Geodetic Observation of Seismic Cycles before, during, and after the 2020 Monte Cristo Range, Nevada Earthquake

2020 ◽  
Author(s):  
William C. Hammond ◽  
Geoffrey Blewitt ◽  
Corné Kreemer ◽  
Richard D. Koehler ◽  
Seth Dee
Keyword(s):  
Great Basin ◽  
Length Change ◽  
Postseismic Deformation ◽  
Seismic Gap ◽  
Coseismic Displacement ◽  
Viscoelastic Deformation ◽  
Surface Rupture ◽  
Event Time ◽  
Time Modeling ◽  
The Individual

Abstract The 15 May 2020, M 6.5 Monte Cristo Range, Nevada earthquake (MCE) occurred inside the footprint of the semicontinuous MAGNET and continuous Network of the Americas Global Positioning System (GPS) networks, which provide precise geodetic coverage in the western Great basin. The event occurred in the White Mountain seismic gap between twentieth century events in the eastern central Walker Lane, on an east-northeast extension of faults in the Candelaria Hills. The earthquake precipitated a rapid and sustained GPS field response, which is providing data on the MCE pre-, co-, and postseismic deformation. The response was especially rapid owing to ∼1 dozen MAGNET stations immediately surrounding the epicenter being fortuitously occupied with receivers at event time. Modeling the coseismic displacements suggests that the MCE offset was ∼1  m, greater than the individual observations of surface rupture, but consistent with the seismic moment. Although the epicenter is separated from most of the observed surface rupture by ∼10  km, the slip plane inferred from the GPS data spans the gap, suggesting deep slip continuity that tapered toward the surface, making the event partially blind. However, the range of magnitudes estimated from geologic, geodetic, and seismic data overlap in the range of Mw 6.3–6.4. Postseismic displacement over several months occurred in directions aligned with the coseismic displacement, suggesting afterslip of over 9% of the coseismic displacement, too large to be explained by aftershock seismicity, suggesting that most postseismic deformation was aseismic. The interseismic direction of no-length change was very closely aligned to the MCE slip azimuth, as expected for a strike-slip event. This alignment is sensitive to transient postseismic viscoelastic deformation from previous earthquakes in the western Great basin, which may have temporarily improved the alignment. Thus, these viscoelastic transients may have created conditions favoring the slip to occur on the MCE fault.

scholarly journals Performance Evaluation of Different SAR-Based Techniques on the 2019 Ridgecrest Sequence

2021 ◽  
Vol 13 (4) ◽  
pp. 685
Author(s):  
Marco Polcari ◽  
Mimmo Palano ◽  
Marco Moro
Keyword(s):  
Performance Evaluation ◽  
Strike Slip ◽  
Seismic Sequence ◽  
Fault Rupture ◽  
Coseismic Displacement ◽  
Surface Rupture ◽  
Eastern California Shear Zone ◽  
Tectonic Framework ◽  
Gnss Network ◽  
The One

We evaluated the performances of different SAR-based techniques by analyzing the surface coseismic displacement related to the 2019 Ridgecrest seismic sequence (an Mw 6.4 foreshock on July 4th and an Mw 7.1 mainshock on July 6th) in the tectonic framework of the eastern California shear zone (Southern California, USA). To this end, we compared and validated the retrieved SAR-based coseismic displacement with the one estimated by a dense GNSS network, extensively covering the study area. All the SAR-based techniques constrained the surface fault rupture well; however, in comparison with the GNSS-based coseismic displacement, some significant differences were observed. InSAR data showed better performance than MAI and POT data by factors of about two and three, respectively, therefore confirming that InSAR is the most consolidated technique to map surface coseismic displacements. However, MAI and POT data made it possible to better constrain the azimuth displacement and to retrieve the surface rupture trace. Therefore, for cases of strike-slip earthquakes, all the techniques should be exploited to achieve a full synoptic view of the coseismic displacement field.

scholarly journals Quantifying changes and trends in glacier area and volume in the Austrian Ötztal Alps (1969-1997-2006)

2009 ◽  
Vol 3 (2) ◽  
pp. 205-215 ◽  
Author(s):  
J. Abermann ◽  
A. Lambrecht ◽  
A. Fischer ◽  
M. Kuhn
Keyword(s):  
Length Change ◽  
High Temporal Resolution ◽  
Glacier Area ◽  
Thickness Change ◽  
Additional Information ◽  
Digital Elevation ◽  
Glacier Changes ◽  
The Individual ◽  
Individual Size ◽  
Area And Volume

Abstract. In this study we apply a simple and reliable method to derive recent changes in glacier area and volume by taking advantage of high resolution LIDAR (light detection and ranging) DEMs (digital elevation models) from the year 2006. Together with two existing glacier inventories (1969 and 1997) the new dataset enables us to quantify area and volume changes over the past 37 years at three dates. This has been done for 81 glaciers (116 km2) in the Ötztal Alps which accounts for almost one third of Austria's glacier extent. Glacier area and volume have reduced drastically with significant differences within the individual size classes. Between 1997 and 2006 an overall area loss of 10.5 km2 or 8.2% occurred. Volume has reduced by 1.0 km3 which accounts for a mean thickness change of −8.2 m. The availability of three comparable inventories allows a comprehensive size and altitude dependent analysis of glacier changes but lacks a high temporal resolution. For the comparison of rates of changes between the two different periods (1969 to 1997 with 1997 to 2006) we propose two approaches in this study: a) to estimate mean overall rates of changes (including a period of advance) and b) to extract periods of net-retreat by using additional information (length change and mass balance measurements). Analysis of the resulting acceleration factors reveals that the retreat of volume and mean thickness changes has accelerated significantly more than that of area changes.

Coseismic Displacement and Recurrence Interval of the 1973 Ragay Gulf Earthquake, Southern Luzon, Philippines

2015 ◽  
Vol 10 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Hiroyuki Tsutsumi ◽  
◽  
Jeffrey S. Perez ◽  
Jaime U. Marjes ◽  
Kathleen L. Papiona ◽  
...  
Keyword(s):  
Slip Rate ◽  
Recurrence Interval ◽  
Geologic Mapping ◽  
Fault Creep ◽  
Coseismic Displacement ◽  
Surface Rupture ◽  
The Past

The 1973 Ragay Gulf earthquake produced an onshore surface rupture approximately 30 km in length along the Guinayangan segment of the Philippine fault in southern Luzon Island. Through geologic mapping and paleoseismic trenching, we have characterized the amount of coseismic offsets, the average recurrence interval, and the slip rate of the segment. The coseismic offsets we identified in the field were fairly constant along the fault, ranging from 1 to 2 m. Paleoseismic trenching at the Capuluan Tulon site exposed stratigraphic evidence for three or possibly four surfacerupturing events after the deposition of strata dated at AD 410–535. The average recurrence interval was calculated to be 360–780 years, which is close to that for the Digdig fault, the source fault of the 1990 central Luzon earthquake. The slip rate, based on the calculated recurrence interval and offsets during the 1973 earthquake, has been calculated to be 2.1–4.4 mm/yr. This rate is significantly smaller than the geodetic slip and creep rates of 20–25 mm/yr estimated for the Philippine fault on the islands of Masbate and Leyte. The slip rate deficit may be explained by the possibilities of underestimation of the recurrence interval due to possible missing paleoseismic events within the stratigraphic records, the occurrence of larger earthquakes in the past, and the aseismic fault creep between the surface-rupturing earthquakes.

Rapid Geodetic Observations of Spatiotemporally Varying Postseismic Deformation Following the Ridgecrest Earthquake Sequence: The U.S. Geological Survey Response

2020 ◽  
Vol 91 (4) ◽  
pp. 2108-2123 ◽  
Author(s):  
Benjamin A. Brooks ◽  
Jessica Murray ◽  
Jerry Svarc ◽  
Eleyne Phillips ◽  
Ryan Turner ◽  
...  
Keyword(s):  
Time Series ◽  
Horizontal Displacement ◽  
The United States ◽  
Satellite System ◽  
Earthquake Sequence ◽  
Postseismic Deformation ◽  
Displacement Fields ◽  
Surface Rupture ◽  
Global Navigation Satellite ◽  
The U.S

Abstract The U.S. Geological Survey’s geodetic response to the 4–5 July 2019 (Pacific time) Ridgecrest earthquake sequence comprised primarily the installation and/or reoccupation of Global Navigation Satellite System (GNSS) monumentation. Our response focused primarily on the United States’ Navy’s China Lake Naval Air Weapons Station base (NAWSCL). This focus was because much of the surface rupture occurred on the NAWSCL and because of NAWSCL access restrictions only permitting Federal and State of California personnel. In total, we measured or are still measuring at 24 sites, 14 of which were on the NAWSCL and, as of this writing, operational. The majority of sites were set up as continuous stations logging at either 1 sample per second or 1 sample per 15 s. Two stations were recording a 200 m cross-rupture aperture starting ∼10  hr after the M 6.4 event, and they recorded the coseismic displacements of the M 7.1. Approximately, 1 hr after the M 7.1 event, two new stations were recording a ∼200  m cross-rupture aperture of the surface rupture. In the days following, we established the rest of the stations ranging to a distance of ∼15  km from the M 7.1 principal rupture trace. The lack of differential displacement across the M 6.4 rupture during the M 7.1 event suggests that it did not reactivate the M 6.4 plane. The lack of differential cross-fault displacement for both events suggests that rapid shallow afterslip did not occur at those two locations. The postseismic time series from these stations shows centimeters of horizontal displacement over periods of a few months. They record a mixture of fault-parallel and fault-normal displacements that, in conjunction with analysis of more spatially complete Interferometric Synthetic Aperture Radar displacement fields, suggest that both poroelastic and afterslip phenomena occur along the M 6.4 and 7.1 rupture planes. Using preliminary data from these and other regional stations, we also explore the Ridgecrest sequence’s effect on regional GNSS time series and the differentiation of long-term postseismic motions and secular deformation rates. We find that redefining a common-mode noise filter using different GNSS stations that are assumed to be unaffected by the earthquakes results in small but systematic differences in the regional velocity field estimate.

Strain-Rate-Dependent Deformation Behavior of Carbon-Black-Filled Rubber under Monotonic and Cyclic Straining

2007 ◽  
Vol 340-341 ◽  
pp. 1017-1024 ◽  
Author(s):  
Yoshihiro Tomita ◽  
K. Azuma ◽  
M. Naito
Keyword(s):  
Strain Rate ◽  
Cyclic Deformation ◽  
Deformation Behavior ◽  
Viscoelastic Deformation ◽  
Rate Dependent ◽  
Filled Rubber ◽  
Deformation Behaviors ◽  
Deformation Processes ◽  
The Individual ◽  
Cyclic Straining

The constitutive equation of rubber is derived by employing a nonaffine molecular chain network model for an elastic deformation behavior and the reptation theory for a viscoelastic deformation behavior. The results reveal the roles of the individual springs and dashpot, and the strain rate dependence of materials and disentanglement of molecular chains in the monotonic and cyclic deformation behaviors, particularly softening and hysteresis loss, that is, the Mullins effect, occurring in stress-stretch curves under cyclic deformation processes.

scholarly journals Models of postseismic deformation after megaearthquakes: the role of various rheological and geometrical parameters of the subduction zone

2014 ◽  
Vol 6 (1) ◽  
pp. 427-466 ◽  
Author(s):  
O. Trubienko ◽  
J.-D. Garaud ◽  
L. Fleitout
Keyword(s):  
Vertical Velocity ◽  
Horizontal Velocity ◽  
Postseismic Deformation ◽  
Geometrical Parameters ◽  
Strong Impact ◽  
Far Field ◽  
Coseismic Displacement ◽  
Volcanic Arc ◽  
Low Viscosity

Abstract. The postseismic deformations following subduction megaearthquakes are characterized by a horizontal velocity which, once non-dimensionalized by the coseismic displacement, increases with distance to the trench then presents an almost constant value for distances between 500 and 1500 km. The vertical velocity features a strong narrow peak on the trenchward side of the volcanic arc. Subsidence is observed in the far-field. In order to understand better the implications of these observations, the influence of the geometry of low viscosity regions in subduction zones on the postseismic deformations is analyzed using a 2-D finite element model with viscoelastic rheologies. The slab dip in the top 80 km Θtop, and deeper Θbottom and the locking depth all have a limited impact on the ratio of horizontal postseismic velocity over coseismic displacement. The smaller Θbottom, the smaller the amplitude of the predicted vertical velocity in the middle-field (200–500 km from the trench). The presence of the slab at asthenospheric depths affects very significantly both the horizontal and vertical velocities. Models with an 80 km thick lithosphere, where the relaxation occurs only in the asthenosphere, are characterized by a trenchward horizontal velocity decreasing very moderately in the middle-field and an uplift maximum on the continental side of the volcanic arc, at odds with the observations. A low viscosity channel (LVCh) over the deep parts of the subduction interface or a low viscosity wedge (LVW) have a considerable impact on the middle-field horizontal and vertical velocities: the trenchward horizontal velocities are very significantly increased while the vertical velocities are characterized by strong uplift over the deep parts of the subduction interface. In the case of a low viscosity wedge, a marked subsidence further away from the trench, on the continent side of the volcanic arc is predicted. While the low-viscosity wedge affects little the far-field horizontal velocities, the LVCh increases them significantly. The thicknesses of the lithosphere and the asthenosphere also have a strong impact on both the middle-field and the far-field velocities. The larger they are, the further from the trench are the maxima of the ratio of the postseismic over coseismic horizontal displacement and of the far-field subsidence. 3-D modeling with a geometry as precise as possible of the various zones with postseismic creep associated with each megaearthquake is necessary to derive more precise conclusions. However, the 2-D modeling results obtained here, compared with postseismic data, point towards lithospheres and asthenospheres surprisingly similar in various areas of the world, with thicknesses around 70 and 200 km respectively and towards the presence of a LVW and/or a LVCh. The systematic description of the role of each parameter presented here will facilitate the choice of the parameters to vary in 3-D models.

scholarly journals Partitioned postseismic deformation associated with the 2009 Mw 6.3 L'Aquila earthquake surface rupture measured using a terrestrial laser scanner

2010 ◽  
Vol 37 (10) ◽  
pp. n/a-n/a ◽  
Author(s):  
M. Wilkinson ◽  
K. J. W. McCaffrey ◽  
G. Roberts ◽  
P. A. Cowie ◽  
R. J. Phillips ◽  
...  
Keyword(s):  
Laser Scanner ◽  
Postseismic Deformation ◽  
Terrestrial Laser Scanner ◽  
L’Aquila Earthquake ◽  
Surface Rupture

scholarly journals Comparative Study of the Tempering Behavior of Different Martensitic Steels by Means of In-Situ Diffractometry and Dilatometry

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5058
Author(s):  
Martin Hunkel ◽  
Juan Dong ◽  
Jeremy Epp ◽  
Daniel Kaiser ◽  
Stefan Dietrich ◽  
...  
Keyword(s):  
Comparative Study ◽  
Length Change ◽  
Low Alloy Steels ◽  
Low Carbon ◽  
Martensitic Steels ◽  
High Alloy ◽  
Microstructural Effects ◽  
Alloy Steels ◽  
The Individual

Martensitic steels are tempered to increase the toughness of the metastable martensite, which is brittle in the as-quenched state, and to achieve a more stable microstructure. During the tempering of steels, several particular overlapping effects can arise. Classical dilatometric investigations can only detect effects by monitoring the integral length change of the sample. Additional in-situ diffractometry allowed a differentiation of the individual effects such as transformation of retained austenite and formation of cementite during tempering. Additionally, the lattice parameters of martensite and therefrom the tetragonality was analyzed. Two low-alloy steels with carbon contents of 0.4 and 1.0 wt.% and a high-alloy 5Cr-1Mo-steel with 0.4 wt.% carbon were investigated by dilatometry and in-situ diffractometry. In this paper, microstructural effects during tempering of the investigated steels are discussed by a comparative study of dilatometric and diffractometric experiments. The influence of the chemical composition on the tempering behavior is illustrated by comparing the determined effects of the three steels. The kinetics of tempering is similar for the low-alloy steels and shifted to much higher temperatures for the high-alloy steel. During tempering, the tetragonality of martensite in the steel with 1.0 wt% carbon shifts towards a low carbon behavior, as in the steels with 0.4 wt.% carbon.

scholarly journals Crustal velocity and interseismic strain-rate on possible zones for large earthquakes in the Garhwal–Kumaun Himalaya

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
John P. Pappachen ◽  
Rajesh Sathiyaseelan ◽  
Param K. Gautam ◽  
Sanjit Kumar Pal
Keyword(s):  
Strain Rate ◽  
Active Fault ◽  
Surface Strain ◽  
Seismic Gap ◽  
Surface Rupture ◽  
Nw Himalaya ◽  
Crustal Velocity ◽  
Central Seismic Gap ◽  
Large Earthquakes ◽  
Low Strain Rate

AbstractThe possibility of a major earthquake like 2015 Gorkha–Nepal or even greater is anticipated in the Garhwal–Kumaun region in the Central Seismic Gap of the NW Himalaya. The interseismic strain-rate from GPS derived crustal velocities show multifaceted strain-rate pattern in the region and are classified into four different strain-rate zones. Besides compressional, we identified two NE–SW orienting low strain rate (~ 20 nstrain/a) zones; namely, the Ramganga-Baijro and the Nainital-Almora, where large earthquakes can occur. These zones have surface locking widths of ~ 72 and ~ 75 km respectively from the Frontal to the Outer Lesser Himalaya, where no significant surface rupture and associated large earthquakes were observed for the last 100 years. However, strain reducing extensional deformation zone that appears sandwiched between the low strain-rate zones pose uncertainties on the occurences of large earthquakes in the locked zone. Nevertheless, such zone acts as a conduit to transfer strain from the compressional zone (> 100 nstrain/a) to the deforming frontal active fault systems. We also observed a curvilinear surface strain-rate pattern in the Chamoli cluster and explained how asymmetric crustal accommodation processes at the northwest and the southeast edges of the Almora Klippe, cause clockwise rotational couple on the upper crust moving over the MHT.

How Has GPS Velocity Field Changed Along the 1999 Izmit Rupture 20 Years After the 1999 Izmit, Turkey Earthquake?

2020 ◽  
Author(s):  
Seda Özarpacı ◽  
Uğur Doğan ◽  
Semih Ergintav ◽  
Ziyadin Çakır ◽  
Alpay Özdemir ◽  
...  
Keyword(s):  
Postseismic Deformation ◽  
Seismic Gap ◽  
Near Fault ◽  
Seismic Deformations ◽  
The North ◽  
Western Segment ◽  
Far Fault ◽  
Gps Velocity Field ◽  
Epicentral Region ◽  
Gps Observations

<p>A seismic gap along the western segment of the North Anatolian Fault, in the Marmara-Izmit region, was identified before the 1999 M7.6, Izmit and M7.4 Duzce earthquakes, so the region along the coseismic fault has been monitored with geodetic techniques for decades, providing well defined pre-, co- and post-seismic deformations. Here, we report new continuous and survey GPS measurements with near-fault (~2 – 10 km to the fault) and far-fault (~50 – 70 km from the fault) stations, including 7 years (2013 – 2019) of continuous observations, and 5 near-fault campaigns (every six months between 2014 – 2016) to further investigate postseismic deformation. GPS observations were processed with the GAMIT/GLOBK (v10.7) GNSS software. We used these observations to estimate the spatial distribution of current aseismic after-slip, along the 1999 Izmit rupture. We also searched for spatiotemporal changes of shallow creep events along the surface trace. With elastic models and GPS observations, we determined a shallow creep rate that reaches a maximum around the epicenter of the 1999 Izmit earthquake of about 12.7 ± 1.2 mm/yr, consistent with published InSAR results. Creep rates decrease both east and west of the epicentral region. Moreover, we show that broad-scale postseismic effects that diminish logarithmically, continue at present. (This study is supported by TUBITAK 1001 project no: 113Y102 and 117Y278)</p>

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