We develop an earthquake catalog using the Cascadia Initiative ocean bottom seismometer data set for the entire Cascadia subduction zone
Subduction zone and Juan de Fuca plate seismicity increases from north to south, with distinct increase in seismicity south of 46°N
Seismicity varies with incoming plate smoothness and hydration, tied to observed trends in intraplate deformation and underthrust sediment

Geodetic Evidence for a Blind Fault Segment at the Southern End of the San Jacinto Fault Zone

Authors: Ekaterina Tymofyeyeva, Yuri Fialko

First Published: 27 January 2018

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We combine InSAR and GPS data to derive maps of three‐component interseismic surface velocity and strain rate
Strain rate anomaly at the southern end of the San Jacinto fault lends support to a hypothesized blind fault segment
Slip rate on a blind fault segment is 13 plus‐minus 3 mm/yr, higher than on the nearby Coyote Creek fault

Using Low‐Frequency Earthquake Families on the San Andreas Fault as Deep Creepmeters

Authors: A. M. Thomas, N. M. Beeler, Q. Bletery, R. Burgmann, D. R. Shelly

First Published: 22 January 2018

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We define slip episodes, or clusters of individual LFE occurrence, based on properties of LFE recurrence intervals
We formalize the definition of a creepmeter and determine its applicability to LFE families on the deep San Andreas Fault
We find that episodic families meter creep and reflect surrounding SSEs, while continuous families reflect asperities that fail in response to continuous creep

Segmentation of Slow Slip Events in South Central Alaska Possibly Controlled by a Subducted Oceanic Plateau

Authors: Haotian Li, Meng Wei, Duo Li, Yajing Liu, YoungHee Kim, Shiyong Zhou

First Published: 15 January 2018

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We simulate SSEs in south central Alaska with a nonplanar fault model
Along‐strike variation of effective normal stress controls the segmentation of SSEs
The segmentation is likely related to the subducted Yakutat Plateau

Uplift of the Western Transverse Ranges and Ventura Area of Southern California: A Four‐Technique Geodetic Study Combining GPS, InSAR, Leveling, and Tide Gauges

Authors: William C. Hammond, Reed J. Burgette, Kaj M. Johnson, Geoffrey Blewitt

First Published: 15 January 2018

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We estimate the uplift rate of the Western Transverse Ranges in southern California from integrated GPS, InSAR, leveling, and tide gauge data
Geodetic imaging of topographic growth reveals the vertical response to contraction across the Big Bend of the San Andreas Fault system
Geographically continuous uplift of 1–2 mm/yr is asymmetric across the San Andreas Fault and decreases to subsidence near the coast

Observations and Modeling of Coseismic and Postseismic Deformation Due To the 2015 Mw 7.8 Gorkha (Nepal) Earthquake

Authors: Kang Wang, Yuri Fialko

First Published: 10 January 2018

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We developed FEM of the 2015 Gorkha earthquake that accounts for variations in topography and material properties across the Himalayan arc
Space geodetic observations reveal transient deformation following the Gorkha earthquake that is best explained by downdip afterslip
Observed deformation is inconsistent with models of a low‐viscosity (order of 1018 Pa s or less) channel in the lower crust beneath Tibet

Variability of the Space‐Time Evolution of Slow Slip Events Off the Boso Peninsula, Central Japan, From 1996 to 2014

Authors: Jun'ichi Fukuda

First Published: 10 January 2018

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Five Boso slow slip events (SSEs) exhibit variable nucleation style and space‐time evolution of slip
Overall evolution of the SSEs and relative timing between onsets of slow slip and accompanying seismicity correlate with nucleation style
Slip expansion/propagation patterns vary among the SSEs and correlate well with the space‐time migration of seismicity

December 2017

Sustained Water Loss in California's Mountain Ranges During Severe Drought From 2012 to 2015 Inferred From GPS

Authors: Donald F. Argus, Felix W. Landerer, David N. Wiese, Hilary R. Martens, Yuning Fu, James S. Famiglietti, Brian F. Thomas, Thomas G. Farr, Angelyn W. Moore, Michael M. Watkins

First Published: 26 December 2017

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Elastic vertical displacements are inverted to infer change in total water storage in mountain ranges in the western U.S. from 2006 to 2017
Sierra Nevada uplift during severe drought from 2012 to 2015 is primarily solid Earth's elastic response to water loss in the Sierra Nevada
More water in the ground in California's mountains is lost during drought and gained during heavy precipitation than in hydrology models

Stress Models of the Annual Hydrospheric, Atmospheric, Thermal, and Tidal Loading Cycles on California Faults: Perturbation of Background Stress and Changes in Seismicity

Authors: Christopher W. Johnson, Yuning Fu, Roland Bürgmann

First Published: 26 December 2017

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Mechanical models are developed to quantify stress changes for the regional fault geometry induced by seven sources of annual loading
Annual hydrospheric loading in California produces the largest Coulomb stress changes of 0.5–2 kPa on regional fault systems
Annual stress changes of ≤5 kPa in the principal orientation of the background stress field modulate low‐magnitude seismicity

Dynamic Rupture Modeling of the M7.2 2010 El Mayor‐Cucapah Earthquake: Comparison With a Geodetic Model

Authors: C. Kyriakopoulos, D. D. Oglesby, G. J. Funning, Kenny J. Ryan

First Published: 19 December 2017

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Similar slip pattern between dynamic rupture model and geodetic model
First‐order geometric effects on fault slip distribution
Topographic effects on fault slip rates

A geodetic matched filter search for slow slip with application to the Mexico subduction zone

Authors: B. Rousset, M. Campillo, C. Lasserre, W. B. Frank, N. Cotte, A. Walpersdorf, A. Socquet, V. Kostoglodov

First Published: 18 December 2017

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We developed a geodetic matched filter that specifically allows for the search of low‐amplitude slow slip events
Synthetic tests show that this method is able to resolve Mw> 6 events in the context of the Mexico subduction zone
The application on real data between 2005 and 2014 enables to detect 28 slow slip events of Mw between 6.3 and 7.2 in the Guerrero area

Mixed‐Mode Slip Behavior of the Altotiberina Low‐Angle Normal Fault System (Northern Apennines, Italy) through High‐Resolution Earthquake Locations and Repeating Events

Authors: Luisa Valoroso, Lauro Chiaraluce, Raffaele Di Stefano, Giancarlo Monachesi

First Published: 18 December 2017

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High‐resolution locations describe the anatomy of the Altotiberina low‐angle normal fault and of its complex synthetic and antithetic splays
The spatiotemporal seismicity distribution agrees with the geodetic models reporting a frictionally heterogeneous low‐angle ATF plane
The rate of occurrence of repeating events along the ATF seems to modulate the seismicity in its hanging wall block

Resolving the Detailed Spatiotemporal Slip Evolution of Deep Tremor in Western Japan

Authors: Kazuaki Ohta, Satoshi Ide

First Published: 4 December 2017

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We propose a new slip inversion method for resolving the detailed slip evolution of deep tremor
Slip distributions of deep tremor illuminate the patchy source regions of slow earthquakes in western and central Shikoku, Japan
The size of the slip region may potentially control the visibility of very low frequency earthquake signals

November 2017