Yifang Cheng's research while affiliated with University of California, Berkeley and other places

... Due to the small radius and short rupture duration of small earthquakes, they are usually approximated as a double-couple point source, which has two nodal planes and divides the reference focal sphere into four quadrants with different first-motion polarities (Lay & Wallace, 1995). Note that many small earthquakes may also have considerable non-double-couple components but are difficult to constrain, like the co-rupture of multiple faults, fluid-related earthquakes, and rock-damage-related earthquakes (e.g., Cheng et al., 2021;Martínez-Garzón et al., 2017;Miller et al., 1998). Traditionally, the polarities are picked from seismic stations, mapped back to the focal sphere based on ray paths, and used to fit four quadrants and two nodal planes, such as the FPFIT method (Reasenberg, 1985). ...

... To further constrain the nodal planes, many studies increase observations per event using other waveform features, like S/P amplitude ratios (e.g., Hardebeck & Shearer, 2003;Julian & Foulger, 1996;Kisslinger et al., 1981), and absolute P-wave and S-wave amplitudes (e.g., Ebel & Bonjer, 1990;Kwiatek et al., 2016;Nakamura et al., 1999;Rögnvaldsson & Slunga, 1993) (Figure 1). Recently, the rapid development in machine learning algorithms also helped increase the observations by using high-accuracy polarity picker and phase picker trained using millions of labeled waveforms (Cheng & Ben-Zion, 2020;Ross et al., 2018). ...

... Y. Cheng et al., 2020;H. Meng & Ben-Zion, 2018b;Roux et al., 2015;Share et al., 2017;Sheng et al., 2021;Y. Wang et al., 2019) and among the Ridgecrest aftershocks ...

... In the last two decades wireless sensor networks (WSN) have received a lot of attention from the industrial and research community because many applications require remote sensing and control capabilities [1]- [3]. More recently, they have become a crucial part of Internet of Things (IoT) [4]- [6]. ...

... On other planets, two challenges are the facts that environmental conditions can be extreme and the device must run automatically without human operation. Utilizing a distributed sensor network (DSN) [6]- [9] could be a solution to this problem: in this network, every node can be a unit with necessary sensors and computers; using a decentralized algorithm makes sure that a robust network which can operate without a head node. All nodes collect and process data independently, while communicating with each other in order to generates a nearsurfaces image. ...

... Based on quantitative observations as in Figure 9, we propose a model that an asperity can slip aseismically under low loading rate (Figure 11a) but can also slip seismically once the local h* shrinks below the asperity size by fast loading (Figure 11b). It should be noted that this model is also supported by the results of another experimental study (McLaskey & Yamashita, 2017), a recent numerical simulation (Schaal & Lapusta, 2019), the transient behaviors of seismicity modulated by a nearby major earthquake (Cheng & Ben-Zion, 2019;Hatakeyama et al., 2017), and the correlation between local slip rate and tremor activity on the Cascadia subduction zone (Bartlow et al., 2011). ...

... In addition, this method is less dependent on the velocity model. This method has been widely used in the relocation of earthquake sequences and earthquake swarms in China and abroad (Lanza et al., 2019;Li et al., 2019;Yi et al., 2019;Fang et al., 2018;Momeni and Tatar, 2018;Xie et al., 2018;Xu et al., 2015;Zhang et al., 2014;Zhao et al., 2013;Yu et al., 2010;Chen et al., 2009). ...

... It is a pronounced seismic risk, particularly to the populated Riverside and San Bernardino Counties. In addition to near-optimal alignment with present-day plate motion (McGill et al., 2015;Meade & Hager, 2005), the SJFZ's high rates of distributed seismicity are related to fault and lithological heterogeneities, extensive inelastic damage (e.g., Allam & Ben-Zion, 2012), and the associated activation of secondary faults and other nearby structures as it prepares in a volumetric sense (e.g., Cheng et al., 2018;Powers & Jordan, 2010;Renard et al., 2019) for the next major earthquake. At depths greater than about 10 km, there is evidence of northeast dipping features within the SJFZ (Nemser & Cowan, 2009;Ross, Hauksson, & Ben-Zion, 2017), a potential inheritance from past convergent tectonics (Schulte-Pelkum et al., 2020). ...

... Kwiatek et al. (2015) also worked on the induced seismicity in the northern part of Geysers GPP, due to long-term fluid injection. Cheng and Chen (2018) performed a statistical analysis on the distance of observed seismic events induced by the Salton Sea GPP operation, and found that the magnitude of events located outside the defined ring of a GPP (radius of 2−5 km) is five times less than the ones located near the power plant. Broccardo et al. (2020) estimated the seismic risk of the Geldinganes GPP in Iceland. ...