Preprints
Filtering by Subject: Earth Sciences
Evolving marginal terranes during Neoproterozoic supercontinent reorganisation: constraints from the Bemarivo Domain in northern Madagascar
Published: 2018-11-30
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Madagascar is important for unravelling the geodynamic evolution of the transition between the Rodinia and Gondwana supercontinents as it contains several suites of c. 850–700 Ma magmatic rocks that have been postulated to correlate with other ex-Rodinia terranes. The Bemarivo Belt of northern Madagascar contains the youngest suite of these magmatic rocks that date to c. 750–700 Ma. We present [...]
Exceptionally large block-and-ash flows: a detailed study of the 2005 and 2010 eruption deposits of Shiveluch volcano
Published: 2018-11-28
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
Two of the largest known historic block-and-ash flow (BAF) fields are located on Shiveluch volcano, Kamchatka. The deposits were produced during retrogressive and pulsatory dome collapse events that occurred over 6-9 hour-long eruptions on 27-28 February 2005 and 27 October 2010. The BAFs that were produced by these partial dome collapse events extend up to 19 km from the dome and inundate areas [...]
Chronology and phenomenology of the 1982 and 2015 Wolf volcano eruptions, Galápagos Archipelago
Published: 2018-11-21
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
The 1982 and 2015 eruptions are the first at Wolf volcano, Galápagos Archipelago, with eyewitness accounts and satellite imagery. Both eruptions are characterized by a rapid, intense initial phase and multiple eruptive vents leading to the formation of large ‘a‘ā lava fields with scarce pāhoehoe deposits, mostly associated with the waning phases. The 1982 eruption started on 28 August from an [...]
Joint inversion of co-seismic and early post-seismic slip: Application to the 2009 Mw6.3 LAquila earthquake, Central Italy
Published: 2018-11-21
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Geodetic data provide static information on the displacement of the surface of the Earth, and allow for a detailed analysis of earthquake characteristics. Yet, geodetic data are generally characterized by either a good temporal or a good spatial resolution, but rarely both. This lack of resolution affects our understanding of the evolution of seismic and aseismic processes. Here, we propose a [...]
Calibration of astigmatic particle tracking velocimetry based on generalized Gaussian feature extraction
Published: 2018-11-21
Subjects: Artificial Intelligence and Robotics, Computer Sciences, Earth Sciences, Engineering, Fluid Dynamics, Hydrology, Life Sciences, Physical Sciences and Mathematics, Physics
Flow and transport in porous media are driven by pore scale processes. Particle tracking in transparent porous media allows for the observation of these processes at the time scale of ms. We demonstrate an application of defocusing particle tracking using brightfield illumination and a CMOS camera sensor. The resulting images have relatively high noise levels. To address this challenge, we [...]
Imbalance in the modern hydrologic budget of topographic catchments along the western slope of the Andes (21–25 S)
Published: 2018-11-20
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
Rates of water discharge often exceed groundwater recharge in arid catchments. This apparent mass imbalance within a catchment may be reconciled through either regional-scale groundwater flow between topographic drainages and/or the draining of stored groundwater recharged during pluvial periods. We investigate discrepancies in the modern hydrologic budget of catchments along the west flank of [...]
Sea floor bedforms and their influence on slope accommodation
Published: 2018-11-20
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
In deep-water settings, the accommodation space for sediment transported by turbidity flows relates to the difference between the elevation of the depositional surface and its equilibrium profile. As a consequence, accommodation space creation, or disruption, may depend from changes in the physiography of the receiving basin, or changes in the flow properties. In topographically complex slopes, [...]
Quantifying relationships between environmental factors and power dissipation on the most prolific days in the largest tornado ‘outbreaks’
Published: 2018-11-20
Subjects: Earth Sciences, Other Earth Sciences, Physical Sciences and Mathematics
An outbreak can occur as a single day or a multi-day event characterized by many tornadoes associated with specific regional scale environmental factors. The objective of this research is to quantify the relationship between environmental factors and tornado activity using big tornado days that occur in the largest multi-day groups in the United States. First, the largest groups across space and [...]
Earth Science is Ready for Preprints: The First Year of EarthArXiv
Published: 2018-11-14
Subjects: Earth Sciences, Education, Physical Sciences and Mathematics
Preprints — scholarly papers that precede publication in a peer-reviewed journal — speed the delivery and accessibility of academic work and lead to faster reuse by the scientific community, as evidenced by rapid citations and social media discussions. In the past year, EarthArXiv has emerged as a community-led initiative devoted to open scholarly communication. EarthArXiv became the first [...]
Rapid and accurate estimates of streamflow depletion caused by groundwater pumping using analytical depletion functions
Published: 2018-11-13
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Environmental Sciences, Hydrology, Natural Resources Management and Policy, Physical Sciences and Mathematics, Water Resource Management
Reductions in streamflow due to groundwater pumping (‘streamflow depletion’) can negatively impact water users and aquatic ecosystems but are challenging to estimate due to the time and expertise required to develop numerical models often used for water management. Here, we develop analytical depletion functions, which are simpler approaches consisting of (i) stream proximity criteria which [...]
A Small Scale Study of the Weathering Rates of Marble Gravestones Dated from 1958-1962
Published: 2018-11-12
Subjects: Earth Sciences, Environmental Sciences, Geology, Physical Sciences and Mathematics
Marble is known to weather quicker when exposed to air pollution. This has led to the suggestion that gravestones could be used to study the long term degradation of marble and be used as indicators of past pollution levels. This small scale study examined the weathering rates of a group of marble gravestones of similar age and location. The study found no evidence to suggest that these [...]
Early and persistent supershear rupture of the 2018 Mw 7.5 Palu earthquake
Published: 2018-11-10
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Supershear earthquakes with rupture velocity exceeding shear-wave speeds, previously observed in laboratory experiments and large strike-slip events, often have an initial sub-shear stage before they transition to supershear. In this study, integrated geophysical observations of the 2018 Mw 7.5 Palu, Indonesia earthquake, provide robust evidence of an early and persistent supershear rupture [...]
A Simple Model for Deglacial Meltwater Pulses
Published: 2018-11-08
Subjects: Earth Sciences, Geophysics and Seismology, Glaciology, Physical Sciences and Mathematics
Evidence from radiocarbon dating and complex ice sheet modeling suggests that the fastest rate of sea level rise in Earths recent history coincided with collapse of the ice saddle between the Laurentide and Cordilleran ice sheets during the last deglaciation. In this study, we derive a simple, two-equation model of two ice sheets intersecting in an ice saddle. We show that two conditions are [...]
Co-location of the downdip end of seismic coupling and the continental shelf break
Published: 2018-11-08
Subjects: Earth Sciences, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics
Along subduction margins, the morphology of the near shore domain records the combined action of erosion from ocean waves and permanent tectonic deformation from the convergence of plates. We observe that at subduction margins around the globe, the edge of continental shelves tends to be located above the downdip end of seismic coupling on the megathrust (locking depth). Coastlines lie farther [...]
An investigation of multi-fault rupture scenarios using a variety of Coulomb stress modelling criteria: methods paper and full results
Published: 2018-11-08
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
A series of Coulomb stress models are used to simulate the independently-derived (Holden et al., 2011) rupture process of Mw 7.1 Darfield earthquake. The 7-fault source model of Beavan et al. (2012) is used for all models. Model differences include (i) differences in the static stress thresholds (0,1,5,10 MPa) that must be reached or exceeded to initiate rupture on a receiver fault, (ii) [...]