The Cascadia Coastlines and Peoples Hazards Research Hub, or Cascadia CoPes hub, answers calls by Pacific Northwest coastal communities for a coordinated research agenda to help them achieve resilience.
Funding Source: US National Science Foundation
Collaborating Institutions: Oregon State University (lead), University of Washington, Swinomish Indian Tribal Community, USGS, University of Oregon, Humboldt State University, WA and OR SeaGrant, William D. Ruckelshaus Center, Arizona State University, Georgia Tech
GeoScape Team Members: Alison Duvall (co-PI), Paul Morgan (graduate student), Erich Herzig (graduate student)
Stretching from Cape Mendocino in California through the Salish Sea, the Cascadia subduction zone puts the region at risk from "The Really Big One" - a megaquake. In addition to acute risks of earthquakes, tsunamis and landslides, Cascadia also faces chronic risks including coastal erosion and regional flooding. Climate change is amplifying many of these threats, as sea level rise and weather extremes increase.
The Cascadia CoPes hub brings together groups interested in coastal resilience to help coordinate research with and for Pacific Northwest coastal communities to increase community adaptive capacity. With the participation of researchers from across the region the hub aims to achieve this through advances in understanding processes such as: subduction megaquake frequency, how geological processes influence biodiversity, how tsunamis move debris, best management practices to keep coastal communities connected and protected from hazards, and how and for whom risk governance processes may be exclusionary in the region. To achieve equitable and just outcomes, the Cascadia CoPes hub strives to respect and incorporate traditional and local ecological knowledge.
An important part of the hub is the Cascadia Coastal Hazards and Resilience Training, Education and Research, or CHARTER, program. This program offers formal and informal training, education and hazards science research from middle school to graduate and postdoctoral levels. The CHARTER Fellows program provides a unique opportunity for students who identify as BIPOC (Black, Indigenous and people of color); Latinx; LGBTQ; first generation; and/or low-income, in all academic disciplines to participate in hazards and resilience research.
Informing and enabling integrated hazard assessment, mitigation, and adaption - including comprehensive planning, policy making, and engineering - through targeted scientific advances in collaboration with coastal communities.
Team 1: Tectonic Geohazard Sources and Integrated Probabilistic Modeling
Although we are involved in all aspects of the Hub, our research focuses on Team 1 goals of understanding Cascadia tectonic geohazard sources and integrated probabilistic modeling.
In particular, our group is leading the way on mapping, modeling, and understanding Cascadia landslides.
In the coastal and inland Pacific Northwest, seasonal precipitation combined with large, periodic storms and earthquakes trigger many thousands of landslides. With each event and season, precipitation and/or strong-ground shaking mobilizes rock, sediment and soil from Cascadia hillslopes, which is then continuously transported seaward by flooding rivers and offshore currents. Sediment from landslides may dam river channels, leading to either continuous adjustments in response to changes in sediment supply, or outburst floods that rapidly alter river channel morphology – both of which can impact downstream communities. Both the steady and punctuated, catastrophic erosional pulses can initiate complicated geomorphic responses and continuous adjustments that persist for years or even decades following the events that precipitated the geomorphic cascade.
Understanding landslides and their cascading impacts thus, has enormous practical importance because they pose substantial risks to the ecosystems, communities, and infrastructure of coastal Cascadia communities. Despite this, there are still key uncertainties as to when and how landslides might be initiated, where the detritus produced by these events might go, and how long and far the cascading impacts that are produced by these disturbances might extend.
We follow a three prong research approach. Objective 1: Mapping and dating submarine and aerial landslides along WA coastal regions and inland, along evacuation corridors. Understanding spatial occurrence, mechanisms and controls on past landsliding will provide valuable insight into predicting future landslide occurrence under changing climatic, seismic, and land-use conditions. Objective 2: Application of a multimodal, regional scale framework for modeling coseismic and precipitation-induced landslide risk, which implements simple, physically-based models in a probabilistic system. Objective 3: Using numerical landscape evolution modeling to consider landslide inputs of sediment from storms or earthquakes into river channels and the resultant geomorphic process cascade. With these models, we can consider how pulsed extreme events such as earthquakes and storms compare to steady seasonal precipitation-driven landslides that affect the landscape over a range of timescales.
To accomplish this work, we leverage existing high-resolution space-born imaging and computer simulations of M9 Cascadia earthquakes (from Project M9), with new field studies and landslide mapping, geochronology dating of landscape features, and landscape evolution modeling. Together, these objectives will allow us to answer fundamental applied and theoretical science questions of how the geomorphic record in Cascadia reflects changes in the drivers of landscape evolution, including landslides from extreme events, and how Earth’s surface is likely to respond to future forcings.
We are in the early phases of this project, but be sure to check back often to see our latest results!
LaHusen, S.R., Duvall, A.R., Booth, A.M., Struble, W., Grant, A., Wartman, J., Roering,
J., and Montgomery, D.R., 2020, Storms trigger more deep-seated landslides than
Cascadia earthquakes in the Oregon Coast Range, USA. Science Advances, 6(38), DOI:10.1126/sciadv.aba6790
Booth, A.M., LaHusen, S.R., Duvall, A.R., and Montgomery, D.R., 2017, Holocene
history of deep-seated landsliding in the North Fork Stillaguamish River valley from
surface roughness analysis, radiocarbon dating, and numerical landscape evolution
modeling: Journal of Geophysical Research, Earth Surface, v. 122, 17 pp.
LaHusen, S.R., Duvall, A.R., Booth, A.M., and Montgomery, D.R., 2016, Surface
roughness dating of long-runout landslides near Oso, Washington (USA), reveals
persistent postglacial hillslope instability: Geology, v.44(2), 4 pp.