Community news

Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

Did you know?

That arete and pinnacle karst is a landscape of naked reticulated raw-topped ridges having almost vertical slopes and a relief of as much as 120 meters. the ridges rise above forest- covered corridors and depressions. found in new guinea at elevations of 2,000 meters and more [10]. both pinnacle karst and arete karst are varieties of limestone landscape formed under equatorial rain forest cover. they are characterized by vertical sided blades of bare rock fretted by dissolution [9].?

Checkout all 2699 terms in the KarstBase Glossary of Karst and Cave Terms

What is Karstbase?

Search KARSTBASE:

keyword
author

Browse Speleogenesis Issues:

KarstBase a bibliography database in karst and cave science.

Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
See all featured articles
Featured articles from other Geoscience Journals
Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
Microbial mediation of complex subterranean mineral structures, Tirato, Nicola; Torriano, Stefano F.F;, Monteux, Sylvain; Sauro, Francesco; De Waele, Jo; Lavagna, Maria Luisa; D’Angeli, Ilenia Maria; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso Renzo Rezio
Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), Briestensky, Milos; Rowberry, Matt; Stemberk, Josef; Stefanov, Petar; Vozar, Jozef; Sebela, Stanka; Petro, Lubomir; Bella, Pavel; Gaal, Ludovit; Ormukov, Cholponbek;
See all featured articles from other geoscience journals

Search in KarstBase

Your search for earthquake (Keyword) returned 43 results for the whole karstbase:
Showing 31 to 43 of 43
Direct measurement of present-day tectonic movement and associated radon flux in Postojna Cave, Slovenia, 2010, Sebela, S. , Vaupotic, J. , Kostak B. , Stemberk, J.
Micro-tectonic deformations have been monitored continuously in 3D in Postojna Cave, Slovenia with TM 71 extensometers since 2004. Two instruments, 260 m apart, were installed on the Dinaric oriented (NW-SE) fault zone that is situated about 1,000 m north of the inner zone of the regionally important Predjama Fault.Monitoring on both instruments has shown small tectonic movements (i.e., a general dextral horizontal movement of 0.05 mm in four years [Postojna 1] and extension of 0.03 mm in fouryears [Postojna 2]). Between the longer or shorter calm periods, eleven extremeshavebeen recorded regarding characteristic changes in displacement. The largest short-term movement was a compression of 0.04 mm in seven days, detected in March 2005, which coincided with the 25 km distant Ilirska Bistrica earthquake (ML 5 3.9). About twomonths before the earthquake an extension of 0.05 mm occurred and one month before the earthquake the strain changed into a compression of 0.05 mm. The largest permanent peak was detected at the end of 2004. Along the y-axis (Postojna 1) there was a dextral horizontal movement of 0.075 mm in one month (November 10 to December 15, 2004). After the sinistral horizontal movement of 0.02 mm (December 1527, 2004), the y-axis retained its permanent position on 0.05 mm, where it remained for more than a year. Regarding the extremes, ten earthquakes were selected that coincided with tectonic micro-displacements. In terms of speleogenesis, the monitored fault zone represents a stable cave environment. Because radon flux is known to change significantly during tectonic and seismic activities, radon air concentrations were monitored in parallel since 2006. During horizontal movements, either dextral or sinistral, radon pathways underground were partly closed, thus hindering radon migration and reducing its concentration in the cave air. Extension movements do not appear to have affected radon transport. Alternatively, the compression process (Postojna 2, FebruaryAugust 2007) appears to have opened some newroutesfor radon transport, facilitating radon migration and increasing its concentration in air.

Active Erosion of Flat Interfluve Summits Above the Multi-storey Artesian Ozark Aquifer , 2010, Elfrink, N. M.

Migrating regional ground water divides can create unstable zones of relatively stagnant flow in upland areas. Unlike traditional upland ground water divides, the process of flow reversal causes these zones to reject recharge. Artesian pressure surfaces limit the downward infiltration of precipitation and form the subenvelope above which ground water sapping can create a ‘peneplain’ (Stearns, 1967). Only regolith and rock above the pressure surface subenvelope is available for epigenic erosion. Inertia is eventually overcome and ground water circulation substantially increases as hydraulically-advantaged, ‘entrenched’ river systems capture the isolated packets of stagnant ground water. As artesian pressure is lost in the upper story, losing streams form. The losing streams may eventually be consumed by the steep slopes of an entrenching stream, thus completing the reversal of flow. Water level data suggest that the dewatering of stagnant divide areas can be hastened by distant earthquakes.

A variety of observations in Missouri, including recent studies using heat pulse flow meters, show that pressurized sandstone aquifers are widespread beneath upland divides and at surprisingly high elevations. The ground water in the sandstones is confined by relatively tight carbonates. Ground water leaves these confined aquifers by slowly percolating upward through the confining carbonate into shallow bedrock fractures. Storm events then flush shallow mineral-laden ground water into surface streams, which is why floodwaters tend to be dominated by ground water (Frederickson & Criss, 1999). In the major valleys, transverse speleogenesis reverses the hydraulic role of the carbonate beds (Klimchouk, 2003). Classic artesian hydrology generally ignores these mechanisms and cannot explain why most large Ozark caves are associated with sandstones. Unlike classic artesian systems, artesian aquifers in the Ozarks typically lack a marginal recharge zone. Artesian pressures are maintained by ongoing vertical movements. A subsidence rate of approximately 1 mm/yr in the Northern Mississippi Embayment (Calais, 2008) would cause the Ozark ground water divide to migrate to the north and west at approximately 0.7 meter per year, assuming a constant gradient. Flat interfluve summits form as the flow reversal process unfolds.

Once thought to be remnants of ancient peneplains formed near sea-level, isotopic evidence now indicates that modern Ozark summits are actually being sapped by relatively shallow but significant zones of chemical migration. The flat summit surfaces and the steep stream valleys form simultaneously as the landscape is lowered and drainages are rearranged. There is no need to postulate the prior existence of a low elevation peneplain. The uppermost artesian pressure surface acts as the base level, not sea level. Flat interfluve surfaces can form at any elevation, depending on hydrologic conditions. The summit surfaces appear flat because they are essentially created by a regional ground water surface that is widespread and relatively flat.


Honshu, Japan Earthquake of March 11, 2011 9.0 Magnitude recorded in the Edwards Aquifer, San Antonio, Texas, 2011, Schindel, Geary M.

The Edwards Aquifer is a large karst aquifer located in south-central Texas USA. The Index Well J-17, in which water levels in the aquifer are continuously monitored since 1934, detected distinctly the March 11, 2011 Honshu, Japan earthquake (9.0 magnitude). The Edwards Aquifer fluctuated approximately 0.3 meters (1 foot) during the initial response and continued to oscillate for approximately two hours after the event.


Collapse sinkholes distribution in the carbonate massifs of central and southern Apennines, 2011, Santo Antonio, Ascione Alessandra, Del Prete Sossio, Di Crescenzo Giuseppe, Santangelo Nicoletta

This study focuses on karst collapse sinkholes of the southern and central Apennines region (Italy), and has the aim of outlining and discussing the factors which contribute to the occurrence of collapse phenomena. By the analysis of the morphometrical/morphological features of the about 600 initially identified sinkholes, about 50% were interpreted as collapse sinkholes related to karst phenomena, which are the object of this study. These were geo-referred and organised in a data base, in which information on the geological-structural and hydrogeological features of areas affected by the collapses was also reported. The collapse sinkhole inventory was paralleled by an analysis of the distribution of the main mineral springs (H2S- and CO2- rich waters), of travertine bodies and of extensional faults with late Quaternary activity, which were all considered significant to the study due to the interrelations linking travertines, karst solution processes, CO2- rich waters and faults. Furthermore, with the aim of investigating the role of seismic shaking in the occurrence of the collapses, the karst collapse sinkhole distribution was compared with the distribution of stronger historical earthquake epicentres. The results of this regional scale synthesis suggests a possible key to the interpretation of karst collapse phenomena. The latter, in fact, appear correlated to the combination of peculiar conditions, which may be envisaged in the presence of active faults and mineral waters. The study, in particular, suggests that karst collapse sinkholes result from enhanced dissolution phenomena related to the rising of fluids of deep origin, for which active faults represent preferred pathways, and favoured by the presence
of a relatively shallow water table. In the collapse events,
an important role is possibly played by seismic shaking


Active tectonics and earthquake destructions in caves of northern and central Switzerland, 2012, Becker Arnfried, Huselmann Philipp, Eikenberg Jost, Gilli Eric

The present publication focuses on the study of caves in northern and central Switzerland in order to detect and date historical earthquakes and active tectonic displacements by investigations of broken and resealed or displaced speleothems datable by U/Th and 14C. While it can be shown that these methods are potentially suitable, the ages obtained are often beyond the range of historically recorded earthquakes, and it cannot be proved that the observed and dated events are related to a seismic event. Particularly this is true for the caves in central Switzerland, where most ages in the Melchsee-Frutt region were beyond the limits of the U/Th method, or of late Pleistocene age in the Siebenhengste-Hohgant region. A direct comparison with known historical (or prehistoric) earthquakes was not possible. In contrast to central Switzerland, the results in the Basle region of northern Switzerland indicates cave and speleothem damages in one cave within the epicentral area of the 1356 Basle earthquake. 14C datings allowed to directly relate the speleothem damages to this M 6.5 earthquake. Further dating results from caves in northern Switzerland on speleothems and organic material in cave deposits supplied ages which indicate older events not related to the historical Basle earthquake. The detection of active fault displacements and prehistoric strong earthquakes can only be achieved by a very careful deciphering of the palaeo-environmental records and many more age determinations which allow to separate active tectonic displacements and seismic events from other events not related to tectonics, i.e. glaciations, creep of sediments, catastrophic floods etc.


Cryogenic fracturing of calcite flowstone in caves: theoretical considerations and field observations in Kents Cavern, Devon, UK, 2012, Lundberg Joyce, Mcfarlane Donald A.

Several caves in Devon, England, have been noted for extensive cracking of substantial flowstone floors. Conjectural explanations have included earthquake damage, local shock damage from collapsing cave passages, hydraulic pressure, and cryogenic processes. Here we present a theoretical model to demonstrate that frost-heaving and fracture of flowstone floors that overlie wet sediments is both a feasible and likely consequence of unidirectional air flow or cold-air ponding in caves, and argue that this is the most likely mechanism for flowstone cracking in caves located in Pleistocene periglacial environments outside of tectonically active regions. Modeled parameters for a main passage in Kents Cavern, Devon, demonstrate that 1 to 6 months of -10 to -15° C air flow at very modest velocities will result in freezing of 1 to 3 m of saturated sediment fill. The resultant frost heave increases with passage width and depth of frozen sediments. In the most conservative estimate, freezing over one winter season of 2 m of sediment in a 6-m wide passage could fracture flowstone floors up to ~13 cm thick, rising to ~23 cm in a 12-m wide passage. Natural flaws in the flowstone increase the thickness that could be shattered. These numbers are quite consistent with the field evidence.


Possible relation between the sudden sinking of river Ika and the sequence of weak earthquakes in September-October 2010 near Ika vas (central Slovenia), 2012, Gosar A. , Brenč, Ič, M.

During heavy rainfalls between September 17 and 19, 2010 large part of Slovenia has suffered extensive floods that last for nearly two weeks. For the river Iška record discharge of 59.3 m3/s was measured on September 19 on the gauging station in Iška vas located at the southern rim of Ljubljansko barje. In the first hour of September 21, 2010 two weak earthquakes (ML=0.6 and ML=0.2) occurred within one minute near Iška vas. They were felt by some inhabitants who reported also a rumbling noise (brontides). During the flood recession period, the water of river Iška started to sink into the gravely stream bed or rocky left banks and the gauging profile completely dried on September 23, day and a half after the first earthquake. Water reappeared again on September 25. In the period September 21 − October 4 additional seven weak earthquakes occurred in the same area. All earthquakes from this series occurred at or near the surface and deviate in hypocentral depth from the seismicity pattern characteristic for the southern rim of Ljubljansko barje, which was analysed for comparison. The epicentres of the first two earthquakes are in good agreement with the location of the dried river bed. It is therefore probable that both phenomena are related. Analyses of seismograms have shown that it is not likely that the observed events are collapse earthquakes, but they are tectonic events. Although earthquakes were relatively weak, it seems that they could be accompanied by small near-surface tectonic movements, because they occurred at the position of a known fault. These movements are probably connected to the opening of pre-existing fissures in the karstified valley bottom, although the primary reason for sinking of the river is that high waters removed the clogged river bed that enables intensive sinking into the river bottom during the flood.


Possible relation between the sudden sinking of river Ika and the sequence of weak earthquakes in September-October 2010 near Ika vas (central Slovenia), 2012, Gosar Andrej, Brenč, Ič, Mihael

During heavy rainfalls between September 17 and 19, 2010 large part of Slovenia has suffered extensive floods that last for nearly two weeks. For the river Iška record discharge of 59.3 m3/s was measured on September 19 on the gauging station in Iška vas located at the southern rim of Ljubljansko barje. In the first hour of September 21, 2010 two weak earthquakes (ML=0.6 and ML=0.2) occurred within one minute near Iška vas. They were felt by some inhabitants who reported also a rumbling noise (brontides). During the flood recession period, the water of river Iška started to sink into the gravely stream bed or rocky left banks and the gauging profile completely dried on September 23, day and a half after the first earthquake. Water reappeared again on September 25. In the period September 21 − October 4 additional seven weak earthquakes occurred in the same area. All earthquakes from this series occurred at or near the surface and deviate in hypocentral depth from the seismicity pattern characteristic for the southern rim of Ljubljansko barje, which was analysed for comparison. The epicentres of the first two earthquakes are in good agreement with the location of the dried river bed. It is therefore probable that both phenomena are related. Analyses of seismograms have shown that it is not likely that the observed events are collapse earthquakes, but they are tectonic events. Although earthquakes were relatively weak, it seems that they could be accompanied by small near-surface tectonic movements, because they occurred at the position of a known fault. These movements are probably connected to the opening of pre-existing fissures in the karstified valley bottom, although the primary reason for sinking of the river is that high waters removed the clogged river bed that enables intensive sinking into the river bottom during the flood.

 

Karstification as a Predisposing Factor of Seismically Triggered Landslides: Case Study from the Crimean Mountains (Ukraine): Introduction to the Problem, 2013, Hradeck J. , Pnek T. , ilhn K. , Smolkov V.

Deep-seated gravitational deformations are significant denudational agents of rock slopes at the margins of karstified plateaus of the Crimean Mountains (CM). The CM evolved during Mesozoic–Cenozoic times as a response to the deformation between the Black Sea domain and East-European platform. The southwestern part of the area is characterized by steep, up to 1000-m-high coastal escarpments consisting of Late Jurassic limestones overlying tuff layers and weak Late Triassic flysch with sporadic small intrusions of Middle Jurassic diorites, gabbros and granites. Steep rock slopes contrast with elevated, highly karstified plateaus situated approximately 500–1300 m a.s.l. The aim of this article is to show long-term evolution of a giant rock slope failure close to the Black Sea coast in the southwestern tip of the CM near Foros Town. The failure evolved in highly anisotropic limestones overlying plastic flysch layers where the main head scarp follows a strike-slip fault. The Foros slope failure is an excellent demonstration of the significance of a preparatory stage in the evolution of large deep-seated slope deformations. Inherited and undisturbed horizontal slickensides on the sub-vertical, inactive fault surface serve as good evidence of significant extensional movement of the surface blocks away from the main headscarp. The studied deformation shows that in a relatively small area tensional (cutting) surfaces can be formed by a great variety of rock discontinuities such as the strike-slip fault, joints and steeply inclined bedding planes. The presence of well-developed, nowadays weathered, speleothems furthermore points to significant karstification that provided additional widening of spaces within rock mass. Gravitational movement destroyed and unroofed several cave systems originally presented at the former edge of a karst plateau. Our findings reveal that large rock slope failures can be added to the factors contributing to the evolution of unroofed caves. Although triggering factors of the activation of individual parts of slope deformations can be determined only hypothetically, lessons learned from widespread landslide activity during and after the 1927 Yalta earthquake and rainfall-driven landslides in the vicinity of Feodosia Town make us consider both seismic loading of slopes and high pore-pressures during heavy winter rainfalls or rapid spring snowmelt to be significant factors. Beside seismic activity, intensive Late Holocene slope processes can be attributed to intensive human activity.

 


INVESTIGATIONS OF LARGE SCALE SINKHOLE COLLAPSES, LAIBIN, GUANGXI, CHINA, 2013, Gao Yongli, Luo Weiquan, Jiang Xiaozhen, Lei Mingtang, Dai Jianling

A series of sinkholes collapsed at Jili village and Shanbei village, Laibin Guangxi, China in June 2010. A large underground stream exists in the north-south transect of the study area and passes the collapse site. Preliminary investigations revealed that extremely heavy rainfall between May 31 and June 1 2010 may have triggered this collapse event. The precipitation, as high as 469.8 mm within one day, was a record high in the study area. A long period of drought in 2009 followed by extremely heavy rainfall along with cave roof collapse may have caused the collapse event on June 3 2010. The “water hammer” effect and collapse-triggered earthquakes caused severe ground failure and fractures in residential houses and Jili Dam. Several collapse events were caused by extreme weather conditions in Guangxi over the past few years. Further studies of the relationship between extreme weather events and sinkhole collapses will help minimize the damage or impact to human infrastructure by avoiding areas susceptible to collapse or by designing infrastructure to better withstand subsidence


Early results of micro-deformation measurements in Magdalena Jama (Slovenia) by a vertical static pendulum, 2013, Kalenda Pavel, Neumann Libor, Šebela Stanka

Vertical static pendulums have been installed in mines or caves in Central Europe since 2007. Two­dimensional optical measurement of the tilt of a rock mass and continuous fully digital on­line evaluation of results makes possible the detection of a small tilt of the surroundings with a resolution of tens of nanoradians or the deformation of the surroundings in the horizontal plane with resolution of hundreds of nanometres. The paper describes the measurement device and the first results of the measurements in Magdalena Jama, which is part of the Postojna Cave System (Slovenia). The correlation of deformation between distant stations shows the existence of stress variations that are not only of local origin (high floods, local seismicity, and aseismic deformations). The stress field has a wider, and not only regional, character with effects that can be observed very far from the origin.


Radon, carbon dioxide and fault displacements in central Europe related to the Tohoku Earthquake, 2014, Briestensky Milos, Thinova Lenka, Praksova Renata, Stemberk Josef, Rowberry Matt D. , Knejflova Zuzana

Tectonic instability may be measured directly using extensometers installed across active faults or it may be indicated by anomalous natural gas concentrations in the vicinity of active faults. This paper presents the results of fault displacement monitoring at two sites in the Bohemian Massif and Western Carpathians. These data have been supplemented by radon monitoring in Mladec Caves and by carbon dioxide monitoring in Zbrasov Aragonite Caves. A significant period of tectonic instability is indicated by changes in the fault displacement trends and by anomalous radon and carbon dioxide concentrations. This was recorded around the time of the catastrophic MW = 9.0 Tohoku Earthquake which hit eastern Japan on 11 March 2011. It is tentatively suggested that the Tohoku Earthquake in the Pacific Ocean and the unusual geodynamic activity recorded in the Bohemian Massif and Western Carpathians both reflect contemporaneous global tectonic changes.


Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), 2015, Briestensky Milos, Rowberry Matt, Stemberk Josef, Stefanov Petar, Vozar Jozef, Sebela Stanka, Petro Lubomir, Bella Pavel, Gaal Ludovit, Ormukov Cholponbek,

The EU-TecNet monitoring network uses customised three-dimensional extensometers to record transient deformations across individual faults. This paper presents the first results from two newly established monitoring points in the Balkan Mountains in Bulgaria. The data from Saeva Dupka, recorded across an EEN-WWS striking fault, show sinistral strike-slip along the fault and subsidence of the southern block. Much of the subsidence occurred around the time of the distal MW = 5.6 Pernik Earthquake. An important transient deformation event, which began in autumn 2012, was reflected by significant compression and subsequent extension across the monitored fault. The data from Bacho Kiro, recorded across a NE-SW striking fault, show sinistral strike-slip along the fault and subsidence of the northwestern block. The same important deformation event was reflected by changes in the strike-slip, dip-slip, and horizontal opening/closing trends. These results have been compared to data from other monitoring points in the Western Carpathians, External Dinarides, and Tian Shan. Many of the sites evidence simultaneous displacement anomalies and this observation is interpreted to reflect the widespread propagation of a tectonic pressure pulse towards the end of 2012.


Results 31 to 43 of 43
You probably didn't submit anything to search for