35th Anniversary of the Eruption of Mount St. Helens

st_helens_bookmark_originalThe months and days leading up to the May 18, 1980 eruption
of Mount St. Helens were tense and filled with a sense of
unknown. Few people really knew that there were giant volcanoes in their backyard, and fewer yet had ever seen such a volcano erupt.

As news and images of the eruption began to circulate, people across the world really began to understand what a volcano can do. The giant ash cloud rose in to the sky, blocking the sun, disrupting flights across the country, and raining shards of volcanic glass and ash across much of Washington and other western states.

As spectacular and terrifying as the eruption was, the damage was just beginning. Giant landslides made from ash and melted snow and ice (called lahars) descended from the mountain and 00151 copyfilled nearby rivers and streams. These lahars carried tremendous amounts of debris, from blown-down trees, to cars and entire houses that destroyed bridges as they flowed downstream.

volcano_hazard_summary_map-01

Summary of volcanic hazards in Washington state

The events of May 18, 1980 helped the residents of Washington and the rest of the nation
know what to expect from future eruptions. Volcanoes line the west coast of the United States, from Mount Baker in northern Washington to Mount Lassen in northern California. Most of these volcanoes have erupted in the past 10,000 years and are considered active, although it is impossible to predict exactly which of the dozen or so volcanoes will erupt next.

ger_mtsthelens_4-16-83

Volcanic eruptions are usually, but not always, preceded by changes that can be detected by geologists. Monitoring these ‘vital signs’ is largely the task of the Cascade Volcano Observatory. Visit our website, ready.gov, and the Cascade Volcano Observatory for more information about volcanoes, their hazards, and how to prepare in case of an emergency.

In celebration of the 35th anniversary, we are releasing three sets of annotated slides that document many aspects of the historic eruption. Sets 1 and 2 were previously released, but each photo has been digitally restored in order to remove the ‘smurf blue’ coloring in the original slide or negative. Set 3 has never before been released and contains a series of striking photos recently discovered in our archive.

Slide set #1: 20 slides from March through June, 1980 [PDF; 23MB]

Slide set #2: 20 slides from May 18, 1980 through May 13, 1981 [PDF; 24MB]

Slide set #3: 16 slides from 1974 through 1981 [PDF; 25MB]

Roadside geology of Mount St. Helens National Volcanic Monument and vicinity
Entire guide [PDF; 56MB]
Part 1 [PDF; 28MB]
Part 2 [PDF; 28MB]

Nepal quake reminder of Washington’s tectonic influences

Originally posted on Ear to the Ground:

The U.S. Geological Survey produced a report on the magnitude 7.8 earthquake that struck Nepal April 25 and the surrounding aftershocks that continued throughout much of south central Asia. The U.S. Geological Survey produced a report on the magnitude 7.8 earthquake that struck Nepal April 25 and the surrounding aftershocks that continued throughout much of south central Asia.

The magnitude 7.8 earthquake that devastated the Kathmandu Valley of Nepal Saturday was the strongest quake in the world so far this year and a reminder of the importance of properly planning in advance for natural disasters. More than 4,000  were reported dead, as buildings collapsed in cities surrounding the fault line.

The shallow depth of the quake’s epicenter was placed between 7 and 10 miles. Waves were amplified through sedimentary basin of a former lake, increasing the destruction. The strength of the quake was so strong it was picked up by a Pacific Northwest Seismic Network seismometer at Gold Mountain on the Kitsap Peninsula.

Saturday’s earthquake was the result of the northward movement of the Indian tectonic Plate under the…

View original 274 more words

April issue of TsuInfo is now published

tsuinfo_banner

TSUINFO ALERT IS A BI-MONTHLY newsletter that links scientists, emergency responders, and community planners to the latest tsunami research. This newsletter is published by the Washington Department of Natural Resources, Division of Geology and Earth Resources on behalf of the National Tsunami Hazard Mitigation Program, a state/federal partnership funded through the National Oceanic and Atmospheric Administration. It is made possible by a grant from the Federal Emergency Management Agency via the Washington Military Department, Division of Emergency Management.

April, 2015 (v. 17, no. 2) [PDF; 1 MB]

Lessons remain vital four years after deadly Japan earthquake, tsunami

Originally posted on Ear to the Ground:

On March 11 four years ago, the earth reminded us of its destructive and unstoppable power when a magnitude 9 earthquake touched off a tsunami and caused tens of thousands of deaths and devastated much of the nation’s infrastructure.

Waves from the tsunami reached the coast of Washington and other western states, where they damaged California coastal communities and washed some of the estimated 1.5 million tons of debris on shores.

Not only is the anniversary a time to remember those lost in Japan, but it should also serve as a reminder that Washington needs to be prepared for a similar geologic hazard threat.

An earthquake fault with similar potential lies just off the coasts of Washington, Oregon and British Columbia. Geologists say it is not a matter of ‘if’ but ‘when’ the Cascadia fault off our coast unleashes another mega quake. To get a picture of what we may…

View original 272 more words

Remembering the 2001 Nisqually earthquake…and preparing for the next one

Do you know what to do if an earthquake were to happen today?

February 28th marks the 14-year anniversary of the 2001 M6.8 Nisqually earthquake and it’s worth taking a moment to reflect on being prepared for geologic emergencies.

Earthquakes, tsunamis, and landslides are all geologic hazards that we face in Washington. Though these events cannot be predicted precisely, they are inevitable—it’s just a matter of when and where.

When an earthquake happens, there will not be time to Google what you are supposed to do (Drop! Cover! Hold On!). After the earthquake, the internet might not work at all. Know what to do ahead of time and be prepared.


The February TsuInfo Alert newsletter is now published

tsuinfo_banner

TSUINFO ALERT IS A BI-MONTHLY newsletter that links scientists, emergency responders, and community planners to the latest tsunami research. This newsletter is published by the Washington Department of Natural Resources, Division of Geology and Earth Resources on behalf of the National Tsunami Hazard Mitigation Program, a state/federal partnership funded through the National Oceanic and Atmospheric Administration. It is made possible by a grant from the Federal Emergency Management Agency via the Washington Military Department, Division of Emergency Management.

February, 2015 (v. 17, no. 1) [PDF; 1 MB]

Newly published: Rock aggregate resource inventory map of Pierce County, Washington

We are pleased to announce the release of a new publication!

Rock aggregate resource inventory map of Pierce County, Washington
by
Daniel W. Eungard and Jessica L. Czajkowski

Ever wonder where the best and worst rock aggregate is within Pierce County? This question keeps us up at night and here is the answer!

Ever wonder where the best and worst rock aggregate is within Pierce County? This question keeps us up at night and here is the answer!

Summary: Rock aggregate is one of the fundamental building blocks of roads, bridges, and buildings that use concrete. Luckily for us in Washington, the Pleistocene glaciers that once covered all of the Puget Lowland deposited vast amounts of these valuable resources as they advanced and retreated. Ever-expanding population centers, however, threaten the availability of these aggregate resources. 

This publication continues DGER’s work to map and characterize the sand, gravel, and bedrock resources of Washington. This effort aids county and regional planners as they consider which areas should be reserved for future aggregate resource development.