Preprints
Filtering by Subject: Physical Sciences and Mathematics
The 2007 Caldera Collapse of Piton de la Fournaise Volcano: Source Process from Very-Long-Period Seismic Signals
Published: 2019-05-31
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
In April 2007, Piton de la Fournaise volcano experienced its largest caldera collapse in at least 300 years. This event consisted of a series of 48 subsidence increments characterized by very-long-period (VLP) seismic signals equivalent to Mw 4.4 to 5.4. Source analysis of VLP events suggests a piston-like mechanism with a collapsing crack source corresponding to the contraction of the magma [...]
Marine biomarkers from ice cores reveal enhanced high-latitude Southern Ocean carbon sink during the Antarctic Cold Reversal
Published: 2019-05-31
Subjects: Biogeochemistry, Earth Sciences, Glaciology, Paleontology, Physical Sciences and Mathematics
Determining the feedbacks that modulate Southern Ocean carbon dynamics is key to understanding past and future climate. The global pause in rising atmospheric CO2 during the period of mid- to high-latitude southern surface cooling known as the Antarctic Cold Reversal (ACR, 14,700-12,700 years ago) provides an opportunity to disentangle competing influences. We present highly-resolved and [...]
Comments on, Scaled Random Number Simulation of High Correlation Coeffieients for Gasoline Range Compound Concentrations (unpublished results), disclosed in EarthArXiv, 5 April, 2019, by Lloyd R. Snowdon.
Published: 2019-05-30
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
The paper comments on disclosure EarthArXiv 5 April, 2019 by L. R. Snowdon discounting correlations between light hydrocarbons suggesting steady-state catalysis in the origin of petroleum. The correlations are shown to be valid and Snowdons arguments not relevant.
How erosive are submarine landslides?
Published: 2019-05-30
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology
Submarine landslides (slides) are ubiquitous on continental margins. They can pose a major hazard by triggering tsunami and damaging essential submarine infrastructure. Slide volume, which is a key parameter in hazard assessment, can change after initiation through substrate and/or water entrainment. However, the erosive capacity of slides is uncertain. Here, we quantify slide erosivity by [...]
A shallow earthquake swarm close to hydrocarbon activities: discriminating between natural and induced causes for the 2018–19 Surrey, UK earthquake sequence
Published: 2019-05-30
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Earthquakes induced by subsurface industrial activities are a globally emotive issue, with a growing catalogue of induced earthquake sequences. However, attempts at discriminating between natural and induced causes, particularly for anomalously shallow seismicity, can be challenging. An earthquake swarm during 2018–19 in south-east England with a maximum magnitude of ML 3.2 received great public [...]
Past and projected weather pattern persistence with associated multi-hazards in the British Isles
Published: 2019-05-30
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Hazards such as heatwaves, droughts and floods are often associated with persistent weather patterns. Atmosphere-Ocean General Circulation Models (AOGCMs) are important tools for evaluating projected changes in extreme weather. Here, we demonstrate that 2-day weather pattern persistence, derived from the Lamb Weather Types (LWTs) objective scheme, is a useful concept for both investigating [...]
Concurrent wet and dry hydrological extremes at the global scale
Published: 2019-05-30
Subjects: Climate, Earth Sciences, Hydrology, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Multi-hazard events can be associated with larger socio-economic impacts than single-hazard events. Understanding the spatio-temporal interactions that characterise the former is, therefore, of relevance to disaster risk reduction measures. Here, we consider two high-impact hazards, namely wet and dry hydrological extremes, and quantify their global co-occurrence. We define these using the [...]
Creep on seismogenic faults: Insights from analogue earthquake experiments
Published: 2019-05-30
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Tectonic faults display a range of slip behaviors including continuous and episodic slip covering rates of more than 10 orders of magnitude (m/s). The physical control of such kinematic observations remains ambiguous. To gain insight into the slip behavior of brittle faults we performed laboratory stick-slip experiments using a rock analogue, granular material. We realized conditions under which [...]
Slab Rollback Orogeny model for the evolution of the Central Alps: Seismo-Thermo-Mechanical test
Published: 2019-05-30
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Forces associated with subduction of cold and dense oceanic plates control the motions and deformations of convergent margins. However, how these forces sustain mountain building processes — especially after slab breakoff — is still poorly known. Here we investigate this conundrum by performing 2-D, visco-elasto-plastic, seismo-thermo-mechanical numerical modeling, which simulates both tectonic [...]
Gondwana accretion tectonics and implications for the geodynamic evolution of eastern Arabia: first structural evidence of the existence of the Cadomian Orogen in Oman (Jabal Akhdar Dome, Central Oman Mountains)
Published: 2019-05-30
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The present work describes two early Cambrian folding events within Cryogenian to earliest Cambrian rocks of the western Jabal Akhdar Dome (Central Oman Mountains). This sequence is truncated at an angular unconformity and topped by Permo-Mesozoic sedimentary shelf strata. The Permo-Mesozoic is brittlely deformed and largely unfolded. This differs in style and intensity of deformation with the [...]
A Stella® version of the Arctic Mediterranean Double Estuarine Circulation model: SAMDEC v1.0
Published: 2019-05-30
Subjects: Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Arctic Mediterranean can be described as a double estuarine circulation regime. This observed circulation feature, which connects the North Atlantic to the Arctic Ocean, is composed of two interconnected branches of circulation: an overturning circulation, where dense water formed in the Nordic Seas returns toward the Atlantic and an estuarine circulation, where the East Greenland Current [...]
Teleseisms and Microseisms on an Ocean-Bottom Distributed Acoustic Sensing Array
Published: 2019-05-30
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Sparse seismic instrumentation in the oceans limits our understanding of deep Earth dynamics and submarine earthquakes. Distributed acoustic sensing (DAS), an emerging technology that converts optical fiber to seismic sensors, allows us to leverage pre-existing submarine telecommunication cables for seismic monitoring. Here we report observations of microseism, local surface gravity waves, and a [...]
Lake Level Fluctuations in the Northern Great Basin for the Last 25,000 years
Published: 2019-05-30
Subjects: Climate, Earth Sciences, Environmental Sciences, Geology, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology
During the Last Glacial Maximum (LGM; ~23,000 to 19,000 years ago or ka) and through the last deglaciation, the Great Basin physiographic region in the western United States was marked by multiple extensive lake systems, as recorded by proxy evidence and lake sediments. However, temporal constraints on the growth, desiccation, and timing of lake highstands remain poorly constrained. Studies aimed [...]
Implicitly localized ensemble observational update to cope with nonlocal/nonlinear data constraints in large-size inverse problems
Published: 2019-05-30
Subjects: Applied Mathematics, Earth Sciences, Physical Sciences and Mathematics
Many practical applications involve the resolution of large-size inverse problems, without providing more than a moderate-size sample to describe the prior probability distribution. In this situation, additional information must be supplied to augment the effective dimension of the available sample. This is the role played by covariance localization in the large-size applications of the ensemble [...]
A constant Chinese Loess Plateau dust source since the Late Miocene
Published: 2019-05-30
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
The Pliocene-Pleistocene boundary marks a major change in global climate and East Asian monsoon dynamic. However, the role of the global atmospheric dust-cycle over this time is unclear; in particular, whether, changes in the dust cycle influenced climate change, or resulted from it. Chinese loess records past dust-cycle history and the influences of aridification and monsoon circulation over the [...]