Yellowstone National Park Press Release on unusual hydrothermal activity
http://www.nps.gov/yell/press/0362.htm
Yellowstone National Park News Release
July 22, 2003 03-62
http://www.nps.gov/yell/press/0362.htm
INCREASED THERMAL ACTIVITY AT NORRIS GEYSER BASIN REQUIRES TEMPORARY CLOSURE
Yellowstone National Park Superintendent Suzanne Lewis announced
today that due to high ground temperatures and increased thermal
activity that could affect visitor and employee safety, a portion of
the Back Basin at Norris Geyser Basin on the west side of the park
has been temporarily closed. Yellowstone's more popular features
within the Norris Geyser Basin, including Steamboat and Echinus
Geysers and all of Porcelain Basin, remain open to the public.
The temporary closure, effective July 23, is clearly marked and
covers most of the western portion of the Back Basin trail starting
at the Norris Museum. There are approximately 12,500 feet of trails
in the Norris Geyser Basin-with approximately 5,800 feet affected by
the temporary closure.
Norris is the hottest and most seismically active geyser basin in
Yellowstone. Recent activity in the Norris Geyser Basin has included
formation of new mud pots, an eruption of Porkchop Geyser (dormant
since 1989), the draining of several geysers, creating steam vents
and significantly increased measured ground temperatures (up to 200
degrees Fahrenheit). Additional observations include vegetation dying
due to thermal activity and the changing of several geysers' eruption
intervals. Vixen Geyser has become more frequent and Echinus Geyser
has become more regular.
Park staff continue to monitor temperatures and thermal features in
the area. When conditions have returned to acceptable ground
temperatures and stable surface conditions have improved, the trail
will be reopened. Norris is another example of Yellowstone's thermal
features that are constantly evolving and changing.
Attached with the press release are a set of questions and answers
and maps of the area.
-NPS-
(http://www.nps.gov/yell/press/images/norrislocatormap.gif)
(http://www.nps.gov/yell/press/images/norrismapclosure.jpg)
QUESTIONS AND ANSWERS
NORRIS GEYSER BASIN TEMPORARY CLOSURE
July 22, 2003
1. Where is Norris Geyser Basin?
Norris Geyser Basin is located in the northern section of Yellowstone
National Park, 22 miles south of Mammoth Hot Springs.
2. Is Yellowstone safe for an individual or their family to visit
Norris Geyser Basin and Yellowstone in general?
Yes. The changes at Norris are part of the dynamics of Yellowstone;
thermal areas are ever changing, and the recent temporary closure is
a precaution to assure visitor and staff safety in an area where
increased thermal activity has been noted.
Keep in mind that all thermal features have water that is near or
above boiling. Visitors should remain on established boardwalks and
trails whenever in thermal areas.
3. Is it safe for employees to live and work at Norris Geyser Basin
and Yellowstone in general?
Yes, as noted above. Safety is the top priority for both park
visitors and park staff. The area is closed to most park staff and
all concessioner staff. For those employees that may have to enter
the area, a job hazard analysis is being completed.
4. What is the boiling temperature at Norris Geyser Basin?
The altitude of Norris Geyser Basin is 7,500 feet. Water boils at
about 200 degrees Fahrenheit at Norris Geyser Basin. Typically, water
boils at 212 degrees Fahrenheit at sea level.
5. What led to the temporary closure at Norris Geyser Basin?
Park staff have measured ground temperatures of 200 degrees
Fahrenheit in the closure area-an unacceptable level for visitor and
employee safety. Also, many thermal features in the Back Basin have
heated up as indicated by expelling steam-rather than water and
steam. Concerns for visitor and staff safety regarding the high
ground temperatures and presence of steam necessitated a temporary
closure at this time. A portion of the trail system has been closed
to allow the assessment of any potential steam eruptions.
6. How long has this activity been occurring?
The most recent change in thermal activity began July 11, 2003, as
noted by NPS staff and electronic instrumentation. A new mud pot and
other thermal features were formed in the Back Basin area, and
Porkchop Geyser (dormant since 1989) erupted on July 16.
Historically, Norris is one of the more dynamic areas in the park and
is ever changing.
7. Is the park concerned that there will be a volcanic eruption at Norris?
Park staff and other scientists have no evidence that volcanic
activity is occurring at Norris Geyser Basin. In any geothermal area,
there always exist the possibility of steam eruptions as indicated by
the many geysers in Yellowstone
8. How have drought conditions influenced what is happening at Norris?
We do not know what impacts drought conditions have had on Norris Geyser Basin.
9. When will the temporary closure at Norris be lifted?
Park staff will continue to monitor ground temperatures and geyser
activity in the Norris area. The temporary closure will be lifted
when conditions have returned to acceptable ground temperatures and
stable surface conditions have improved.
10. Are wildlife affected by this increased thermal activity?
We do not expect any affect on Yellowstone's wildlife. Wildlife in
Yellowstone has adapted to living in thermal areas.
11. Does the recent closure of the Gibbon, Madison, and Firehole
Rivers have anything to do with the increased thermal activity at
Norris?
No. Although some river temperatures in Yellowstone are affected by
thermal activity, the major control on Yellowstone's river
temperatures is air temperature and water levels. The park has been
experiencing high air temperatures over the past several weeks.
12. How many people visit the Norris Geyser Basin on a daily basis?
Norris is one of the more popular geyser basins in the park. For
instance, last week rangers contacted 3,786 visitors at the
information desk at the Norris Geyser Basin Museum.
13. Are other areas in the park being affected by thermal activity?
Currently, we have no evidence for increased thermal activity in
other areas of the park. We have a large network of seismic
instrumentation throughout the park that is monitored on a daily
basis.
14. You noted that Porkchop Geyser showed recent thermal activity?
What happened at Porkchop Geyser?
Porkchop Geyser was the site of a steam eruption. Porkchop Geyser was
in continuous steam eruption from 1985 to 1989 when it was destroyed
by the 1989 explosion.
Map of the location of Norris Geyser Basin.
(http://www.nps.gov/yell/press/images/norrislocatormap.gif)
Map of the temporary closure area.
(http://www.nps.gov/yell/press/images/norrismapclosure.jpg)
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