A geodetic plate motion and Global Strain Rate Model

Abstract

We present a new global model of plate motions and strain rates in plate boundary zones constrained by horizontal geodetic velocities. This Global Strain Rate Model (GSRM v.2.1) is a vast improvement over its predecessor both in terms of amount of data input as in an increase in spatial model resolution by factor of $2.5 in areas with dense data coverage. We determined 6739 velocities from time series of (mostly) continuous GPS measurements; i.e., by far the largest global velocity solution to date. We transformed 15,772 velocities from 233 (mostly) published studies onto our core solution to obtain 22,511 velocities in the same reference frame. Care is taken to not use velocities from stations (or time periods) that are affected by transient phenomena; i.e., this data set consists of velocities best representing the interseismic plate velocity. About 14% of the Earth is allowed to deform in 145,086 deforming grid cells (0.25 longitude by 0.2 latitude in dimension). The remainder of the Earth's surface is modeled as rigid spherical caps representing 50 tectonic plates. For 36 plates we present new GPS-derived angular velocities. For all the plates that can be compared with the most recent geologic plate motion model, we find that the difference in angular velocity is significant. The rigid-body rotations are used as boundary conditions in the strain rate calculations. The strain rate field is modeled using the Haines and Holt method, which uses splines to obtain an self-consistent interpolated velocity gradient tensor field, from which strain rates, vorticity rates, and expected velocities are derived. We also present expected faulting orientations in areas with significant vorticity, and update the no-net rotation reference frame associated with our global velocity gradient field.Finally, we present a global map of recurrence times for M w 57.5 characteristic earthquakes.

The earthquake deformation cycle

“…For good reviews of GNSS methodology see Misra and Enge (2006) and Blewitt (2007). Nevada, Reno, who have used the data to produce a global map of tectonic strain (Kreemer et al, 2014). Their latest model has is posted on a~25 km grid and uses~20,000 individual point velocities.…”

Statistical significance of trends in Zenith Wet Delay from re-processed GPS solutions

“…The position time series derived from Global Positioning System (GPS) observations are widely used to analyze and interpret a wide range of geophysical processes (Teferle et al 2008;Wöppelmann et al 2009;Kreemer et al 2014). Previous studies presented that the noise properties, i.e.…”

Geodynamic Activity of Modern Structures and Tectonic Stress Fields in Northeast Asia

“…Для анализа были использованы значения ско-ростей горизонтальных смещений из обобщающей работы [Kreemer et al, 2014], в которой объединены материалы GPS-исследований по всему миру с соб-ственным решением и в которую вошли также ре-зультаты работ [Steblov et al, 2003;Apel et al, 2006;Freymueller et al, 2008]. При дублировании скоро-стей GPS-пунктов, взятых из разных источников, а также для рядом расположенных пунктов были выбраны единственные значения скорости, исходя из следующих критериев: предпочтение отдава-лось более поздней публикации; выбиралась ско-рость смещения GPS-пункта с наименьшей ошиб-кой; при незначительных расхождениях значений скоростей и ошибок для близко расположенных пунктов GPS принимались усредненные значения.…”