Liquefaction, flow, and associated ground failure

Circular ◽  
1973 ◽  
Author(s):  
T. Leslie Youd
Keyword(s):  
Ground Failure

Seismic microzoning in New Zealand

1971 ◽  
Vol 4 (1) ◽  
pp. 43-50
Author(s):  
W. R. Stephenson
Keyword(s):  
New Zealand ◽  
Structural Damage ◽  
Seismic Waves ◽  
Multiple Reflection ◽  
Ground Failure ◽  
Seismic Microzoning ◽  
Popular View ◽  
Wave Trains ◽  
Local Geology ◽  
Ground Damage

"Seismic Microzoning" means many different things to different people. There is always included the element of different damage in nearby areas, but how the differences arise, how we should study them, and how we should apply the results of our studies, are still uncertain. To some people, microzoning refers to structural damage due to ground failure; faulting, slumping and liquefaction all belong in this category. To others, microzoning is the effects of the focussing of seismic waves by boundaries, resulting in modified ground damage and building damage. A third very popular view of microzoning holds that it concerns multiple reflection of seismic waves in layers, with interference of the wave trains giving rise to maxima, where ground and structural damage will be accentuated. Microzoning can be defined as the division of land areas into small regions of differing local geology for which differences in earthquake attack on structures are specified. This paper is an attempt to set down aspects of microzoning in a logical manner, and to relate them. It also discusses activities here and overseas, and considers where microzoning and microzoning research in New Zealand should head.

The Qir, Iran earthquake of April 10, 1972

1973 ◽  
Vol 63 (1) ◽  
pp. 339-354 ◽  
Author(s):  
Thomas V. McEvilly ◽  
Reza Razani
Keyword(s):  
Shear Failure ◽  
Fars Province ◽  
Structural Failure ◽  
Ground Failure ◽  
Mountainous Regions ◽  
Earthquake Resistant ◽  
Load Carrying ◽  
Zagros Range ◽  
Almost All ◽  
Epicentral Region

abstract The destructive earthquake, Ms = 7.1 (BRK), occurred at 0537 a.m. local time, near an agricultural center in the mountainous Zagros Range of the Fars Province in the south of Iran. Leveling virtually all structures in the epicentral region, the shock killed nearly 25 per cent of the population of about 23,000 people in the devastated villages within a radius of about 50 km from the epicenter. Hardest hit was the valley complex of Qir, Karzin, and Afzar. The high percentage of death was mainly caused by structural failure and the collapse of the heavy roof of almost all adobe and masonry residential structures in the area. Structural failure of buildings with modern steel-beam roofs and of the traditional adobe and masonry-walled buildings with heavy timbered roofs in the region was due primarily to the lateral shear failure of poorly constructed adobe and masonry, lack of earthquake-resistant vertical load-carrying columns or elements, and lack of bracing and adequate tie-in in the roofs. Engineered buildings also collapsed, generally, because of defects in engineering and construction practices. Only minor cases of ground failure were observed, mainly slides in steep mountainous regions and some collapse of steep banks of rivers and irrigation channels.

Types and Areal Distribution of Ground Failure Associated with the 2019 Ridgecrest, California, Earthquake Sequence

2020 ◽  
Vol 110 (4) ◽  
pp. 1567-1578 ◽  
Author(s):  
Randall W. Jibson
Keyword(s):  
Epicentral Distance ◽  
Wide Band ◽  
Field Investigation ◽  
Earthquake Sequence ◽  
Lateral Spread ◽  
Fault Rupture ◽  
Rock Falls ◽  
Epicentral Area ◽  
Ground Failure ◽  
Almost All

ABSTRACT The July 2019 Ridgecrest, California, earthquake sequence included the largest earthquake (M 7.1) to strike the conterminous United States in the past 20 yr. To characterize the types, numbers, and areal distributions of different types of ground failure (landslides, liquefaction, and ground cracking), I conducted a field investigation of ground failure triggered by the sequence around the periphery of the epicentral area (which had limited access). The earthquake sequence triggered sparse and widely scattered landslides over an area of ∼22,000  km2 and at a maximum epicentral distance of 114 km; these metrics are within the upper bounds as compared with global averages for earthquakes of similar size. Some rock falls blocked primary and secondary roads, but no other landslide damage was reported. Almost all of the landslides in the peripheral area were small rock falls (∼1–10  m3), but a few larger (∼100  m3) rock slides also occurred. Though there are only informal reports about ground failure in the immediate epicentral area and we lack a detailed survey there, the small number (hundreds) and size of the landslides still seems to be far below global averages for M 7.1. This could be a result of the arid landscape and lack of a deeply weathered zone of soil and regolith. Liquefaction occurred along part of the western margin of Searles Valley. One large (∼0.4  km2) lateral spread caused by liquefaction severely damaged parts of Trona. Minor liquefaction also occurred in a ∼100-m-wide band along the fault-rupture zone in some places.

scholarly journals Global Earthquake Response with Imaging Geodesy: Recent Examples from the USGS NEIC

2019 ◽  
Vol 11 (11) ◽  
pp. 1357 ◽  
Author(s):  
William D. Barnhart ◽  
Gavin P. Hayes ◽  
David J. Wald
Keyword(s):  
Disaster Response ◽  
Human Impacts ◽  
Earthquake Response ◽  
Ground Shaking ◽  
Ground Failure ◽  
The World ◽  
Source Models ◽  
Impact Products ◽  
Seismic Wavefield

The U.S. Geological Survey National Earthquake Information Center leads real-time efforts to provide rapid and accurate assessments of the impacts of global earthquakes, including estimates of ground shaking, ground failure, and the resulting human impacts. These efforts primarily rely on analysis of the seismic wavefield to characterize the source of the earthquake, which in turn informs a suite of disaster response products such as ShakeMap and PAGER. In recent years, the proliferation of rapidly acquired and openly available in-situ and remotely sensed geodetic observations has opened new avenues for responding to earthquakes around the world in the days following significant events. Geodetic observations, particularly from interferometric synthetic aperture radar (InSAR) and satellite optical imagery, provide a means to robustly constrain the dimensions and spatial complexity of earthquakes beyond what is typically possible with seismic observations alone. Here, we document recent cases where geodetic observations contributed important information to earthquake response efforts—from informing and validating seismically-derived source models to independently constraining earthquake impact products—and the conditions under which geodetic observations improve earthquake response products. We use examples from the 2013 Mw7.7 Baluchistan, Pakistan, 2014 Mw6.0 Napa, California, 2015 Mw7.8 Gorkha, Nepal, and 2018 Mw7.5 Palu, Indonesia earthquakes to highlight the varying ways geodetic observations have contributed to earthquake response efforts at the NEIC. We additionally provide a synopsis of the workflows implemented for geodetic earthquake response. As remote sensing geodetic observations become increasingly available and the frequency of satellite acquisitions continues to increase, operational earthquake geodetic imaging stands to make critical contributions to natural disaster response efforts around the world.

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