Searching for Transient Slow Slips Along the San Andreas Fault Near Parkfield Using Independent Component Analysis

Abstract

At plate boundaries, interseismic surface strain can be interpreted in terms of fault coupling (i.e., the extent of kinematic locking of a fault) and allows to infer where a fault is prone to release elastic energy through slip, either seismically or aseismically (e.g., Avouac, 2015;Bürgmann, 2018). However, such interpretation does not account for temporal variations in slip rate, though frequently observed in various seismo-tectonic contexts and at different spatial and temporal scales (Jolivet & Frank, 2020, and references therein). Long-term (>1 year) variations of interseismic coupling have been detected in Sumatra, Parkfield and along the Cascadia subduction zone (Barbot et al., 2013;Materna et al., 2019;Tsang et al., 2015). On shorter time scale (<1 year), slow slip events (SSEs) have been observed in areas previously thought to be either locked or slipping continuously, both in subduction zones (e.g.,

Detection of slow slip events along the southern Peru - northern Chile subduction zone

“…Event #7 locates in the region struck by the Iquique earthquake in 2014 (Figure 9c, and S36) during the post-seismic relaxation that followed the mainshock (Meng et al, 2015;Hoffmann et al, 2018;Shrivastava et al, 2019) (M w 6.1 and duration of 28 days in June 2014). Such slow slip events embedded within a post-seismic sequence have already been observed following the Illapel earthquake (Tissandier et al, 2023) and in a completely different setting, following the 2004 Parkfield earthquake, along the San Andreas Fault (Michel et al, 2022). 2007) earthquakes.…”

“…Finally, slow slip appears to be an important ingredient of the preparation phase of earthquakes (e.g., Ruegg et al, 2001;Ruiz et al, 2014;Radiguet et al, 2016;Socquet et al, 2017;Voss et al, 2018). More recently, it has been proposed that a significant fraction of observed geodetic displacement in seismically active regions results from the occurrence of slow slip events (Jolivet and Frank, 2020, and reference therein), suggesting a burst-like, episodic behavior of aseismic slip at all time scales from seconds to decades in places as varied as Mexico (Frank, 2016;Rousset et al, 2017;Frank and Brodsky, 2019), Cascadia (Michel et al, 2019a;Ducellier et al, 2022;Itoh et al, 2022), along the San Andreas Fault (Khoshmanesh and Shirzaei, 2018;Rousset et al, 2019;Michel et al, 2022), the Haiyuan fault in Tibet (Jolivet et al, 2015a;Li et al, 2021), on the Alto Tiberina and Pollino fault systems in Italy (Gualandi et al, 2017;Cheloni et al, 2017;Essing and Poli, 2022), or Japan (Nishimura et al, 2013;Takagi et al, 2019;Nishikawa et al, 2019;Uchida et al, 2020). All observations suggest the importance of accounting for Non-technical summary Earthquakes correspond to a sudden release of elastic energy stored in the crust as a response to the relative motion of tectonic plates.…”

A review on how Big Data can help to monitor the environment and to mitigate risks due to climate change

“…Analysis centers process all these datasets to provide the position time series to the public for various geodetic applications (e.g., surveying, hydrogeological studies, space-weather, estimation of the movement of tectonic plates, monitoring inflation and deflation events in volcanoes [13], [14]). Furthermore, dedicated investigations are conducted to estimate specific transient signals, such as slow slip events and co-/post-/inter-seismic transients [15], which can serve as precursors to natural hazards like landslides [16]. Traditionally, geotechnical surveys and GNSS permanent stations have been utilized to detect specific small amplitude short-time signals, aiding the activation of early-warning systems.…”

Recent Advances in Modelling Geodetic Time Series and Applications for Earth Science and Environmental Monitoring

“…Moreover, analysis of the variations in the position over time provides important information about various geophysical processes. Examples are the estimation of the motion of tectonic plates, the deflation/inflation event of volcanos, the offsets produced by earthquakes, the vertical land motion of continents induced by post-glacial rebound, the movement of glaciers, and the estimation of particular transient signals (e.g., slow slip events and post-seismic transients [20]) which are sometimes precursors of natural hazards (e.g., landslides [21]). For example, large landslides in steep alpine slopes are a considerable threat to vulnerable communities and infrastructures.…”