Preprints
Filtering by Subject: Physical Sciences and Mathematics
Illuminating a Contorted Slab with a Complex Intraslab Rupture Evolution during the 2021 Mw 7.3 East Cape, New Zealand Earthquake
Published: 2021-07-18
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The state-of-stress within subducting oceanic plates controls rupture processes of deep intraslab earthquakes. However, little is known about how the large-scale plate geometry and the stress regime relate to the physical nature of the deep-intraslab earthquakes. Here we find, by using globally and locally observed seismic records, that the moment magnitude 7.3 2021 East Cape, New Zealand [...]
New systemically measured sand mining budget for the Mekong Delta reveals rising trends and significant volume underestimations
Published: 2021-07-16
Subjects: Civil and Environmental Engineering, Earth Sciences, Physical Sciences and Mathematics, Planetary Sciences
The river beds of the Mekong Delta are some of the most intensively sand mined places in the world, however sand mining budgets are limited to rough and indirect estimates. Here, we provide a systematic, semi-physically based estimation of the Mekong Delta’s sand mining budget. We provide a quantified budget that overcomes limitations resulting from previous reliance on officially declared [...]
Influence of zones of pre-existing crustal weakness on strain localization and partitioning during rifting: Insights from analogue modeling using high resolution 3D digital image correlation
Published: 2021-07-15
Subjects: Earth Sciences, Physical Sciences and Mathematics
The factors controlling the selective reactivation of pre-existing crustal structures and strain localization process in natural rifts have been studied for decades but remain poorly understood. We present the results of surface strain analysis of a series of analogue rifting experiments designed to test the influence of the size, orientation, depth, and geometry of pre-existing crustal weak [...]
Noise in the Cretaceous Quiet Zone uncovers plate tectonic chain reaction
Published: 2021-07-13
Subjects: Education, Physical Sciences and Mathematics
Global plate reorganizations, intriguing but loosely defined periods of profoundly changing plate motions, may be caused by a single trigger such as a continental collision or a rising mantle plume. But whether and how such triggers propagate throughout a plate circuit remains unknown. Here, we show how a rising mantle plume set off a ‘plate tectonic chain reaction’. Plume rise has been shown to [...]
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 [...]
The effect of lateral variations in Earth structure on Last Interglacial sea level
Published: 2021-07-12
Subjects: Physical Sciences and Mathematics
It is generally agreed that the Last Interglacial (LIG; 130 – 115 ka)was a time when global average temperatures and global mean sea level were higher than they are today. However, the exact timing, magnitude, and spatial pattern of ice melt is much debated. One difficulty in extracting past global mean sea level from local observations is that their elevations need to be corrected for glacial [...]
Energetics and mixing of stratified, rotating flow over abyssal hills
Published: 2021-07-12
Subjects: Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
One of the proposed mechanisms for energy loss in the ocean is through dissipation of internal waves, in particular above rough topography where internal lee waves are generated. Rates of dissipation and diapycnal mixing are often estimated using linear theory and a constant value for mixing efficiency. However, previous oceanographic measurements found that non-linear dynamics may be important [...]
A convolutional neural network approach to estimate earthquake kinematic parameters from back-projection images
Published: 2021-07-09
Subjects: Physical Sciences and Mathematics
The retrieval of earthquake finite-fault kinematic parameters after the occurrence of an earthquake is a crucial task in observational seismology. Routinely-used source inversion techniques are challenged by limited data coverage and computational effort, and are subject to a variety of assumptions and constraints that restrict the range of possible solutions. Back-projection (BP) imaging [...]
The origin and 3D architecture of a km-scale deep-water scour-fill: example from the Skoorsteenberg Fm., Karoo Basin, South Africa
Published: 2021-07-08
Subjects: Physical Sciences and Mathematics
Scours, and scour fields, are common features on the modern seafloor of deep-marine systems, particularly downstream of submarine channels, and in channel-lobe-transitions-zones. High-resolution images of the seafloor have improved the documentation of the large scale, coalescence, and distribution of these scours in deep-marine systems. However, their scale and high aspect ratio mean they can be [...]
Impact of igneous intrusion and associated ground deformation on the stratigraphic record
Published: 2021-07-08
Subjects: Physical Sciences and Mathematics
The geomorphology and sediment systems of volcanic areas can be influenced by uplift (forced folding) related to subsurface migration and accumulation of magma. Seismic geomorphological analysis presents a unique tool to study how surface morphology and subsurface magma dynamics relate, given seismic reflection data can image buried landscapes and underlying intrusions in 3D at resolutions of [...]
Channel incision into a submarine landslide: an exhumed Carboniferous example from the Paganzo Basin, San Juan, Argentina
Published: 2021-07-08
Subjects: Physical Sciences and Mathematics
Emplacement of submarine landslides, or mass transport deposits, can radically reshape the physiography of continental margins, and strongly influence subsequent sedimentary processes and dispersal patterns. The irregular relief they generate creates obstacles that force reorganisation of sediment transport systems. Subsurface and seabed examples show that channels can incise directly into [...]
Melting temperature changes during slip across subglacial cavities drive basal mass exchange
Published: 2021-07-07
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
The importance of glacier sliding has motivated a rich literature describing the thermomechanical interactions between ice, liquid water, and bed materials. Early recognition of the gradient in melting temperature across small bed obstacles led to focussed studies of regelation. An appreciation for the limits on ice deformation rates downstream of larger obstacles highlighted a role for [...]
Reconstructing Aerosols Vertical Profiles with Aggregate Output Learning
Published: 2021-07-02
Subjects: Physical Sciences and Mathematics
Aerosol-cloud interactions constitute the largest source of uncertainty in assessments of anthropogenic climate change. This uncertainty arises in part from the inability to observe aerosol amounts at the cloud formation levels, and, more broadly, the vertical distribution of aerosols. Hence, we often have to settle for less informative two-dimensional proxies, i.e. vertically aggregated data. [...]
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 [...]
A CMIP6 ensemble for downscaled monthly climate normals over North America
Published: 2021-07-01
Subjects: Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Use of downscaled global climate model projections is expanding rapidly as climate change vulnerability assessments and adaptation planning become mainstream in many sectors. Many climate change impact analyses use climate model projections downscaled at very high spatial resolution (~1km) but very low temporal resolution (20- to 30-year normals). These applications have model selection [...]