Wildfires
Wildfires can lead to devastating consequences including catastrophic debris flows, anomalously high nutrient export, severe property damage, casualties, and ecosystem type conversion. Assessment of the environmental impacts of large wildfires, and adequately modeling and mitigating the associated risks are important questions that should be urgently addressed. Over the last decade, California experienced record-breaking wildfires. In the early 2020's, wildfires in California burned more area than previous decades back to at least the late 1800's. Weather extremes driven by climate change have also led to major wildfires globally in regions such as Australia and Hawaii. Consequences that result from these extreme wildfires are not well established and will be important to unravel as time progresses.
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Whittier Fire Scar from the Upper Bill Wallace Trail in Goleta, California
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Mars Analogs
The Perseverance rover is currently exploring Jezero Crater on Mars, which is a region defined by ultramafic highlands and fluvial/lacustrine sediments that host carbonate minerals, which likely formed while liquid water was present on the Martian surface. However, unlike Earth, where Ca-carbonates dominate near-surface carbonate compositions, surficial Martian carbonates are dominated by Mg-carbonates (including magnesite), which are dissimilar carbonate minerals with different geochemical properties. Assessing and validating the capacity for naturally forming Mg-carbonates to capture and preserve geochemical signatures pertaining to paleoenvironmental conditions on Earth will lay the groundwork for analyzing and interpreting Martian samples following Mars 2020 sample return.
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White magnesite nodules in fluvial sediments exposed in the Yaamba Magnesite mine in Queensland, Australia
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Noble Gas Geochemistry
Constraints on the siting, retention timescales, and mobility of noble gases in different geological materials at both near surface and elevated temperatures is useful for the for 1) selecting isotope-mineral systems for geochronology, thermochronology, and/or cosmogenic nuclide dating applications, and 2) unravaling complex metasomatic processes. Interrogation of the siting of noble gases in natural samples, and calibration of their diffusive behavior well controlled laboratory settings can shed light on geochemical processed that take place in the deep Earth, are reveal promising isotope-mineral systems that can be applied to date to diverse arrays of geological processes.
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Field photo of peridotites below Sisters Glacier - Twin Sisters Mountain
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Thermodynamics of Crustal Rocks
Magmatic and metamorphic processes in the deep Earth govern the evolution of our planet. Chemical reactions that occur deep in Earth's crust and mantle can 1) lead to enormous volcanic eruptions and earthquakes, and 2) shape the continents as we know them. To understand these geochemical processes, we cannot rely on chemistry as it occurs on Earth's surface, but must rather extrapolate using thermodynamic models calibrated to a range of magmatic temperatures and pressures. |
Modeled volumes (green) and the measured volumes (blue) plotted against a model volume surface for the Mg-hastingsite -- pargasite -- hastingsite -- ferropargasite quadrilateral.
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