Preprints
Filtering by Subject: Physical Sciences and Mathematics
Non-crossing nonlinear regression quantiles by monotone composite quantile regression neural network, with application to rainfall extremes
Published: 2017-12-05
Subjects: Artificial Intelligence and Robotics, Climate, Computer Sciences, Earth Sciences, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Statistical Models, Statistics and Probability
The goal of quantile regression is to estimate conditional quantiles for specified values of quantile probability using linear or nonlinear regression equations. These estimates are prone to "quantile crossing", where regression predictions for different quantile probabilities do not increase as probability increases. In the context of the environmental sciences, this could, for example, lead to [...]
Synchronization of great subduction megathrust earthquakes: Insights from scale model analysis
Published: 2017-12-04
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The size of great subduction megathrust earthquakes is controlled mainly by the number of adjacent asperities failing synchronously and the resulting rupture length. Here we investigate experimentally the long-term recurrence behavior of a pair of asperities coupled by quasi-static stress transfer over hundreds of seismic cycles. We statistically analyze long (c. 500 ka) time-series of M8-9 [...]
The crisis of a paradigm. A methodological interpretation of Tohoku and Fukushima catastrophe
Published: 2017-12-04
Subjects: Earth Sciences, Environmental Studies, Geophysics and Seismology, Physical Sciences and Mathematics, Social and Behavioral Sciences, Tectonics and Structure
The 2011 Japanese disaster often presented as a ‘new Chernobyl’ accumulated the effects of earthquake, tsunami and of the subsequent nuclear accident at Fukushima. In the light of this disaster, we review methodological rea- sons both from geophysical and philosophical perspectives that lead the scientific and technological communities to flawed conclusions, prime cause of the disaster. The [...]
Estimating geological CO2 storage security to deliver on climate mitigation
Published: 2017-12-04
Subjects: Earth Sciences, Environmental Sciences, Natural Resources Management and Policy, Physical Sciences and Mathematics
Carbon capture and storage (CCS) can help nations meet their Paris CO2 reduction commitments cost-effectively. However, lack of confidence in geologic CO2 storage security remains a barrier to CCS implementation. Here we present a numerical program that calculates CO2 storage security and leakage to the atmosphere over 10,000 years. This combines quantitative estimates of geological subsurface [...]
Visions of Volcanoes
Published: 2017-12-03
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
The long nineteenth century marked an important transition in the understanding of the nature of combustion and fire, and of volcanoes and the interior of the earth. It was also a period when dramatic eruptions of Vesuvius lit up the night skies of Naples, providing ample opportunities for travellers, natural philosophers, and early geologists to get up close to the glowing lavas of an active [...]
Ice shelf rift propagation and the mechanics of wave-induced fracture
Published: 2017-11-28
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
Distant storms, tsunamis, and earthquakes generate waves on floating ice shelves. Previous studies, however, have disagreed about whether the resulting wave-induced stresses may cause ice shelf rift propagation. Most ice shelf rifts show long periods of dormancy suggesting that they have low background stress concentrations and may therefore be susceptible to wave-induced stresses. Here, I [...]
Lithospheric flexure and rheology determined by climate cycle markers in the Corinth Rift
Published: 2017-11-28
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
Geomorphic strain markers accumulating the effects of many earthquake cycles help to constrain the mechanical behaviour of continental rift systems as well as the related seismic hazards. In the Corinth Rift (Greece), the unique record of onshore and offshore markers of Pleistocene ~100-ka climate cycles provides an outstanding possibility to constrain rift mechanics over a range of timescales. [...]
Sedimentology and reservoir properties of tabular and erosive offshore transition deposits in wave-dominated, shallow-marine strata: Book Cliffs, USA
Published: 2017-11-28
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology
Facies models for wave-dominated shorelines include an "offshore transition zone" between shelfal mudstones and nearshore shoreface sandstones. Offshore transition zone deposits are commonly tabular sandstone beds interbedded with continuous mudstone beds. However, observations from the Blackhawk Formation show that the offshore transition zone locally consists of erosive-based sandstone beds [...]
How, where and when do radial faults grow near salt diapirs?
Published: 2017-11-27
Subjects: Earth Sciences, Geology, Other Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
We examine 3-D seismic reflection data from the Santos Basin, offshore Brazil to determine how, where and when do radial faults grow near a sub-circular salt diapir (stock). We show roof stretching alone cannot account for the large heights and lengths of the kilometre-scale radial faults, suggesting stock widening (‘stem push’), a mechanism implied in numerical models but not yet documented in [...]
The evolution of REE mineralisation within the Ditrău Alkaline Complex, Romania: interplay of magmatic and hydrothermal processes
Published: 2017-11-27
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
The Ditrău Igneous Complex (NE Romania) is a tilted Mesozoic layered alkaline intrusion (~19 km diameter), with enrichments in rare earth elements (REE), niobium, tantalum and molybdenum. It has the potential to contribute to a secure and sustainable European REE mining industry, ensuring supply security for these critical metals. The complex comprises layered ultramafic rocks, alkali gabbros, [...]
The role of coseismic Coulomb stress changes in shaping the hard-link between normal fault segments
Published: 2017-11-27
Subjects: Earth Sciences, Geology, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The mechanism and evolution of fault linkage is important in the growth and development of large faults. Here we investigate the role of coseismic stress changes in shaping the hard-links between parallel normal fault segments (or faults), by comparing numerical models of the Coulomb stress change from simulated earthquakes on two en echelon fault segments to natural observations of hard-linked [...]
Rupture Process during the Mw 8.1 2017 Chiapas Mexico Earthquake: Shallow Intraplate Normal Faulting by Slab Bending
Published: 2017-11-25
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
A seismic source model for the Mw 8.1 2017 Chiapas, Mexico, earthquake was constructed by kinematic waveform inversion using globally observed teleseismic waveforms, suggesting that the earthquake was a normal-faulting event on a steeply dipping plane, with the major slip concentrated around a relatively shallow depth of 28 km. The modeled rupture evolution showed unilateral, down-dip propagation [...]
Throw Rate Variability on Gravity-Driven Normal Faults; Constraints from the Gudrun Fault, South Viking Graben, Offshore Norway
Published: 2017-11-24
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
The growth and throw rate variability on normal faults can reflect fault interaction, plate tectonic forces and, in gravity-driven systems, variations in sediment loading. Because earthquakes may occur as faults slip, it is important to understand what processes influence throw rate variability on normal faults to be able to predict seismic hazards in extensional terranes. Furthermore, the rate [...]
Temperatures recorded by cosmogenic noble gases since the last glacial maximum in the Maritime Alps
Published: 2017-11-24
Subjects: Earth Sciences, Geochemistry, Geomorphology, Glaciology, Other Earth Sciences, Physical Sciences and Mathematics
While proxy records have been used to reconstruct late Quaternary climate parameters throughout the European Alps, our knowledge of deglacial climate conditions in the Maritime Alps is limited. Here, we report temperatures recorded by a new and independent geochemical technique—cosmogenic noble gas paleothermometry—in the Maritime Alps since the last glacial maximum. We measured cosmogenic 3He in [...]
The INTAV intercomparison of electron-beam microanalysis of glass by tephrochronology laboratories, results and recommendation
Published: 2017-11-24
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
The INternational focus group on Tephrochronology And Volcanism (INTAV) of the International Union for Quaternary Research (INQUA) has conducted an intercomparison of tephrochronology laboratories with electron-beam microanalytical data on volcanic glasses submitted from 27 instruments at 24 institutions in 9 countries. This assessment includes most active tephrochronology laboratories and [...]