Preprints

Filtering by Subject: Planetary Geophysics and Seismology

Estimates on the possible annual seismicity of Venus

Iris van Zelst, Julia Maia, Ana-Catalina Plesa, et al.

Published: 2023-03-31
Subjects: Planetary Geophysics and Seismology

There is a growing consensus that Venus is seismically active, although its level of seismicity could be very different from that of Earth due to the lack of plate tectonics. Here, we estimate upper and lower bounds on the expected annual seismicity of Venus by scaling the seismicity of the Earth. We consider different scaling factors for different tectonic settings and account for the lower [...]

Linking the core heat content to Earth's accretion history

Vincent Clesi, Renaud Deguen

Published: 2023-03-25
Subjects: Earth Sciences, Geochemistry, Geophysics and Seismology, Planetary Geochemistry, Planetary Geophysics and Seismology

In this study we use a parameterized model of differentiation in a magma ocean setting, in which the magma ocean depth evolves during accretion, to predict the composition of the primordial core. We couple this chemical model to a thermal evolution model of the accreting metal to estimate the Earth's core heat content at the end of its formation. We find geochemically consistent models. All these [...]

Can homogeneous nucleation resolve the inner core nucleation paradox?

Alfred Wilson, Dario Alfè, Andrew Walker, et al.

Published: 2023-03-24
Subjects: Condensed Matter Physics, Earth Sciences, Geophysics and Seismology, Mineral Physics, Planetary Geophysics and Seismology, Planetary Mineral Physics

False positives are common in single-station template matching

Jack Broderick Muir, Benjamin Fernando

Published: 2023-02-17
Subjects: Earth Sciences, Geophysics and Seismology, Planetary Geophysics and Seismology, Planetary Sciences

Template matching has become a cornerstone technique of observational seismology. By taking known events, and scanning them against a continuous record, new events smaller than the signal-to-noise ratio can be found, substantially improving the magnitude of completeness of earthquake catalogues. Template matching is normally used in an array setting, however as we move into the era of planetary [...]

Comment on "Estimates on the Frequency of Volcanic Eruptions on Venus" by Byrne & Krishnamoorthy (2022)

Iris van Zelst

Published: 2022-11-30
Subjects: Other Planetary Sciences, Physical Sciences and Mathematics, Planetary Geology, Planetary Geophysics and Seismology, Planetary Sciences

Byrne & Krishnamoorthy (2022) estimated the frequency of volcanic eruptions on Venus by scaling the eruption frequency obtained from a database containing Earth data. In reproducing their study, I found that the estimated number of new and ongoing volcanic eruptions on Venus in a given year is approximately 42, instead of the previously reported 120 eruptions. This updated estimate of Byrne & [...]

Machine learning and marsquakes: a tool to predict atmospheric-seismic noise for the NASA InSight mission

Alexander Stott, Raphael Garcia, Armand Chédozeau, et al.

Published: 2022-04-27
Subjects: Geophysics and Seismology, Planetary Geophysics and Seismology

The SEIS experiment on the NASA InSight mission has catalogued hundreds of marsquakes so far. However, the detectability of these events is controlled by the weather which generates seismic noise. This affects the catalogue on both diurnal and seasonal scales. We propose to use machine learning methods to fit the wind, pressure and temperature data to the seismic energy recorded in the 0.4-1 Hz [...]

A minimally cemented shallow crust beneath InSight

Vashan Wright, Jhardel Dasent, Richard Kilburn, et al.

Published: 2022-04-21
Subjects: Planetary Geology, Planetary Geophysics and Seismology, Planetary Hydrology, Planetary Sciences, Planetary Sedimentology

Ice and other mineral cements in Mars’ shallow subsurface affect the mechanical properties of the shallow crust, the geologic processes that shape the planet’s surface, and the search for past or extant Martian life. Cements increase seismic velocities. We use rock physics models to infer cement properties from seismic velocities. Model results confirm that the upper 300 m of Mars beneath InSight [...]

Internal Planetary Feedbacks, Mantle Dynamics, and Plate Tectonics

Adrian Lenardic, Johnny Seales

Published: 2022-03-18
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Planetary Geophysics and Seismology, Planetary Sciences, Tectonics and Structure

Isolating planetary feedbacks, and feedback analysis, are prevalent aspects of climate and Earth surface process science. An under appreciation of internal planet feedbacks, and feedback analysis for plate tectonics research, motivate this chapter. We review feedbacks that influence the Earth's thermal evolution and expand them to include magmatic history and planetary water budgets. The [...]

An anisotropic equation of state for high pressure, high temperature applications

Robert Myhill

Published: 2021-09-25
Subjects: Condensed Matter Physics, Geophysics and Seismology, Materials Science and Engineering, Mineral Physics, Physical Sciences and Mathematics, Planetary Geophysics and Seismology, Planetary Mineral Physics

This paper presents a strategy for consistently extending isotropic equations of state to model anisotropic materials over a wide range of pressures and temperatures under nearly hydrostatic conditions. The method can be applied to materials of arbitrary symmetry. The paper provides expressions for the deformation gradient tensor, the lattice parameters, the isothermal elastic compliance tensor [...]

Safety and Belonging in the Field: A Checklist for Educators

Sarah E Greene, Gawain T. Antell, Jake Atterby, et al.

Published: 2021-08-19
Subjects: Atmospheric Sciences, Biogeochemistry, Climate, Cosmochemistry, Earth Sciences, Education, Environmental Education, Environmental Health and Protection, Environmental Indicators and Impact Assessment, Environmental Monitoring, Environmental Sciences, Environmental Studies, Fresh Water Studies, Geochemistry, Geographic Information Sciences, Geography, Geology, Geomorphology, Geophysics and Seismology, Glaciology, Higher Education, Human Geography, Hydrology, Life Sciences, Meteorology, Mineral Physics, Natural Resource Economics, Natural Resources and Conservation, Natural Resources Management and Policy, Nature and Society Relations, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Oil, Gas, and Energy, Other Earth Sciences, Other Environmental Sciences, Other Geography, Other Oceanography and Atmospheric Sciences and Meteorology, Other Planetary Sciences, Outdoor Education, Paleobiology, Paleontology, Physical and Environmental Geography, Physical Sciences and Mathematics, Planetary Biogeochemistry, Planetary Geochemistry, Planetary Geology, Planetary Geomorphology, Planetary Geophysics and Seismology, Planetary Glaciology, Planetary Hydrology, Planetary Mineral Physics, Planetary Sciences, Planetary Sedimentology, Remote Sensing, Sedimentology, Social and Behavioral Sciences, Soil Science, Spatial Science, Speleology, Stratigraphy, Sustainability, Tectonics and Structure, Volcanology, Water Resource Management

Ensuring taught fieldwork is a positive, generative, collective, and valuable experience for all participants requires considerations beyond course content. To guarantee safety and belonging, participants’ identities (backgrounds and protected characteristics) must be considered as a part of fieldwork planning and implementation. Furthermore, getting fieldwork right is an important step in [...]

Stress and Strain during Shock Metamorphism

Auriol S. P. Rae, Michael H. Poelchau, Thomas Kenkmann

Published: 2021-04-15
Subjects: Geology, Planetary Geology, Planetary Geophysics and Seismology, Tectonics and Structure

Shock metamorphism is the process by which rocks, and the minerals within them, transform during the passage of a shock wave. Shock effects, such as shatter cones, are critical for the identification of impact structures and have commonly been used to infer mechanical and structural information on the cratering process. To make these inferences, the mechanics of shock wave behavior must be [...]

No cryosphere-confined aquifer below InSight on Mars

Michael Manga, Vashan Wright

Published: 2021-02-24
Subjects: Planetary Geophysics and Seismology, Planetary Hydrology, Planetary Sciences

The seismometer deployed by the InSight lander measured the seismic velocity of the Martian crust. We use a rock physics model to interpret those velocities and constrain hydrogeological properties. The seismic velocity of the upper ~10 km is too low to be ice-saturated. Hence there is no cryosphere that confines deeper aquifers. An increase in seismic velocity at depths of ~10 km could be [...]

Bias correction of global climate model using machine learning algorithms to determine meteorological variables in different tropical climates of Indonesia

Juan Nathaniel

Published: 2020-12-11
Subjects: Applied Statistics, Atmospheric Sciences, Planetary Geophysics and Seismology, Statistical Models

Accurate and localized forecasting of climate variables are important especially in the face of uncertainty imposed by climate change. However, the data used for prediction are either incomplete at the local level or inaccurate because the simulation models do not explicitly consider local contexts and extreme events. This paper, therefore, attempts to bridge this gap by applying tree-based [...]

Seismic electric signals (SES) and earthquakes: A review of an updated VAN method and competing hypotheses for SES generation and earthquake triggering

Daniel S. Helman

Published: 2020-04-07
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Studies, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Planetary Geophysics and Seismology, Planetary Sciences, Social and Behavioral Sciences

Electromagnetic phenomena are sometimes associated with seismic events, but earthquake prediction using seismic electric signals (SES) has not been seriously considered since the early 1990s. There are several causes: (1) false alarms that have created panics in Greece, and (2) a strong critique of the Varotsos-Alexopoulos-Nomicos (VAN) method used there. An updated VAN method that includes time [...]

Analytical prediction of seismicity rate due to tides and other oscillating stresses

Elias Rafn Heimisson, Jean-Philippe Avouac

Published: 2020-03-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Planetary Geophysics and Seismology, Planetary Sciences, Tectonics and Structure

Oscillatory stresses are ubiquitous on earth and other solid-surface bodies. Tides and seasonal signals perpetually stress faults in the crust. Relating seismicity to these stresses offers fundamental insight into earthquake triggering. We present a simple model that describes seismicity rate due to perpetual oscillatory stresses. The model applies to large amplitude, non-harmonic, and [...]

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