Volcano Profile: Mt. Hood
Back in the days when Eruptions was on Wordpress, I held a vote about what volcano should be the next to be profiled on this blog. The winner was Mt. Hood in Oregon, and after much waiting, the profile is here. I will actually be out of town until Monday doing some house shopping in this little town. Enjoy this look at one of the most picturesque (and hazardous - #4 in fact) volcanoes in the lower 48 states.
VOLCANO PROFILE: MT. HOOD
Mt. Hood, Oregon in August 2008 taken by Erik Klemetti.
Mt. Hood taken near Timberline Lodge showing Crater Rock in the avalanche scar. Taken by Erik Klemetti in August 2008.
- Notable Recent Eruptions and History: As noted above, the most recent significant eruption was the "Old Maid" episode that created the Crater Rock dome and sent pyroclastic flows (mostly in the form of dome-collapse block & ash flows) and lahars down the SW side of the volcano towards Troutdale. The Old Maid period erupted ~0.15 km3 of dacite lava. Prior to the Old Maid period, the Timberline eruptive period ran from ~1,400 to 1,800 years ago and produced at much as 1.1 km3 of erupted material, mostly in the form of pyroclastic flows and debris flows. Again, the eruptions were on the SW side of the volcanic edifice, sending flows down the drainages on that side as far as 80 km / 50 miles downriver. Hood may have been relatively quiet between the Timberline and Pollalie (12-15,000 years ago) during the end of the last Glacial Maximum. There are also some satellite eruptions that occurred near Mt. Hood, including the Parkdale Flow (below), a basaltic andesite lava flow, that erupted ~7,700 years ago.
The 7,700 year-old Parkdale Lava flow near Mt. Hood being inspected by Dr. Adam Kent, Dr. Kari Cooper and associated graduate students (Gary Eppich, Mark Stelten and Alison Koleszar) in August 2008. Photo by Erik Klemetti.
- Mitigation:The USGS has prepared an excellent volcano hazard map (below) for the eventual next eruption of Mt. Hood. There are three major threats: (1) lahars and debris flows traveling down the Sandy, White and Hood Rivers; (2) debris from the flows could reach the Columbia River, causing problems with power generation at the Bonneville Dam and; (3) ash disrupting air travel in and out of Portland (and to a lesser degree Seattle) International Airport - anyone who has flow into Portland knows the planes fly right next to the summit of the volcano. Other hazards include pyroclastic flows and volcanic bombs (along with lahars) for Timberline Lodge, Government Camp and other settlements/ski lodges on the edifice itself, travel along Highway 35 could be severely (if not permanently) crippled.
Volcanic hazards for Mt. Hood, Oregon. Image courtesy of the USGS