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.

Documentation of Surface Fault Rupture and Ground-Deformation Features Produced by the 4 and 5 July 2019 Mw 6.4 and Mw 7.1 Ridgecrest Earthquake Sequence

2020 ◽  
Vol 91 (5) ◽  
pp. 2942-2959 ◽  
Author(s):  
Daniel J. Ponti ◽  
James Luke Blair ◽  
Carla M. Rosa ◽  
Kate Thomas ◽  
Alexandra J. Pickering ◽  
...  
Keyword(s):  
Slope Failure ◽  
Ground Deformation ◽  
Field Measurements ◽  
Earthquake Hazard ◽  
Earthquake Sequence ◽  
Digital Data ◽  
Fault Rupture ◽  
Ground Failure ◽  
Eastern California Shear Zone ◽  
Deformation Features

Abstract The Mw 6.4 and Mw 7.1 Ridgecrest earthquake sequence occurred on 4 and 5 July 2019 within the eastern California shear zone of southern California. Both events produced extensive surface faulting and ground deformation within Indian Wells Valley and Searles Valley. In the weeks following the earthquakes, more than six dozen scientists from government, academia, and the private sector carefully documented the surface faulting and ground-deformation features. As of December 2019, we have compiled a total of more than 6000 ground observations; approximately 1500 of these simply note the presence or absence of fault rupture or ground failure, but the remainder include detailed descriptions and other documentation, including tens of thousands of photographs. More than 1100 of these observations also include quantitative field measurements of displacement sense and magnitude. These field observations were supplemented by mapping of fault rupture and ground-deformation features directly in the field as well as by interpreting the location and extent of surface faulting and ground deformation from optical imagery and geodetic image products. We identified greater than 68 km of fault rupture produced by both earthquakes as well as numerous sites of ground deformation resulting from liquefaction or slope failure. These observations comprise a dataset that is fundamental to understanding the processes that controlled this earthquake sequence and for improving earthquake hazard estimates in the region. This article documents the types of data collected during postearthquake field investigations, the compilation effort, and the digital data products resulting from these efforts.

Geological effects and tectonic environment of the November 26, 2019, Mw 6.4 Durres earthquake (Albania)

2020 ◽  
Author(s):  
Eutizio Vittori ◽  
Anna Maria Blumetti ◽  
Valerio Comerci ◽  
Pio Di Manna ◽  
Luigi Piccardi ◽  
...  
Keyword(s):  
Tectonic Setting ◽  
Active Tectonics ◽  
Historical Earthquakes ◽  
Sar Interferometry ◽  
Lateral Spread ◽  
Rock Falls ◽  
Epicentral Area ◽  
Tectonic Environment ◽  
Regional Tectonic ◽  
Area North

Summary The Mw 6.4 November 26, 2019, earthquake has been the strongest in the last decades in Albania, causing damages of intensity VIII to IX EMS in the epicentral region around Durres. The region north of Durres has experienced a maximum uplift of ca. 11 cm, based on SAR interferometry, which represents the main environmental effect induced by the earthquake. Other coseismic environmental effects were liquefaction mostly in the coastal area north and south of Durres, lateral spread in the Erzen river banks and possibly minor rock falls. As a whole, the observed effects are indicative of an intensity VIII to IX in the ESI scale. The rupture parameters that best fits the earthquake data (seismic moment, hypocentre depth, GPS data, deformation field from SAR interferometry), based on Coulomb modelling, show a reverse slip of 0.6 m on a NW-SE trending plane dipping 25° northeast, 20 km long and ca. 12 km wide, from 19.5 to ca. 15 km deep. The surface projection of the upper tip of the rupture is on the coast north of Durres. The inferred Coulomb stress change does not impose any significant load on the surrounding major faults, i.e. Kruja thrust, Lezha transfer fault, and the offshore thrust fault responsible for the 1979 Mw 7.1 Montenegro earthquake. The historical earthquakes and the regional tectonic setting, dominated by plate collision and important transfer fault zones suggest that the last earthquake might not be representative of the actual maximum seismic and surface faulting hazards in northwestern Albania, a region of fast industrial and touristic growth. This calls for detailed active tectonics studies with a palaeoseismological perspective in the region surrounding the epicentral area, where the two main towns in Albania lie.

scholarly journals Reconnissance report on geotechnical and geological aspects of the 14-16 April 2016 Kumamoto earthquakes, Japan

2017 ◽  
Vol 50 (3) ◽  
pp. 365-393 ◽  
Author(s):  
Gabriele Chiaro ◽  
Gavin Alexander ◽  
Pathmanathan Brabhaharan ◽  
Christopher Massey ◽  
Junichi Koseki ◽  
...  
Keyword(s):  
Large Scale ◽  
Field Investigation ◽  
Lateral Spreading ◽  
Earth Dam ◽  
Engineering Practice ◽  
Fault Rupture ◽  
Rock Falls ◽  
Ground Shaking ◽  
Fault Trace ◽  
Volcanic Caldera

On 16 April 2016, a moment magnitude (Mw) 7.0 earthquake struck the Island of Kyushu, Japan. Two major foreshocks (Mw 6.2 and Mw 6.0) contributed to devastation in Kumamoto City, Mashiki Town and in the mountainous areas of the Mount Aso volcanic caldera. This report summarises geotechnical and geological aspects of the earthquakes that were observed during a field investigation conducted by the NZSEE Team in collaboration with Japanese engineers and researchers. Many houses and other buildings, roads, riverbanks, and an earth dam, either on or adjacent to the surface fault rupture or projected fault trace, were severely damaged as a result of both the strong ground shaking and permanent ground displacement. In the Mount Aso volcanic caldera, traces of medium to large scale landslides and rock falls were frequently observed. A number of landslides impacted homes and infrastructure, and were reported to have killed at least 10 people out of the 69 confirmed deaths associated with the earthquake. In a few suburbs of Kumamoto City and in Mashiki Town, localised liquefaction took place, causing lateral spreading, differential settlements of the ground and riverbanks, sinking and tilting of buildings, foundation failures, cracks on roads, and disruption of water and sewage pipe networks. The overall effects from liquefaction related hazards appeared relatively minor compared to the damage caused by shaking, landslides and surface fault rupture. Based on the field survey, key findings are highlighted and recommendations to NZ engineering practice are made in the report.

scholarly journals Reconnaissance field investigation of the Landers earthquake (Ms 7.5) of June 28, 1992,
 San Bernadino County, California, USA

1992 ◽  
Vol 25 (3) ◽  
pp. 230-241
Author(s):  
Kelvin Berryman
Keyword(s):  
Los Angeles ◽  
Field Investigation ◽  
Fault Rupture ◽  
Epicentral Area ◽  
Landers Earthquake ◽  
Rupture Length ◽  
California Institute Of Technology ◽  
Institute Of Technology ◽  
Relationship Of ◽  
The Relationship

The Landers earthquake (Ms 7.5) occurred at 4.58 am local time, and was located about 10 km north of the town of Yucca Valley, close to the small town of Landers, and about 170 km ENE of Los Angeles (Fig. 1). At the time the author was in Reno, Nevada, involved in a field study of the 1915 rupture of the Pleasant Valley fault. Fieldwork was completed on July 8, and on July 9 the author drove with a Reno-based colleague, Dr. Steven Wesnousky, firstly to Los Angeles to consult with seismologists and geologists at U. S. Geological Survey (Pasadena) and California Institute of Technology (Caltech), and then to Yucca Valley to inspect surface faulting and damage in the epicentral area. We reached Yucca Valley at about 6 pm on July 10, and remained in the area until the evening of July 14. Some objectives in inspecting the fault rupture were to look at the distribution of slip along the length of the fault break; the relationship of faulting to pre-existing traces; and the relationship of the fault rupture to the total length of each of the faults that ruptured. The earthquake magnitude and total rupture length are similar to what has been proposed for the segment of the Wellington fault that runs through the Wellington metropolitan area.

The sirch (Kerman, Iran) earthquake of 28 July 1981—A field investigation

1982 ◽  
Vol 72 (3) ◽  
pp. 841-861
Author(s):  
Hojjat Adeli
Keyword(s):  
Vertical Displacement ◽  
Field Investigation ◽  
Steel Buildings ◽  
Maximum Width ◽  
Epicentral Area ◽  
Historical Monuments ◽  
Fresh Surface ◽  
The City ◽  
The Town ◽  
Epicentral Region

abstract On 28 July 1981 at 17:22 UTC, the Kerman province of southern Iran was shaken by the largest and the most destructive earthquake in its history. Its surface-wave magnitude was about 7.2. The epicenter of the earthquake was located about 45 km southeast of the city of Kerman, the capital of the Kerman province. The shock killed nearly 3,000 people, left more than 31,000 homeless, and destroyed virtually all buildings in the epicentral region within a radius of 30 km. The hardest hit place was the town of Sirch where about 2,000 people died out of a population of 3,500. Surface fractures were observed in several areas, and the earthquake was apparently associated with a fresh surface normal faulting. The maximum vertical displacement was about 1 m. The maximum width of the fracture was 0.5 m. Also, extensive landsliding and numerous rockfalls were observed within the area of maximum damage. Most houses in the epicentral area are of adobe construction, made of sundried clay brick walls, and heavy domed roofs or vaults with clay or mud mortar. Most casualties were due to the collapse of these adobe buildings. However, the performance of unreinforced or reinforced brick buildings, historical monuments, steel buildings, and other types of structures during the earthquake is also discussed in this paper.

scholarly journals The Zagreb (Croatia) M5.5 Earthquake on 22 March 2020

Geosciences ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 252 ◽  
Author(s):  
Snježana Markušić ◽  
Davor Stanko ◽  
Tvrtko Korbar ◽  
Nikola Belić ◽  
Davorin Penava ◽  
...  
Keyword(s):  
Structural Engineering ◽  
Main Shock ◽  
Residential Buildings ◽  
Tectonic Setting ◽  
Time Lapse ◽  
Earthquake Sequence ◽  
Epicentral Area ◽  
Local Soil ◽  
Seismic Amplification ◽  
Zagreb Area

On 22 March 2020, Zagreb was struck by an M5.5 earthquake that had been expected for more than 100 years and revealed all the failures in the construction of residential buildings in the Croatian capital, especially those built in the first half of the 20th century. Because of that, extensive seismological, geological, geodetic and structural engineering surveys were conducted immediately after the main shock. This study provides descriptions of damage, specifying the building performances and their correlation with the local soil characteristics, i.e., seismic motion amplification. Co-seismic vertical ground displacement was estimated, and the most affected area is identified according to Sentinel-1 interferometric wide-swath data. Finally, preliminary 3D structural modeling of the earthquake sequence was performed, and two major faults were modeled using inverse distance weight (IDW) interpolation of the grouped hypocenters. The first-order assessment of seismic amplification (due to site conditions) in the Zagreb area for the M5.5 earthquake shows that ground motions of approximately 0.16–0.19 g were amplified at least twice. The observed co-seismic deformation (based on Sentinel-1A IW SLC images) implies an approximately 3 cm uplift of the epicentral area that covers approximately 20 km2. Based on the preliminary spatial and temporal analyses of the Zagreb 2020 earthquake sequence, the main shock and the first aftershocks evidently occurred in the subsurface of the Medvednica Mountains along a deep-seated southeast-dipping thrust fault, recognized as the primary (master) fault. The co-seismic rupture propagated along the thrust towards northwest during the first half-hour of the earthquake sequence, which can be clearly seen from the time-lapse visualization. The preliminary results strongly support one of the debated models of the active tectonic setting of the Medvednica Mountains and will contribute to a better assessment of the seismic hazard for the wider Zagreb area.

A time-domain study of the attenuation of 10-Hz waves in the New Madrid seismic zone

1978 ◽  
Vol 68 (2) ◽  
pp. 343-355
Author(s):  
Otto W. Nuttli
Keyword(s):  
Time Domain ◽  
Epicentral Distance ◽  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
Damage Potential ◽  
P Waves ◽  
Anelastic Attenuation ◽  
Design Earthquake ◽  
Almost All ◽  
New Madrid

Abstract From a time-domain study, the amplitude of 10-Hz P waves in the New Madrid seismic zone was found to fall off as the inverse 1.4 power of the epicentral distance. The amplitude of 10-Hz Lg waves was found to decay as for an Airy phase with a coefficient of anelastic attenuation of 0.006 km-1. In almost all cases the Lg motion was found to be larger than that of P, even at epicentral distances of 5 km and less. Thus design earthquake motions need to be concerned with Lg waves, whose coda also have a longer duration than those of the P waves. The apparent Q for the 10-Hz Lg waves is 1500, identical to that found previously by Nuttli (1973) for higher mode 1-Hz Lg waves. The attenuation of 10-Hz Lg waves is sufficiently small that one must pay attention to their damage potential at distances as large as a few hundred kilometers.

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.

scholarly journals Liquefaction and Related Ground Failure from July 2019 Ridgecrest Earthquake Sequence

2020 ◽  
Vol 110 (4) ◽  
pp. 1549-1566 ◽  
Author(s):  
Paolo Zimmaro ◽  
Chukwuebuka C. Nweke ◽  
Janis L. Hernandez ◽  
Kenneth S. Hudson ◽  
Martin B. Hudson ◽  
...  
Keyword(s):  
Lateral Spreading ◽  
Earthquake Sequence ◽  
Ground Failure ◽  
Liquefaction Susceptibility ◽  
Ground Deformations ◽  
Us Military ◽  
Liquefaction Hazard ◽  
Frame Buildings ◽  
Sand Boils ◽  
Wood Frame

ABSTRACT The 2019 Ridgecrest earthquake sequence produced a 4 July M 6.5 foreshock and a 5 July M 7.1 mainshock, along with 23 events with magnitudes greater than 4.5 in the 24 hr period following the mainshock. The epicenters of the two principal events were located in the Indian Wells Valley, northwest of Searles Valley near the towns of Ridgecrest, Trona, and Argus. We describe observed liquefaction manifestations including sand boils, fissures, and lateral spreading features, as well as proximate non-ground failure zones that resulted from the sequence. Expanding upon results initially presented in a report of the Geotechnical Extreme Events Reconnaissance Association, we synthesize results of field mapping, aerial imagery, and inferences of ground deformations from Synthetic Aperture Radar-based damage proxy maps (DPMs). We document incidents of liquefaction, settlement, and lateral spreading in the Naval Air Weapons Station China Lake US military base and compare locations of these observations to pre- and postevent mapping of liquefaction hazards. We describe liquefaction and ground-failure features in Trona and Argus, which produced lateral deformations and impacts on several single-story masonry and wood frame buildings. Detailed maps showing zones with and without ground failure are provided for these towns, along with mapped ground deformations along transects. Finally, we describe incidents of massive liquefaction with related ground failures and proximate areas of similar geologic origin without ground failure in the Searles Lakebed. Observations in this region are consistent with surface change predicted by the DPM. In the same region, geospatial liquefaction hazard maps are effective at identifying broad percentages of land with liquefaction-related damage. We anticipate that data presented in this article will be useful for future liquefaction susceptibility, triggering, and consequence studies being undertaken as part of the Next Generation Liquefaction project.

A Qualitative Study of Courtship and Reproductive Behavior in the Pearl Gourami, Trig'Hogaster Leeri (Bleeker)

Behaviour ◽  
1968 ◽  
Vol 32 (1-3) ◽  
pp. 70-84 ◽  
Author(s):  
Rudolph J. Miller ◽  
Darrell D. Hall
Keyword(s):  
Reproductive Behavior ◽  
Structural Features ◽  
Lateral Spread ◽  
Phase 3 ◽  
Male And Female ◽  
Color Changes ◽  
Stereotyped Behaviors ◽  
Preparatory Phase ◽  
One Year ◽  
Almost All

AbstractAn ethological study of courtship and reproductive behavior of the anabantoid fish, Trichogaster leeri (Bleeker), was conducted on 6 breeding pairs in aquaria. Sexual behavior in this species is characterized by stereotyped behaviors and a distinct temporal pattern of activities that presumably aids in species isolation. Data were taken on form and structural features of bubble-nests, colors of male and female, and behaviors occurring during daily or twice-daily 15-minute observation periods over a period of approximately one year. Spawning sequences usually last 2 to 5 hours in this species and are characterized by several different bout types (interactions between male and female), which may be initiated by either male or female. The major phases observed were: (1) prespawning preparatory phase (2) courtship phase (3) clasp (4) swimming inhibition (5) postspawning aggression and (6) interval between bouts. The prespawning phase in males is generally characterized by establishment of a nest-territory, development of breeding color, and elongation of dorsal and anal fin soft-rays. This phase in females is usually marked by increased abdominal plumpness and changes in color and body-markings. Strictly speaking, only the latter parts of this phase occur during spawnings. Spawning bouts (stages 2, 3, and 4 of the ethogram) comprise approximately 7% of all bouts and many of these do not follow an "ideal" pattern. Spawning bouts usually last 50-55 seconds with courtship requiring 12-15 seconds, the clasp about 25 seconds, swimming inhibition 2-5 seconds, and postspawning aggression 3-6 seconds. Female courtship butting precedes almost all spawnings and appears to release leading-to-the-nest, lateral spread display, and curving in sexually responsive males. Spawning bouts generally contain fewer female courtship butts than most other sexual bouts and a conspicuous difference exists between female courtship butting means in spawning and pseudospawning bouts. Although reproductive behavior in T. leeri is stereotyped, variation in form, sequence, and duration of components is evident. Flexibility and adaptability are common so that variation within certain limits may be tolerated and/or compensated for. Hyperaggressiveness, physiological condition, low sexual motivation, mechanical problems, and previous experience appear to be important factors in determining the success of sexual bouts in T. leeri. Reproductive color changes, body-marking changes, and sexual dimorphism provide visual stimuli that may aid in the synchronization of reproductive behavior.

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