Oregon State University

College of Earth, Ocean, and Atmospheric Sciences

Geology and Geophysics

Weekly Seminar Series, Spring 2017

DateSpeakerTitleHost
4/6/17Ken Creager, UWIntegrating results from the imaging Magma Under St. Helens (iMUSH) projectAdam Schultz
4/12/17Kamini Singha, Colorado School of MinesSpecial Lecture (not a G&G Seminar): National Ground Water Research and Education Foundation Darcy Lecture – in OWEN 103 – not Burt 193 - The Critical Role of Trees in Critical Zone Science: An Exploration of Water Fluxes in the Earth's Permeable SkinDorthe Wildenschild
4/13/17Jim O'Connor, USGS Pacific Region (Portland)The Great Missoula Floods of the Last Ice AgeHeather Dawn Bervid
4/20/17Emilie Hooft, UOAdvances in seismic imaging of volcanic systems: Examples from arc volcanoes and the mid-ocean ridge.Adam Schultz
4/27/17Laura Moore, UNC Chapel HillFrom stem to landform: Vegetation controls on coastal foredune morphology, dune state and barrier response to climate changePeter Ruggiero
5/4/17Karl Kappler, Quakefinder, Inc.A prototype algorithm for the extraction and classification of electromagnetic signals in magnetometer dataAdam Schultz
5/11/17Cameron DavidsonWas southern Alaska once part of California? Implications of the Yavapai-Mazatzal detrictal zircon ages in the Chugach Prince William TerranePeter Davidson
5/18/17Susan Petty, AltaRock Energy, Inc.Geologic Conceptual models, Numerical Modeling and Developing Enhanced Geothermal SystemsAdam Schultz
5/25/17Alex Iriondo, UNAM, Mexico D.F.Channeling of metamorphic fluids along Paleoproterozoic crustal discontinuities in NW Mexico to form orogenic quartz-gold veins during the last stages of the Laramide OrogenyJohn Dilles
6/1/17Alain Bonneville, PNNLGeological Storage of CO2: Science and Technology ChallengesAdam Schultz
6/8/17Seth Moran, USGSThe Cascades Volcano Observatory: Research, monitoring, and the science of preparing for low-probability, high-consequence eventsAdam Schultz
Free and open to the public!

Contact Adam Schultz at 541-737-9832 or Adam.Schultz@oregonstate.edu with any questions.

Selected seminar abstracts:


Ken Creager, April 6, 2017:
Integrating results from the imaging Magma Under St. Helens (iMUSH) project

The iMUSH project integrates active and passive source seismic experiments with magnetotelluric (MT) observations and petrology to better understand the structure and dynamics of the Mount St Helens (MSH) magmatic system from the subducted plate to the surface. The geophysical experiments included a 70-element broadband seismometer array with 10-km station spacing within 50 km of the MSH edifice from summer 2014 through 2016, 23 shots recorded in 2014 by geophones at 6000 sites including 900 Nodal stations, and ~150 MT stations within ~100 km of MSH in 2013-2015. A few papers are already published on the active-source seismic experiment, and data from all the highly successful geophysical experiments are actively being processed. Preliminary results include new 3-D images of P-wave, S-wave and P/S-wave velocity as well as 3-D electrical conductivity models. Mid-lower crustal velocities are generally fast to the west of MSH, consistent with the presence of the accreted Siletz terrain, and slow to the east consistent with generally higher temperatures. P-wave speeds are generally slow in the upper crust (~5-15 km depth) in a narrow zone coincident with the St. Helens seismic Zone (SHZ) that cuts through MSH with a NNW-SSE orientation. This may correspond to fluids rising from the eastern edge of an inferred hydrated mantle wedge. There is also some evidence from MT data for high electrical conductivity in places along this trend. High Vp/Vs and high electrical conductivity extend under the Indian Heaven volcanic field at depths of 5-15 km potentially associated with regions of partial melt and/or fluids. The area above this strong electrical conductor has low P-wave speeds, and the lower crust beneath Indian Heaven has high P-wave speeds. The area of high conductivity also extends north between MSH and Mount Adams almost as far as Mount Rainier.


Kamini Singha, April 12, 2017:
The Critical Role of Trees in Critical Zone Science: An Exploration of Water Fluxes in the Earth's Permeable Skin (this is a Water Resources Seminar, not a G&G Seminar)

Earth's "critical zone" – the zone of the planet from treetops to base of groundwater – is critical because it is a sensitive region, open to impacts from human activities, while providing water necessary for human consumption and food production. Quantifying water movement in the subsurface is critical to predicting how water-driven critical zone processes respond to changes in climate and human perturbation of the natural system. While shallow soils and aboveground parts of the critical zone can be easy to instrument and explore, the deeper parts of the critical zone – through the soils and into rock – are harder to access, leaving many open questions about the role of water in this environment.

This presentation opens the black box in the subsurface and sheds light on a few key subsurface processes that control water movement and availability: linkages between changes in evapotranspiration and subsurface water stores, water movement in three dimensions over large areas, and potential control of slope aspect on subsurface permeability. Geophysical tools are central to the quantitative study of these problems in the deeper subsurface where we don't have easy access for observation. In particular, this lecture explores the role of trees in the critical zone, and their connection to soil moisture, groundwater and streams through innovative imaging.


Jim O'Connor, April 13, 2017:
The Great Missoula Floods of the Last Ice Age

The Missoula Floods of the last Ice Age in the Pacific Northwest were the largest freshwater floods yet known on the surface of the Earth. The flood-formed landscape is a spectacular example of the power of geologic processes, one that has inspired new insights into geomorphic processes and planetary landscapes. But the Missoula Floods are also a story of controversy; an example of dogma and personality obscuring and facilitating the quest for knowledge. This is science in action, not always pretty, but continuously motivated by the wonderment of discovery.


Emilie Hooft, April 20, 2017:
Advances in seismic imaging of volcanic systems: Examples from arc volcanoes and the mid-ocean ridge

The depth and geometry of the magma system beneath volcanoes as well as the regional tectonic setting control magma evolution and eruptive behavior and also is the heat source that drives water circulation in the crust. To better image the structure beneath volcanoes we are integrating seismic waveform studies with travel time tomography. I will describe this approach for two backarc volcanos, Newberry volcano in central Oregon and the Santorini volcano in the Hellenic volcanic arc of Greece, and for a segment of the mid-ocean ridge, the Endeavour segment of the Juan de Fuca ridge.


Laura Moore, April 27, 2017:
From stem to landform: Vegetation controls on coastal foredune morphology, dune state and barrier response to climate change

Foredunes–the seaward-most line of coastal dunes–arise from two-way couplings between vegetation and sediment transport processes. Model experiments and field observations are increasingly demonstrating that these ecomorphodynamic interactions shape the coastal landscape across a range of spatial and temporal scales, and dimensions, with implications for the evolution of barrier landforms. For example, in the cross-shore dimension, the maximum potential height that a coastal foredune can achieve is a function of the distance from the shoreline that dune vegetation can grow–the farther from the shoreline that vegetation establishes, the taller the foredune can grow before steering the wind sufficiently above the beach to prevent sand transport to the dune. In the alongshore dimension, the lateral growth rate of vegetation relative to the vertical growth rate of vegetation controls the timescale at which hummocky dunes anneal and thus, at least partially, determines whether dunes will tend to remain hummocky or grow to become an alongshore-continuous foredune ridge. Likewise, at larger spatial and temporal scales, interactions between the rate of lateral vegetation growth, as potentially controlled by dune slope, can explain the overall morphology of multiple dunes in areas where the shoreline is prograding. On barrier coastlines the morphology of dunes arising from these vegetation controls plays a critical role in determining island state and the degree to which connectivity with back-barrier marshes will influence overall island-marsh system response to changing climate.


Karl Kappler, May 4, 2017:
A Prototype Algorithm for the Extraction and Classification of Electromagnetic Signals in Magnetometer Data

QuakeFinder and its international collaborators have installed and currently maintain an array of 165 three-axis induction magnetometer instrument sites in California, Peru, Taiwan, Greece, Chile and Sumatra. QuakeFinder has developed an algorithm framework aimed at isolating anomalous signals in the time series, especially signals associated with pre-earthquake signatures.

After introducing the array, results are presented from an application of this framework to magnetometer data. This data driven approach starts with sliding windows applied to uniformly resampled array data with a variety of lengths and overlap. Data variance ( proxy for signal energy) is calculated on each window and a short-term average/ long-term average (STA/LTA) filter is applied to the variance time series. Event identification is done by flagging time intervals in the STA/LTA filtered time series which exceed a threshold.

Flagged time intervals are subsequently fed into a feature extraction program which computes statistical properties of the resampled data. These features are then filtered using a Principal Component Analysis (PCA) based method to cluster similar events. We explore the extent to which this approach categorizes pulses with known sources (e.g. cars, lightning, etc.) and the remaining pulses of unknown origin are analyzed with respect to their relationship with seismicity. We explore functions which map daily pulse-counts to a time series representing the likelihood of a seismic event occurring at some future time. These "pseudo-probabilities" can in turn be represented as Molchan diagrams. The Molchan curve provides an effective cost function for optimization and allows for a rigorous statistical assessment of the validity of pre-earthquake signals in the electromagnetic data.

Bio

Originally from Winnipeg, Manitoba, Karl Kappler completed a B. Sc. in mathematics and physics from the University of Victoria, Canada, and MS and Ph. D. degrees in applied geophysics with an emphasis on signal processing from the University of California at Berkeley. He was a postdoctoral fellow at Lawrence Berkeley National Laboratory from 2008–2011, primarily working in electromagnetic methods applied to UXO problems. He has been a research geophysicist in mineral and oil-and gas applications working on topics ranging from field system development, to data acquisition, processing and interpretation as a consultant as well at SJ Geophysics in Vancouver, Canada and at GMI in San Diego California. Karl is currently Chief Scientist at QuakeFinder – a humanitarian research organization dedicated to earthquake forecasting based in Palo Alto CA. His main research interests are signal and noise separation and understanding noise sources in EM measurements.


Cameron Davidson, May 11, 2017:
Was southern Alaska once part of California? Implications of Yavapai-Mazatzal detrital zircon ages in the Chugach Prince William terrane.

Most of southern Alaska, from Sanak Island in the west to Baranof Island in the southeast (>2000 km), is dominated by deep-water sedimentary rocks that were deposited in a submarine trench, and then accreted onto the North American margin from about 75-35 million years ago. An outstanding question in Alaska geology is where along the margin were these rocks deposited? There are two main hypotheses: 1) the rocks, known as the Chugach-Prince William terrane (CPW), were deposited more or less in place, or 2) the CPW was deposited as far south as California and subsequently transported along the margin to their present position. The purpose of this talk is to examine the evidence used to argue for these mutually exclusive hypotheses, and present recently collected U-Pb and Hf isotopic data from detrital zircon that supports the southern California option.


Susan Petty, May 18, 2017:
Geologic Conceptual models, Numerical Modeling and Developing Enhanced Geothermal Systems

Natural geothermal systems can provide us with insight into how geothermal systems we engineer through stimulation methods to create a circulating geothermal system. The development of circulating hydrothermal systems is of interest not just for development of geothermal power or heat projects, but also for mining geologist to understand ore bodies. In order to manage geothermal projects successfully, we need to understand the natural circulation patterns before development. We can then make a numerical model that matches the geology as we understand it. If that conceptual geologic model can be used to numerically produce the pre-exploitation temperatures and pressures that were observed during exploration drilling. The model can then be used to predict the behavior of the reservoir under exploitation. Often the numerical model needs to be adjust to get a good match to the production history, but the changes must always reflect the actual geology. The numerical model can be used to manage the field, injecting in areas to provide pressure support while at the same time picking up heat from the rock before the fluid returns to the production wells. Engineered or Enhanced Geothermal Systems (EGS) seek to mimic natural systems with high circulating flow rates that contact enough rock to heat the injected cool water up to production temperatures. Numerical models can be used to help create an engineered reservoir that will mimic a naturally circulating geothermal system. We now have numerical modeling software that can simulate fracturing from natural stresses, pressure changes, and thermal stresses. To some extent we can add in the modeling of rock fluid interactions that will occur during geothermal fluid circulation, thus increasing our understanding of enhanced geothermal systems.


Alain Bonneville, June 1, 2017:
Geological Storage of CO2: Science and Technology Challenges

Carbon capture and storage (CCS) is considered as a powerful tool to limit CO2 emissions into the atmosphere by capturing CO2 from large point sources, like coal power plants, and injecting it in underground geological formations. After a general presentation of the method, the major S&T challenges will be discussed and illustrated by the basic and applied research programs conducted at Pacific Northwest National Laboratory and funded by the Department of Energy during the last 10 years.


Seth Moran, USGS CVO, June 8, 2017:
The Cascades Volcano Observatory: Research, monitoring, and the science of preparing for low-probability, high-consequence events

The USGS' Cascades Volcano Observatory (CVO) was formed in 1981 in direct response to the May 18, 1980, eruption of Mount St. Helens (MSH). From then to now its focus has expanded from focusing primarily on MSH in the early 1980s to applying lessons learned from MSH and other volcanoes around the world to the study and monitoring of all Cascade volcanoes in Washington and Oregon. In parallel, the complexity of volcano research and monitoring has expanded over the last 35 years, particularly as technological improvements allow an ever-increasing diversity of data types to be collected, studied, and monitored at volcanoes. These factors, compounded with the myriad issues that have always been present regarding societal interactions with volcanoes, make the job of ensuring that communities near volcanoes are "eruption ready" a complex one - particularly with respect to Cascade Range volcanoes, which, with low eruption rates (two eruptions in the entire Cascade Ranger per century) are classic examples of low-probability, high-consequence events. In this talk I will give a brief overview of CVO and present results from recent research, monitoring, and outreach activities.