Preprints
Filtering by Subject: Physical Sciences and Mathematics
Time scales of shallow magma chamber replenishment at Campi Flegrei caldera.
Published: 2018-05-23
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Volcanology
Ascent of primitive magmas from depth into shallow, partially degassed reservoirs is commonly assumed to be a viable eruption trigger. The resulting processes of convection and mixing have played an important role both in pre- and syn-eruptive stages in many eruptions of different sizes at the unrest Campi Flegrei caldera in Southern Italy. We performed numerical simulations of magma chamber [...]
The effects of differential compaction on clinothem geometries and shelf-edge trajectories
Published: 2018-05-23
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
The geometry of basin margin strata documents changes in water depth, slope steepness, and sedimentary facies distributions. Their stacking patterns are widely used to define shelf-edge trajectories, which reflect long-term variations in sediment supply and relative sea level change. Here, we present a new method to reconstruct the geometries and trajectories of clinoform-bearing basinmargin [...]
Revisiting the surface-energy-flux perspective on the sensitivity of global precipitation to climate change
Published: 2018-05-23
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Climate models simulate an increase in global precipitation at a rate of approximately 1-3% per Kelvin of global surface warming. This change is often interpreted through the lens of the atmospheric energy budget, in which the increase in global precipitation is mostly offset by an increase in net radiative cooling. Other studies have provided different interpretations from the perspective of the [...]
Experimental and Geochemical Modeling Evidences of Mineral Sequestration of CO2 in Saline Siliciclastic aquifers
Published: 2018-05-22
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
The validity of mineral sequestration in saline siliciclastic aquifers in sedimentary basins is assessed in this paper. Mineral sequestration is the precipitation of carbonates due to the dissolution of silicates upon the injection of CO2 in deep geological formations, while solubility trapping is the dissolution of CO2 in the formation water. Saline reservoirs in sedimentary basins seem to [...]
Towards a global interpretation of dual nitrate isotopes in natural water
Published: 2018-05-22
Subjects: Biogeochemistry, Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Sciences, Physical Sciences and Mathematics, Water Resource Management
Modern anthropogenic activities have significantly increased nitrate (NO3-) concentrations in surface waters. Stable isotopes (δ15N and δ18O) in NO3- offer a tool to deconvolute some of the human-made changes in the nitrogen cycle. They are often graphically illustrated on a template designed to identify different sources of NO3- and denitrification. In the two decades since this template was [...]
Geophysical Investigations of WW2 UK air-raid shelters
Published: 2018-05-22
Subjects: Earth Sciences, Other Earth Sciences, Physical Sciences and Mathematics
Just before WW2, the British government prepared for an aerial onslaught that was predicted to raze cities and cause mass casualties. By 1938, the Air Raid Precautions Act officially stated that population protection would be through dispersal, meaning evacuation and small-scale protection, local authority responsibility often devolving to householders. Archaeological records of remaining [...]
Measuring Higher-Mode SurfaceWave Dispersion Using a Transdismensional Bayesian Approach
Published: 2018-05-21
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We present a method for measuring the dispersion of higher mode surface wave phase velocities from a single seismogram using a hierarchical transdimensional Bayesian approach. The 1-D shear velocity profiles down to 800km depth between sources and seismic stations are regarded as the controlling parameters to tune the phase velocities of fundamental and higher modes. The misfits between [...]
Determination of the diffusion constants of dimethylsulfide and dimethylsulfoniopropionate by diffusion-ordered nuclear magnetic resonance spectroscopy
Published: 2018-05-18
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The diffusion coefficients (D) for both dimethylsulfide (DMSP) and dimethylsulfoniopropionate (DMSP) were determined using diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY). Diffusion coefficients were measured across a temperature range (285 – 315 K, 12 – 42°C) and DDMSP was determined in both artificial seawater (30.5‰) and in MilliQ water (0‰). Diffusion constants were within [...]
Prognostic validation of a neural network unified physics parameterization
Published: 2018-05-17
Subjects: Atmospheric Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Weather and climate models approximate diabatic and sub-grid-scale processes in terms of grid-scale variables using parameterizations. Current parameterizations are de- signed by humans based on physical understanding, observations and process modeling. As a result, they are numerically efficient and interpretable, but potentially over-simplified. However, the advent of global high-resolution [...]
Metabolite cycling indicated by long-range correlation in a sediment bioreactor mixed microbial community
Published: 2018-05-16
Subjects: Biogeochemistry, Earth Sciences, Environmental Sciences, Geochemistry, Physical Sciences and Mathematics
Geophysical surveys add value to biogeochemical studies because of their ability to characterize systems remotely, and their precise time resolution. One limitation, however, is their lack of biogeochemical process specificity. Here, electrochemical time series from an oxic-anoxic cyclical bioreactor experiment were reanalyzed with detrended fluctuation analysis (DFA) to distinguish dominant [...]
Surface albedo as a proxy for land-cover clearing in seasonally dry forests: evidence from the Brazilian Caatinga
Published: 2018-05-16
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Indicators and Impact Assessment, Environmental Monitoring, Environmental Sciences, Natural Resources and Conservation, Other Environmental Sciences, Physical Sciences and Mathematics
Ongoing increase in human and climate pressures, in addition to the lack of monitoring initiatives, makes the Caatinga one of the most vulnerable forests in the world. The Caatinga is located in the semi-arid region of Brazil and its vegetation phenology is highly dependent on precipitation, which has a high spatial and temporal variability. Under these circumstances, satellite image-based [...]
Dynamics of settling-driven convection beneath a sediment laden buoyant overflow: implications for the length-scale of deposition in lakes and the coastal ocean
Published: 2018-05-16
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
The length-scale of deposition beneath a buoyant sediment-laden river plume can be strongly influenced by enhanced settling-driven convection, and is directly related to the horizontal velocity of the plume and a sedimentation time-scale. In our experiments, a buoyant plume of fresh water and sediment spreads over a denser saline layer. The speed of the plume increases with the net density [...]
Fish species classification in underwater video monitoring using Convolutional Neural Networks
Published: 2018-05-15
Subjects: Animal Sciences, Aquaculture and Fisheries Life Sciences, Computer Sciences, Environmental Monitoring, Environmental Sciences, Life Sciences, Other Life Sciences, Physical Sciences and Mathematics, Software Engineering
This report presents a case study for automatic fish species classification in underwater video monitoring of fish passes. Although the presented approach is based on the FishCam monitoring system, it can be used with any video-based monitoring system. The presented classification scheme in this study, is based on Convolutional Neural Networks that do not require the calculation of any [...]
Extrusion dynamics of deep-water volcanoes
Published: 2018-05-15
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Volcanology
Submarine volcanism accounts for c. 75% of the Earths volcanic activity. Yet difficulties with imaging their exteriors and interiors mean the extrusion dynamics and erupted volumes of deep water volcanoes remain poorly understood. Here, we use high-resolution 3-D seismic reflection data to examine the external and internal geometry, and extrusion dynamics of two Late Miocene-Quaternary, [...]
The land ice contribution to sea level during the satellite era
Published: 2018-05-14
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
Since 1992, there has been a revolution in our ability to quantify the land ice contribution to SLR using a variety of satellite missions and technologies. Each mission has provided unique, but sometimes conflicting, insights into the mass trends of land ice. Over the last decade, over fifty estimates of land ice trends have been published, providing a confusing and often inconsistent picture. [...]