Mount St. Helens Updated Info from USGS

From our friends at United States Geologic Survey

Analysis of current behavior at Mount St. Helens indicates that the volcano remains active and is showing signs of long-term uplift and earthquake activity, but there are no signs of impending eruption. Since the end of the 2004-2008 dome-building eruption at Mount St. Helens, scientists at the USGS Cascades Volcano Observatory (CVO) and the Pacific Northwest Seismic Network (PNSN) have been monitoring subtle inflation of the ground surface and minor earthquake activity reminiscent of that seen in the years following the 1980-1986 eruptions.

Careful analysis of these two lines of evidence now gives us confidence to say that the magma reservoir beneath Mount St. Helens has been slowly re-pressurizing since 2008. It is likely that re-pressurization is caused by arrival of a small amount of additional magma 4-8 km (2.5-5 miles) beneath the surface. This is to be expected while Mount St. Helens is in an active period, as it has been since 1980, and it does not indicate that the volcano is likely to erupt anytime soon. Re-pressurization of a volcano’s magma reservoir is commonly observed at other volcanoes that have erupted recently, and it can continue for many years without an eruption.

USGS and PNSN are continuing to monitor ground deformation and seismicity at Mount St. Helens. In an effort to learn more about activity beneath the volcano, they will conduct two additional types of measurements this summer. Surveys will measure the types and amounts of volcanic gases being released, and the strength of the gravity field at the volcano. Both types of measurements are sensitive to changes in the amount or depth of subsurface magma. The information collected at Mount St. Helens continues to help scientists interpret behaviors at other volcanoes and to improve eruption forecasting capabilities. Additional research results will be posted in USGS Updates, Information Statements, and on the USGS-CVO website.

In a previously planned but related development, an experiment called “Imaging Magma Under St. Helens” (iMUSH) will start this summer and run for the next few years. The experiment, jointly funded by the National Science Foundation and USGS, is designed to produce a better picture of the magma plumbing system under the volcano. It may also provide new insights into the ongoing re-pressurization process.

The USGS Cascades Volcano Observatory and Pacific Northwest Seismic Network continue to monitor Mount St. Helens and other volcanoes of the Cascade Range for signs of increased unrest. The likelihood of detecting short-term precursory phenomena before the next eruption at Mount St. Helens is enhanced by the existence of an effective monitoring network established in response to recent eruptions. Efforts are underway to bring networks at other dangerous volcanoes in the Cascade Range up to a similar standard.


The USGS and the Pacific Northwest Seismic Network at University of Washington continue to watch conditions at Mount St. Helens closely.

Earthquake Terms to Know

There's been a lot of shaking and quaking north of us the past few days.  Take a minute to familiarize yourself with some earthquake terms from our friends at www.ready.gov


Aftershock - An earthquake of similar or lesser intensity that follows the main earthquake.

Earthquake - A sudden slipping or movement of a portion of the earth’s crust, accompanied and followed by a series of vibrations.

Epicenter - The place on the earth’s surface directly above the point on the fault where the earthquake rupture began. Once fault slippage begins, it expands along the fault during the earthquake and can extend hundreds of miles before stopping.

Fault - The fracture across which displacement has occurred during an earthquake. The slippage may range from less than an inch to more than 10 yards in a severe earthquake.

Magnitude - The amount of energy released during an earthquake, which is computed from the amplitude of the seismic waves. A magnitude of 7.0 on the Richter Scale indicates an extremely strong earthquake. Each whole number on the scale represents an increase of about 30 times more energy released than the previous whole number represents. Therefore, an earthquake measuring 6.0 is about 30 times more powerful than one measuring 5.0.

Seismic Waves - Vibrations that travel outward from the earthquake fault at speeds of several miles per second. Although fault slippage directly under a structure can cause considerable damage, the vibrations of seismic waves cause most of the destruction during earthquakes.

Event Calendar

So many great events are coming up in our fair county!  This Saturday check out the Earth Day festivities at the Cowlitz County Expo Center from 10:00 a.m. to 3:00 p.m.  The Department of Emergency Management will have a fun booth with disaster preparedness information and giveaways. 

On Saturday, April 26th from 10:00 a.m. to 2:00 p.m. the Castle Rock CARE Coalition presents a Health and Safety Fair at the Castle Rock Senior Center at 222 2nd Avenue.  There will be free bike helmets for kids, blood pressure checks, community garden info, giveaways and more.  If you bring in a can of food or outdated/unneeded prescription medication (for destruction) you will receive a ticket for a prize drawing.

Tuesday, April 29th guest speaker Lourdes Alvarado-Ramos, the Director of WA Department of Veterans Affairs will give a presentation called "When Women Come Marching Home."  The program will feature a documentary and a panel discussion with local women veterans about the challenges faced by women veterans.  The presentation will take place at the Wollenberg Auditorium at Lower Columbia College at 6:30 p.m.

Wednesday, May 7th come check out the Regional Senior Connections Fair at the Three Rivers Mall from 9:00 a.m. to 2:00 p.m.  There will be over 30 vendors, services providers and agencies there to provide information about senior services and benefits in our county.  There will be giveaways, prize drawings, entertainment and a fashion show!

Earth Day!

If you're looking for a fun activity this weekend, come check out our disaster preparedness booth at the Earth Day festival at the Cowlitz County Expo Center.  The fun is free with lots of Earth-friendly, hands-on exhibits and entertainment, this Saturday from 10-3:30.

Standing on Shaky Ground

From:  www.FEMA.gov

 

With a series of tremors and aftershocks recently hitting Southern California, earthquake preparedness may be fresh on the minds of California residents. According to reports, the Los Angeles area hasn’t experienced an earthquake in excess of 5 magnitude since 1997, and it’s been 20 years since a 6.7 magnitude earthquake struck Northridge, CA where 57 people lost their lives. Earthquakes can strike anywhere at any time. That’s why preparedness is vital.

Throughout the year individual states provide opportunities to do statewide drills. One upcoming opportunity is the Great Utah Shakeout scheduled for April 17. You can join over 750,000 people planning to participate in the Drop, Cover and Hold On earthquake drill. This is part of the national Great ShakeOut initiative which provides a focused time every October for millions worldwide to practice how to Drop, Cover, and Hold On during Great ShakeOut earthquake drills.  The Great ShakeOut is also a national supporter of America’s PrepareAthon! and will be featured as one of the campaign’s fall hazard activities later this year!

Looking for additional steps you can take before, during and after an earthquake to protect your family and property? Visit www.ready.gov/earthquakes. Some of these steps have also been outlined below.

 Before an Earthquake:

·       Fasten shelves and bookcases securely to a wall;

·       Brace top heavy objects; and

·       Hold earthquake drills with your family:  Drop, Cover and Hold On.

During an Earthquake:

·       Drop to the ground; Take Cover; Hold On;

·       Minimize your movements to a few steps; and

·       Stay inside until the shaking stops.

After an Earthquake:

·       When the shaking stops, look around to be sure it’s safe to move;

·       Look for and extinguish small fires which are a common hazard;

·       Go to a designated shelter. Text SHELTER + your ZIP CODE to 43362 (4FEMA) to find the nearest shelter.

Take your earthquake preparedness to the next level with Beat the Quake, an interactive game from the Earthquake Country Alliance. It’s fun for the entire family!