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The Parkfield segment of the San Andreas Fault (SAF) sits at the transition between the locked Cholame segment to the South and the SAF creeping segment to the North. The Parkfield segment hosts regular ∼Mw $\sim {\boldsymbol{M}}_{\boldsymbol{w}}$6 earthquakes followed by postseismic deformation. Recent studies based on geodetic data have highlighted spatial and temporal variations of aseismic slip rate in addition to postseismic slip along this section of the fault. We combine Global Navigation Satellite Systems (GNSS) and seismicity data over the 2006–2018 period to detail a comprehensive picture of transient slip events. We produce a catalog of relocated seismicity and repeating earthquakes. We use a variational Bayesian independent component analysis decomposition on GNSS data to separate geodetic deformation due to non‐tectonic sources from signals of potential tectonic origin. We then reconstruct the temporal evolution of fault slip and detect potential slip transients. Those events, determined as mostly aseismic with the exception of one related to a Mw ${\boldsymbol{M}}_{\boldsymbol{w}}$4.8 earthquake, occur more frequently during the 2004 Mw ${\boldsymbol{M}}_{\boldsymbol{w}}$6 post‐seismic period than during the subsequent inter‐seismic phase. Our study illustrates the rich dynamics of seismic and aseismic slip during both post‐ and inter‐seismic periods along active faults. Plain Language Summary: Faults can slip abruptly, generating earthquakes and seismic waves, or slowly and aseismically. Such a slow motion has now been observed along multiple active faults and is recognized as one of the important processes influencing the Earth's crust stress field. Aseismic slip interacts with earthquakes, and monitoring its time evolution on faults help us in better modeling the seismic cycle. Here we focus our attention on the Parkfield fault segment, sitting along the San Andreas Fault in California in between a section that generated a large earthquake (M7.9) in 1857 and a 150‐km‐long central creeping section that slips aseismically. We dig in noisy time series of surface displacements measured by GNSS (Global Navigation Satellite System) to detect and model small variations of aseismic slip rate (10–100 mm/year) along the fault. We find multiple candidate slow slip events during the period following the 2004 Parkfield earthquake, confirming and expanding previous independent observations. While aseismic slip following earthquakes was first thought to be a steady release of tectonic stress, we show that, in Parkfield, it is evolving with sudden jumps and slowdown. Key Points: Independent Component Analysis of GPS time series highlights slip transients along the San Andreas Fault after the 2004 M6 Parkfield eventWe document the spatio‐temporal distribution of seismic and aseismic slip historySlow Slip Events are more frequent during the 2004 M6 post‐seismic period than the subsequent interseismic period [ABSTRACT FROM AUTHOR]

Recent studies have shown that the Himalayan region is under the threat of earthquakes of magnitude nine or larger. These estimates are based on comparisons of the geodetically inferred moment deficit rate with the seismicity of the region. However, these studies did not account for the physics of fault slip, specifically the influence of frictional barriers on earthquake rupture dynamics, which controls the extent and therefore the magnitude of large earthquakes. Here we combine an improved probabilistic estimate of moment deficit rate with results from dynamic models of the earthquake cycle to more fully assess the seismogenic potential of the Main Himalayan Thrust (MHT). We propose a straightforward and efficient methodology for incorporating outcomes of physics‐based earthquake cycle models into hazard estimates. We show that, accounting for uncertainties on the moment deficit rate, seismicity and earthquake physics, the MHT is prone to rupturing in Mw 8.7 earthquakes every T > 200 years. Plain Language Summary: Recent studies have shown that the Himalayan region is under the threat of earthquakes of magnitude nine or larger. To draw such estimates, researchers compare how surface deformation translates as potential slip on a fault with the rate at which measured earthquakes occur. In short, these studies only consider the kinematics of the region and compare current seismicity with how much earthquakes are to be expected in the future considering the statistics of earthquakes do not change with time. Therefore, these studies do not take advantage of the recent advances in fault physics. Here, we compare surface deformation rates, earthquake catalogs and numerical simulations of the earthquake cycle to assess the seismogenic potential of the Main Himalayan Thrust (MHT). Our methodology incorporates outcomes of physics‐based earthquake cycle simulations into hazard estimates. We show that, accounting for all available uncertainties, the MHT is prone to rupturing in Mw 8.7 earthquakes every T > 200 years. Key Points: Combine probabilistic estimate of moment deficit rate with results from earthquake cycle dynamic models to assess the seismogenic potentialStraightforward and efficient methodology for incorporating outcomes of physics‐based earthquake cycle models into hazard estimatesMain Himalayan Thrust prone to rupturing in M8.7, accounting for uncertainties on moment deficit rate, seismicity and earthquake physics [ABSTRACT FROM AUTHOR]

The 2016 Kumamoto earthquake sequence occurred on the Futagawa-Hinagu fault zone near the Aso volcano on Kyushu island. The sequence was initiated with two major ( Mw ≥ 6.0) foreshocks, and the mainshock ( Mw = 7.0) occurred 25 h after the second major foreshock. We combine GPS, strong motion, synthetic aperture radar images, and surface offset data in a joint inversion to resolve the kinematic rupture process of the mainshock and coseismic displacement of the foreshocks. The joint inversion results reveal a unilateral rupture process for the mainshock involving sequential rupture of four major asperities. The slip area of the foreshocks and mainshock and the aftershock loci form a detailed complementary pattern. The mainshock rupture terminates near the rim of the caldera, leaving a ~10 km long gap of aftershocks. This area is characterized by high temperature and low shear wave velocity, density, and resistivity, which may be related to the partially melted geothermal condition. Ductile material property near the volcano may act as a 'material barrier' to the dynamic rupture. Topographic weight of the caldera increases compressional normal stress on the fault plane, which may behave as a 'stress barrier.' Long-term seismic hazard and deformation behaviors related to these two types of barriers are discussed in terms of the associated frictional mechanism. Significant postseismic creeps observed near the volcano area indicates a velocity strengthening frictional behavior near the rupture termination, which confirms that the 'material barrier' mechanism is likely the dominant rupture termination mechanism. [ABSTRACT FROM AUTHOR]

Megathrust earthquakes tend to be confined to fault areas locked in the interseismic period and often rupture them only partially. For example, during the 2015 M7.8 Gorkha earthquake, Nepal, a slip pulse propagating along strike unzipped the bottom edge of the locked portion of the Main Himalayan Thrust (MHT). The lower edge of the rupture produced dominant high-frequency (>1 Hz) radiation of seismic waves. We show that similar partial ruptures occur spontaneously in a simple dynamic model of earthquake sequences. The fault is governed by standard laboratory-based rate-and-state friction with the aging law and contains one homogenous velocity-weakening (VW) region embedded in a velocity-strengthening (VS) area. Our simulations incorporate inertial wave-mediated effects during seismic ruptures (they are thus fully dynamic) and account for all phases of the seismic cycle in a self-consistent way. Earthquakes nucleate at the edge of the VW area and partial ruptures tend to stay confined within this zone of higher prestress, producing pulse-like ruptures that propagate along strike. The amplitude of the high-frequency sources is enhanced in the zone of higher, heterogeneous stress at the edge of the VW area. [ABSTRACT FROM AUTHOR]

Hereditary spastic paraplegias (HSPs) are characterized by progressive lower limb spasticity and weakness. Mutations in the SPG3A gene, which encodes the large guanosine triphosphatase atlastin, are the second most common cause of autosomal dominant hereditary spastic paraplegia. In a large SPG3A screen of 70 hereditary spastic paraplegia subjects, a novel in‐frame deletion, p.del436N, was identified. Characterization of this deletion showed that it affects neither the guanosine triphosphatase activity of atlastin nor interactions between atlastin and spastin. Interestingly, immunoblot analysis of lymphoblasts from affected patients demonstrated a significant reduction in atlastin protein levels, supporting a loss‐of‐function disease mechanism. Ann Neurol 2007 [ABSTRACT FROM AUTHOR]