Pliocene-Pleistocene break-up of the Sierra Nevada–White-Inyo Mountains block and formation of Owens Valley

Geology ◽  
1978 ◽  
Vol 6 (8) ◽  
pp. 461 ◽  
Author(s):  
Steven B. Bachman
Keyword(s):  
1971 ◽  
Vol 61 (5) ◽  
pp. 1413-1432 ◽  
Author(s):  
Frank J. Gumper ◽  
Christopher Scholz

abstract Microseismicity, composite focal-mechanism solutions, and previously-published focal parameter data are used to determine the current tectonic activity of the prominent zone of seismicity in western Nevada and eastern California, termed the Nevada Seismic Zone. The microseismicity substantially agrees with the historic seismicity and delineates a narrow, major zone of activity that extends from Owens Valley, California, north past Dixie Valley, Nevada. Focal parameters indicate that a regional pattern of NW-SE tension exists for the western Basin and Range and is now producing crustal extension within the Nevada Seismic Zone. An eastward shift of the seismic zone along the Excelsior Mountains and left-lateral strike-slip faulting determined from a composite focal mechanism indicate transform-type faulting between Mono Lake and Pilot Mountain. Based on these results and other data, it is suggested that the Nevada Seismic Zone is caused by the interaction of a westward flow of mantle material beneath the Basin and Range Province with the boundary of the Sierra Nevada batholith.


1934 ◽  
Vol 24 (4) ◽  
pp. 345-384 ◽  
Author(s):  
Vincent P. Gianella ◽  
Eugene Callaghan

Summary The Cedar Mountain, Nevada, earthquake took place at about 10h 10m 04s p.m., December 20, 1932. It was preceded by a foreshock noted locally and followed by thousands of aftershocks, which were reported as still continuing in January 1934. No lives were lost and there was very little damage. The earthquake originated in southwest central Nevada, east of Mina. A belt of rifts or faults in echelon lies in the valley between Gabbs Valley Range and Pilot Mountains on the west and Cedar Mountain and Paradise Range on the east. The length of this belt is thirty-eight miles in a northwesterly direction, and the width ranges from four to nine miles. The rifts consist of zones of fissures which commonly reveal vertical displacement and in a number of places show horizontal displacement. The length of the rifts ranges from a few hundred feet to nearly four miles, and the width may be as much as 400 feet. The actual as well as indicated horizontal displacement is represented by a relative southward movement of the east side of each rift. The echelon pattern of the rifts within the rift area indicates that the relative movement of the adjoining mountain masses is the same. The direction of relative horizontal movement corresponds to that along the east front of the Sierra Nevada at Owens Valley and on the San Andreas rift.


1980 ◽  
Vol 70 (5) ◽  
pp. 1557-1572
Author(s):  
J. D. VanWormer ◽  
Alan S. Ryall

abstract Precise epicentral determinations based on local network recordings are compared with mapped faults and volcanic features in the western Great Basin. This region is structurally and seismically complex, and seismogenic processes vary within it. In the area north of the rupture zone of the 1872 Owens Valley earthquake, dispersed clusters of epicenters agree with a shatter zone of faults that extend the 1872 breaks to the north and northwest. An area of frequent earthquake swarms east of Mono Lake is characterized by northeast-striking faults and a crustal low-velocity zone; seismicity in this area appears to be related to volcanic processes that produced thick Pliocene basalt flows in the Adobe Hills and minor historic activity in Mono Lake. In the Garfield Hills between Walker Lake and the Excelsior Mountains, there is some clustering of epicenters along a north-trending zone that does not correlate with major Cenozoic structures. In an area west of Walker Lake, low seismicity supports a previous suggestion by Gilbert and Reynolds (1973) that deformation in that area has been primarily by folding and not by faulting. To the north, clusters of earthquakes are observed at both ends of a 70-km-long fault zone that forms the eastern boundary of the Sierra Nevada from Markleeville to Reno. Clusters of events also appear at both ends of the Dog Valley Fault in the Sierra west of Reno, and at Virginia City to the east. Fault-plane solutions for the belt in which major earthquakes have occurred in Nevada during the historic period (from Pleasant Valley in the north to the Excelsior Mountains on the California-Nevada Border) correspond to normaloblique slip and are similar to that found by Romney (1957) for the 1954 Fairview Peak shock. However, mechanisms of recent moderate earthquakes within the SNGBZ are related to right- or left-lateral slip, respectively, on nearly vertical, northwest-, or northeast-striking planes. These mechanisms are explained by a block faulting model of the SNGBZ in which the main fault segments trend north, have normal-oblique slip, and are offset or terminated by northwest-trending strike-slip faults. This is supported by the observation that seismicity during the period of observation has been concentrated at places where major faults terminate or intersect. Anomalous temporal variations, consisting of a general decrease in seismicity in the southern part of the SNGBZ from October 1977 to September 1978, followed by a burst of moderate earthquakes that has continued for more than 18 months, is suggestive of a pattern that several authors have identified as precursory to large earthquakes. The 1977 to 1979 variations are particularly noteworthy because they occurred over the entire SNGBZ, indicating a regional rather than local cause for the observed changes.


1973 ◽  
Vol 63 (2) ◽  
pp. 571-586
Author(s):  
Dean S. Carder

abstract An experiment to investigate the major earth structure along a profile from the Nevada Test Site (NTS) to the Pacific Ocean across two sections of the Sierra Nevada, one in the Kings Canyon area and the other which includes Huntington Lake, was undertaken by the Earthquake Mechanism Laboratory of the National Oceanic and Atmospheric Administration (NOAA). Instrumental coverage included 35 temporary and seven permanent seismographs. Energy sources included four high-yield and 20 intermediate- to low-yield nuclear explosions under the NTS, one high-yield explosion under Amchitka Island of Alaska, two earthquakes near Santa Rosa, and one earthquake in Monterey Bay. An upper-mantle speed of 7.9 km/sec satisfied most of the observed data except under the Sierra where the velocity was somewhat lower than this. An earthquake in Monterey Bay helped to close the west end of the profile. The Sierra Nevada “root” in large part can be attributed to relatively low upper-mantle speed under the Sierras (estimated at 7.64 km/sec) which extends to an indefinite depth and which possibly may serve as lens to refract late arriving high-energy waves to coastal areas. Crustal thickness from the Sierra foothills eastward varies from 25 to 35 km, the thinner portion under the Sierra crest and Owens Valley, near Independence, and the thicker sections under the western Sierra and the basin ranges east of Owens Valley. West of Fresno, the crust thins more or less gradually to about 20 km in thickness under the western coast ranges. This profile contrasts with that from an earlier study, across the Central Valley south of Stockton, where no such thinning under the Central Valley was observed. The sub-Sierra crust east of Fresno is somewhat complicated. Low-angle thrusting toward the east is indicated.


Author(s):  
Egill Hauksson ◽  
Brian Olson ◽  
Alex Grant ◽  
Jennifer R. Andrews ◽  
Angela I. Chung ◽  
...  

Abstract The 2020 Mw 5.8 Lone Pine earthquake, the largest earthquake on the Owens Valley fault zone, eastern California, since the nineteenth century, ruptured an extensional stepover in that fault. Owens Valley separates two normal-faulting regimes, the western margin of the Great basin and the eastern margin of the Sierra Nevada, forming a complex seismotectonic zone, and a possible nascent plate boundary. Foreshocks began on 22 June 2020; the largest Mw 4.7 foreshock occurred at ∼6  km depth, with primarily normal faulting, followed ∼40  hr later on 24 June 2020 by an Mw 5.8 mainshock at ∼7  km depth. The sequence caused overlapping ruptures across a ∼0.25  km2 area, extended to ∼4  km2, and culminated in an ∼25  km2 aftershock area. The mainshock was predominantly normal faulting, with a strike of 330° (north-northwest), dipping 60°–65° to the east-northeast. Comparison of background seismicity and 2020 Ridgecrest aftershock rates showed that this earthquake was not an aftershock of the Ridgecrest mainshock. The Mw–mB relationship and distribution of ground motions suggest typical rupture speeds. The aftershocks form a north-northwest-trending, north-northeast-dipping, 5 km long distribution, consistent with the rupture length estimated from analysis of regional waveform data. No surface rupture was reported along the 1872 scarps from the 2020 Mw 5.8 mainshock, although, the dipping rupture zone of the Mw 5.8 mainshock projects to the surface in the general area. The mainshock seismic energy triggered rockfalls at high elevations (>3.0  km) in the Sierra Nevada, at distances of 8–20 km, and liquefaction along the western edge of Owens Lake. Because there were ∼30% fewer aftershocks than for an average southern California sequence, the aftershock forecast probabilities were lower than expected. ShakeAlert, the earthquake early warning system, provided first warning within 9.9 s, as well as subsequent updates.


2012 ◽  
Vol 51 (7) ◽  
pp. 1333-1352 ◽  
Author(s):  
Peter Sheridan ◽  
Simon Vosper

AbstractThe downslope windstorm during intensive observation period (IOP) 6 was the most severe that was detected during the Terrain-Induced Rotor Experiment (T-REX) in Owens Valley in the Sierra Nevada of California. Cross sections of vertical motion in the form of a composite constructed from aircraft data spanning the depth of the troposphere are used to link the winds experienced at the surface to the changing structure of the mountain-wave field aloft. Detailed analysis of other observations allows the role played by a passing occluded front, associated with the rapid intensification (and subsequent cessation) of the windstorm, to be studied. High-resolution, nested modeling using the Met Office Unified Model (MetUM) is used to study qualitative aspects of the flow and the influence of the front, and this modeling suggests that accurate forecasting of the timing and position of both the front and strong mountaintop winds is crucial to capture the wave dynamics and accompanying windstorm. Meanwhile, far ahead of the front, simulated downslope winds are shallow and foehnlike, driven by the thermal contrast between the upstream and valley air mass. The study also highlights the difficulties of capturing the detailed interaction of weather systems with large and complex orography in numerical weather prediction.


Author(s):  
Jonathan S. Adams ◽  
Bruce A. Stein

Unusually heavy rains in the winter of 1969 transformed California’s normally dry Owens Valley, causing an explosion of grasses and reeds along the edge of the Owens River. Lying in the eastern rain shadow of the Sierra Nevada, not far from Death Valley, the river flows south down the valley before disappearing into a dry lake bed. By summer the heavy vegetation along the river and its adjacent spring-fed marshes was sucking up moisture and releasing it into the hot, dry air. At the same time, the flow from one of these springs suddenly and mysteriously dropped, and parts of a wetland called Fish Slough began to dry up fast. The disappearance of the small pools that make up Fish Slough would have gone unnoticed in a world not reshaped by human hands. Desert springs and marshes can be verdant one year, parched the next. Human activity, however, had made Fish Slough a vital place. The need for water to support Los Angeles and other cities has led to all manner of water projects, including dams, reservoirs, canals, and aqueducts. One of those projects, the Los Angeles Aqueduct, diverted nearly all the water from the Owens River beginning in 1913, greatly reducing the flows that once created seasonally flooded shallows along the river’s edge. Those shallow, warm waters provided ideal habitat for a unique species offish, the Owens pupfish (Cyprinodon radiosus). The loss of habitat, along with the introduction of exotic species like largemouth bass, gradually eliminated the pupfish from most of its relatively limited range, until the species remained only in Fish Slough. If the marsh disappeared, so would the Owens pupfish. Alerted to the potential disaster, Phil Pister, a fishery biologist working nearby with the California Department of Fish and Game, and two colleagues grabbed nets, buckets, and aerators and raced for the pond (Pister 1993). They removed the last 800 of the two-inch-long pupfish to wire mesh cages in the main channel of the slough. As his colleagues drove off, thinking the pupfish at least temporarily secure, Pister realized that the cages were in eddies out of the main current and that the water in the eddies was not carrying enough dissolved oxygen.


2008 ◽  
Vol 136 (9) ◽  
pp. 3536-3552 ◽  
Author(s):  
Shiyuan Zhong ◽  
Ju Li ◽  
C. David Whiteman ◽  
Xindi Bian ◽  
Wenqing Yao

Abstract The climatology of high wind events in the Owens Valley, California, a deep valley located just east of the southern Sierra Nevada, is described using data from six automated weather stations distributed along the valley axis in combination with the North American Regional Reanalysis dataset. Potential mechanisms for the development of strong winds in the valley are examined. Contrary to the common belief that strong winds in the Owens Valley are westerly downslope windstorms that develop on the eastern slope of the Sierra Nevada, strong westerly winds are rare in the valley. Instead, strong winds are highly bidirectional, blowing either up (northward) or down (southward) the valley axis. High wind events are most frequent in spring and early fall and they occur more often during daytime than during nighttime, with a peak frequency in the afternoon. Unlike thermally driven valley winds that blow up valley during daytime and down valley during nighttime, strong winds may blow in either direction regardless of the time of the day. The southerly up-valley winds appear most often in the afternoon, a time when there is a weak minimum of northerly down-valley winds, indicating that strong wind events are modulated by local along-valley thermal forcing. Several mechanisms, including downward momentum transfer, forced channeling, and pressure-driven channeling all play a role in the development of southerly high wind events. These events are typically accompanied by strong south-southwesterly synoptic winds ahead of an upper-level trough off the California coast. The northerly high wind events, which typically occur when winds aloft are from the northwest ahead of an approaching upper-level ridge, are predominantly caused by the passage of a cold front when fast-moving cold air behind the surface front undercuts and displaces the warmer air in the valley. Forced channeling by the sidewalls of the relatively narrow valley aligns the wind direction with the valley axis and enhances the wind speeds.


2017 ◽  
Vol 56 (4) ◽  
pp. 1003-1023 ◽  
Author(s):  
Stefano Serafin ◽  
Lukas Strauss ◽  
Vanda Grubišić

AbstractA 5-yr climatology of westerly wind events in Owens Valley, California, is derived from data measured by a mesoscale network of 16 automatic weather stations. Thermally driven up- and down-valley flows are found to account for a large part of the diurnal wind variability in this approximately north–south-oriented deep U-shaped valley. High–wind speed events at the western side of the valley deviate from this basic pattern by showing a higher percentage of westerly winds. In general, strong westerly winds in Owens Valley tend to be more persistent and to display higher sustained speeds than strong winds from other quadrants. The highest frequency of strong winds at the valley floor is found in the afternoon hours from April to September, pointing to thermal forcing as a plausible controlling mechanism. However, the most intense westerly wind events (westerly windstorms) can happen at any time of the day throughout the year. The temperature and humidity variations caused by westerly windstorms depend on the properties of the approaching air masses. In some cases, the windstorms lead to overall warming and drying of the valley atmosphere, similar to foehn or chinook intrusions. The key dynamical driver of westerly windstorms in Owens Valley is conjectured to be the downward penetration of momentum associated with mountain waves produced by the Sierra Nevada ridgeline to the west of the valley.


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