The 26 December 2004 Sumatra-Andaman earthquake initiated slowly, with small slip and a slow rupture speed for the first 40 to 60 seconds. Then expanded at of about 2.5 kilometers per second toward north northwest, extending 1200 1300 along Andaman trough. Peak displacements reached approximately 15 meters 600-kilometer segment plate boundary offshore northwestern Sumatra southern Nicobar islands. Slip was less in northern 400 500 aftershock zone, least some that region may have occurred on...

Four great earthquakes (1952, 1960, 1964, and 2004) have occurred since seismic monitoring began only two the installation of a global network. A reexamination 1964 (M 9.2) Prince William Sound (PWS), Alaska, earthquake is timely due to 2004 Sumatra because it adds constraints potential range source parameters for these types infrequent events aids in ability predict ground motions other subduction zone including Cascadia. We first measured durations high‐frequency energy radiation from...

We digitized teleseismic and regional records of the 1944 Tonankai earthquake. used multiple time window method to invert these for spatial temporal distribution slip rake. assume a 220 × 140 km fault with spacing 20 maximum rupture velocity 2.5 km/s. The inversion resolved an asperity along accretionary wedge under Shima Atsumi Peninsulas. propagated from southwest northeast, there was little near hypocenter, consistent absence uplift in overlying submarine forearc basin. peak is 2.3 m,...

The moment tensors and centroid depths are estimated for eastern California western Nevada earthquakes from regionally recorded long-period seismograms using the moment-tensor inversion method. We compiled tensor solutions into a catalog complete with M W > 4 since 1990. in this study mostly located within aftershock zones of Eureka Valley, Double Spring Flat, Coso, Ridgecrest, Fish Lake Scotty's Junction, remaining distributed across region. validated by comparison Harvard (CMT) P -wave...

The December 2004 Sumatra-Andaman earthquake emphasized the need for a consistent and comprehensive assessment of tsunami hazard. We have developed method Probabilistic Tsunami Hazard Analysis (PTHA) based on traditional Seismic (PSHA) therefore completely with standard seismic practice. In lieu attenuation relations, it uses summation finite-difference Green's functions that been pre-computed individual subfaults, which enables us to rapidly construct scenario waveforms from an aggregate...

Research Article| September 26, 2018 Body‐Wave Methods of Distinguishing between Explosions, Collapses, and Earthquakes: Application to Recent Events in North Korea William R. Walter; Walter aLawrence Livermore National Laboratory, L‐046, 7000 East Avenue, Livermore, California 94550 U.S.A., bwalter@llnl.gov Search for other works by this author on: GSW Google Scholar Douglas A. Dodge; Dodge Gene Ichinose; Ichinose Stephen C. Myers; Myers Michael E. Pasyanos; Pasyanos Sean Ford Author...

Research Article| August 15, 2018 Absolute Locations of the North Korean Nuclear Tests Based on Differential Seismic Arrival Times and InSAR Stephen C. Myers; Myers aGeophysical Monitoring Programs, Lawrence Livermore National Laboratory, L‐046, Livermore, California 94550 U.S.A. Search for other works by this author on: GSW Google Scholar Sean R. Ford; Ford Robert J. Mellors; Mellors Scott Baker; Baker bBOS Technologies LLC, Lafayette, Colorado 80026 G. Ichinose Author Article Information...

Research Article| September 19, 2018 Moment Tensor Source‐Type Analysis for the Democratic People's Republic of Korea–Declared Nuclear Explosions (2006–2017) and 3 2017 Collapse Event Andrea Chiang; Chiang aLawrence Livermore National Laboratory, 7000 East Avenue, MC‐043, MC‐046, Livermore, California 94550 U.S.A., chiang4@llnl.govford17@llnl.govichinose1@llnl.govmatzel1@llnl.govmyers30@llnl.govwalter5@llnl.gov Search other works by this author on: GSW Google Scholar Gene A. Ichinose;...

Abstract On 15 May 2020 an Mww 6.5 earthquake occurred beneath the Monte Cristo Range in Mina Deflection region of western Nevada. Rapid deployment eight temporary seismic stations enabled detailed analysis its productive and slowly decaying aftershock sequence (p=0.8), which included ∼18,000 autodetected events 3.5 months. Double-difference, waveform-based relative relocation 16,714 earthquakes reveals a complex network faults, many cross inferred 35-km-long east–northeast-striking,...

We investigate the potential of local earthquakes to generate tsunamis and seiches within Lake Tahoe. calculated long wavelength oscillations generated by 3 hypothetical M w >7 earthquake scenarios for faults with normal slip directly under outside lake basin. The involving fault are North Tahoe‐Incline Village West Tahoe‐Dollar Point scenarios. Genoa scenario involves a that crops out 10 km east lake. Faulting beneath generates tsunami followed seiche continues hours waves as high m....

Research Article| April 01, 2005 A 40,000 year unchanging seismic regime in the Dead Sea rift Z.B. Begin; Begin 1Geological Survey of Israel, 30 Malche Yisrael Street, Jerusalem 95501, Israel Search for other works by this author on: GSW Google Scholar D.M. Steinberg; Steinberg 2Department Statistics and Operations Research, Tel Aviv University, Levanon 69778, G.A. Ichinose; Ichinose 3URS Group International Inc., 566 El Dorado, Pasadena, California 912101-2560, USA S. Marco 4Department...

We investigate the crustal thickness under Peninsular Ranges using P‐to‐S converted phases of teleseismic body waves recorded on a temporary broadband seismometer array and isolated by receiver function method. Ps minus P times at sites west compositional boundary that separates batholith into east zones indicate relatively flat, deep Moho. decrease eastward, Moho depth estimates (made from delays velocities seismic tomography) constant 36 to 41 km thick crust in western zone. In eastern...

Abstract The 12 September 1994 Mw 5.8 Double Spring Flat, Nevada, earthquake initiated at the intersection of a northeast- and northwest-striking set conjugate faults within an overlapping zone between Genoa Antelope Valley fault zones, eastern Sierra Nevadan range frontal system. mainshock ruptured on northeast-striking plane. Eight days after mainshock, aftershock activity migrated from plane to fault. Over next 2 years, aftershocks southward onto another then zone. focal mechanisms 17 M...

We inverted teleseismic data for the 1965 Seattle‐Tacoma earthquake slip and rake. The had 2 asperities of 12 16 km near hypocenter with average 2.8 m respectively (M o = 9.4 × 10 25 dyne‐cm; M w 6.6). also strong‐motion 2001 Nisqually earthquake. This subevents an asperity area 45 between 59 62 depth 1.7 26 6.8). Shake‐maps peak ground acceleration (PGA) spectral (S a ) were generated using time‐domain approach including model, site, basin‐depth corrections based on California geology....

We reanalyzed the 13 April 1949 Olympia, Washington, earthquake by using digitized records and first-motion polarities from long-period seismograms. The moment-tensor mechanism is normal faulting with a down-dip-trending T axis similar in style to other Cascadia intraslab earthquakes. total seismic moment 1.3 × 1026 dyne cm ( M w 6.7) hypocenter depth 60 km. Additional inverse modeling for kinematic rupture process assuming steeply east-dipping fault plane tensor resulted slightly higher of...

Abstract We performed relative locations of six event pairs based on surface wave (SW) and body (BW) differential traveltimes the 9 September 2016, 6 January 12 February 2013, 25 May 2009 announced North Korea nuclear explosions. The SW for 2013 events were inconsistent with BWs when paired other events, only 2016/9 2016 pair was consistent. Apparent phase shift is investigated respect to BW locations. formed beneath southeast slope Mount Mant'ap, have largest shifts amplitude ratio...

SUMMARY We introduce a seismic identification method for collapse events using moment tensors (MTs). start by computing full (six-element) MT solutions 43 identified from around the world, and statistically characterizing population on hypersphere. then test large data set of over 1000 MTs western U.S. against distribution collapses MT-based similarly as used testing explosions. Known explosions are readily identified, along with other anomalous in Geysers central California coast....

Abstract The November 1995 Border Town, Nevada, earthquake sequence occurred near the California-Nevada border approximately 20 km northwest of Reno, Nevada. largest (Mw = 4.5) was widely felt throughout Reno-Sparks-Truckee region. This event on a west-dipping high-angle fault at depth 14 and shows dip-slip motion preferred fault-plane orientation strike N10°E, dip 70° W, rake −75°. We have relocated 27 aftershocks one foreshock using records from local network two portable digital...

We used teleseismic body waves, regional low‐gain strong motion seismograms, and horizontal geodetic displacements from triangulation surveys to invert for the slip distribution of 1948 Fukui, Japan, earthquake using multiple time window method. The ruptured unilaterally a depth 10 km north with very little (0–0.5 m) evenly distributed across fault 24 by 18 over period about s. At 9 s after initiation rupture, an adjacent along same strike south hypocenter 20–30 toward Fukui city mostly...

Research Article| March 01, 2014 Seismic and Infrasonic Analysis of the Major Bolide Event 15 February 2013 Michael Antolik; Antolik aQuantum Technology Sciences, Inc., 1980 N. Atlantic Avenue, Cocoa Beach, Florida 32931 U.S.A.mantolik@qtsi.com Search for other works by this author on: GSW Google Scholar Gene Ichinose; Ichinose bAir Force Technical Applications Center, 1030 South Highway A1A, Patrick Air Base, 32925 U.S.A. Jonathan Creasey; Creasey Dean Clauter Author Article Information...

Abstract A series of four chemical explosions were detonated in a deep borehole within the Yucca Flat Dry Alluvium Geology (DAG) at Nevada National Security Site between 2018 and 2019. The two larger 50 tons (DAG‐2) 10 (DAG‐4) TNT equivalent yield triggered energetic aftershock sequences numbering 1392 347 microearthquakes, respectively, first days. No significant activity was observed for smaller 1‐ton (DAG‐1 DAG‐3). We used back‐projection method based on travel‐time migration stacking...

SUMMARY Event screening is an explosion monitoring practice that aims to identify event as (‘screened in’) or not out’). Confidence in can be increased if multiple independent approaches are used. We describe a new approach using the seismic moment tensor and its representation on hypersphere, specifically 5-sphere of 6-degree unit vectors representing normalized symmetric tensor. The sample tensors from data set unimodal parametrized by Langevin distribution, which sometimes referred Normal...

Abstract There are benefits from the addition of rotational motions to translational displacements for moment tensor (MT) inversions. The radiation pattern is orthogonal shear pattern, thus incorporating rotations equivalent gaining another observation point on focal sphere. We demonstrated this by simulating curl and displacement wavefields a regional distance station. Thus, one 6‐C station (3‐Component + 3‐Component rotational) gathers same information as two 3‐C stations at 90° azimuth...