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Full-Text Articles in Geology
Slip Pulse And Resonance Of The Kathmandu Basin During The 2015 Gorkha Earthquake, Nepal, John Galetzka, Walter Szeliga
Slip Pulse And Resonance Of The Kathmandu Basin During The 2015 Gorkha Earthquake, Nepal, John Galetzka, Walter Szeliga
All Faculty Scholarship for the College of the Sciences
Detailed geodetic imaging of earthquake ruptures enhances our understanding of earthquake physics and associated ground shaking. The 25 April 2015 moment magnitude 7.8 earthquake in Gorkha, Nepal was the first large continental megathrust rupture to have occurred beneath a high-rate (5-hertz) Global Positioning System (GPS) network. We used GPS and interferometric synthetic aperture radar data to model the earthquake rupture as a slip pulse ~20 kilometers in width, ~6 seconds in duration, and with a peak sliding velocity of 1.1 meters per second, which propagated toward the Kathmandu basin at ~3.3 kilometers per second over ~140 kilometers. The smooth slip …
The Mantle Transition Zone Beneath West Antarctica: Seismic Evidence For Hydration And Thermal Upwellings, E. L. Emry, A. A. Nyblade, J. Juliá, S. Anandakrishnan, R. C. Aster, D. A. Wiens, Audrey D. Huerta, T. J. Wilson
The Mantle Transition Zone Beneath West Antarctica: Seismic Evidence For Hydration And Thermal Upwellings, E. L. Emry, A. A. Nyblade, J. Juliá, S. Anandakrishnan, R. C. Aster, D. A. Wiens, Audrey D. Huerta, T. J. Wilson
All Faculty Scholarship for the College of the Sciences
Although prior work suggests that a mantle plume is associated with Cenozoic rifting and volcanism in West Antarctica, the existence of a plume remains conjectural. Here we use P wave receiver functions (PRFs) from the Antarctic POLENET array to estimate mantle transition zone thickness, which is sensitive to temperature perturbations, throughout previously unstudied parts of West Antarctica. We obtain over 8000 high‐quality PRFs using an iterative, time domain deconvolution method filtered with a Gaussian width of 0.5 and 1.0, corresponding to frequencies less than ∼0.24 and ∼0.48 Hz, respectively. Single‐station and common conversion point stacks, migrated to depth using the …
Rapid Middle To Late Miocene Slip Along The Zanskar Normal Fault, Greater Himalayan Range, Nw, India: Constraints From Low-Temperature Thermochronometry, Brett L. Shurtleff
Rapid Middle To Late Miocene Slip Along The Zanskar Normal Fault, Greater Himalayan Range, Nw, India: Constraints From Low-Temperature Thermochronometry, Brett L. Shurtleff
All Master's Theses
The Zanskar normal fault (ZF) is a NW-striking, moderately NE-dipping, normal fault that bounds the northern flank of the Greater Himalaya Range, NW India. The ZF is the far west continuation of the South Tibetan Detachment System (STDS), a major arc-parallel normal sense shear zone that spans the length of the Himalayan orogen. Detailed new zircon and apatite (U-Th)/He (ZHe and AHe) and apatite fission-track (AFT) thermochronometric data from high-grade (amphibolite-migmatite) Greater Himalayan Sequence (GHS) metamorphic rocks, exposed in the footwall immediately adjacent to the ZF, provide constraints on the middle Miocene to present exhumation history of the footwall. The …
Geologic Mapping In The Black Mountain Area, Northern Eastern California Shear Zone: Testing A Kinematic And Geometric Fault Slip Transfer Model, Kevin M. Delano
Geologic Mapping In The Black Mountain Area, Northern Eastern California Shear Zone: Testing A Kinematic And Geometric Fault Slip Transfer Model, Kevin M. Delano
All Master's Theses
New geologic mapping, structural, kinematic, and 40Ar/39Ar geochronology studies in the Black Mountain area, northern eastern California shear zone, are used to test a kinematic fault slip transfer model for the Owens Valley fault-Mina deflection transition. In the Black Mountain area, range bounding ~NNW- to ~NS-striking and lesser NW- to NE-striking normal faults cut Mesozoic, Miocene (22.42 ± 0.05 Ma), Pliocene (3.53 ± 0.06 to 3.29 ± 0.02 Ma), and early-middle Pleistocene (1936 ± 12.7 to 766 ± 3.1 ka) rocks. Palinspastically restored cross-sections show that offset Pliocene markers record 1.5 +0.7/-0.6 km of ~ENE-WSW extension since …