Ok, so here’s an update for you.
Previous Thread #2 - Last post in early March 2005.
Previous Thread #1 - Last post in December 2004.
Despite the massive non-coverage by the media of Mount St. Helens of late, the volcano is still hot and heavy and shows no signs of taking a rest. Since quite a few people ask questions comparing the “new” dome with the “old” dome, here are some facts published just today:
Old Dome
Actual Name - Unnamed.
Growth Period - Six Years (1980-1986)
Size - Approximately 3,500 feet in diameter.
Altitude / Vertical Height - 7, 155 feet, nearly 876 feet above the 1980 crater floor.
Volume - Approximately 97 million cubic yards.
New Dome
Actual Name - Unofficially called the “Whaleback”
Growth Period - Five Months (October 2004-April 2005)
Size - Approximately 1,550 feet long and 500 fett wide.
Altitude / Vertical Height - 7,642 feet (as of February 1, 2005), nearly 1,363 feet above the 1980 crater floor, 500 feet above the top of the old 1980-86 lava dome and 700 feet above the 2000 glacier surface. The top of the new dome is now only about 130 feet below the level of Shoestring Notch on the southeast crater rim and about 700 feet below the south crater rim.
Volume - Approximately 50 million cubic yards.
(For comparison Hoover Dam contains three and a quarter million cubic yards of concrete and it took almost two years to pour that amount.)
The Johnston Ridge Observatory (JRO), home of the Mount St. Helens VolcanoCam will reopen for the 2005 season on Friday, May 6, 2005. Barring any significant changes with the volcano, the JRO will end its visitor season on October 30.
One big change with visitation to the JRO is that the Washington State DOT will close the road between the Coldwater Ridge Visitor Center (open all year) and the JRO every night from 9pm until 7am the next morning. They are taking no chances with any potential eruptions which might occur at night.
Too bad, too. It is a real thrill going up to the JRO in the middle of the night in summer during the full moon. It’s my experience that if the volcano were to have a significant eruption at night, you would be relatively safe at the JRO (unless the eruption approaches the 1980 eruption in intensity). The danger would come trying to flee back down the road and possibly being swept up by a lahar.
(If you are thinking of getting a permit to climb Mount St. Helens, forget it for this year. The Forest Service is apparently not going to issue any climbing permits for this year because of the volcanic activity.)
Now I have it from an excellent source the USGS is planning on releasing information as early as tomorrow that a new third dome is growing. The Whaleback (second dome) is highly unstable. There are numerous rockfalls as the Whaleback breaks up. There was a mini-ash plume just yesterday around 11:30 am local time when part of it crashed. The VolcanoCam caught the ash plume, while the USGS Sugar Bowl Camera captured some greats shots of the ash aftermath. Apparently the this new third dome is beginning to grow from the same vent that produced the Whaleback dome.
Finally, one of the things I’ve noticed plotting the 3x earthquakes that occurred in late March and early April is that all of them are not centered below the crater under the domes, but underneath the south flank of Mount St. Helens. Check them for yourself and make your own prognostications about where the next major eruption just might break out …