WEEK 5- VOLCANIC HAZARDS

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’…(J:

·         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).

Today the US hazards map shows the following U.S. volcanoes as to be above normal background (elevated unrest or eruptions) or have shown activity that warranted an Information Release (for example, an earthquake swarm):

Bogoslof- Alert Level=WARNING. Aviation Color Code=Red.

Kilauea and Cleveland- Alert Level=WATCH. Aviation Color Code=Orange. Note: Kilauea has been erupting for 34 years!

Mauna Loa Alert Level=ADVISORY. Aviation Color Code=Yellow.

A great image below from Hawaii's NSP. Lots of current videos and information about the park here.

WEEK 3- E-A-R-T-H-Q-U-A-K-E-S

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.

Re: the first issue, the new US map of seismicity (see image from USGS) shows the (obvious, in not pink) ring of fire portion on the West coast but also a central area in the middle of the plate. I’d like to talk a bit more about this non-obvious one. 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)... if the earth shakes in any of those areas, you cannot say you do not know why....tectonics, tectonics, tectonics....

In the last years, a few papers have come out discussing man-made quakes. USGS has great articles about those. The number of earthquakes has increased dramatically over the past few years within the central and eastern United States. Nearly 450 earthquakes magnitude 3.0 and larger occurred in the four years from 2010-2013, over 100 per year on average. USGS scientists have found that at some locations the increase in seismicity coincides with the injection of wastewater in deep disposal wells. Much of this wastewater is a byproduct of oil and gas production and is routinely disposed of by injection into wells specifically designed for this purpose.