MINIMIZING VOLCANIC HAZARDS: USGS ALERT CODES

The Colima volcano (Mexico) has been active since July and has covered local villages in ash leading to evacuations. Also, Hawaii is in the elevated volcanic activity list this week. This week Geol9 is exploring the volcanic hazards in different countries and their warning systems. I’ll be focusing on the US.

There are several ways we minimize the danger of volcanic activity (apart from the obvious of ‘getting out of the way’…(:

• Forecasting (earthquakes as early warnings (although in 2014 a Japanese volcano erupted without any previous seismicity (livescience article), land swelling before eruption, gas emissions, etc.)

• Volcanic Alert Codes (USGS): the levels of alert and the aviation code levels commonly change at the same time (chart on right). A non-erupting volcano will have a green icon, and a red one indicates an imminent eruption (see USGS Alert Codes).

Active lava lake at Kīlauea's summit. Lava flows active northeast of Puʻu ʻŌʻō. 

As this morning, the US hazards map shows:

Kilauea Alert Level=WATCH. Aviation Color Code=ORANGE. As of Sep 21, 2015, 09:02 

Shishaldin Alert Level=WATCH. Aviation Color Code=ORANGE. As of Sep 20, 2015, 11:04. Low-level activity likely continues. 

Cleveland Alert Level=WATCH. Aviation Color Code=ORANGE. As of Sep 20, 2015, 11:04. Low level unrest continues.

There are also advisories (yellow) for Mauna Loa and Pagan volcanoes.

 Ring of Fire, anyone?

SMALL TSUNAMI WAVES REACH CALIFORNIA, HAWAII: TODAY

The following is an excerpt of the weather channel latest news re: the M 8.3 strong earthquake off Chile yesterday:

Tsunami advisories are in effect for Hawaii and Southern California after a powerful magnitude-8.3 earthquake struck the Pacific Ocean waters just off the coast of Chile Wednesday evening, generating a dangerous 15-foot tsunami along parts of the Chilean coast. Chilean authorities said at least 10 epeople died as a result of earthquake-related incidents. The tsunami is fanning out across much of the Pacific Ocean, though the worst of its power is expected to be focused westward toward French Polynesia, including Tahiti.

This is a good test for the west coast and Hawaii to see if their preparation and alertness methods work.

The tsunami waves records have just been updated:

http://www.weather.com/news/news/chile-major-earthquake-tsunami-warning

TSUNAMI RISK IN THE US

The most vulnerable states are: Hawaii, Alaska, Washington, Oregon, and California (and the U.S. Caribbean islands). The 1964 Alaska tsunami led to 110 deaths, some as far away as Crescent City, California. A tsunami that originated along the Washington, Oregon, and California coasts in 1700 overran Native American fishing camps and caused damage in Japan.

As always in geology, the past will help us understand what might happen in the future. A map of tsunami events from the year 900 to 1964 (USGS image) tells the tale. These events were caused by earthquakes ranging in magnitudes 9.2 to 7.3. These are areas that could be hit again.

What do we do?

Well, as the figure shows, in case of ‘earthqake’, run to higher ground immediately and go to Finland…(:

Also, there are several institutions with great resources/warning systems we should monitor. The National Oceanic and Atmospheric Administration's website has updated information on tsunami watches, warnings or advisories for the US. NOAA also has a tsunami strategic plan describing their recommendations/vision for 2012-2020 and how to make US more resilient and prepared for tsunamis.

Closer to home, the Department of Conservation in California has downloadable tsunami inundation maps that show the areas at risk (in pink, different from the flooding risk maps that are blue). The map near Marina, where the MPC Education Center is located and I teach sometimes, shows the area near the Salinas river as a completely inundated area. Good to know..

This is very useful information. We cannot forget the Japan 2011 tsunami was felt in the other side of the Pacific, Santa Cruz, California. Remember the harbor video?

S-H-A-K-I-N-G IN THE USA

If I want to know something about earthquakes, the first websites I go to are: the USGS Real Time Earthquakes Website or the IRIS monitoring website.

This week we are exploring seismicity and what countries do to prevent/mitigate the hazard.

The new 2014 US map of seismicity (see image from USGS) shows the (obvious, in pink) ring of fire portion on the West coast but also a central area in the middle of the plate. This area, called the New Madrid Zone was shaken by a M8(!) in 1811. The reason for the activity is a very old intraplate rift placed below the area (see image from http://showme.net).

There is a brand new effort by the USGS: the ShakeAlert system, developed for the West coast using some of the existing systems. Today, the technology exists to detect earthquakes, so quickly, that an alert can reach some areas before strong shaking arrives. The purpose of an EEW (Earthquake Early Warning) system is to identify and characterize an earthquake a few seconds after it begins, calculate the likely intensity of ground shaking that will result, and deliver warnings to people and infrastructure in harm’s way. Studies of earthquake early warning methods in California have shown that the warning time would range from a few seconds to a few tens of seconds, depending on the distance to the epicenter of the earthquake. 

A few seconds of warning might make all the difference (enough to stop transit/elevators and to drop, cover, hold on).

All for now-