Preprints
Filtering by Subject: Planetary Geophysics and Seismology
Constraining Earth's core composition from inner core nucleation.
Published: 2024-08-02
Subjects: Earth Sciences, Geophysics and Seismology, Mineral Physics, Physical Sciences and Mathematics, Planetary Geophysics and Seismology, Planetary Mineral Physics, Planetary Sciences
Mantle avalanches in a Venus-like stagnant lid planet
Published: 2024-06-28
Subjects: Planetary Geophysics and Seismology, Planetary Mineral Physics, Planetary Sciences
Stagnant lid planets are characterized by a globe-encircling, conducting lid that is thick and strong, which leads to reduced global surface heat flows. Consequently, the mantles of such planets can have warmer interiors than Earth, and interestingly, a pyrolitic mantle composition under warmer conditions is predicted to have a distinctly different mantle transition zone compared to the [...]
Grüneisen parameter formalism in the study of the Earth's core formation: a sensitivity study
Published: 2024-03-21
Subjects: Condensed Matter Physics, Earth Sciences, Geochemistry, Geology, Mineral Physics, Other Earth Sciences, Planetary Geophysics and Seismology, Planetary Mineral Physics, Planetary Sciences
The Grüneisen parameter is an important parameter for the thermal state and evolution of the core, but its uncertainties and their implications are sometimes overlooked . Several formalisms using different parameters values have been used in different studies, making comparison between studies difficult. In this paper, we use previously published datasets to test the sensitivity of modeling the [...]
AxiSEM3D - an introduction to using the code and its applications
Published: 2024-03-19
Subjects: Geophysics and Seismology, Planetary Geophysics and Seismology
Welcome to the wonderful world of AxiSEM3D, a flexible, high-performance computational method for solving the elastodynamic wave equation in three-dimensional, hetereogeneous media. It has been used in seismology for the Earth, the Sun, the Moon, and many of other rocky planets and moons of the Solar System. In this manual, we will explore the practicalities of using this code, touching on the [...]
Estimates on the possible annual seismicity of Venus
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
Published: 2023-03-26
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?
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
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)
Published: 2022-12-01
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
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
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
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
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
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
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 [...]