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Articles 1291 - 1320 of 1880

Full-Text Articles in Earth Sciences

Exploring Links Between Physical And Probabilistic Models Of Volcanic Eruptions: The Soufriere Hills Volcano, Montserrat, Charles B. Connor, R. S. J. Sparks, R. M. Mason, Costanza Bonadonna, S. R. Young Jul 2003

Exploring Links Between Physical And Probabilistic Models Of Volcanic Eruptions: The Soufriere Hills Volcano, Montserrat, Charles B. Connor, R. S. J. Sparks, R. M. Mason, Costanza Bonadonna, S. R. Young

Geology Faculty Publications

Probabilistic methods play an increasingly important role in volcanic hazards forecasts. Here we show that a probability distribution characterized by competing processes provides an excellent statistical fit (>99% confidence) to repose intervals between 75 vulcanian explosions of Soufrière Hills Volcano, Montserrat in September–October, 1997. The excellent fit is explained by a physical model in which there are competing processes operating in the upper volcano conduit on different time scales: pressurization due to rheological stiffening and gas exsolution, and depressurization due to development of permeability and gas escape. Our experience with the Soufrière Hills Volcano eruption sequence suggests that volcanic …

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Hydrogeologic Principles Useful In Predicting The Effects Of Stream Flow Alterations On Shallow Groundwater And Associated Riparian Vegetation, Mark Cable Rains Jul 2003

Hydrogeologic Principles Useful In Predicting The Effects Of Stream Flow Alterations On Shallow Groundwater And Associated Riparian Vegetation, Mark Cable Rains

Geology Faculty Publications

Numerous studies have shown that stream water and shallow groundwater are tightly linked in alluvial settings, and that changes in stream stage are propagated rapidly across alluvial aquifers (Castro and Hornberger 1991, Sophocleous 1991). Thus, many researchers have assumed that stream stages approximate water tables in alluvial aquifers (Auble et al. 1994, Stromberg and Patten 1996). This assumption is valid in some cases but invalid in other cases, particularly in arid basin terrain and more humid mountain terrain. Even when this assumption is valid, this relationship only implies correlation and not causation so the potential effects of stream flow alterations …

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Holocene Slip Rate Of The Wasatch Fault Zone, Utah, From Geodetic Data: Earthquake Cycle Effects, Rocco Malservisi, Timothy H. Dixon, Peter C. Lafemina, Kevin P. Furlong Jul 2003

Holocene Slip Rate Of The Wasatch Fault Zone, Utah, From Geodetic Data: Earthquake Cycle Effects, Rocco Malservisi, Timothy H. Dixon, Peter C. Lafemina, Kevin P. Furlong

School of Geosciences Faculty and Staff Publications

GPS data define a broad zone of present day deformation in the eastern Basin and Range province, western US. Using finite element models with elastic upper crust over viscoelastic lower crust/upper mantle and incorporating earthquake cycle effects, we show that these data are consistent with a model whereby most contemporary fault slip is focused on the Wasatch fault zone. Modeled rates of horizontal extension are 3.0–4.5 mm/yr, in agreement with Holocene geologic data. The models are non-unique, in part because much of the Wasatch fault is in the late stages of the earthquake cycle, when surface velocity gradients across the …

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Earthscoping The Inner Workings Of Magmatic Systems, Michael Hamburger, Stephen R. Mcnutt, Daniel Dzurisin, Jonathan Fink, David P. Hill, Charles Meertens, Chris Newhall, Susan Owen, John A. Power Jun 2003

Earthscoping The Inner Workings Of Magmatic Systems, Michael Hamburger, Stephen R. Mcnutt, Daniel Dzurisin, Jonathan Fink, David P. Hill, Charles Meertens, Chris Newhall, Susan Owen, John A. Power

School of Geosciences Faculty and Staff Publications

In the shadow of one of the world's great volcanic systems, an intensive 3‐day workshop was undertaken to work toward developing a scientific plan for the magmatic systems component of the U.S. National Science Foundation's (NSF) EarthScope Initiative. This NSF‐sponsored workshop was designed to provide direction to the EarthScope planning committee and the NSF in developing scientific, technical, deployment, and management decisions related to the magmatic systems component of EarthScope. The meeting featured a mixture of oral and poster scientific sessions, breakout group and plenary discussions, and a field trip to examine one of the targets of the EarthScope magmatic …

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Melting Processes And Fluid And Sediment Transport Rates Along The Alaska-Aleutian Arc From An Integrated U-Th-Ra-Be Isotope Study, Rhiannon George, Simon Turner, Chris Hawkesworth, Julie Morris, Chris Nye, Jeffrey G. Ryan, Shu-Hui Zheng May 2003

Melting Processes And Fluid And Sediment Transport Rates Along The Alaska-Aleutian Arc From An Integrated U-Th-Ra-Be Isotope Study, Rhiannon George, Simon Turner, Chris Hawkesworth, Julie Morris, Chris Nye, Jeffrey G. Ryan, Shu-Hui Zheng

Geology Faculty Publications

A comprehensive data set for young lavas erupted along the Alaska-Aleutian arc is used to examine how fluid and sediment transport rates and melting processes vary in response to systematic changes in subduction rate and dip along the arc and across the ocean-continent boundary. Positive correlations between convergence rate, volcano volume, and 238U excesses suggest that magmatic output is closely linked to the size of the fluid flux which occurred <10 kyr prior to eruption. Sediment-sensitive tracers like Th/Nb, Ce/Ce*, and 10Be/9Be also increase with convergence rate. However, the inferred 10Be/9Be ratio of this component is low relative to that in the incoming sediments, …

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City Of Gainesville Basin Planning Initiative: A Report With Recommendations, Jen Larson, Kelly Marrinson, Josh Muller, Keven Regan, Thomas Ankersen, Thomas Crisman, Mark Clark Mar 2003

City Of Gainesville Basin Planning Initiative: A Report With Recommendations, Jen Larson, Kelly Marrinson, Josh Muller, Keven Regan, Thomas Ankersen, Thomas Crisman, Mark Clark

School of Geosciences Faculty and Staff Publications

No abstract provided.

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The Duration-Amplitude Distribution Of Volcanic Tremor, John P. Benoit, Stephen R. Mcnutt, Vilma Barboza Mar 2003

The Duration-Amplitude Distribution Of Volcanic Tremor, John P. Benoit, Stephen R. Mcnutt, Vilma Barboza

School of Geosciences Faculty and Staff Publications

The duration-amplitude distribution of volcanic tremor was examined in eight volcanoes and one geothermal area. An exponential model, implying a scale-bound source process, is found to be a better fit to the data than a power law (scale invariant) model. The exponential model well describes tremor associated with magmatic and phreatic eruptions, shallow and deep source regions, and geothermal sources. We tested the exponential model described by: , where d is the duration of tremor greater than or equal to a particular amplitude DR, dt is the total duration of tremor, and the inverse of λ is …

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Beach Profile Evolution Under Plunging And Spilling Breakers, Ping Wang, Bruce A. Ebersole, Ernest R. Smith Jan 2003

Beach Profile Evolution Under Plunging And Spilling Breakers, Ping Wang, Bruce A. Ebersole, Ernest R. Smith

Geology Faculty Publications

Beach-profile evolution, along with measurements of waves, currents, and sediment concentration, under spilling and plunging breakers of similar height were studied in the three-dimensional Large-Scale Sediment Transport Facility at the U.S. Army Engineer Research and Development Center. Unidirectional irregular waves were generated over a fine-sand beach. Beach-profile shape reached equilibrium after 1,330 and 280 min of spilling and plunging wave actions, respectively. Near the main breaker line, the profile evolved differently under plunging and spilling breakers. Across most of the midsurf zone dominated by surf bores, the equilibrium profile shapes were similar. Uniform energy dissipation per unit volume at equilibrium, …

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Evaluation Of The Cerc Formula Using Large-Scale Laboratory Data, Ernest R. Smith, Ping Wang, Jun Zhang Jan 2003

Evaluation Of The Cerc Formula Using Large-Scale Laboratory Data, Ernest R. Smith, Ping Wang, Jun Zhang

Geology Faculty Publications

Longshore transport experiments were conducted in a large-scale physical model to evaluate predictions of the CERC formula with measured longshore sediment transport rates. It was found that the CERC formula produced reasonable estimates if the coefficient K was calibrated and applied to waves with similar breaker type. The calibrated K values are much smaller than values that are commonly used, and there appears to be a strong dependency of transport rate on breaker type. Additional comparisons were made with the formula proposed by Kamphuis (1991). The Kamphuis equation, which includes wave period, a factor that influences breaking, gave good estimates. …

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Minerogenesis Of Volcanic Caves Of Kenya, Paolo Forti, Ermanno Galli, Antonio Rossi Jan 2003

Minerogenesis Of Volcanic Caves Of Kenya, Paolo Forti, Ermanno Galli, Antonio Rossi

International Journal of Speleology

Kenya is one of the few countries in which karst cavities are scarce with respect to volcanic ones, which are widespread throughout the whole country. The great variability in lava composition allowed the evolution of very different cavities, some of which are amongst the largest lava tubes of the world. As normal for such a kind of cave, the hosted speleothems and cave minerals are scarce but important from the minerogenetic point of view. Anyway up to present no specific mineralogical research have been carried out therein. During the 8th International Symposium on Volcanospeleology, held in Nairobi in February 1998, …

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Caves And Karsts Of Northeast Africa, William R. Halliday Jan 2003

Caves And Karsts Of Northeast Africa, William R. Halliday

International Journal of Speleology

At least potentially karstifiable rocks cover much of the surface of Egypt and northern Libya. Study of caves and other karstic features of this region has been hampered by lack of roads, rapid disintegration of the surface of friable, poorly consolidated limestone, wind-blown sand and other factors. Interbedding with marly aquicludes hampers speleogenesis locally. Calcareous and evaporite karsts are present, however, and their waters are important albeit generally limited resources. Large quantities of fresh water are lost through submarine springs downslope from Libya’s Gebel al Akhdar range; the caves and karst of that range may be among the world’s greatest. …

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Contribution To The Speleology Of Sterkfontein Cave, Gauteng Province, South Africa, J. E. J. Martini, P. E. Wipplinger, H. F. G. Moen, A. Keyser Jan 2003

Contribution To The Speleology Of Sterkfontein Cave, Gauteng Province, South Africa, J. E. J. Martini, P. E. Wipplinger, H. F. G. Moen, A. Keyser

International Journal of Speleology

The authors present more data about the speleological aspect of the Sterkfontein Cave, famous for its bone breccia which yielded abundant hominid remains. They also briefly review the previous voluminous studies by numerous authors, which are mainly dealing with the paleontology, stratigraphy and sedimentology of the breccia. The present investigations were oriented to hitherto poorly investigated aspects such as detail mapping of the cave, its country rock stratigraphy and recording the underground extension of the basal part of the breccia body. The cave consists of a complex network of phreatic channels, developed along joints in Neoarchaean cherty dolostone over a …

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Human Impact On Karst: The Example Of Lusaka (Zambia), Jo De Waele, Roberto Follesa Jan 2003

Human Impact On Karst: The Example Of Lusaka (Zambia), Jo De Waele, Roberto Follesa

International Journal of Speleology

Lusaka, the capital of Zambia with over 2,000,000 inhabitants, is built on an extensive plateau composed mainly of schists and dolomitic marbles, constituting a very important aquifer that provides the city with almost half of its drinking water needs. Recent demographic growth, leading to uncontrolled urban expansion, and mismanagement of the water resource and of urban waste has lead, in the past 20 years, to an overexploitation of the aquifer and to a generalised water quality depletion, putting in serious danger the future social and economical development of the capital. This third world city has, for these reasons, become a …

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Tree-Mould Caves In Slovakia, Ludovít Gaál Jan 2003

Tree-Mould Caves In Slovakia, Ludovít Gaál

International Journal of Speleology

Four tube-shaped caves are described in this work, which origined in consequence of weathering the trees. Their length ranges from 5.8 to 17 m. All of them occur in neovolcanic rocks of Middle Slovakia, in epiclastic andesite conglomerates, breccias or in the tuffs. Some other caverns are close to the entrance of this caves, however they are inaccessible for a man. Thin rim of silicates (opal or chalcedony) occurs in some of them.

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Martel's Routes In Mammoth Cave, Kentucky, 1912, Trevor R. Shaw Jan 2003

Martel's Routes In Mammoth Cave, Kentucky, 1912, Trevor R. Shaw

International Journal of Speleology

Martel’s own copy of the Hovey 1912 guidebook to Mammoth Cave has his routes marked faintly in pencil on the printed cave plans. These plans are reproduced here, with his routes indicated on them. He generally followed the four standard tourist routes which now included Kaemper’s 1908 discoveries to Violet City, but instead of visiting the Maelstrom he went to Hovey’s Cathedral and Gerta’s Grotto.

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Littoral Dripstone And Flowstone--Non-Spelean Carbonate Secondary Deposits, Danko Taborosi, Kevin Stafford Jan 2003

Littoral Dripstone And Flowstone--Non-Spelean Carbonate Secondary Deposits, Danko Taborosi, Kevin Stafford

International Journal of Speleology

Speleothem-like dripstone and flowstone deposits can form in the non-spelean environments of marine notches on tropical carbonate coastlines. Hereby termed “littoral dripstone” and “littoral flowstone” to distinguish them from genuine cave deposits, they reflect the basic speleothem types: draperies, stalactites, stalagmites, and columns. Nevertheless, these formations lack the luster and crystallinity of cave analogues, and are not nearly as well-developed, dense, and massive. They are composed of layered microcrystalline aragonite and calcite, are generally highly porous, and invariably overlie dissolutional and bioerosional karren. Because true speleothems, often found in the remnants of solution voids breached by coastal erosion, are also …

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Seismic Cycle And Rheological Effects On Estimation Of Present-Day Slip Rates For The Agua Blanca And San Miguel-Vallecitos Faults, Northern Baja California, Mexico, Timothy H. Dixon, J. Decaix, F. Farina, K. Furlong, Rocco Malservisi Oct 2002

Seismic Cycle And Rheological Effects On Estimation Of Present-Day Slip Rates For The Agua Blanca And San Miguel-Vallecitos Faults, Northern Baja California, Mexico, Timothy H. Dixon, J. Decaix, F. Farina, K. Furlong, Rocco Malservisi

School of Geosciences Faculty and Staff Publications

Geodesy can be used to infer long‐term fault slip rates, assuming a model for crust and upper mantle rheology. We examine the sensitivity of fault slip rate estimates to assumed rheology for the Agua Blanca and San Miguel‐Vallecitos faults in northern Baja California, Mexico, part of the Pacific–North America plate boundary zone. The Agua Blanca fault is seismically quiet, but offset alluvial fans indicate young activity. Current seismicity is confined to the nearby San Miguel‐Vallecitos fault, a small offset fault better aligned with plate motion. GPS measurements between 1993 and 1998 suggest that both faults are active, with a combined …

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Seismotectonics Of The Explorer Region, Jochen Braunmiller, John Nábělek Oct 2002

Seismotectonics Of The Explorer Region, Jochen Braunmiller, John Nábělek

School of Geosciences Faculty and Staff Publications

The Explorer region offshore western Canada is a tectonically complex area surrounded by the Pacific, North America, and Juan de Fuca plates. Existing tectonic models for the region differ fundamentally. Proposed plate configurations range from multiple independent plate fragments to an Explorer plate now fused to North America along the continental margin and cut by Pacific–North America transform faults in the west. We present new seismological data constraining the region's current tectonics. We use three-component regional waveforms to determine the source parameters of 84 earthquakes with magnitude greater than 4. Combined with 34 Harvard centroid moment tensor solutions, they represent …

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Satellite Imagery Proves Essential For Monitoring Erupting Aleutian Volcano, Kenneson Dean, Jonathan Dehn, Stephen R. Mcnutt, Christina Neal, Richard Moore, Dave Schneider May 2002

Satellite Imagery Proves Essential For Monitoring Erupting Aleutian Volcano, Kenneson Dean, Jonathan Dehn, Stephen R. Mcnutt, Christina Neal, Richard Moore, Dave Schneider

School of Geosciences Faculty and Staff Publications

Mt. Cleveland is one of more than 40 active volcanoes in Alaska that is monitored by the Alaska Volcano Observatory (AVO). It is located on the western half of Chuginadak, a remote and uninhabited island in the east central Aleutians that lies 1526 km southwest of Anchorage. The closest inhabited community, Nikolski, is 75 km to the east on Umnak Island (Figure 1). Mt. Cleveland erupted explosively on 19 February and on 11 and 19 March 2001. Because the volcano is not yet monitored with seismic, deformation, or other geophysical instruments, satellite imagery was the only effective tool for detecting …

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Consistency Of Geologic And Geodetic Displacements During Andean Orogenesis, David Hindle, Jonas Kley, Eryn Klosko, Seth Klosko, Timothy H. Dixon, Edmundo Norabuena Apr 2002

Consistency Of Geologic And Geodetic Displacements During Andean Orogenesis, David Hindle, Jonas Kley, Eryn Klosko, Seth Klosko, Timothy H. Dixon, Edmundo Norabuena

School of Geosciences Faculty and Staff Publications

Present-day displacements within the Central Andes are being measured using high precision GPS geodesy. Until now, comparison of such ground motions within deforming plate boundary zones to those on a geologic time scale has not been possible due to lack of sufficient geological data. In the Central Andes, a comparable dataset for the past 25 Ma of mountain building can be reconstructed. Here, we use new interpretations of shortening rates averaged over 25–10 Ma and 10 Ma–present and find that whilst displacement directions have remained virtually constant and parallel, an acceleration has occurred synchronously with a slowing of convergence between …

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Revel: A Model For Recent Plate Velocities From Space Geodesy, Giovanni F. Sella, Timothy H. Dixon, Ailin Mao Apr 2002

Revel: A Model For Recent Plate Velocities From Space Geodesy, Giovanni F. Sella, Timothy H. Dixon, Ailin Mao

School of Geosciences Faculty and Staff Publications

We present a new global model for Recent plate velocities, REVEL, describing the relative velocities of 19 plates and continental blocks. The model is derived from publicly available space geodetic (primarily GPS) data for the period 1993–2000. We include an independent and rigorous estimate for GPS velocity uncertainties to assess plate rigidity and propagate these uncertainties to the velocity estimates. The velocity fields for North America, Eurasia, and Antarctica clearly show the effects of glacial isostatic adjustment, and Australia appears to depart from rigid plate behavior in a manner consistent with the mapped intraplate stress field. Two thirds of tested …

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Longshore Sand Transport – Initial Results From The Large-Scale Sediment Transport Facility, Ping Wang, Bruce A. Ebersole, Ernest R. Smith Mar 2002

Longshore Sand Transport – Initial Results From The Large-Scale Sediment Transport Facility, Ping Wang, Bruce A. Ebersole, Ernest R. Smith

Geology Faculty Publications

Accurate predictions of the total rate of longshore sand transport (LST) and its cross-shore distribution pattern in the surf zone are central to many coastal engineering studies. Present understanding and methods for calculating the LST rate are largely developed based on field studies (e.g., Komar and Inman 1970; Inman et al. 1981; Kraus et al. 1982; Bodge and Dean 1987a, b; Dean 1989; Schoonees and Theron 1993; Miller 1998; Wang, Kraus, and Davis 1998; Wang 1998; Wang and Kraus 1999; Miller 1999). The Coastal Engineering Research Center (CERC) formula (Shore Protection Manual 1984), which is based on field measurements, is …

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Mechanisms Of Karst Breakdown Formation In The Gypsum Karst Of The Fore-Ural Region, Russia (From Observations In The Kungurskaja Cave), Vjacheslav Andrejchuk, Alexander Klimchouk Jan 2002

Mechanisms Of Karst Breakdown Formation In The Gypsum Karst Of The Fore-Ural Region, Russia (From Observations In The Kungurskaja Cave), Vjacheslav Andrejchuk, Alexander Klimchouk

International Journal of Speleology

The fore-Ural is a classical region of intrastratal gypsum karst. The intensive development of karst in the Permian gypsums and anhydrites causes numerous practical problems, the subsidence hazard being the most severe. Mechanisms of karst breakdown formation were studied in detail in the Kunguskaya Cave area. The cave and its setting are characteristic to the region and, being a site of detalied stationary studies for many years, the cave represents a convenient location for various karst and speleological investigations. Breakdown structures related to cavities of the Kungurskaya Cave type develop by two mechanisms: gravitational (sagging and fall-in of the ceilings …

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Cave Breakdown By Vadose Weathering, R. A. L. Osborne Jan 2002

Cave Breakdown By Vadose Weathering, R. A. L. Osborne

International Journal of Speleology

Vadose weathering is a significant mechanism for initiating breakdown in caves. Vadose weathering of ore bodies, mineral veins, palaeokarst deposits, non-carbonate keystones and impure, altered or fractured bedrock, which is intersected by caves, will frequently result in breakdown. Breakdown is an active, ongoing process. Breakdown occurs throughout the vadose zone, and is not restricted to large diameter passages, or to cave ceilings. The surfaces of disarticulated blocks are commonly coated, rather than having fresh broken faces, and blocks continue to disintegrate after separating from the bedrock. Not only gypsum, but also hydromagnesite and aragonite are responsible for crystal wedging. It …

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Subsidence Hazards In Different Types Of Karst: Evolutionary And Speleogenetic Approach, Alexander Klimchouk Jan 2002

Subsidence Hazards In Different Types Of Karst: Evolutionary And Speleogenetic Approach, Alexander Klimchouk

International Journal of Speleology

The typology of karst, based on distinguishing the successive stages of general hydrogeological evolution, between which major boundary conditions and the overall circulation pattern change considerably, gives a natural clue, properly to classify and tie together karst breakdown settings, speleogenetic styles and breakdown development mechanisms. Subsidence hazards vary substantially between the different karst types so that classifying individual karst according to typology can provide an integrated general assessment. This provides a useful basis for selection and realization of region- and site-specific assessment schemes and management strategies. Intrastratal karst types, subjacent karst in particular, are most potent in generating subsidence problems. …

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The Engineering Classification Of Karst With Respect To The Role And Influence Of Caves, Tony Waltham Jan 2002

The Engineering Classification Of Karst With Respect To The Role And Influence Of Caves, Tony Waltham

International Journal of Speleology

The engineering classification of karst defines various complexities of ground conditions, in terms of the hazards that they provide to potential construction. Karst is divided into five classes (from immature to extreme). The three key parameters within the classification are caves (size and extent), sinkholes (abundance and collapse frequency) and rockhead (profile and relief). As one component of karst, caves are a hazard to foundation integrity, though natural surface collapses over caves are extremely rare. A cave roof is normally stable under engineering loading where the roof thickness is greater than 70% of the cave width. Construction can proceed over …

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Karst Breakdown Mechanisms From Observations In The Gypsum Caves Of The Western Ukraine: Implications For Subsidence Hazard Assessment, Alexander Klimchouk, Vjacheslav Andrejchuk Jan 2002

Karst Breakdown Mechanisms From Observations In The Gypsum Caves Of The Western Ukraine: Implications For Subsidence Hazard Assessment, Alexander Klimchouk, Vjacheslav Andrejchuk

International Journal of Speleology

The term karst breakdown is employed in this paper to denote the totality of processes and phenomena of gravitational and/or hydrodynamic destruction of the ceiling of a karst cavity and of the overlying sediments. It refers not only to the existence of a surface subsidence (collapse) feature but, first of all, to the “internal” (hidden in the subsurface) structures that precede development of a surface form. This study reports and discusses the results of direct mapping and examination of breakdown structures in the gypsum karst of the Western Ukraine, at the level of their origin, i.e. in caves. The accessibility …

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Collapse Dolines And Deflector Faults As Indicators Of Karst Flow Corridors, France Šušteršič Jan 2002

Collapse Dolines And Deflector Faults As Indicators Of Karst Flow Corridors, France Šušteršič

International Journal of Speleology

The paper concerns collapse dolines, which appear to be one of the best-defined surface karst phenomena. Despite this appearance, one may find quite different views in the literature, and some of the aspects of their morphogenesis have been overlooked completely. Among these aspects the most obvious is the question of the ongoing development of the closed depression. Five of the most common collapse doline types found in Slovenia are considered in terms of general systems theory, leading to a conclusion that cave roof collapse remains the crucial event in a collapse doline’s development. However, the collapse event itself may be …

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Stability Appraisal Of The Medvedova Konta Pothole, Jože Kortnik Jan 2002

Stability Appraisal Of The Medvedova Konta Pothole, Jože Kortnik

International Journal of Speleology

Until 1956 the underground details of areas around Pokljuka were practically unknown due to the area’s non-karstic outward appearance. However, the presence of karst phenomena on this Alpine plain is undoubtedly indicated, primarily by the absence of a surface drainage network. A mathematical model was made of the Medvedova konta pothole, in which two different sets of material properties were used, corresponding to the Triassic limestone that forms the bedrock under the greater part of Pokljuka. The model simulates the gradual thinning of the ceiling of the underground hall, from the surface downwards, until its collapse. The paper presents a …

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Collapse Above The World's Largest Potash Mine (Ural, Russia), Vjacheslav Andrejchuk Jan 2002

Collapse Above The World's Largest Potash Mine (Ural, Russia), Vjacheslav Andrejchuk

International Journal of Speleology

This paper reports the results of the study of a huge collapse that occurred in June 1986 within the area of the 3rd Berezniki potash mine (the Verkhnekamsky potash deposit, Ural). Processes that took place between the first appearance of a water inflow through the mine roof and the eventual collapse are reconstructed in detail. The origin and development of a cavity that induced the collapse are revealed. Two factors played a major role in the formation of the collapse: the presence of a tectonic fold/rupture zone with in both the salt sequence and the overburden (the zone of crush …

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