Preprints
Filtering by Subject: Physical Sciences and Mathematics
Processing Seismic Ambient Noise Data with the Continuous Wavelet Transform to Obtain Reliable Empirical Green’s Functions
Published: 2020-02-21
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We propose a new data processing flow to compute empirical Green’s functions (EGF) from ambient seismic noise based on a soft thresholding designaling and denoising method using the continuous wavelet transform. The designaling algorithm is carried out during the initial data processing to remove earthquakes and other transient signals in the seismic record. A continuous wavelet transform [...]
Tracking Flooding Phase Transitions and Establishing a Passive Hotline with AI-Enabled Social Media Data
Published: 2020-02-21
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Environmental Monitoring, Environmental Sciences, Hydrology, Physical Sciences and Mathematics, Water Resource Management
Flooding management requires collecting real-time onsite information widely and rapidly. As an emerging data source, social media demonstrates an advantage of providing in-time, rich data in the format of texts and photos and can be used to improve flooding situation awareness. The present study shows that social media data, with additional information processed by Artificial Intelligence (AI) [...]
Using computer-aided image processing to estimate chemical composition of igneous rocks: A potential tool for large-scale compositional mapping
Published: 2020-02-20
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
Digital cameras, particularly on smartphones, have led to the proliferation of amateur photographers. Of interest here is the use of smartphone cameras to conduct rapid, low-cost compositional mapping of geologic bedrock, such as plutons and batholiths, in combination with chemical analyses of rocks in the laboratory. This paper discusses some of the challenges in geochemical mapping using image [...]
Plant Physiology Increases the Magnitude and Spread of the Transient Climate Response in CMIP6 Earth System Models
Published: 2020-02-20
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Increasing concentrations of CO2 in the atmosphere not only influence climate through CO2’s effect as a greenhouse gas but also through its impact on plants. Plants respond to atmospheric CO2 concentrations in several ways that can alter surface energy and water fluxes and thus surface climate, including changes in stomatal conductance, water use, and canopy leaf area. These plant physiological [...]
New composite bio- and isotope stratigraphies spanning the Middle Eocene Climatic Optimum at tropical ODP Site 865 in the Pacific Ocean
Published: 2020-02-20
Subjects: Earth Sciences, Geology, Paleontology, Physical Sciences and Mathematics, Stratigraphy
The Middle Eocene Climatic Optimum (MECO) at ca. 40 Ma is one of the largest of the transient Eocene global warming events. However, it is relatively poorly known from tropical settings as few sites span the entirety of the MECO event and/or host calcareous microfossils, which are the dominant proxy carrier. Ocean Drilling Program (ODP) Pacific Ocean Site 865 in the low-latitude North Pacific [...]
Evolution of a mixed siliciclastic-carbonate deep-marine system on an unstable margin: the Cretaceous of the Eastern Greater Caucasus, Azerbaijan
Published: 2020-02-20
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Mixed siliciclastic-carbonate deep-marine systems (mixed systems) are less documented in the geological record than pure siliciclastic systems. The similarities and differences between these systems are therefore poorly understood. A well-exposed Late Cretaceous mixed system on the northern side of the Eastern Greater Caucasus (EGC), Azerbaijan, provides an opportunity to study the interaction [...]
The effect of surge on riverine flood hazard and impact in deltas globally
Published: 2020-02-20
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
Current global riverine flood risk studies assume a constant mean sea level boundary. In reality high sea levels can propagate up a river, impede high river discharge, thus leading to elevated water levels. Riverine flood risk in deltas may therefore be underestimated. This paper presents the first global scale assessment of the joint influence of riverine and coastal drivers of flooding in [...]
Evidence of recurrent mass movement in front of the maximum slip area of the 1960 Chile earthquake: Implications for risk assessment and paleoseismology
Published: 2020-02-20
Subjects: Earth Sciences, Geology, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics
We present evidence that suggests a new risk scenario for the Valdivia basin in south Chile, located in the area of the magnitude 9.5 1960 earthquake. In 1960, three mass movements, triggered by the earthquake shaking, dammed the upper course of the San Pedro River and threatened Valdivia City until it was opened in a controlled manner by its inhabitants. Published historical accounts indicate [...]
Organic carbon and microbial activity in marine sediments on a global scale throughout the Quaternary
Published: 2020-02-20
Subjects: Earth Sciences, Other Earth Sciences, Physical Sciences and Mathematics
Microbial degradation of organic carbon in marine sediments is a key driver of global element cycles on multiple time scales. However, it is not known to what depth microorganisms alter organic carbon in marine sediments or how microbial rates of organic carbon processing change with depth, and thus time since burial, on a global scale. To better understand the connection between the dynamic [...]
Array-based iterative measurements of SmKS travel times and their constraints on outermost core structure
Published: 2020-02-20
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Vigorous convection in Earths outer core led to the suggestion that it is chemically homogeneous. However, there is increasing seismic evidence for structural complexities close to the outer cores upper and lower boundaries. Both body waves and normal mode data have been used to estimate a P-wave velocity, Vp, at the top of the outer core (the E layer), which is lower than that in the Preliminary [...]
Realistic River Image Synthesis using Deep Generative Adversarial Networks
Published: 2020-02-20
Subjects: Artificial Intelligence and Robotics, Civil and Environmental Engineering, Computer Sciences, Engineering, Environmental Engineering, Physical Sciences and Mathematics
In this paper, we investigate an application of image generation for river satellite imagery. Specifically, we propose a generative adversarial network (GAN) model capable of generating high-resolution and realistic river images that can be used to support models in surface water estimation, river meandering, wetland loss and other hydrological research studies. First, we summarized an augmented, [...]
Enabling high-performance cloud computing for Earth science modeling on over a thousand cores: application to the GEOS-Chem atmospheric chemistry model
Published: 2020-02-20
Subjects: Computer Sciences, Earth Sciences, Physical Sciences and Mathematics
Cloud computing platforms can facilitate the use of Earth science models by providing immediate access to fully configured software, massive computing power, and large input datasets. However, slow inter-node communication performance has previously discouraged the use of cloud platforms for massively parallel simulations. Here we show that recent advances in the network performance on the Amazon [...]
Large-scale crustal structure beneath Singapore using receiver functions from a dense urban nodal array
Published: 2020-02-19
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Geophysics has a role to play in the development of smart cities, for example through geohazard mitigation and subsurface imaging for underground construction. This is particularly true for Singapore, one of the worlds most densely populated countries. Imaging of Singapores subsurface is required to identify geological faults, model shaking from future earthquakes and provide a framework for [...]
Connecting a broad spectrum of transient slip on the San Andreas fault
Published: 2020-02-12
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Strain accumulated on the deep extension of some faults are episodically released during transient slow-slip events which can subsequently load the shallow seismogenic region. At the San Andreas fault, the characteristics of slow-slip events are difficult to constrain geodetically due to their small deformation signal. Slow-slip events are often accompanied by coincident tremor bursts composed of [...]
Constraints on mantle viscosity and Laurentide ice sheet evolution from pluvial paleolake shorelines in the western United States
Published: 2020-02-12
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics
The deformation pattern of the paleoshorelines of extinct Lake Bonneville were among the first features to indicate that Earths interior responds viscoelastically to changes in surface loads (Gilbert, 1885). Here we revisit and extend this classic study of isostatic rebound with updated lake chronologies for Lake Bonneville and Lake Lahontan as well as revised elevation datasets of shoreline [...]