Preprints
Filtering by Subject: Physical Sciences and Mathematics
A statistics-based reconstruction of high-resolution global terrestrial climate for the last 800,000 years
Published: 2019-01-18
Subjects: Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Statistical Models, Statistics and Probability
Curated global climate data have been generated from climate model outputs for the last 120,000 years, whereas reconstructions going back even further have been lacking due to the high computational cost of climate simulations. Here, we present a statistically-derived global terrestrial climate dataset for every 1,000 years of the last 800,000 years. It is based on a set of linear regressions [...]
Ionospheric Correction of InSAR Time Series Analysis of C-band Sentinel-1 TOPS Data
Published: 2019-01-18
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The Copernicus Sentinel-1A/B satellites operating at C-band in TOPS mode bring unprecedented opportunities for measuring large-scale tectonic motions using interferometric synthetic aperture radar. However, while the ionospheric effects are only about one sixteenth of those at L-band, the measurement accuracy might still be degraded by long-wavelength signals due to the ionosphere. We implement [...]
Supraglacial pond evolution in the Everest region, central Himalaya, 2015-2018.
Published: 2019-01-18
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
Supraglacial ponds are characteristic of debris-covered glaciers and can greatly enhance local melt rates. They can grow rapidly and coalesce to form proglacial lakes, presenting a major hazard. Here, we use Sentinel-2A satellite imagery (10 m) to quantify the spatiotemporal changes of 6,425 supraglacial ponds for 10 glaciers in Everest region of Nepal between 2015 and 2018. During the study [...]
Explosive eruptions with little warning: Experimental petrology and geodetic observations from the 2014 eruption of Kelud, Indonesia
Published: 2019-01-17
Subjects: Earth Sciences, Life Sciences, Physical Sciences and Mathematics, Volcanology
Explosive eruptions that occur with little or no precursory unrest pose the greatest hazards from volcanoes to nearby populations. Here we focus on the pre-eruptive conditions for these explosive events, their triggers and how these eruptions evolve. An example of such an event is the 2014 explosive eruption of Kelud volcano, where we have conducted a set of petrological experiments to understand [...]
Earthquakes within Earthquakes: Patterns in Rupture Complexity
Published: 2019-01-17
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Earthquake source time functions carry information about the complexity of seismic rupture. We explore databases of source time functions of earthquakes and find that source time functions are composed of distinct peaks that we call subevents. We observe that earthquake complexity, as represented by the number of subevents, grows with earthquake magnitude. We find that subevent magnitudes are [...]
Interactions between glacier dynamics, ice structure, and climate at Fjallsjökul, south-east Iceland
Published: 2019-01-16
Subjects: Environmental Sciences, Other Environmental Sciences, Physical Sciences and Mathematics
Over recent decades, the number of outlet glaciers terminating in lakes in Iceland has increased in line with climate warming. The mass-balance changes of these lake-terminating outlet gla-ciers are sensitive to rising air temperatures, due to altered glacier dynamics and increased surface melt. This study aims to better understand the relationship between proglacial lake development, climate, [...]
The organic component of the earliest sulfur cycling
Published: 2019-01-16
Subjects: Biogeochemistry, Earth Sciences, Physical Sciences and Mathematics
The chemistry of the Early Earth is widely inferred from the elemental and isotopic compositions of sulfidic sedimentary rocks, which are presumed to have formed globally through the reduction of seawater sulfate or locally from hydrothermally supplied sulfide. Here we argue that, in the sulfate-poor ferruginous oceans of the Archean eon, organic sulfur must have played an important and [...]
Supraglacial pond evolution in the Everest region, central Himalaya, 2015-2018.
Published: 2019-01-15
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
Supraglacial ponds are characteristic of debris-covered glaciers and can greatly enhance local melt rates. They can grow rapidly and coalesce to form proglacial lakes, presenting a major hazard. Here, we use Sentinel-2A satellite imagery (10 m) to quantify the spatiotemporal changes of 6,425 supraglacial ponds for 10 glaciers in Everest region of Nepal between 2015 and 2018. During the study [...]
A new crustal fault formed the modern Corinth Rift
Published: 2019-01-11
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
This review shows how collective analysis of morphotectonic elements on uplifting rift margins can constrain the mechanical behaviour of continents during early rifting. This is shown for the modern Corinth Rift, one of the fastest-extending and most seismically active continental regions worldwide. We reconstruct the growth of the normal fault system that accommodates most of the rift strain and [...]
Forearc high uplift by lower crustal flow during growth of the Cyprus-Anatolian margin
Published: 2019-01-10
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
We present a model for the dynamic formation of the forearc high of southern Anatolia where sedimentation in the forearc basin leads to thermally-activated deformation in the lower crust. Our thermo-mechanical models demonstrate that forearc sedimentation increases the temperature of the underlying crust by “blanketing” the heat flux and increasing Moho depth. Deformation switches from frictional [...]
Geometry of flexural uplift by continental rifting in Corinth, Greece
Published: 2019-01-10
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
Understanding early rifting of continental lithosphere requires accurate descriptions of up-bended rift margins and footwalls that correlate in space and time with the elastic flexural uplift that produces them. Here, we characterize the geometry of elastic flexural uplift produced by continental rifting at its spatiotemporal scale in nature (10s km; 10^4-10^6 yr) using geomorphic evidence from [...]
Transient rivers characterize evolving crustal-scale flexure in the Corinth Rift
Published: 2019-01-10
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
Crustal elastic flexure on the flanks of rift-forming faults is a key feature to characterize continental rifting processes that can be resolved by means of transient river drainages on rift footwalls. Here we show that the elastic flexure dynamics of the uplifting southern shoulder of the rapidly-extending, asymmetric Corinth Rift (Greece) are recorded in 3D by its fluvial network. We explore [...]
Anticline growth by shortening during crustal exhumation of the Moroccan Atlantic margin
Published: 2019-01-10
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
It is unclear how the crustal-scale erosional exhumation of continental domains of the Moroccan Atlantic margin and the excessive subsidence of its rifted domains affected the Late Jurassic-Early Cretaceous post-rift evolution of the margin. To constrain the km-scale exhumation, we study the structural evolution of the Jbel Amsittene. This anticline is located on the coastal plain of the [...]
Seismic and aseismic fault growth lead to different fault orientations
Published: 2019-01-10
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Orientations of natural fault systems are subject to large variations. They often contradict classical Andersonian faulting theory as they are misoriented relative to the prevailing regional stress field. This is ascribed to local effects of structural or stress heterogeneities and reorientations of structures or stresses on the long-term. To better understand the relation between fault [...]
Cooperative chemical-mechanical interactions during ion exchange promote rotational ordering in hydrated montmorillonite
Published: 2019-01-09
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
Ion exchange in clays plays a major role in water, nutrient, and contaminant storage and transport in clay-rich media including soils, sediments, and suspensions. Here, we show that ion exchange between sodium and potassium in hydrated montmorillonite is a cooperative process that couples ionic transport to interlayer forces that alter mesoscale particle structures. Fluctuations in cation [...]