Geologists, geophysicists and earth scientists from different institutions across the West Coast are forming a coalition to research the Cascadia Subduction Zone to increase understanding of the fault and aid in preparation for forecasted earthquakes.
CRESCENT is a conjunction that primarily includes universities across the West Coast, with UO as the project lead and Oregon State University, Central Washington University and University of Washington as the co-leads. CRESCENT is also collaborating with the U.S. Geological Survey, state and local agencies, Diego Melgar, associate professor of geophysics in the Department of Earth Sciences at UO, said.
“CRESCENT represents an effort to get scientists aligned and working on researching problems so that we can make faster progress in understanding what’s possible,” Melgar said.
Cascadia is a fault spanning from British Columbia to Cape Mendocino, California. According to the Pacific Northwest Seismic Network, the fault has produced magnitude 9.0 or more significant earthquakes in the past and will continue to do so in the future.
Some scientists have dubbed this large-scale predicted earthquake “The Big One,” according to the Office of the Vice President for Research and Innovation. “The Big One” is forecasted to cause catastrophic damage along the West Coast, and scientists at the Cascadia Region Earthquake Science Center will work to mitigate the damage through various technologies.
“[Cascadia] is very capable of making very large earthquakes [and] we know throughout geologic history that Cascadia has made earthquakes with the largest magnitude nine,” Melgar said.
One goal of CRESCENT is to “study the underlying science behind earthquake processes,” according to Melgar. These studies will allow scientists to understand the hazards expected in the region, like shaking and tidal waves.
According to the Oregon State University Newsroom, CRESCENT has three pillars that comprise the center’s work: workforce development, foundational science and community collaboration.
The science pillar is split into five working interdependent groups tasked with different topics, Pieter-Ewald Share, assistant professor of geophysics in OSU’s College of Earth, Ocean and Atmospheric Sciences, said..
“What we are doing now is bringing all these groups together to create a product that gives us a much more comprehensive and holistic understanding of what the earth is doing beneath our feet in the Pacific Northwest,” Share said.
Some of the research groups focus on answering a specific set of basic science questions. Answering these fundamental science questions will allow CRESCENT scientists to answer the more complex questions, Valerie Sahakian, assistant professor and geophysicist in the Department of Earth Sciences, said..
Sahakian said the groups would focus on seismic velocity, or “the speed with which a seismic wave travels through a medium,” according to SpringerLink.
She said the other topics of interest are faults, shaking, crustal strain, coastal paleo seismology and tsunami inundation, or “the horizontal distance inland that a tsunami penetrates…” according to the U.S. Geological Survey.
Specifically, Sahakian said the center will look to answer these questions:
S1: How do tectonics drive earthquake hazards?
S2: How is strain accumulated and released throughout the earthquake cycle?
S3: What is the temporal and spatial variability of past earthquakes?
S4: What are the controls on rupture dynamics during megathrust events?
S5: What seismic hazard is from intra-plate (crust and slab) earthquakes?
S6: What is the nature of solid motion in the CSZ?
S7: What are the tsunami sources in the CSZ, and what controls inundation?
“We are focusing on the basic science that will let us even get to the point of answering those questions,” Sahakian said. “Those are the big questions that we need for a more resilient society but there’s much we need to understand even before we can get to that.”
Each group is contributing a different product to the center. The first two are creating community models that depict the layout of the earth. Melgar said that others are creating dynamic simulations of earthquakes, or gathering data on past earthquakes.
The first group will focus on seismic velocity, or how fast the seismic waves travel through the fault rock. She said that CRESCENT scientists will build a community velocity model; a three-dimensional model that depicts the fault’s geology.
“Once we have this model, we can use it to make numerical simulations of earthquakes, basically create an earthquake, send it through the model and then see what shaking will be like at the surface,” Sahakian said.
The second research group will focus on gathering information about the fault, such as its location, the kind of fault and frequency of earthquakes on that fault. From there, Sahakian said CRESCENT scientists will create a community fault model.
The third research group is looking at dynamic earthquake ruptures and tsunami models. Sahakian said they will examine how much the forecasted earthquake breaks the fault and whether it will happen on the seafloor.
The fourth research group will focus on crustal strain, seismicity and slow slip. Sahakian said they would look at the stress in the earth’s crust and how little earthquakes contribute to stress building.
The final research group will examine coastal paleo seismology or coastal earthquakes that occurred in the past. Sahakian said they will determine where past earthquakes happened, how much they broke the fault and more.
Share said “all the groups will depend on each other to achieve a comprehensive understanding of Cascadia and what is beneath our feet.”
Share emphasized that the point of the center is to provide public knowledge of the earth and the rocks beneath their feet, not scare them.
“We are not here to instill fear about the next big event that might occur at some point in the future,” Share said. “It is more of a bunch of knowledge that we will uniquely generate through the center and we want to give the people in the communities on the ground that knowledge and they can then take it from there.”
Melgar said the collaboration officially began on Oct. 1 of this year, and the big kickoff meeting will occur on Oct. 23.
