Geological Evidence of Great Earthquakes along the Eastern Himalayan Foothills

2021 ◽  
Vol 97 (8) ◽  
pp. 823-826
Author(s):  
R. Jayangonda Perumal
Keyword(s):  
Geological Evidence ◽  
Great Earthquakes ◽  
Himalayan Foothills

Recent Issues Affecting Forecast of Subduction Zone Great Earthquakes in Japan Through Paleoseismological Study

2014 ◽  
Vol 9 (3) ◽  
pp. 330-338 ◽  
Author(s):  
Masanobu Shishikura ◽  
Keyword(s):  
Subduction Zone ◽  
Tohoku Earthquake ◽  
Japanese Government ◽  
Earthquake Forecasting ◽  
Disaster Prevention ◽  
Prevention Measures ◽  
Class Model ◽  
Geological Evidence ◽  
Potential Effectiveness ◽  
Great Earthquakes

Because the 2011 great Tohoku earthquake was accompanied by phenomena similar to those associated with the 869 Jogan earthquake, as reconstructed on the basis of historical and geological evidence, paleoseismology is recognized for its potential effectiveness in earthquake forecasting. In attempts to avoid such unexpected situations as the 2011 Tohoku event when taking disaster prevention measures, the Japanese government and local administrations announced a maximum class model for earthquakes and tsunamis that is not based on paleoseismological evidence. Thus, paleoseismologists must both inductively study the reconstruction of evidence fromthe past and deductively evaluate the maximum class earthquake and tsunami.

scholarly journals Recurrence and Extent of Great Earthquakes in Southern Alaska During the Late Holocene from an Analysis of the Radiocarbon Record of Land-Level Change and Village Abandonment

Radiocarbon ◽  
2007 ◽  
Vol 49 (3) ◽  
pp. 1323-1385 ◽  
Author(s):  
Ian Hutchinson ◽  
Aron L Crowell
Keyword(s):  
Late Holocene ◽  
Plate Boundary ◽  
Gulf Of Alaska ◽  
Great Earthquake ◽  
Plate Interface ◽  
Geological Evidence ◽  
Level Change ◽  
Great Earthquakes ◽  
Coastal Deposits ◽  
Independent Behavior

The incidence of plate-boundary earthquakes across 3 prospective tectonic segments at the Alaska subduction zone (ASZ) in the late Holocene is reconstructed from geological evidence of abrupt land-level change and archaeological evidence of discontinuities in occupation of native villages. Bracketing radiocarbon ages on uplifted and down-dropped coastal deposits indicate that great earthquakes likely ruptured the plate interface in the eastern segment (Prince William Sound [PWS]) about 800, 1400, 2200–2300, 2600–2700, 3100–3200, and 3600–3700 cal BP. Evidence for an event about 1900 yr ago, and the possibility that the 2600–2700 cal BP event was a closely spaced series of 3 earthquakes, is restricted to parts of Cook Inlet. Geological evidence from the central (Kenai [KEN]) segment is fragmentary, but indicates that this segment likely ruptured about 1400 yr ago and in the triple event about 2600–2700 yr ago. The geological record from the Kodiak-Katmai (KOKA) segment at the western end of the ASZ has limited time-depth, with localized evidence for ruptures about 500, 1000, and 1300 yr ago. 14C ages and stratigraphic descriptions from 82 prehistoric villages and camps on the coast of the Gulf of Alaska reveal fluctuations in site activity that correlate with paleoseismic episodes. Hiatuses in site occupation occurred about 800, 1400, and 2200 yr ago in the PWS and KEN segments. The fragmentary older record from the KEN segment also reveals a hiatus about 2700 yr ago. The 2200–2300 and 2600–2700 cal BP events are also recorded in the KOKA segment, and the great earthquake at about 3200 cal BP may also be recorded there. This suggests that, although the PWS and KEN segments behave as a coherent unit of the Alaska megathrust, the KOKA segment is characterized by semi-independent behavior. At least 2, and perhaps as many as 4, of the last 7 prehistoric great earthquakes at this plate boundary did not propagate this far west.

Data Echoes: Sound, Evidence, and Acoustic Methods in Energy Landscapes

2021 ◽  
pp. 016224392110345
Author(s):  
James Maguire
Keyword(s):  
Geothermal Energy ◽  
Energy Production ◽  
Model Building ◽  
Acoustic Method ◽  
Time Frame ◽  
Energy Landscapes ◽  
Geological Evidence ◽  
Temporal Form ◽  
Acoustic Methods ◽  
Intractable Problem

This paper explores an informal acoustic method developed by a group of industrial geologists working in geothermal energy landscapes in the southwest of Iceland. Through a series of ethnographic descriptions, this paper renders the work these geologists carry out in sonic terms, emphasizing how they use their bodies as sonic detectors in the production of geological evidence. Sound, the paper argues, is what allows geologists to make the intractable problem of volcanic cooling doable. It does this by differentiating two forms of evidence. Primary evidence, which ends up as data in geological reports, and secondary sonic evidence, which is what establishes that this primary evidence is, in fact, evidence. The paper introduces the concept data echoes as a way to think about how sound articulates between these evidential protocols. As echo, sound works as an outside, which, while remaining external to official protocols of knowledge production, nevertheless helps to constitute distinctions that are meaningful to the production of those categories. As data echoes through the various moments of data capture, analysis, and model building, sound’s temporal form helps to predict the time frame of volcanic cooling, as it affects both the immediate energy production scenarios and the long durée of volcanic time.

Assessment of eco-hydrological parameters for important sympodial bamboo species in Himalayan foothills

2021 ◽  
Vol 193 (8) ◽  
Author(s):  
Rajesh Kaushal ◽  
Ambrish Kumar ◽  
N. M. Alam ◽  
I. Singh ◽  
D. Mandal ◽  
...  
Keyword(s):  
Bamboo Species ◽  
Hydrological Parameters ◽  
Himalayan Foothills

Spatiotemporal clustering of great earthquakes on a transform fault controlled by geometry

2021 ◽  
Author(s):  
Jamie D. Howarth ◽  
Nicolas C. Barth ◽  
Sean J. Fitzsimons ◽  
Keith Richards-Dinger ◽  
Kate J. Clark ◽  
...  
Keyword(s):  
Transform Fault ◽  
Great Earthquakes ◽  
Spatiotemporal Clustering

scholarly journals Surface-Rupturing Historical Earthquakes in Australia and Their Environmental Effects: New Insights from Re-Analyses of Observational Data

Geosciences ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 408 ◽  
Author(s):  
King ◽  
Quigley ◽  
Clark
Keyword(s):  
Observational Data ◽  
Environmental Effects ◽  
Active Faults ◽  
Magnetic Data ◽  
Future Research ◽  
Surface Rupture ◽  
Secondary Fracture ◽  
Geological Evidence ◽  
Surface Ruptures ◽  
Strong Control

We digitize surface rupture maps and compile observational data from 67 publications on ten of eleven historical, surface-rupturing earthquakes in Australia in order to analyze the prevailing characteristics of surface ruptures and other environmental effects in this crystalline basement-dominated intraplate environment. The studied earthquakes occurred between 1968 and 2018, and range in moment magnitude (Mw) from 4.7 to 6.6. All earthquakes involved co-seismic reverse faulting (with varying amounts of strike-slip) on single or multiple (1–6) discrete faults of ≥ 1 km length that are distinguished by orientation and kinematic criteria. Nine of ten earthquakes have surface-rupturing fault orientations that align with prevailing linear anomalies in geophysical (gravity and magnetic) data and bedrock structure (foliations and/or quartz veins and/or intrusive boundaries and/or pre-existing faults), indicating strong control of inherited crustal structure on contemporary faulting. Rupture kinematics are consistent with horizontal shortening driven by regional trajectories of horizontal compressive stress. The lack of precision in seismological data prohibits the assessment of whether surface ruptures project to hypocentral locations via contiguous, planar principal slip zones or whether rupture segmentation occurs between seismogenic depths and the surface. Rupture centroids of 1–4 km in depth indicate predominantly shallow seismic moment release. No studied earthquakes have unambiguous geological evidence for preceding surface-rupturing earthquakes on the same faults and five earthquakes contain evidence of absence of preceding ruptures since the late Pleistocene, collectively highlighting the challenge of using mapped active faults to predict future seismic hazards. Estimated maximum fault slip rates are 0.2–9.1 m Myr-1 with at least one order of uncertainty. New estimates for rupture length, fault dip, and coseismic net slip can be used to improve future iterations of earthquake magnitude—source size—displacement scaling equations. Observed environmental effects include primary surface rupture, secondary fracture/cracks, fissures, rock falls, ground-water anomalies, vegetation damage, sand-blows / liquefaction, displaced rock fragments, and holes from collapsible soil failure, at maximum estimated epicentral distances ranging from 0 to ~250 km. ESI-07 intensity-scale estimates range by ± 3 classes in each earthquake, depending on the effect considered. Comparing Mw-ESI relationships across geologically diverse environments is a fruitful avenue for future research.

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