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Cascade Range Weekly Update
Friday, July 10, 2020 2:05 PM US/Pacific
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN
Cascades Volcano Observatory's mission
The U.S. Geological Survey's Cascades Volcano Observatory strives to serve the national interest by helping people to live knowledgeably and safely with volcanoes in WA, OR, and ID.

HOT STUFF   (archive)
Young Volcanoes in WA, OR & ID1

Postponed to May 2021: the CVO Open House
May 07, 2020

The U.S. Geological Survey–Cascades Volcano Observatory has rescheduled its public open house from May 2020 to May 2021. Information about the rescheduled open house will be posted in early 2021.

Earthquake swarm detected at Mount Hood
April 14, 2020

During April 12-13, 2020, the Mount Hood monitoring network detected a burst of about 100 small earthquakes on Mount Hood, south of Timberline Lodge. The earthquakes are associated with regional tectonic faulting and not volcanic activity. While the swarm represents a temporary uptick in seismicity at the volcano, Mount Hood remains at normal, background levels of activity.

The Pacific Northwest Seismic Network located about 30 earthquakes at depths that range from 3 to 7 km below sea level (1.8 to 4.3 mi) with most occurring between 5.5 and 7 km bsl (3.4 to 4.3 mi). Most of the earthquakes have been less than a magnitude M1.0 (too small to be felt at the surface) with a maximum magnitude of M2.0. There have been no felt reports on the USGS Earthquake Hazards Program "Did You Feel It" web page.

The April 2020 swarm is similar to previous swarms that occurred in 2019, 2016, 2014 and 2012. Based on a similarity to past seismic sequences near Mount Hood and studies of seismicity in the Mount Hood area, we infer that these earthquakes are occurring on tectonic faults related to Basin and Range extension and not directly related to volcanic processes occurring beneath Mount Hood.

CVO continues operations amid COVID-19
March 26, 2020

The Cascades Volcano Observatory continues to monitor volcanoes and issue weekly updates of volcanic activity. Through telework and other adaptations we are able to maintain our monitoring networks and analysis of incoming data. Our field crews visit field stations as needed to maintain the quality and functionality of the network. All work will follow guidelines and instructions from the federal government.

Our priority is to continue the important work of the Department of the Interior and the USGS, while also maintaining the health and safety of our employees and community. Based on guidance from the White House, the CDC, and state and local authorities, we are shifting our operations to a virtual mode and have minimal staffing within our offices. If you need additional assistance, please contact

New guide describes news media management protocols
March 26, 2020

The USGS Cascades Volcano Observatory News Media Management Guide—General Protocols and Templates evolved from a smaller document hastily assembled out of necessity during the complex and overwhelming news media interest in the 2004–2008 eruption of Mount St. Helens. The protocols and templates are applicable to (1) normal conditions when CVO has an opportunity to be proactive with its messages and to raise general awareness, (2) general responses to news media and TV documentary inquiries, (3) intense news media interest where the responsibility to communicate information and hazards rests primarily with staff at CVO, and (4) intense and overwhelming news media interest that requires a multiagency response. This guide reflects general protocols in effect at the time of publication and may be modified over time.

The guide is intended for use by the CVO scientist-in-charge, communications staff, scientists, and guest communications colleagues, and this public version, with CVO names and contact information removed, may be useful to other agencies developing their own communications protocols and templates.

Now available online, a high-resolution digital elevation model of Mount St. Helens and upper North Fork Toutle River basin
March 26, 2020

In 2017, the U.S. Forest Service contracted for the acquisitions of airborne lidar surveys of Mount St. Helens and upper North Fork Toutle River basin, as part of a larger 2017-2018 survey of the Gifford Pinchot National Forest. The USGS subsequently combined and reprojected 81 raster datasets provided by the USFS into a single digital elevation model (DEM) of the ground surface, including beneath forest cover (that is, 'bare earth').

This new online data release contains digital elevation data as a 1-meter resolution raster dataset (.tif file) and can be used to support a variety of earth science investigations. Click the link to download High-resolution digital elevation model of Mount St. Helens and upper North Fork Toutle River basin, based on airborne lidar surveys of July-September, 2017.

Another seismic swarm at Mount Rainier
March 12, 2020

Beginning on March 10, 2020, a minor swarm of approximately 20 earthquakes occurred under the summit of Mount Rainier. Thirteen of those events were large enough to be located. The largest earthquake in the swarm was a Magnitude 1.5, and depths focused between 1.5 and 2.0 km (about 1 to 1.2 miles) below sea level. Earthquake rates have since returned to normal, background levels.

Swarms under the summit of Mount Rainier are fairly common, with the last one occurring in late 2019. Such swarms are thought to occur due to minor changes in the hydrothermal system of the volcano.

Seismic data for Mount Rainier and other Cascade Range volcanoes are available from the Pacific Northwest Seismic Network and Activity Updates for volcanoes in the Cascade Volcano Observatory's area of responsibility are posted weekly.

Registration is open for Mount Rainier teacher training in the Park.
February 20, 2020

Mount Rainier National Park is a unique classroom, rich in resources for observing geologic change. Join us July 27–31, 2020, for a 5-day educator workshop in the Park, where we will explore the diverse and dynamic processes that have shaped the volcano and share new classroom ideas that will engage middle school students. Free camping is available to participants and Washington State clock hours are available. Registration information is on the Mount Rainier Teacher Professional Development webpage.

Field guides provide history and context for your next field trip to Mount St. Helens
November 21, 2019

Exposures in valleys surrounding Mount St. Helens reveal records of diverse geologic processes including debris avalanche, lahar, huge water wave on a nearby lake, pyroclastic density currents (surge and flow), tephra fall, lava flow, growth of domes, and past glaciation. This new field guide provides detailed information for 28 self-guided field trip stops, many of which explore effects of the several catastrophes that constituted the May 18, 1980 eruption.

Follow the link to download Field trip guide to Mount St. Helens, Washington—Recent and ancient volcaniclastic processes and deposits.

Other Mount St. Helens field guides include:

Additional field-trip guides for selected volcanoes and volcanic landscapes of the western United States can be downloaded from the USGS Publications Warehouse.

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