Abstract The static stress drop of an earthquake is indicator the state a specific fault before rupture initiation. primarily controlled by ambient field, strength, complexity, and presence fluids. This study aims to investigate spatio‐temporal distribution values 2016–2017 multi‐fault seismic sequence in central Italy, which includes three earthquakes with M w ≥ 5.9 (Amatrice, Visso, Norcia earthquakes), over 95,000 aftershocks ( 0.5–6.5). We estimate using circular crack model corner...

Abstract We investigate the effects of site response on source parameter estimates using earthquakes recorded by LArge‐n Seismic Survey in Oklahoma (LASSO). While it is well known that near‐surface unconsolidated sediments can cause an apparent breakdown earthquake self‐similarity, influence laterally varying conditions remains unclear. analyze across 1825‐station array a river plain within area 40 km 23 vertical ground motions from 14 regional earthquakes. radiation pattern controls P‐wave...

ABSTRACT The clustering behavior of injection-induced earthquakes is examined using one month data recorded by the LArge-n Seismic Survey in Oklahoma (LASSO) array. 1829-node seismic array was deployed a 25 km×32 km area active saltwater disposal northern between 14 April and 10 May 2016. Injection rates study are nearly constant around time deployment. We develop local magnitude (ML) equation for region estimate magnitudes 1104 determined earthquake range from ML 0.01 to 3.0. majority...

Abstract Spectral analysis is widely used to estimate and refine earthquake source parameters such as radius, seismic moment, stress drop. This study aims quantify the precision of single spectra empirical Green's function spectral ratio approach using Large‐ n Seismic Survey in Oklahoma (LASSO) array. The dense station coverage an area local saltwater disposal offers a unique opportunity observe radiation pattern effects subsequent estimates small earthquakes ( M < 3). results suggest...

Research Article| March 27, 2018 Reassessing the Mycenaean Earthquake Hypothesis: Results of HERACLES Project from Tiryns and Midea, Greece Klaus‐G. Hinzen; Hinzen aArchaeoseismology Group, Geology Archaeoseismology, Institute for Mineralogy, University Cologne, Vinzenz‐Pallotti‐Straße 26, D‐51429 Bergisch Gladbach, Germany, hinzen@uni-koeln.de, s.reamer@uni-koeln.de, c.fleischer@uni-koeln.de, g.schweppe@uni-koeln.de, hector@agiusa.com, jana.tzislakis@gmx.de, kilian.kemna@rub.de Search other...

Abstract Numerous normal‐faulting aftershocks in subduction forearcs commonly follow large megathrust earthquakes. Postseismic normal faulting has been explained by stress changes induced the drop along megathrust. However, details of forearc and aftershock triggering mechanisms remain poorly understood. Here, we use numerical force‐balance models combined with Coulomb failure analysis to show that supports faulting, but forearc‐wide is feasible within a narrow range values preseismic states...

Abstract This work presents a high resolution source property study of hydraulic fracturing induced earthquakes in the Montney Formation, low‐permeability tight shale reservoir Kiskatinaw area, northeast British Columbia, Canada. We estimate parameters, including focal mechanism solutions (FMSs), seismic moment, spectral corner frequency, and static stress drop values recorded between July 2017 2020. Waveform‐similarity‐based event classification 8,283 yields 52 families (clusters) 1,014...

Abstract Hydraulic fracturing (HF) operations are widely associated with induced seismicity in the Western Canadian Sedimentary Basin. This study correlates injection parameters of 12,903 HF stages Kiskatinaw area northeast British Columbia an enhanced catalog containing 40,046 earthquakes using a supervised machine learning approach. It identifies relevant combinations geological and operational related to individual efforts decipher fault activation mechanisms. Our results suggest that...

Earth and Space Science Open Archive Presented WorkOpen AccessYou are viewing the latest version by default [v1]Quantifying earthquake source parameter uncertainties associated with local site effects using a dense arrayAuthorsHilaryChangiDRachelAbercrombieiDNoriNakataColinPenningtonKilianKemnaiDElizabethCochraniDRebeccaHarringtonSee all authors Hilary ChangiDCorresponding Author• Submitting AuthorMassachusetts Institute of TechnologyiDhttps://orcid.org/0000-0002-9402-6089view email...

Abstract X‐ray diffraction mineralogical analysis of geological sequences is a well‐established procedure in both academia and industry, rendering large volume data short‐analytical time. Yet, standard treatment resulting interpretations present limitations related to the inherent complexities natural materials (e.g. compositional variety, structural ordering), are often time consuming focussed on very detailed inspection. Several alternatives were evaluated terms advantages disadvantages...

Stress in active subduction forearcs is controlled primarily by friction along the megathrust and gravitational force. The competing deviatoric compressive tensional stresses generated gravity, respectively, are of same order magnitude result very low stress forearc. near neutral state supported observations reversal, that a change from compression to tension, caused small shear drops (<10MPa) after recent large earthquakes. However, studies quantify compare at various stages seismic...

Earthquake stress drop values estimated from ground-motion spectra commonly vary by several orders of magnitude, particularly for small earthquakes (~M < 3). Stress-drop have been found to with faulting style, type (intraplate, interplate), depth, and exhibit differences between natural induced earthquakes. Nevertheless, distinguishing uncertainties real trends across data sets is challenging, in part due the variation methodological approaches observational constraints. However,...

Large megathrust earthquakes like the 2011 Mw 9.0 Tohoku earthquake (Japan) are followed by numerous aftershocks in subduction zone forearc overlying seismogenic fault. The can include normal-faulting events despite thrust mechanism of main shock. Postseismic normal faulting has been explained stress changes induced coseismic drop along megathrust. However, details and aftershock triggering mechanisms remain poorly constrained. Here we use numerical force-balance models combined with Coulomb...

The 2016 Amatrice-Norcia seismic sequence in central Italy activated a system of normal faults the Apennines and ruptured surface along Monte Vettore fault. Due to complex rupture behavior, including antithetic proposed reactivation an old thrust front, offers unique opportunity study relationship between fault complexity, ruptures, earthquake source properties. Here, we focus on first two months sequence, 30 October Mw 6.5 mainshock near Norcia more than 25000 aftershocks. Using continuous...

The 2016 Amatrice-Norcia seismic sequence in central Italy activated a system of normal faults the Apennines and ruptured surface along Monte Vettore fault. Due to complex rupture behavior, including antithetic proposed reactivation an old thrust front, offers unique opportunity study relationship between fault complexity, ruptures, earthquake source properties. Here, we focus on first two months sequence, 30 October Mw 6.5 mainshock near Norcia more than 25000 aftershocks. Using continuous...

<p>The LArge-n Seismic Survey in Oklahoma (LASSO) array recorded local seismicity 2016 a region of active saltwater disposal. The month-long deployment 1,833 vertical-component nodes had nominal station spacing 400 m and covered 25 by 32 km<sup>2</sup> area. We estimate event magnitudes focal mechanisms the induced using vertical component waveforms from catalog 1375 earthquakes. Here we use developed to investigate spatio-temporal evolution source...

<p>An increasing number of M3+ earthquakes have been associated with Hydraulic Fracturing (HF) injection activity in low-permeable tight shale formations the Western Canada Sedimentary Basin (WCSB) last decade. These include a M<sub>w </sub>4.6 on 08/17/2015 near Ft. St. John, M<sub>L</sub> 4.5 11/30/2018, and two 3.2 10/05/2019, 10/08/2019 Dawson Creek, British Columbia. Increased seismic Dawson-Septimus area prompted...

<p>The extensive development over the last decade of low-permeability tight shale formations in Western Canada Sedimentary Basin (WCSB) using hydraulic fracturing (HF) techniques for oil and gas exploration has been associated with  an increasing number M3+ earthquakes (e.g., M<sub>L</sub> 4.5 on 30 November 2018 near Dawson Creek, a M<sub>w </sub>4.6 17 August 2016 Fort St. John). Avoiding economic losses due...

<div><span>The c</span><span>ommunity</span><span>-led</span> <span>s</span><span>tress </span><span>d</span><span>rop </span><span>v</span><span>alidation...