Preprints
Filtering by Subject: Geophysics and Seismology
Assessment of a claimed ultra-low frequency electromagnetic (ULFEM) earthquake precursor
Published: 2021-07-16
Subjects: Earth Sciences, Geophysics and Seismology
Anomalous ultra-low frequency electromagnetic (ULFEM) pulses occurring before the M5.4 2007 and M4.0 2010 Alum Rock earthquakes have been claimed to increase in number days to weeks prior to each earthquake. We re-examine the previously reported ultra-low frequency (ULF: 0.01-10 Hz) magnetic data recorded at a QuakeFinder site located 9 km from the earthquake hypocenter, as well as data from a [...]
Multivariate statistical appraisal of regional susceptibility to induced seismicity: application to the Permian Basin, SW United States
Published: 2021-07-12
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Induced earthquake sequences are typically interpreted through causal triggering mechanisms. However, studies of causality rarely consider large regions and why some regions experiencing similar anthropogenic activities remain largely aseismic. Therefore, it can be difficult to forecast seismic hazard at a regional scale. In contrast, multivariate statistical methods allow us to find the [...]
A reappraisal of active tectonics along the Fethiye-Burdur trend, southwestern Turkey
Published: 2021-07-07
Subjects: Geophysics and Seismology, Tectonics and Structure
We investigate active tectonics in southwestern Turkey along the trend between Fethiye, near the eastern end of the Hellenic subduction zone, and Burdur, on the Anatolian plateau. Previously, regional GPS velocity data have been used to propose either (1) a NE-trending zone of strike-slip faulting coined the Fethiye-Burdur Fault Zone, or (2) a mix of uniaxial and radial extension accommodated by [...]
Excitation of back-arc tsunamis from megathrust ruptures: The underdog hazard in the Sea of Japan
Published: 2021-07-02
Subjects: Earth Sciences, Geophysics and Seismology
The 2011 Tohoku earthquake created a moderate tsunami in the back-arc Sea of Japan basin. This tsunami went largely unnoticed due to its small size and the significant coverage of the large fore-arc waves. We present a physical dislocation model for the excitation of back-arc tsunamis and identify fault dip as the main geometrical contributor to the propagation of back-arc tsunamis. Using [...]
Subduction earthquakes controlled by incoming plate geometry: The 2020 M>7.5 Shumagin, Alaska, earthquake doublet
Published: 2021-07-01
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
In 2020, an earthquake doublet, a M7.8 on July 22nd and a M7.6 on October 19th, struck the Alaska-Aleutian subduction zone beneath the Shumagin Islands. This is the first documented earthquake doublet involving a megathrust event and a strike-slip event. The first event partially ruptured a seismic gap, which has not hosted large earthquakes since 1917, and the second event was unusual as it [...]
Interplay of seismic and a-seismic deformation during the 2020 sequence of Atacama, Chile.
Published: 2021-06-30
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
An earthquake sequence occurred in the Atacama region of Chile throughout September 2020. The sequence initiated by a mainshock of magnitude Mw6.9, followed 17 hours later by a Mw6.4 aftershock. The sequence lasted several weeks, during which more than a thousand events larger than Ml 1 occurred, including several larger earthquakes of magnitudes between 5.5 and 6.4. Using a dense network that [...]
Deglaciation-enhanced mantle CO2 fluxes at Yellowstone imply positive climate feedback
Published: 2021-06-25
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Glaciology, Tectonics and Structure, Volcanology
The generation of mantle melts in response to decompression by glacial unloading has been linked to enhanced volcanic activity and volatile release in Iceland and in global eruptive records. However, it is unclear whether this process is also important in magmatically-active systems that do not show evidence of enhanced eruption rates. For example, the deglaciation of the Yellowstone ice cap did [...]
Rift kinematics preserved in deep-time erosional landscape below the northern North Sea
Published: 2021-06-25
Subjects: Earth Sciences, Geology, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Our understanding of continental rifting is, in large parts, derived from the stratigraphic record. This record is, however, incomplete as it does not often capture the geomorphic and erosional signal of rifting. New 3D seismic reflection data reveals a Late Permian-Early Triassic landscape incised into the pre-rift basement of the northern North Sea. This landscape, which covers at least 542 [...]
A Multiphysics approach to constrain the dynamics of the Altiplano-Puna magmatic system
Published: 2021-06-25
Subjects: Computer Sciences, Earth Sciences, Geology, Geophysics and Seismology, Numerical Analysis and Scientific Computing, Volcanology
Continuous Interferometric Synthetic Aperture Radar (InSAR) monitoring (> 25 years) has revealed a concentric surface deformation pattern above the Altiplano-Puna magma body (APMB) in the central Andes. Here, we use a joint interpretation of seismic imaging, gravity anomalies and InSAR data to constrain location, 3D geometry and density of the magma body. By combining gravity modelling, [...]
An autonomous petrological database for geodynamic simulations of magmatic systems
Published: 2021-06-24
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Tectonics and Structure, Volcanology
Self-consistent modelling of magmatic systems is challenging as the melt continuously changes its chemical composition upon crystallization, which may affect the mechanical behaviour of the system. Melt extraction and subsequent crystallization create new rocks while depleting the source region. As the chemistry of the source rocks changes locally due to melt extraction, new calculations of the [...]
Insights into the compositional evolution of crustal magmatic systems from coupled petrological-geodynamical models
Published: 2021-06-24
Subjects: Geology, Geophysics and Seismology, Tectonics and Structure, Volcanology
The evolution of crustal magmatic systems is incompletely understood, as most studies are limited either by their temporal or spatial resolution. Exposed plutonic rocks represent the final stage of a long-term evolution punctuated by several magmatic events with different chemistry and generated under different mechanical conditions. Although the final state can be easily described, the nature of [...]
Paleomagnetism from multi-orogenic terranes is "not a simple game": Pyrenees' Paleozoic warning
Published: 2021-06-21
Subjects: Geophysics and Seismology, Tectonics and Structure
Paleomagnetism is a versatile tool in the Earth sciences: it provides critical input to geological time scales and plate tectonic reconstructions. Despite its undeniable perks, paleomagnetism is not without complications. Remagnetizations overprinting the original magnetic signature of rocks are frequent, especially in orogens which tend to be the areas with better rock exposure. Unraveling the [...]
Modeling P waves in seismic noise correlations: Advancing fault monitoring using train traffic sources
Published: 2021-06-19
Subjects: Applied Mathematics, Earth Sciences, Geophysics and Seismology, Physics
The theory of Green's function retrieval essentially requires homogeneously distributed noise sources. Even though these conditions are not fulfilled in nature, low-frequency (<1 Hz) surface waves generated by ocean-crust interactions have been used successfully to image the crust with unprecedented spatial resolution. In contrast to low-frequency surface waves, high-frequency (>1 Hz) body waves [...]
Geodynamic, geodetic, and seismic constraints favour deflated and dense-cored LLVPs
Published: 2021-06-18
Subjects: Cosmochemistry, Earth Sciences, Geochemistry, Geophysics and Seismology, Mineral Physics, Physical Sciences and Mathematics
Two continent-sized features in the deep mantle, the large low-velocity provinces (LLVPs), influence Earth's supercontinent cycles, mantle plume generation, and its geochemical budget. Seismological advances have steadily improved LLVP imaging, but several fundamental questions remain unanswered, including: What is their vertical extent? And, are they purely thermal anomalies, or are they also [...]
Constraining families of dynamic models using geological, geodetic and strong ground motion data: the Mw 6.5, October 30th, 2016, Norcia earthquake, Italy
Published: 2021-06-10
Subjects: Geophysics and Seismology
The 2016 Central Italy earthquake sequence is characterized by remarkable rupture complexity, including highly heterogeneous slip across multiple faults in an extensional tectonic regime. The dense coverage and high quality of geodetic and seismic data allow to image intriguing details of the rupture kinematics of the largest earthquake of the sequence, the Mw 6.5 October 30th, 2016 Norcia [...]