Earth Sciences Commons^™

Karstology And The Opening Of Caves During Motorway Construction In The Karst Region Of Slovenia, Martin Knez, Tadej Slabe

International Journal of Speleology

The nature of karst makes constructing a roadway across karst areas a complex task, which is why karstologists take part in motorway construction across Slovenia’s karst. Working with planners, karstologists select the best route on the basis of preliminary research. Then they carry out regular karstological monitoring of the construction, to study newly discovered karst phenomena, mostly caves, and also help builders overcome the challenges of karst in a way that will preserve nature as much as possible. During the recent construction of a section of motorway, more than three hundred caves were encountered within a sixty-kilometre stretch of road. …

Subsidence Hazards As A Consequence Of Dam, Reservoir And Tunnel Construction, Petar Milanovic

International Journal of Speleology

Considering all man-made structures in karst areas, dams, reservoirs and tunnels are the most vulnerable in relation to induced subsidence and caverns. Reservoirs that are located entirely or partially on karstified rocks covered with unconsolidated sediments are especially subsidence-prone. As a consequence of induced subsidence a number of reservoirs in karst areas failed and were never fully filled. Such subsidence formation is very damaging because the development is unpredictable and practically instantaneous. Reservoirs in karst areas may fail to fill despite an extensive site investigation programs and sealing treatment. Every problem is unique and past experiences are never repeated. This …

Karst Subsidence In South-Central Apulia, Southern Italy, Marco Delle Rose, Mario Parise

International Journal of Speleology

Subsidence in the karst of Apulia (Southern Italy), one of the classical karst areas of Italy, is described in this paper. The carbonate rocks that make up the geological structure of the Apulia region are affected by subsidence, which is of different type and intensity depending upon geological, topographical, and hydrogeological conditions. In particular, we discriminate between inland subsidence and coastal subsidence. Inland subsidence is generally restricted to the presence of individual cavities, either empty or partly or totally filled with deposits produced by dissolution of soluble rocks underground. Locally, such subsidence can cause severe effects on anthropogenic structures above. …

Development Of A Large-Scale Laboratory Facility For Sediment Transport Research, David G. Hamilton, Bruce A. Ebersole, Ernest R. Smith, Ping Wang

Geology Faculty Publications

No abstract provided.

Influence Of The Earthquake Cycle And Lithospheric Rheology On The Dynamics Of The Eastern California Shear Ζone, R. Malservisi, K. Furlong, Timothy H. Dixon

School of Geosciences Faculty and Staff Publications

The Eastern California Shear Zone is bounded by the high heat flow region of the Basin and Range province and the low heat flow region of the Sierra Nevada block. This difference in thermal state influences the rheology of the lower crust/upper mantle, resulting in a viscosity contrast between the two regions. We analyze the effect of such a contrast on the kinematics and dynamics of the shear zone with numerical models. This viscosity contrast drives asymmetric strain accumulation in the upper crust, producing an asymmetric surface velocity field. An additional consequence of this strain pattern is the potential for …

Refined Kinematics Of The Eastern California Shear Zone From Gps Observations, 1993-1998, M. Meghan Miller, Daniel J. Johnson, Timothy H. Dixon, Roy K. Dokka

School of Geosciences Faculty and Staff Publications

Global Positioning System (GPS) results from networks spanning the Eastern California shear zone and adjacent Sierra Nevada block, occupied annually between 1993 and 1998, constrain plate margin kinematics. We use an elastic block model to relate GPS station velocities to long-term fault slip rate estimates. The model accounts for elastic strain accumulation on the San Andreas fault, as well as faults of the Eastern California shear zone. South of the Garlock fault, 14 mm/yr of dextral shear is distributed across the Eastern California shear zone. Some of this slip penetrates eastward into the Basin and Range, and a collective budget …

Longshore Sediment Transport As A Function Of Energy Dissipation, Ernest R. Smith, Ping Wang

Geology Faculty Publications

Experiments to measure waves, currents, and sediment transport rate for two breaker types, plunging and spilling, were conducted in a large-scale three-dimensional physical model. It was found that there was a large difference in cross-shore distribution and total sediment transport rate between the two breaker types. Total transport rates compared to existing predictive equations. The equations generally did not predict the data well. With the exception of the Kamphuis (1991) equation, which included a dependence on wave period, the predictive equations did not differentiate between breaker types.

Studies On The Cranial Osteology Of The Blind Catfish Horaglanis Krishnai Menon (Pisces, Clariidae), T. V. Anna Mercy, N. Krishna Pillai

International Journal of Speleology

Horaglanis krishnai Menon is a blind catfish inhabiting the dug- out wells at Kottayam, Kerala, South India. Studies on the cranial osteology of the fish show that the bones on the skull are firmly articulated. The frontoparietal fontanella is very large so that the cranium virtually lacks a roof. The sphenotics and alisphenoids are hardly recognizable and the orbital bones are entirely lacking. In osteological features H. krishnai closely resembles Uegitglanis zammaroni. But in H. krishnai the orbital bones are further reduced or even absent. The fontanella is larger than that of any other known catfish. These two species …

Studies On Certain Aspects Of Behaviour In The Blind Catfish Horaglanis Krishnai Menon, T. V. Anna Mercy, N. K. Pillai, N. K. Balasubramanian

International Journal of Speleology

Horaglanis krishnai is a blind catfish inhabiting the dug-out wells at Kottayam, Kerala. This fish has great zoogeographical importance as a similar blind clariid, Uegitglanis zammaroni is found only in the artesian wells of the former Italian Somaliland. Studies on certain behavioural aspects of the fish in captive conditions showed that, this fish even though is blind, exhibited a high degree of thigmotactism. Locomotion, comfort behaviour, feeding and light sensitivity of the fish were studied under laboratory conditions. Though the fish is totally blind and histological study did not reveal the presence of any light sensitive structures, the fish is …

The Distribution Of Plants In Scoska Cave, North Yorkshire, And Their Relationship To Light Intensity, Allan Pentecost, Zhang Zhaohui

International Journal of Speleology

The flora of a small limestone cave was investigated. A total of 59 species was recorded (4 algae, 3 lichens, 47 bryophytes, 4 ferns, 1 angiosperm) making it bryologically the richest cave in Britain and one of the richest in Europe. All but nine of the species had been recorded from other European caves. Species-richness declined irregullarly from the entrance (relative irradiance with respect to open sky 12%) to 34m depth (rel. irradiance 0.004%). Bryophytes were found at 0-16m depth where relative irradiance declined to 0.2% and only algae were encountered at 34m depth. While irradiance, which declined exponentially, was …

Classification Of Terrestrial Subterranean Fauna Of Volcanic Substrates In The Canary Islands, Josè L. Martín, Helga García, Y. P. Oromí

International Journal of Speleology

A system is proposed for classifying the species occurring in the hypogean environment in relation to their ecological and evolutionary characteristics. The ecological criteria utilized relate to the preferred habitat of the animals (the epigean, endogean or hypogean environment) and the evolutionary criteria specify the grade of adaptive modification in three characteristics: reduction of eyes, amount of pigmentation and extent of elongation of the appendages. The object of developing this classification is to provide a system appropriate for those regions - such as those with volcanic rocks - in which the cave faunas include elements originating in different environments, and …

Biogenic Speleothems: An Overview, Paolo Forti

International Journal of Speleology

The idea that speleothems may be somehow influenced by living organisms is rather old, but specific studies have only started in the last few decades and presently there are only a couple of systematic papers on this topic. The role of micro-organisms is perhaps the best investigated even if it is not fully understood, while studies over upper organisms and speleothems in a cavern environment are scarce and details are not always given on the involved genetic mechanisms. The aim of the present paper is to give an updated overview on these topics in order to enhance the interest of …

Deposition Of Calcium Carbonate In Karst Caves: Role Of Bacteria In Stiffe's Cave, Claudia Ercole, Paola Cacchio, Giorgio Cappuccio, Aldo Lepidi

International Journal of Speleology

Bacteria make a significant contribution to the accumulation of carbonate in severa! natural habitats where large amounts of carbonates are deposited. However, the role played by microbial communities in speleothem formation (stalactites, stalagmites etc.) in caves is still unclear. In bacteria carbonate is formed by autotrophic pathways, which deplete CO₂ from the environment, and by heterotrophic pathways, leading to active or passive precipitation. We isolated cultivable heterotrophic microbial strains, able to induce CaCO₃ precipitation in vitro, from samples taken from speleothems in the galleries of Stiffe’s cave, L’Aquila, Italy. We found a large number of bacteria in the …

Comparisons Of Gravity Anomalies At Pseudofaults, Fracture Zones, And Nontransform Discontinuities From Fast To Slow Spreading Areas, Sarah E. Kruse, Sarah F. Tebbens, David F. Naar, Qingyuan Y. Lou, Robert T. Bird

Geology Faculty Publications

Published mechanisms for rift tip propagation at spreading centers include extensional deformation and an initial period of slow spreading. We investigate whether the gravity signal and inferred crustal structure at pseudofaults formed in medium to superfast spreading environments resemble the gravity signal at fracture zones or nontransform discontinuities formed in slow spreading environments. We find that altimetry-based gravity anomalies on the Mathematician, Bauer, Easter, Juan Fernandez, and northern Chile Ridge pseudofaults, located in 75–150 mm/yr (full rate) seafloor spreading environments, are similar in amplitude and form to Atlantic fracture zones with 20–30 mm/yr spreading rates. A 5–15 mGal positive mantle …

Comparative Ecosystem Analysis Of Hydrologic Restoration Of Tates Hell Swamp, Chris Robert, Thomas Crisman, Loren Anderson, Carolyn Kendell

School of Geosciences Faculty and Staff Publications

No abstract provided.

Aseismic Inflation Of Westdahl Volcano, Alaska, Revealed By Satellite Radar Interferometry, Zhong Lu, Charles Wicks, Daniel Dzurisin, Wayne Thatcher, Jeffrey T. Freymuller, Stephen R. Mcnutt, Dorte Mann

School of Geosciences Faculty and Staff Publications

Westdahl volcano, located at the west end of Unimak Island in the central Aleutian volcanic arc, Alaska, is a broad shield that produced moderate-sized eruptions in 1964, 1978–79, and 1991–92. Satellite radar interferometry detected about 17 cm of volcano-wide inflation from September 1993 to October 1998. Multiple independent interferograms reveal that the deformation rate has not been steady; more inflation occurred from 1993 to 1995 than from 1995 to 1998. Numerical modeling indicates that a source located about 9 km beneath the center of the volcano inflated by about 0.05 km³ from 1993 to 1998. On the basis of the …

Application Of Wave-Theoretical Seismoacoustic Models To The Interpretation Of Explosion And Eruption Tremor Signals Radiated By Pavlof Volcano, Alaska, Milton A. Garces, Stephen R. Mcnutt, Roger A. Hansen, John C. Eichelberger

School of Geosciences Faculty and Staff Publications

Tremor and explosion signals recorded on September 29 during the Fall 1996 Pavlof eruption are interpreted using video images, field observations, and seismic data. Waveform analysis of tremor and explosions provided estimates of the melt's volcano-acoustic parameters and the magma conduit dimensions. Initial mass fractions of 0.25% water and 0.025% carbon dioxide in the melt can explain the resonance characteristics of the tremor and explosion pulses inferred from seismic data. The magma conduit is modeled as a three-section rectangular crack. We infer that the tremor-radiating region consists of the lowermost two sections, both with cross-sectional areas of ∼10 m^{2 …}

Present-Day Motion Of The Sierra Nevada Block And Some Tectonic Implications For The Basin And Range Province, North American Cordillera, Timothy H. Dixon, Meghan Miller, Frederic Farina, Hongzhi Wang, Daniel Johnson

School of Geosciences Faculty and Staff Publications

Global Positioning System (GPS) data from five sites on the stable interior of the Sierra Nevada block are inverted to describe its angular velocity relative to stable North America. The velocity data for the five sites fit the rigid block model with rms misfits of 0.3 mm/yr (north) and 0.8 mm/yr (east), smaller than independently estimated data uncertainty, indicating that the rigid block model is appropriate. The new Euler vector, 17.0°N, 137.3°W, rotation rate 0.28 degrees per million years, predicts that the block is translating to the northwest, nearly parallel to the plate motion direction, at 13–14 mm/yr, faster than …

Geologic Factors Controlling Patterns Of Small‐Volume Basaltic Volcanism: Application To A Volcanic Hazards Assessment At Yucca Mountain, Nevada, Charles B. Connor, John A. Stamatakos, David A. Ferrill, Brittain E. Hill, Goodluck I. Ofoegbu, Michael Conway, Budhi Sagar, John Trapp

School of Geosciences Faculty and Staff Publications

The proposed high‐level radioactive waste repository at Yucca Mountain, Nevada, is located within an active volcanic field. Probabilistic volcanic hazard models for future eruptions through the proposed repository depend heavily on our understanding of the spatial controls on volcano distribution at a variety of scales. On regional scales, Pliocene‐Quaternary volcano clusters are located east of the Bare Mountain fault. Extension has resulted in large‐scale crustal density contrast across the fault, and vents are restricted to low‐density areas of the hanging wall. Finite element modeling indicates that this crustal density contrast can result in transient pressure changes of up to 7 …

Gps Geodetic Constraints On Caribbean-North America Plate Motion, Charles Demets, Pamela E. Jansma, Glen S. Mattioli, Timothy H. Dixon, Fred Farina, Roger Bilham, Eric Calais, Paul Mann

School of Geosciences Faculty and Staff Publications

We describe a model for Caribbean plate motion based on GPS velocities of four sites in the plate interior and two azimuths of the Swan Islands transform fault. The data are well fit by a single angular velocity, with average misfits approximately equal to the 1.5–3.0 mm yr⁻¹ velocity uncertainties. The new model predicts Caribbean-North America motion ∼65% faster than predicted by NUVEL-1A, averaging 18–20±3 mm yr⁻¹ (2σ) at various locations along the plate boundary. The data are best fit by a rotation pole that predicts obliquely convergent motion along the plate boundary east of Cuba, but are …

Neotectonics Of Puerto Rico And The Virgin Islands, Northeastern Caribbean, From Gps Geodesy, Pamela E. Jansma, Glen S. Mattioli, Alberto Lopez, Charles Demets, Timothy H. Dixon, Paul Mann, Eric Calais

School of Geosciences Faculty and Staff Publications

The boundary between the North American and Caribbean plates is characterized primarily by left-lateral motion along predominantly east-west striking faults. Seismicity and marine geophysical survey data are consistent with at least two, and possibly three, microplates in the diffuse boundary zone in the northeastern Caribbean: (1) the Gonave, (2) the Hispaniola, and (3) the Puerto Rico-northern Virgin Islands (PRVI). We discuss results from GPS geodetic measurements acquired since 1994 to test the microplate hypothesis, define PRVI translation and rotation within the boundary zone, and constrain PRVI neotectonics. GPS-derived velocities are analyzed with respect to both North American and Caribbean plate …

New Rare Cave Minerals From The Perolas-Santana Karst System (São Paulo State, Brazil), Paolo Forti, Ermanno Galli, Antonio Rossi

International Journal of Speleology

The Perolas-Santana karst system (São Paulo State, Brazil) has been partially studied from the mineralogical point of view. The present paper will contribute to the knowledge of the minerals in these caves, describing the occurrence of euhedral celestite crystals and of a rather rare mineral for a cavern environment: lithiophorite. Thanks to these new discoveries the Perolas-Santana karst system becomes one of the most important in Brazil from a mineralogical point of view. Finally, the result of the chemical analyses carried out on this newly discovered Monoxyhydroxide put in evidence a zonation in the distribution of the different elements which …

Verification Of The Causes Of Glaciations And Sea Level Changes Using The Records Of Calcite Speleothems, Y. Shopov, D. Stoykova, L. Tsankov, M. Sanabria, J. Lundberg, L. Georgiev, P. Forti, D. Georgieva

International Journal of Speleology

The luminescence of calcite speleothems displays an exponential dependence on soil temperature unless there is a dense cover of forest over the cave to dampen it. This relationship is determined primarily by the strength of solar visible and infrared radiation. It is suggested that, as a consequence, the microzonal variations of luminescence often found in speleothems can be used as a proxy index of Solar Insolation. The luminescence solar insolation proxy record of a speleothem from Jewel Cave, South Dakota, USA, was found to display millenial and centennial cycles in the record. It exhibits a rapid increase in solar insolation …

Révision De Quelques Hypothèses Sur Le Creusement Karstique, Jacques Choppy

International Journal of Speleology

Quite often, as we know better karst phenomena and the evolution of the karst environment, several hypotheses on speleogenesis appeared to be flimsy. Some of these hypotheses, concerning processes playing a part in the creation of karst forms, exceed the limits of their field. Others suggest hydraulic mechanisms, and interventions of geological or geographical factors likely to be questioned. Hypotheses relating to the evolution of karst, as well as the classification of karst types, suffer from the lack of an analytical approach. However, some of these hypotheses still have an important place in the current vision of speleologists and karstologists.

Development, Management And Economy Of Show Caves, Arrigo A. Cigna, Ezio Burri

International Journal of Speleology

The problems concerning the development of show caves are here considered by taking into account different aspects of the problem. A procedure to carry out an Environmental Impact Assessment (EIA) has been established in the last decade and it is now currently applied. Such an assessment starts with a pre-operational phase to obtain sufficient information on the undisturbed status of a cave to be developed into a show cave. Successively a programme for its development is established with the scope to optimise the intervention on the cave at the condition that its basic environmental parameters are not irreversibly modified. The …

The Influence Of Cave Tourism On Co2 And Temperature In Baiyun Cave, Hebei, China, Linhua Song, Wei Xiaoning, Liang Fuyuan

International Journal of Speleology

Baiyun Cave in Hebei Province is one of the main show caves in North China. The speleothem landscape is wonderful, but strongly weathered. In order to set up the relationship between visitor flow and CO₂ content and temperature, these parameters were measured at observation sites No. 1 and No. 2 in the tourist peak period of May Day Holiday from May 1 to May 7, 2000. and general tourist season August and October, 2000. The results show that visitor flow strongly affects the fluctuations of cave CO₂ content and temperature, that the cave topography and dimensions affect the …

Is It Always Dark In Caves?, Giovanni Badino

International Journal of Speleology

Underground natural sources of visible light are considered. The main light producer is Cerenkov radiation emitted in air, water and rock by cosmic ray muons, that depends, in a complex way, on shape of mountain and of caves. In general the illumination increases linearly with the cavity dimensions. Other light sources are from secondary processes generated by radioactive decays in rock from minerals luminescence. The natural light fluxes in caves are in general easy to detect but are not used from underground life.

Studying The Importance Of Hurricanes To The Northern Gulf Of Mexico Coast, Gregory W. Stone, Ping Wang, David A. Pepper, J. M. Grymes Iii, Harry H. Roberts, Xiongping Zhang, S. A. Hsu, Oscar K. Huh

Geology Faculty Publications

A pilot study was recently begun dealing with the impacts and post-storm adjustment of barrier islands to severe storms along the northern Gulf of Mexico. The study, funded by the National Science Foundation, may lead to a more comprehensive understanding of coastal morphodynamics and longer term evolution of the coast in that area. Study of the recent impacts and post-storm adjustment of the area to Hurricane Georges is playing a very important role in enhancing our comprehension of the significance of these high-energy events in coastal dynamics.

A few hours before dawn on September 28, 1998, Hurricane Georges made landfall …

Noise In Gps Coordinate Time Series, Ailin Mao, Christopher G.A. Harrison, Timothy H. Dixon

School of Geosciences Faculty and Staff Publications

We assess the noise characteristics in time series of daily position estimates for 23 globally distributed Global Positioning System (GPS) stations with 3 years of data, using spectral analysis and Maximum Likelihood Estimation. A combination of white noise and flicker noise appears to be the best model for the noise characteristics of all three position components. Both white and flicker noise amplitudes are smallest in the north component and largest in the vertical component. The white noise part of the vertical component is higher for tropical stations (±23° latitude) compared to midlatitude stations. Velocity error in a GPS coordinate time …

Sustainable Development Of Agriculture In Karst Areas, South China, Linhua Song

International Journal of Speleology

The exposed carbonate rocks aged from Sinian to Mid-Triassic Periods cover an area of 500,000 km² in south-west China. In karst areas with spectacular landscapes characterized by magnificent tower karst and conical karst, rare surface drainage systems and prevalent subsurface drainage systems, the environment is ecologically very fragile. The rapid increase of population, over deforested and cultivated lands, worsted the ecological system, causing a higher frequency of draught, flood and various disasters, backward economic development, low living standard of the people. In order to improve the sustainability of the agriculture the experience shows that the following operations should be …