. Origin and deformation of high porosity bands in the Takanoobane Rhyolite lava of Aso volcano, Japan

    NASA Astrophysics Data System (ADS)

    Furukawa, K.; Uno, K.

    2015-10-01

    In rhyolite lavas, the high porosity bands are often developed. They potentially act as pathways for gas movement to the lava surface. Since explosive activities of lavas are generally considered to be controlled by degassing system, understanding the origin and deformation process of the high porosity bands is important to assessing volcanic hazards. The Takanoobane rhyolite lava in the middle of Kyushu Island in SW Japan is effused at 51 ± 5 ka. The volume, flow length, and thickness are 0.14 km3, > 2 km, and about 90 m, respectively. The central crystalline part of the lava is characterized by the light-colored bands defined by the high porosity zone (HPZ). On the basis of geological and petrographical studies, we revealed that the HPZ was primary formed by ductile-brittle tearing of the lava (known as cavitation). According to the AMS results, the HPZs were subsequently stretched and flattened laterally during the concentric spreading of the lava. This deformation process could stretch the HPZ not only radially but also laterally. This effective stretching developed the HPZ into pervasive thin bands. Since the HPZs act as degassing pathways to the lava surface, the pervasive HPZ bands may play a role in providing volcanic gasses to void spaces created in surface fold hinges of rhyolite lavas. Thus, this degassing system may promote explosive activity of the lava surface.

  14. Controls on lava-snow interactions from propogation styles during the 2012-13 Tolbachik eruption

    NASA Astrophysics Data System (ADS)

    Edwards, Benjamin; Belousov, Alexander; Belousov, Marina

    2014-05-01

    Knowledge of how volcanism interacts with hydrosphere/cryosphere is critical for understanding the functioning and evolution of the Earth, establishing volcanism-climate linkages, and estimations of related hazards. Until now, no special studies have been focused on interactions between snowpack and advancing incandescent lava during volcanic eruptions, even though snow is the most widely distributed form of solid H2O on the planet. It was thought a priori that snow might melt rapidly in front of active lava flows producing vigorous floods. Here we present results of unique field observations made in the snowpack in front of advancing basaltic lava flows during the 2012-13 eruption at Tolbachik volcano, Kamchatka, Russia. Our observations in the first time demonstrate that in reality heat transfer through lava/snow boundary occurs relatively slowly, so that melting of the majority of the snow pack occurs over the span of several hours-days after emplacement of the lava flows, producing only local and sporadic meltwater floods. Two fundamentally different styles of lava propagation result in two strikingly different responses of snowpack: i) 'a'a lava advancing in a rolling caterpillar-track motion propagates on top of snowpack; the melt water accumulates in (saturates) the layer of snow buried underneath the lava flow and does not interact notably with the lava material, and ii) pahoehoe lava advancing as inflating lobes propagates beneath/inside snowpack, locally generating slowly growing 'snow-domes'; the melt water precipitates down into incandescent lava producing chilling and local thermal shock/quench fragmentation (minor hyaloclastite production). Our observations show that lava-snow interactions can vary significantly depending on styles of flow front advance. Lava flows emplaced over areas covered with snow bear features that can be distinguished in old stratigraphic sequences and used for paleoclimatic reconstructions on Earth, Mars and other planets.

  15. Constraints on Determining the Eruption Style and Composition of Terrestrial Lavas from Space

    NASA Technical Reports Server (NTRS)

    Wright, Robert; Glaze, Lori; Baloga, Stephen M.

    2011-01-01

    The surface temperatures of active lavas relate to cooling rates, chemistry, and eruption style. We analyzed 61 hyperspectral satellite images acquired by the National Aeronautics and Space Administration s Earth Observing-1 (EO-1) Hyperion imaging spectrometer to document the surface temperature distributions of active lavas erupted at 13 volcanoes. Images were selected to encompass the range of common lava eruption styles, specifically, lava fountains, flows, lakes, and domes. Our results reveal temperature distributions for terrestrial lavas that correlate with composition (i.e., a statistically significant difference in the highest temperatures retrieved for mafic lavas and intermediate and felsic lavas) and eruption style. Maximum temperatures observed for mafi c lavas are approx.200 C higher than for intermediate and felsic lavas. All eruption styles exhibit a low-temperature mode at approx.300 C; lava fountains and 'a' a flows also exhibit a higher-temperature mode at approx.700 C. The observed differences between the temperatures are consistent with the contrasting rates at which the lava surfaces are thermally renewed. Eruption styles that allow persistent and pervasive thermal renewal of the lava surface (e.g., fractured crusts on channel-fed 'a' a flows) exhibit a bimodal temperature distribution; eruption styles that do not (e.g., the continuous skin of pahoehoe lavas) exhibit a single mode. We conclude that insights into composition and eruption style can only be gained remotely by analyzing a large spatio-temporal sample of data. This has implications for determining composition and eruption style at the Jovian moon Io, for which no in situ validation is available.

  16. Finite element visualization in the cave virtual reality environment

    SciTech Connect

    Plaskacz, E.J.; Kuhn, M.A.

    1996-03-01

    Through the use of the post-processing software, Virtual Reality visualization (VRviz), and the Cave Automatic Virtual Environment (CAVE), finite element representations can be viewed as they would be in real life. VRviz is a program written in ANSI C to translate the mathematical results generated by finite element analysis programs into a virtual representation. This virtual representation is projected into the CAVE environment and the results are animated. The animation is fully controllable. A user is able to translate the image, rotate about any axis and scale the image at any time. The user is also able to freeze the animation at any time step and control the image update rate. This allows the user to navigate around, or even inside, the image in order to effectively analyze possible failure points and redesign as necessary. Through the use of the CAVE and the real life image that is being produced by VRviz, engineers are able to save considerable time, money, and effort in the design process.

  17. 36 CFR 7.36 - Mammoth Cave National Park.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... crawfish for bait: Bylew, First, Second, Pine, Big Hollow, Buffalo, Ugly, Cub, Blowing Spring, Floating... bicycle use: (i) Connector Trail from the Big Hollow Trailhead to the Maple Springs Trailhead; (ii) Big Hollow Trail; (iii) Mammoth Cave Railroad Bike & Hike Trail; and (iv) White Oak Trail. (2) The...

  18. Bacteria associated with the bleached and cave coral Oculina patagonica.

    PubMed

    Koren, Omry; Rosenberg, Eugene

    2008-04-01

    The relative abundance of bacteria in the mucus and tissues of Oculina patagonica taken from bleached and cave (azooxanthellae) corals was determined by analyses of the 16S rRNA genes from cloned libraries of extracted DNA and from isolated colonies. The results were compared to previously published data on healthy O. patagonica. The bacterial community of bleached, cave, and healthy corals were completely different from each other. A tight cluster (>99.5% identity) of bacteria, showing 100% identity to Acinetobacter species, dominated bleached corals, comprising 25% of the 316 clones sequenced. The dominant bacterial cluster found in cave corals, representing 29% of the 97 clones sequenced, showed 98% identity to an uncultured bacterium from the Great Barrier Reef. Vibrio splendidus was the most dominant species in healthy O. patagonica. The culturable bacteria represented 0.1-1.0% of the total bacteria (SYBR Gold staining) of the corals. The most abundant culturable bacteria in bleached, cave, and healthy corals were clusters that most closely matched Microbulbifer sp., an alpha-proteobacterium previously isolated from healthy corals and an alpha-protobacterium (AB026194), respectively. Three generalizations emerge from this study on O. patagonica: (1) More bacteria are associated with coral tissue than mucus; (2) tissue and mucus populations are different; (3) bacterial populations associated with corals change dramatically when corals lack their symbiotic zooxanthellae, either as a result of the bleaching disease or when growing in the absence of light.

  19. 43 CFR 37.12 - Confidentiality of cave location information.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... administrative review or appeal under 5 U.S.C. 552 or 43 CFR parts 2 or 4. ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Confidentiality of cave location information. 37.12 Section 37.12 Public Lands: Interior Office of the Secretary of the Interior...

  20. 43 CFR 37.12 - Confidentiality of cave location information.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... administrative review or appeal under 5 U.S.C. 552 or 43 CFR parts 2 or 4. ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Confidentiality of cave location information. 37.12 Section 37.12 Public Lands: Interior Office of the Secretary of the Interior...

  1. 43 CFR 37.12 - Confidentiality of cave location information.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... administrative review or appeal under 5 U.S.C. 552 or 43 CFR parts 2 or 4. ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Confidentiality of cave location information. 37.12 Section 37.12 Public Lands: Interior Office of the Secretary of the Interior...

  2. 43 CFR 37.12 - Confidentiality of cave location information.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... administrative review or appeal under 5 U.S.C. 552 or 43 CFR parts 2 or 4. ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Confidentiality of cave location information. 37.12 Section 37.12 Public Lands: Interior Office of the Secretary of the Interior...

  3. Full Immersive Virtual Environment Cave[TM] in Chemistry Education

    ERIC Educational Resources Information Center

    Limniou, M.; Roberts, D.; Papadopoulos, N.

    2008-01-01

    By comparing two-dimensional (2D) chemical animations designed for computer's desktop with three-dimensional (3D) chemical animations designed for the full immersive virtual reality environment CAVE[TM] we studied how virtual reality environments could raise student's interest and motivation for learning. By using the 3ds max[TM], we can visualize…

  4. Cryogenic cave carbonates as an archive of Late Pleistocene permafrost in the Ural Mountains: preliminary results

    NASA Astrophysics Data System (ADS)

    Dublyansky, Yuri; Kadebskaya, Olga; Cheng, Hai; Luetscher, Mark; Spötl, Christoph

    2015-04-01

    A specific type of cave deposits, cryogenic cave carbonates (CCCs), was discovered in the late 1980s in several caves of Central Europe. Unlike 'common' speleothems that form primarily due to degassing of CO2 from Ca2+ and HCO3- -rich waters, CCCs form by freezing-induced segregation (Žák et al., 2004). The formation of CCCs, hence, requires the presence of both liquid water and freezing temperatures. The latter combination may occur in caves in two situations: (1) freezing-thawing cycles in cave entrance zones; and (2) degrading permafrost conditions, when the active layer reaches the cave ceiling, whilst the deeper parts of the cave remain frozen. The latter situation is associated with a particular type of CCCs, which can be used as a marker for permafrost conditions. Because cave carbonates can be accurately dated using the U/Th method, CCCs may be used to identify events of (degrading) palaeo-permafrost conditions. In this study, CCCs were identified and sampled in four caves, located along a 1000 km-long transect from the northern to the southern Ural Associating the CCCs to permafrost conditions was possible on the basis of field observations (locations deep inside the cave, far from entrance zones) and stable isotope properties (strongly depleted δ18O values, inverse correlation between δ18O and δ13C). Chaikovskiy et al. (2014) reported five U/Th analyses of CCC from three caves: 16.7 ka and 104.8 ka (Divja Cave, northern Ural); and 13.4 ka, 86.5 ka and 125.3 ka (Rossijskaya and Usvinskaya Caves, central Ural). In this study we report 25 additional U/Th ages from northern and central Ural, as well as the first CCC age from southern Ural (Shulgan-Tash Cave). Most of the younger ages (

  5. The relationship between caves minerals and hypogene speleogenesis along the Cerna Valley (SW Romania)

    NASA Astrophysics Data System (ADS)

    Onac, B. P.; Sumrall, J.; Tamas, T.; Povara, I.; Veres, D.; Darmiceanu, V.; Lascu, C.

    2009-04-01

    Over 100 caves are known to develop in the Jurassic and Cretaceous limestone that outcrops on both sides of the Cerna Valley in southwestern Romania. High temperature anomalies are rather uncommon in the cave environment; however, in certain caves in the lower part of Cerna Valley one can measure air temperatures as high as 40°C. This situation is due to the presence of thermal water pooling or flowing through the caves or to the hot steam that rises along fractures from deeper thermal water pools. During the long evolution of the thermo-mineral activity along the Cerna Valley interaction has occurred on a wide scale between the cave host rock or/and cave sediments and the ascending hot steam or/and thermal solutions of all types (mainly sulfide-rich). The present work documents the products of these processes and record the occurrence of twenty-four secondary cave minerals (both of primarily or replacement origin) precipitated under particular cave environments. Among these, glauberite, apjonite, halotrichite, pickeringite, rapidcreekite, tamarugite, and darapskite are the most interesting. The mineral samples were investigated by means of X-ray diffraction, electron microprobe, Fourier-transformed infrared spectroscopy, and scanning electron microscope analyses with the scope of linking the cave minerals with possible hypogene speleogenetic processes. The isotopic measurements (δ34S) performed on sulfate speleothems contribute valuable information on both minerals and caves origin. Apart from two minerals (i.e., calcite and gypsum), which were identified in every cave investigated so far, all the others fall into three distinct associations that have resulted from specific reactions under highly particular settings in Diana (sulfate-dominated association), Adam (phosphate-dominated), and Great Sălitrari (sulfate/phosphate/nitrate-rich association) caves. These three remarkable cave occurrences are presented along with morphological features that confirm the

  6. On developing thermal cave detection techniques for earth, the moon and mars

    USGS Publications Warehouse

    Wynne, J.J.; Titus, T.N.; Chong, Diaz G.

    2008-01-01

    The purpose of this study is to (1) demonstrate the viability of detecting terrestrial caves at thermal-infrared wavelengths, (2) improve our understanding of terrestrial cave thermal behavior, (3) identify times of day when cave openings have the maximum thermal contrast with the surrounding surface regolith, and (4) further our understanding of how to detect caves on Earth, the Moon and Mars. We monitored the thermal behavior of two caves in the Atacama Desert of northern Chile. Through this work, we identified times when temperature contrasts between entrance and surface were greatest, thus enabling us to suggest optimal overflight times. The largest thermal contrast for both caves occurred during mid-day. One cave demonstrated thermal behavior at the entrance suggestive of cold-trapping, while the second cave demonstrated temperature shifts suggestive of airflow. We also collected thermograms without knowing optimal detection times; these images suggest both caves may also be detectable during off-peak times. We suggest cave detection using thermal remote sensing on Earth and other planetary objects will be limited by (1) capturing imagery in the appropriate thermal wavelength, (2) the size of cave entrance vs. the sensor's spatial resolution, (3) the viewing angle of the platform in relation to the slope trajectory of the cave entrance, (4) the strength of the thermal signal associated with the cave entrance, and (5) the time of day and season of thermal image capture. Through this and other studies, we will begin to identify the range of conditions under which caves are detectable in the thermal infrared and thus improve our detection capabilities of these features on Earth, the Moon and Mars. ?? 2008 Elsevier B.V.

  7. A post-wildfire response in cave dripwater chemistry

    NASA Astrophysics Data System (ADS)

    Nagra, Gurinder; Treble, Pauline C.; Andersen, Martin S.; Fairchild, Ian J.; Coleborn, Katie; Baker, Andy

    2016-07-01

    Surface disturbances above a cave have the potential to impact cave dripwater discharge, isotopic composition and solute concentrations, which may subsequently be recorded in the stalagmites forming from these dripwaters. One such disturbance is wildfire; however, the effects of wildfire on cave chemistry and hydrology remains poorly understood. Using dripwater data monitored at two sites in a shallow cave, beneath a forest, in southwest Australia, we provide one of the first cave monitoring studies conducted in a post-fire regime, which seeks to identify the effects of wildfire and post-fire vegetation dynamics on dripwater δ18O composition and solute concentrations. We compare our post-wildfire δ18O data with predicted dripwater δ18O using a forward model based on measured hydro-climatic influences alone. This helps to delineate hydro-climatic and fire-related influences on δ18O. Further we also compare our data with both data from Golgotha Cave - which is in a similar environment but was not influenced by this particular fire - as well as regional groundwater chemistry, in an attempt to determine the extent to which wildfire affects dripwater chemistry. We find in our forested shallow cave that δ18O is higher after the fire relative to modelled δ18O. We attribute this to increased evaporation due to reduced albedo and canopy cover. The solute response post-fire varied between the two drip sites: at Site 1a, which had a large tree above it that was lost in the fire, we see a response reflecting both a reduction in tree water use and a removal of nutrients (Cl, Mg, Sr, and Ca) from the surface and subsurface. Solutes such as SO4 and K maintain high concentrations, due to the abundance of above-ground ash. At Site 2a, which was covered by lower-middle storey vegetation, we see a solute response reflecting evaporative concentration of all studied ions (Cl, Ca, Mg, Sr, SO4, and K) similar to the trend in δ18O for this drip site. We open a new avenue for

  8. Lava flow hazard at Fogo Volcano, Cabo Verde, before and after the 2014-2015 eruption

    NASA Astrophysics Data System (ADS)

    Richter, Nicole; Favalli, Massimiliano; de Zeeuw-van Dalfsen, Elske; Fornaciai, Alessandro; da Silva Fernandes, Rui Manuel; Pérez, Nemesio M.; Levy, Judith; Silva Victória, Sónia; Walter, Thomas R.

    2016-08-01

    Lava flow simulations help to better understand volcanic hazards and may assist emergency preparedness at active volcanoes. We demonstrate that at Fogo Volcano, Cabo Verde, such simulations can explain the 2014-2015 lava flow crisis and therefore provide a valuable base to better prepare for the next inevitable eruption. We conducted topographic mapping in the field and a satellite-based remote sensing analysis. We produced the first topographic model of the 2014-2015 lava flow from combined terrestrial laser scanner (TLS) and photogrammetric data. This high-resolution topographic information facilitates lava flow volume estimates of 43.7 ± 5.2 × 106 m3 from the vertical difference between pre- and posteruptive topographies. Both the pre-eruptive and updated digital elevation models (DEMs) serve as the fundamental input data for lava flow simulations using the well-established DOWNFLOW algorithm. Based on thousands of simulations, we assess the lava flow hazard before and after the 2014-2015 eruption. We find that, although the lava flow hazard has changed significantly, it remains high at the locations of two villages that were destroyed during this eruption. This result is of particular importance as villagers have already started to rebuild the settlements. We also analysed satellite radar imagery acquired by the German TerraSAR-X (TSX) satellite to map lava flow emplacement over time. We obtain the lava flow boundaries every 6 to 11 days during the eruption, which assists the interpretation and evaluation of the lava flow model performance. Our results highlight the fact that lava flow hazards change as a result of modifications of the local topography due to lava flow emplacement. This implies the need for up-to-date topographic information in order to assess lava flow hazards. We also emphasize that areas that were once overrun by lava flows are not necessarily safer, even if local lava flow thicknesses exceed the average

  9. Reproductive Seasonality in Nesticus (Araneae: Nesticidae) Cave Spiders

    PubMed Central

    Carver, Linnea M.; Perlaky, Patricia; Cressler, Alan; Zigler, Kirk S.

    2016-01-01

    Spiders of the family Nesticidae are members of cave communities around the world with cave-obligate (troglobiotic) species known from North America, Europe, Asia and the Indo-Pacific. A radiation of Nesticus (Araneae: Nesticidae) in the southern Appalachians includes ten troglobiotic species. Many of these species are of conservation interest due to their small ranges, with four species being single-cave endemics. Despite conservation concerns and their important role as predators in cave communities, we know little about reproduction and feeding in this group. We addressed this knowledge gap by examining populations of two species on a monthly basis for one year. We made further observations on several other species and populations, totaling 671 individual spider observations. This more than doubled the reported observations of reproduction and feeding in troglobiotic Nesticus. Female Nesticus carry egg sacs, facilitating the determination of the timing and frequency of reproduction. We found that Nesticus exhibit reproductive seasonality. Females carried egg sacs from May through October, with a peak in frequency in June. These spiders were rarely observed with prey; only 3.3% (22/671) of individuals were observed with prey items. The frequency at which prey items were observed did not vary by season. Common prey items were flies, beetles and millipedes. Troglobiotic species constituted approximately half of all prey items observed. This result represents a greater proportion of troglobiotic prey than has been reported for various troglophilic spiders. Although our findings shed light on the life history of troglobiotic Nesticus and on their role in cave ecosystems, further work is necessary to support effective conservation planning for many of these rare species. PMID:27280416

  10. Reproductive Seasonality in Nesticus (Araneae: Nesticidae) Cave Spiders.

    PubMed

    Carver, Linnea M; Perlaky, Patricia; Cressler, Alan; Zigler, Kirk S

    2016-01-01

    Spiders of the family Nesticidae are members of cave communities around the world with cave-obligate (troglobio