NSF Awards More Than $1.6M to Six Studies at Earth and Planets Laboratory
In early 2020, the National Science Foundation (NSF) awarded more than $1.6M to six projects from the Carnegie Institution for Science Earth and Planets Laboratory. The Carnegie Institution for Science aims to foster an environment in which scientists can freely pursue their research interests. NSF funding is an important part of that goal.
EPL Director and grant recipient Richard Carlson stated, “Although the support from the Carnegie Institution itself is the foundation upon which EPL's research effort is built, funds received from federal and private grant-giving agencies allow us to expand our research efforts and bring in new equipment and postdocs that dramatically further our investigations of the world around us.”
Many of the projects are collaborative and together they span a broad range of topics, from deep Earth dynamics to how microbes survive in extreme conditions. Explore the projects below.
Collaborative Research: Integrating Petrochronology, Magma Dynamics, and Volcanic Unrest at the Three Sisters Volcanic Complex
Principal Investigator: Hélène Le Mével
Collaborator: Joseph Dufek, University of Oregon
Volcanic eruptions have the potential to threaten agriculture, infrastructure, aviation, and human life at local to global scales. These events represent the intersection of slow geologic processes that proceed over thousands to millions of years and the fast destabilization of the volcanic reservoir which may occur rapidly over only days or years.
These processes can be interrogated through both retrospective geologic studies of past eruptions and current geophysical monitoring.
This project integrates these approaches at the Three Sisters Volcanic Complex, a very high threat potential volcanic system located in the western United States. The new geochemical and geophysical data acquired in this project will be integrated in coupled models of magma dynamics and crustal deformation, ultimately linking the long-term evolution of the magmatic system to the processes at play in the modern magma system.
The goals are to determine hazards specific to the Three Sisters through the investigation of recent eruptions and volcanic unrest and produce new conceptual and quantitative models that can be applied to understand the hazards and improve eruption forecasting for active volcanoes globally.
The results of this project will be disseminated to the general public through animation and videos published on-line and a self-guided geology hiking guide made available to the many recreational visitors to the Three Sisters Wilderness Area.
Collaborative Research: Microbial Hydrogen Oxidation at High Pressure: Role of Hydrogenase and Interspecies Hydrogen Transfer
Principal Investigator: Dionysis Foustoukos
Collaborator: Costantino Vetriani, Rutgers University
Many thermophilic microorganisms inhabiting deep ocean thermal vents rely on hydrogen gas and inorganic carbon as their primary sources of energy. However, the study of these bacteria is limited because scientists have struggled to culture them in the lab due to their adaptations to deep-sea environments experiencing high pressures and temperatures.
The project will use a Carnegie patented bioreactor to sustain a continuous culture of one of these hydrothermal vent bacteria, Nautilia sp. Strain PV-1, under similar conditions to what it would experience on the ocean floor (~ 2500 m water depth, 55℃). The researchers will then study the bacterium’s use of hydrogen under deep-sea pressures (400 atmospheres); whether its cell membrane structure changes under pressure; and how it interacts with a known hydrogen-producing and fermenting deep-sea bacterium, Marinitoga piezophilia.
The project will shed light on the evolution of life under these energy-limited and high-pressure conditions of our oceans, which may be used to understand how life may have arisen on this and other worlds.
Thermal constraints on the role of hydrated oceanic mantle lithosphere in the genesis of intermediate-depth seismicity
Principal Investigators: Peter van Keken and Lara Wagner
Most of Earth’s earthquakes happen near the surface of our planet, but some occur at much greater depths. Earthquakes are generated by subducting tectonic plates, which “recycle” volatile materials like water and carbon into the Earth’s interior. Some volatiles are released from the slab early in this process and make their way back to the surface—and into our atmosphere—through volcanoes, while some may continue to ride with the subducting plate deeper into Earth’s mantle.
Where these volatiles are released could be related to their location—and varying thermal environments—in the subducting plate. For instance, water on the top of the downgoing plate is likely released earlier, ultimately making its way back to the surface of the planet. Meanwhile, water deeper within the plate in the “mantle lithosphere” may travel with the plate for much longer before it is released. The subsequent dehydration of the subducting plate at “intermediate-depths” may be the cause of earthquakes that occur around 70 - 300 km below the surface of the Earth.
To test this idea, the team has identified a geological location where they can investigate water release during intermediate-depth earthquakes. In order to do this, the team will create complex thermal models of the selected subduction zones. Overall, the project will expand our understanding of this specific geologic region, the chemical evolution of our planet, and provide more understanding of how our planet has sustained its life-preserving atmosphere. The modeling approach will be released to the public to expand the study of these complex geologic areas.
Principal Investigators: Yingwei Fei
Early in Earth’s history, energetic giant impacts such as the Moon-forming impact led to a global magma ocean. In this phase of Earth’s development, heavy metallic materials would have separated from the molten silicate mantle in the Earth’s deep magma ocean to form the metallic core. This process leaves a distinct mantle chemical signature and defines the core chemical composition.
With the development of high-temperature and high-pressure techniques combined with analytical tools, the team will simulate the conditions of the deep magma ocean in the laboratory and determine the distribution of elements during the metal-silicate separation. The project will produce unprecedented high-quality metal-silicate element partitioning data that are necessary for understanding the chemistry and evolution of our planet and lead to new frontiers for cutting-edge research.
Overall, the experiments will provide new partitioning data for potassium, silicon, and oxygen to be used to quantify the heat budget and the amounts of light elements sequestered into the core. The proposed work will significantly advance our knowledge of Earth’s deep processes and experimental techniques to investigate the composition of the Earth’s deep interior.
According to principal investigator Yingwei Fei, "The award will allow me to produce unprecedented high-quality element partitioning data to understand the chemistry and evolution of our planet and provide training for young scientists in interdisciplinary research areas. The new high-pressure techniques developed through this project will benefit a broad Solid Earth community."
The Fate of Earth's Plates: Sublithospheric Diamond Constraints on Recycling in Earth’s Mantle Transition Zone
Principal Investigators: Steven Shirey, Anat Shahar, and Michael Walter
Earth’s mantle can be divided into an upper mantle and a lower mantle separated by a region known as the mantle transition zone, which occurs between 410 and 660 km below the Earth’s surface. The active process of plate tectonics brings cold, seawater-altered, and volatile-element-bearing slabs of ocean floor rock into and through this zone where they are thought to pause and heat up.
Upon heating, the plates release volatiles like hydrogen, carbon, and boron into fluids. These carbon-bearing fluids migrate from the slab into the surrounding mantle and cause diamonds to crystallize in regions that constantly produce Earth’s deepest and most energetic earthquakes. This process, known as recycling, has been occurring on Earth for billions of years and is thought to have profound effects on the geochemical composition of the deep mantle.
Mineral inclusions in these ‘superdeep’ diamonds are the only actual samples from this area of the planet’s mantle and thus permit the direct study of the outcome of the recycling process. To that end, the team will investigate hundreds of diamonds to first find the tiny inclusions that contain protected samples from this deep-mantle reservoir. The inclusions will then be studied using an array of sophisticated microanalysis tools at Carnegie and elsewhere.
The fundamental goal of the research is to unravel fluid evolution/melting processes occurring in the slab at mantle transition zone depths by tracking the crust versus mantle portions of the slab as it decarbonates, dehydrates, and releases fluids. How the fluids are released, how they migrate, and what roles they play in modifying the composition of the deep mantle into which they are released are primary questions.
Development of a high-efficiency mass spectrometer: transitioning a high-efficiency ion source to a modern mass spectrometer
Principal Investigator: Richard Carlson
Collaborator: Jesse Reimink, Pennsylvania State University
The precision of mass spectrometry-based isotopic analyses is limited, in large part, by sensor sensitivity. The cavity ion source helps bypass that limitation by producing larger ion beams from geologic samples.
This project will adapt the cavity ion source that was originally developed for the Carnegie-built mass spectrometer so that it can be installed on the modern Thermo-Fisher Triton mass spectrometer. The technology may allow scientists to achieve isotope-ratio precisions currently unattainable with modern thermal ionization mass spectrometers (TIMS).
With enhanced precision, the source-enhanced instrument has the potential to advance research on fundamental questions in the geosciences—from radiometric dating to tracing the chemical processes that formed Earth and other planets. It will also allow for the analysis of smaller rare samples than currently possible.
According to principal investigator Richard Carlson, “This grant will foster a collaborative effort between Jesse Reimink, a former Carnegie postdoc now Assistant Professor at PSU, to continue the design, build, and test of a new type of ion source. The NSF support will allow Dr. Reimink to visit EPL to conduct analyses and will cover the costs of the electronics equipment to be purchased and the machine shop activities needed to construct the new ion source and all its mounting hardware.”