Accretionary Wedge #41: Most Memorable Geologic Event I've Directly Experienced: The Eruption of Mt. St. Helens

In the latest call for posts for the Accretionary Wedge, Ron Schott asked geoscience bloggers to relate "the story of the most memorable or significant geologic event that you've directly experienced".

For me that's easy, and yet also difficult.  Easy because there's really only one significant geologic event that I've directly experienced that I'd call memorable & significant, but difficult because I had just turned 6 years old and don't recall a lot of it.  

On the 18th day of the month of May, 1980, the lower 48 states of the U.S. experienced the eruption of Mt. St. Helens.  Obviously when the mountain starts shakin' in a serious way, you don't live to tell about it from up close.  Over 50 people died from the eruption, including one USGS geologist David Johnston who was monitoring the volcano at the time.  He sent word via radio just as the eruption began "This is it!", and gave his life in the study of this mountain.  I lived about 100 miles north of the volcano in a small town called Bremerton, WA.  I don't recall a whole lot about the event, but I do remember watching some of the news reports on TV.  Reports showed video of the ash-clogged & log-jammed streams, snow plows being used to remove the ash from roads, and pictures of entire forests flattened in one direction like matchsticks.  It was amazing.


The mountain had been building up prior to this, with a large bulge on the north flank.  The catastrophic blast of the mountain that day occurred after the bulge over-steepened the hillside and a huge landslide removed material down the mountain, lowering the pressure on the magma below and releasing the main blast.  The blast mainly came out of one side of the summit, the north face of the mountain.

The ash therefore mainly blew northward, but it didn't reach Bremerton.  Instead, the winds took it eastward.  So we never saw any ash where I lived, but one day after the blast my dad decided to drive south.  He collected a small bottle of the ash, which has sat on my shelf for a number of years now and is pictured in these two photographs.

The experiences of geologists from the USGS and the University of Washington monitoring the mountain at the time are documented very well in a CNN video on youtube that unfortunately I can't embed here, but here's the link:  http://www.youtube.com/watch?v=3XYfBxdVDJE  The video is about 7 minutes long and well worth viewing to get a bigger idea of the impact of this eruption.  Also for more info on the blast itself, check out this USGS eruption fact sheet.

Gas & Coal in current U.S. legislation

As U.S. legislators work out the new energy/climate change bill, 2 different fossil fuel industries have much to gain or lose.  Today's NY Times has an article on natural gas appearing to get the losing end of the stick compared to the coal industry.  The debate to some extent centers on which of these resources will be better in the long run for reducing carbon emissions and for maintaining a long term, economically stable energy source.


The U.S. certainly has a lot more coal reserves than natural gas, and for this reason could be seen as a more stable long-term fuel.  However, coal is without a doubt a bigger source of pollution than natural gas, whether it be carbon dioxide, compounds that cause acid rain, or toxic metals such as mercury, lead, or cadmium.  The article does not point out this fact well enough in my opinion.  It is estimated, for example, that nearly 40% of U.S. mercury emissions come from coal-fired power plants (ref).  Further, the article does not point out well enough the additional environmental harm that coal mining causes over natural gas, such as mountain top removal and strip mining.


One other disturbing point made by the article includes: 
      "Utilities that burn natural gas would earn $30 billion over 10 years in pollution credits that could be sold on the carbon-trading market. But utilities that burn coal will receive tens of billions of dollars worth of free pollution credits, savings that will be passed on to consumers but may serve to delay the closing of some coal plants."  
It would appear that Congress is not attempting to provide a fair & level playing field for the two commodities.  While natural gas can "earn" pollution credits, coal simply gets them for free.  


The article further points out that if Congress were to not pass this bill, natural gas as a power source in the U.S. will likely grow by 30%, which coal growing at only 7%.  With the new legislation being considered, however, the EPA projects that electricity generation from gas would increase by less than 1%.