Preprints
Filtering by Subject: Physical Sciences and Mathematics
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 [...]
Using sedimentological priors to improve 14C calibration of bioturbated sediment archives.
Published: 2021-06-30
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Probability, Statistics and Probability
Radiocarbon (14C) dating is often carried out upon multi-specimen samples sourced from bioturbated sediment archives, such as deep-sea sediment. These samples are inherently heterogeneous in age, but current 14C calibration techniques applied to such age heterogenous samples were originally developed for age homogeneous material. A lack of information about age heterogeneity leads to a systematic [...]
TEMPERATURE, SALINITY AND OXYGEN CLIMATOLOGY OF AFRICAN CONTINENTAL SHELF WATER, SOUTH OF THE EQUATOR, AND CHANGES SINCE 1945
Published: 2021-06-30
Subjects: Physical Sciences and Mathematics
The first temperature, salinity and oxygen climatologies for waters of the continuous southern African continental shelf is presented. It is based on oceanographic data collected since 1945, sub-sampled at depths of 5, 50 and 100 m on a mixed-spatial grid with 0.25° to 0.5° resolution. The climatologies capture spatial heterogeneities and seasonal variability in key ocean variables for the [...]
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 [...]
The late Paleozoic paired metamorphic belt of southern Central Chile: Consequence of a near-trench thermal anomaly?
Published: 2021-06-30
Subjects: Physical Sciences and Mathematics
The hypothesis of a subduction-related Miyashiro-type paired metamorphic belt for the origin of the late Paleozoic igneous and metamorphic complex in the Andean Coastal Cordillera has remained unquestioned since its proposal in the early seventies. A synthesis of the advances in the study of these metamorphic rocks between 33°S and 42°S, revising field relations among geological units, and [...]
Paleoenvironmental change recorded in submarine fans: the Eocene-Oligocene climate transition in the Alpine foreland basin
Published: 2021-06-29
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology
The Eocene-Oligocene transition (EOT) was a period of considerable environmental change, signifying the transition from Paleocene greenhouse to Oligocene icehouse conditions. Preservation of the sedimentary signal of such an environmental change is most likely in net-depositional environments, such as submarine fans, which are the terminal parts of sedimentary systems. Here, using sedimentary and [...]
Controls on submarine canyon connection to the shoreline: a numerical modelling approach
Published: 2021-06-29
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics
Submarine canyons with heads located close to shorelines, known as shore-connected canyons, provide a focussed pathway for basinward sediment transport. Placing greater constraints on the key parameters that control the formation of shore-connected canyons can help us predict the efficiency of sediment export to deep-water under different environmental conditions and through time. Using a [...]
The North Atlantic Warming Hole as Part of a Century-Long Fluctuating Phenomenon
Published: 2021-06-28
Subjects: Physical Sciences and Mathematics
Despite global warming, a region of the North Atlantic has been observed to cool, a phenomenon known as theáNorth Atlantic Warming Holeá(NAWH). The causes of the NAWH remain under debate but its emergence has been linked to a slowdown of the meridional circulation leading to a reduced ocean heat transport into the warming hole region. This note uses previously published evidence to suggest that [...]
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 [...]
Emergent simplicity despite local complexity in eroding fluvial landscapes
Published: 2021-06-25
Subjects: Earth Sciences, Physical Sciences and Mathematics
Much understanding of continental topographic evolution is rooted in measuring and predicting rates at which rivers erode. Flume tank and field observations indicate that stochasticity and local conditions play important roles in determining rates at small scales (e.g. < 10 km, thousands of years). Obversely, preserved river profiles and common shapes of rivers atop uplifting topography indicate [...]
On the Efficacy of Compact Radar Transponders for InSAR Geodesy: Results of Multi-year Field Tests
Published: 2021-06-25
Subjects: Aerospace Engineering, Civil and Environmental Engineering, Earth Sciences, Electrical and Computer Engineering, Engineering, Environmental Sciences, Physical Sciences and Mathematics
Compact and low-cost radar transponders are an attractive alternative to corner reflectors (CR) for SAR interferometric (InSAR) deformation monitoring, datum connection, and geodetic data integration. Recently, such transponders have become commercially available for C-band sensors, which poses relevant questions on their characteristics in terms of radiometric, geometric, and phase stability. [...]
Skillful decadal prediction of unforced southern European summer temperature variations
Published: 2021-06-25
Subjects: Physical Sciences and Mathematics
We assess the capability of decadal prediction simulations from the Coupled Model Intercomparison Project phase 6 (CMIP6) archive to predict European summer temperature during the period 1970-2014. Using a multi-model ensemble average, we show that Southern European (SEU) summer temperatures are highly predictable for up to 10 years in CMIP6. Much of this predictive skill, is related to the [...]