scholarly journals Seismotectonic activity in East Belgium: relevance of a major scarp and two associated landslides in the region of Malmedy

2018 ◽  
Vol 21 (3-4) ◽  
pp. 101-110 ◽  
Author(s):  
Anne-Sophie MREYEN ◽  
Alain DEMOULIN ◽  
Hans-Balder HAVENITH
Keyword(s):  
Seismotectonic Activity

Instability structures, synsedimentary faults and turbidites, witnesses of a Liassic seismotectonic activity in the Dauphiné Zone (French Alps): A case example in the Lower Pliensbachian at Saint-Michel-en-Beaumont

2011 ◽  
Vol 51 (5) ◽  
pp. 344-357 ◽  
Author(s):  
Françoise Bergerat ◽  
Pierre-Yves Collin ◽  
Anne-Céline Ganzhorn ◽  
François Baudin ◽  
Bruno Galbrun ◽  
...  
Keyword(s):  
French Alps ◽  
Seismotectonic Activity

Fault Activation in Central Mongolia during the Holocene: Results of Study of the Mogod Earthquake Ruptures

2021 ◽  
Vol 62 (11) ◽  
pp. 1285-1295
Author(s):  
O.P. Smekalin ◽  
A.V. Chipizubov
Keyword(s):  
Fault Zone ◽  
Complex Structure ◽  
Slip Rates ◽  
The Holocene ◽  
Central Mongolia ◽  
Earthquake Sources ◽  
The Absolute ◽  
Absolute Age ◽  
Seismotectonic Activity ◽  
Seismic Deformation

Abstract —In order to determine the seismotectonic activity of faults in the Holocene, we performed trench studies of the ruptures produced by the catastrophic Mogod earthquake (5 January 1967, M = 7.5–7.8, I0 = 9–10) in the junction zone of the N–S striking Hulzhin Gol fault and the NW striking Tullet fault. Paleoseismic interpretation of seismic-deformation sections and radiocarbon dating of the samples allowed determining the kinematics and obtaining, for the first time, the absolute ages of paleoevents preceding the Mogod earthquake. Analysis of the tectonic conditions for realization of earthquake sources has shed light on the complex structure of ruptures in the area of the Mogod earthquake epicenter, within which three segments differing in the displacement amplitudes and kinematics have been identified. The research data indicate the repeated activation of the Tulet and Hulzhin Gol faults in the Late Pleistocene–Holocene. The absolute age of the latest activation is 596–994 AD for the Tulet fault and 11,379–6235 BC for the Hulzhin Gol fault. The cumulative deformation from paleoearthquakes in the trench sections in the Tulet fault zone points to at least two displacements of thrust kinematics, with the latest of them having an amplitude of 2.8 m. The paleoearthquake in the Hulzhin Gol fault zone is characterized by the presence of lateral slip. The amplitudes of deformations attest to earlier earthquakes similar in energy to the 1967 Mogod event or even stronger in the fault node. The obtained data on the timing of these earthquakes and the amplitudes of the accompanying displacements made it possible to estimate slip rates along the faults: 0.2–0.3 m/kyr horizontal-slip rates on the Hulzhin Gol fault and 0.5–0.7 m/kyr vertical-slip rates on the Tulet fault.

Dynamics of the Relief and Seismotectonic Activity of the Modern Structures in the Delta of the River Lena

Geotectonics ◽  
2019 ◽  
Vol 53 (5) ◽  
pp. 588-600
Author(s):  
L. P. Imaeva ◽  
G. S. Gusev ◽  
V. S. Imaev
Keyword(s):  
Seismotectonic Activity

scholarly journals DNA signature of thermophilic bacteria from the aged accretion ice of Lake Vostok, Antarctica: implications for searching for life in extreme icy environments

2004 ◽  
Vol 3 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Sergey A. Bulat ◽  
Irina A. Alekhina ◽  
Michel Blot ◽  
Jean-Robert Petit ◽  
Martine de Angelis ◽  
...  
Keyword(s):  
Water Body ◽  
Hot Springs ◽  
Cold Water ◽  
Thermophilic Bacteria ◽  
Critical Issue ◽  
Geothermal System ◽  
Extraterrestrial Life ◽  
Lake Vostok ◽  
Accretion Ice ◽  
Seismotectonic Activity

We have used 16S ribosomal genes to estimate the bacterial contents of Lake Vostok accretion ice samples at 3551 m and 3607 m, both containing sediment inclusions and formed 20000–15000 yr ago. Decontamination proved to be a critical issue, and we used stringent ice chemistry-based procedures and comprehensive biological controls in order to restrain contamination. As a result, up to now we have only recognized one 16S rDNA bacterial phylotype with confident relevance to the lake environment. It was found in one sample at 3607 m depth and represents the extant thermophilic facultative chemolithoautotroph Hydrogenophilus thermoluteolus of beta-Proteobacteria, and until now had only been found in hot springs. No confident findings were detected in the sample at 3551 m, and all other phylotypes revealed (a total of 16 phylotypes, 336 clones including controls) are presumed to be contaminants. It seems that the Lake Vostok accretion ice is actually microbe-free, indicating that the water body should also be hosting a highly sparse life. The message of thermophilic bacteria suggests that a geothermal system exists beneath the cold water body of Lake Vostok, what is supported by the geological setting, the long-term seismotectonic evidence from 4He degassing and the ‘18O shift’ of the Vostok accretion ice. The seismotectonic activity that seems to operate in deep faults beneath the lake could sustain thermophilic chemolithoautotrophic microbial communities. Such a primary production scenario for Lake Vostok may have relevance for icy planets and the approaches used for estimating microbial contents in accretion ice are clearly relevant for searching for extraterrestrial life.

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