The Coastal Relief Model for the Washington–Oregon coast receives a significant upgrade
Recently, NOAA NCEI’s Coastal Relief Model of the United States’ Pacific Northwest—known as Coastal Relief Model Volume 8—received its first major upgrade in 22 years. Particularly significant are the improvements made to the model’s spatial resolution, which now provides the public with roughly nine times the detail of the previous version. This more accurate representation of the Pacific Northwest’s land and seafloor elevation allows for better protection of the region’s coastline against the effects of flooding, be it from high tide, tsunamis or storm surges.
What is a Coastal Relief Model?
Coastal Relief Models (CRMs) are digital maps that combine topographic and bathymetric data in order to offer a complete picture of the elevation of a coastal region. While topographical maps and bathymetric maps both visualize the height and depth of geographical formations, they do so for areas above and below sea level, respectively. This means that the data collection methods used to create them are different: Topographical maps use data from airborne and satellite instruments, while bathymetric maps primarily use data collected from shipboard instruments. Due to differences in their purposes and creation processes, the two kinds of maps typically exist independent of one another. However, there is a need to depict the elevation of coastal regions—half of which are above water, and half below.
To address this, NCEI brings together land and underwater elevation data from many different sources to create a seamless map of coastal elevation. These CRMs help support flood and tsunami modeling by showing the full shape of coastal areas both above and below the waterline. CRMs can inform many areas of hazard planning, be it the strengthening of infrastructure, the planning of evacuation routes or the educating of local communities so that they are better prepared.
Key Updates
In the recent update, the most visible upgrades to CRM Volume 8 are the increases in spatial resolution and data coverage. Each pixel of the 2025 version represents an area of approximately 30 by 30 meters, providing roughly nine times more spatial detail than the previous version released in 2003. Increased resolution allows for more accurate modeling of potential flooding by realistically simulating the interaction of sea water with the ground underneath it. Data gaps beyond the continental shelf in the 2003 version have now been filled with newly collected data, fully depicting the bathymetry of the offshore portions of the Pacific Northwest CRM.
The update also removes data mismatches along the coastline, which occur due to differences in data sources and collection methods between land and sea. CRM Volume 8 incorporates recently generated high-resolution data produced between 2023 and 2025 as part of NCEI’s Continuously Updated Digital Elevation Model program, ensuring that the Pacific Northwest coastline reflects the most current publicly available data sources. Furthermore, the update integrates nearly all available NCEI multibeam bathymetric datasets, enabled by improved data filtering methods that allow larger volumes of seafloor data to be reliably included.
Why the Pacific Northwest?
While large earthquakes and tsunamis occur infrequently in the United States’ Pacific Northwest, the region is capable of producing some of the largest events on earth.
The Pacific Northwest is situated next to the Cascadia subduction zone, a 700-mile-long fault spanning from southern Canada to northern Oregon. Though the last major earthquake and tsunami to originate from the Cascadia subduction zone struck the Pacific Northwest region in 1700, scientists believe that the region is long overdue for another. This event could generate an earthquake of magnitude 8 or 9, and tsunami waves as high as 30 to 40 feet. It is estimated that this event could cause more than 10,000 deaths, 30,000 injuries and economic losses of up to $70 billion in the Pacific Northwestern states.
Ironically, the Pacific Northwest’s reputation as an uncommon place for natural disasters to occur puts it in a particularly dangerous position. Since the region is not regularly affected by catastrophic events, much of its infrastructure is not designed to withstand earthquakes or tsunamis, making it particularly vulnerable to their effects.
Nearly 40% of the United States’ population lives on or near the nation’s coasts, which also serve as major hubs for the tourism, fishing and transportation industries. The recent update to CRM Volume 8 reflects the ongoing effort to minimize the damage that natural disasters may bring to these essential and currently underprotected communities.
