As of August 9, 2015, Dr. Seth Moran takes over the leadership of USGS-Cascades Volcano Observatory from John Ewert, who served as the scientist-in-charge for the past five years.
Seth Moran began his USGS career as a research seismologist for the Alaska Volcano Observatory in 1997. In 2003, Moran joined the staff of CVO as the principal USGS seismologist responsible for studying and monitoring Cascade volcanoes. Seth's timing was fortuitous - in the fall of 2004 Mount St. Helens reawakened after 18 years of quiet. As is typical in all eruption responses, Seth assumed many different roles during the response: conducting his own seismic analyses, coordinating research by others outside CVO, being interviewed by the news media, assembling statements for the news media and working with partner agencies in emergency response.
In addition to Mount St. Helens, a significant percentage of Seth's time has been spent maintaining and improving seismic monitoring capabilities at other Cascade volcanoes, such as installing new seismic stations at Mount Rainier National Park, and developing a new network of eight seismic stations at Newberry Volcano in 2011. Seth has also been active in the larger scientific community being a critical player in the Imaging Magma Under St. Helens experiment, known as iMUSH, jointly funded by the National Science Foundation and USGS to produce a better "picture" of the magma "plumbing system" under the volcano.
John Ewert will rotate back to a staff position at CVO with Volcano Disaster Assistance Program focusing on novel approaches to eruption forecasting and updating National Volcano Warning System documents.
On August 13, a series of small debris flows rumbled down Tahoma Creek, in Mount Rainier National Park. No one was injured and damage was limited to the stream channel inside the Park.
Observations and photos taken by National Park Service geologists during an overflight in the afternoon indicate that the debris flows appear to have started at the terminus of South Tahoma Glacier. Some sediment from the debris flow was visible 8 miles downstream at the Highway 706 crossing.
Looking at seismic data from the Pacific Northwest Seismic Network, the vibrations from the debris flow are recorded on seismograms from Rainier station RER, located at Emerald Ridge overlooking Tahoma Creek. The debris flow signal starts at ~9:50 AM PDT. Signals are emergent, pulsatory, and relatively high-frequency, all characteristics of debris flows. There was a period of time from ~9:50 AM through to ~12:45 PM where signals were occurring relatively continuously, with several tens-of-minutes-long higher-amplitude bursts at 10:15-11:10, 11:25-11:50, and 12:30-12:40 that probably correspond to major debris-flow pulses. No debris-flow-like signals showed up overnight.
This event is similar to numerous debris flows that have occurred at Mount Rainier in past decades. Water stored in the glacier was released and quickly gathered up loose mud, sand, soil, and rock to form a debris flow. Small flows are common at Mount Rainier during late summer and early fall; a second group of debris flows commonly develops from torrential rainfall during early winter storms. Between 1985 and now, more than 30 debris flows have rushed down the Tahoma Creek valley.
The visiting public is reminded to stay clear of valley floors during debris flows and to the safety of higher ground when a debris flow is passing.
The May 18, 1980, eruption of Mount St. Helens included a debris avalanche, lateral blast, pyroclastic flows, lahars, and tephra falls, all of which dramatically altered the drainage basins on the volcano. Since the eruption, scientists have been conducting repeat stream channel cross-section surveys to monitor the response of these channels, as part of a long-term hydrologic monitoring project managed by the U.S. Geological Survey. These data are now available in a new online database that contains 243 survey lines, representing ~100 km of topography, collected over more than 30 years. Cross sections are located within two primary drainage basins—the Toutle River on the north and west flanks of the volcano and the Lewis River on the south and east flanks. The dynamic nature of the database will accommodate the addition of future surveys and data revisions as appropriate. Download the Digital database of channel cross-section surveys, Mount St. Helens, Washington, to see more.
Oregon's Newberry Volcano is the largest volcano in the Cascade Range and covers an area the size of Rhode Island (about 3100 km2 or 1200 mi2). Unlike familiar cone-shaped Cascade volcanoes, Newberry was built into the shape of a broad shield by repeated eruptions of mostly fluid lava over the past 400,000 years. Between the lava-producing eruptions the volcano has erupted explosively. The most recent eruption, about 1,300 years ago, was explosive and ended with the extrusion of the Big Obsidian Flow within the volcanic caldera. This new poster of Newberry Volcano uses LiDAR (light detection and ranging) technology to reveal previously unseen detail in the volcano's youngest lava flows and vents—the Lava Butte cinder cone, Newberry's northwest rift zone, Central Pumice Cone and The Big Obsidian Flow. Download the poster Newberry Volcano's Youngest Lava Flows to see more.
Crews from the USGS-Cascades Volcano Observatory return from working with the Alaska Volcano Observatory, Plate Boundary Observatory, and IRIS' Transportable Array to repair, refurbish and rebuild volcano monitoring stations in Alaska, including the installation of a new volcanic gas monitoring site at the summit of Augustine. The station is similar to the SNIF monitoring station that currently operates in the crater of Mount St. Helens. Visit the Alaska Volcano Observatory to see volcano updates and recent images of fieldwork. Read about volcanic gas monitoring at Mount St. Helens and view a month's worth of monitoring data by clicking on Mount St. Helens Monitoring and zooming into the crater to find station SNIF on the interactive map.