ATSNN is proud to provide an exclusive email interview with a number of scientists working in the USGS Yellowstone program. The interview was
submitted on February 6, 2004, and was completed and provided to ATSNN on March 9, 2004. A sincere and heart-felt thank you goes to Dr. Henry
Heasler, Ph.D., Supervisory Geologist, USGS Yellowstone National Park, who served as the focal point for all interview communications. Dr. Heasler’s
willingness to participate in this interview and go the extra mile to ensure each question was submitted to the appropriate USGS scientist is greatly
appreciated. Special thanks also go to ATS members kukla and astrocreep for participating in the development of the interview questions.
These questions were formulated toward the end goal of addressing long-standing questions concerning the current situation at Yellowstone. These
questions have been discussed for some time here at AboveTopSecret.com, as well as at other websites. In addition, ATSNN hoped to address certain
rumors that seem to never have evidence provided with them, such as the dying off of wildlife, etc. We sincerely hope we have achieved these
Q: There have been continuing rumors at various web sites that animals are
either leaving the park en-masse, or dying in large numbers. These rumors include stories of large numbers of fish dying in Yellowstone Lake. The
cause is stated as increased toxic gaseous emissions. Are there animals leaving the park? Or dying in large numbers? Are there large numbers of
fish being found dead in the lake?
A: Toxic emissions are no worse than usual at Yellowstone. The park's wildlife population has undergone no problems due to toxic emissions. Some
of the park’s wildlife is migratory, such as bison, elk, and many species of birds. This year’s migrations were not unusual. Large numbers of dead
fish were not found in Yellowstone Lake, or any other lake in Yellowstone.
Q: What is the condition of the new fumarole near Nymph Lake?
A: Forceful clouds of steam were noted issuing from a line of vents to the northwest of Nymph Lake on March 10, 2003. The thermal activity could be
seen easily and heard from the Norris-Mammoth road. The area of thermally cooked trees became more visible throughout 2003. However, forceful clouds
of steam were no longer visible on December 5, 2003. The changing hydrothermal activity near Nymph Lake is an example of Yellowstone’s dynamic
Q: On 9/15/03, the Old Faithful, Denny Creek and Maple Creek webicorders were showing strong and sustained motion. This motion continued for
almost a day and no quakes registered on the finger list. Can you please explain the nature of the event on 9/15/03 and the discrepancy on the quake
A: The seismic data shown on the webicorders is only stored in online form for a week. The earthquake data are however also archived and accessible
to the public in five forms: (1) as monthly listings of current earthquakes are in the data archives of the University of Utah Seismograph Stations
data archives at www.seis.utah.edu/recenteqs
and also at
(2) in catalogs of epicenters and magnitudes of earthquakes
for the entire recording period of the Yellowstone seismic network, from 1973 to the present, at
, and (3) earthquakes of larger than magnitude 3 are shown and
listed on the U. S. Geological Survey Maps of Recent Earthquake Activity web site at
. For advanced users, digital seismic waveforms for Yellowstone are
archived as part of the ANSS (Advanced National Seismic Network) digital library for regional networks of the U.S. in the Composite Earthquake Catalog
, and in the IRIS (Integrated Research Institutions in Seismology)
data base at www.iris.edu
In general, there are many, many things that can contribute to the signals on seismograms. These include of course earthquakes, but also wind,
passing cars, snowmobiles that we call cultural noise.. To locate as an earthquake, several different seismic stations must record waveforms from the
earthquake that are analyzed digitally and that allow an epicenter to be located. If the earthquake waves for a discrete event cannot be seen on
multiple stations, then they probably aren't an earthquake. Also if they can be correlated, they still might not register as a Yellowstone
earthquake because the earthquake may have been well outside Yellowstone, even around the world for large earthquakes. Our web site doesn't provide
a list of every earthquake that is detected by the Yellowstone seismic network. You can check the University of Utah web site at
to obtain a list of earthquakes that might have caused the readings on
Yellowstone seismometers for last month. Because Yellowstone seismic network is constructed to provide accurate data for the Yellowstone region,
including a strip around its border, the UUSS (University of Utah Seismic Station) web pages (currently used by YVO) only list earthquakes within the
those bounds. All other earthquakes will be located by the relevant local network or by ANSS.
Q: Also, in the period of November/December, as well as in the past two weeks, there have been swarms of earthquakes in Yellowstone (over 20 in a
short period of time at the end of last year; over 30 in one week this month), but the seismic activity reports continue to state “seismic activity
remains at background levels”. Can you please explain magnitudes and frequencies that constitute “a background level” so that we can understand what
would legitimately be measured as above that?
A: Earthquake swarms are groups of earthquakes occurring closely in time and space. This type of activity is common in Yellowstone and is
distinguished by our analysts. However, many of the periods of what appear to be persistent ground shaking and that users may suspect are swarms can
be attributed to wind and cultural noise and to technical problems that appear as seismic events We suspect that the swarms you refer to are from one
or more of these sources. To get a feel for what does trigger an earthquake location, we'd recommend going back to the webicorders for the time
period of any specific event that does make the Yellowstone catalog. You'll notice there are many small events that could have multiple origins. Our
use of background levels refers to our interpretation of the activity for a montly period compared to the long term levels of activity we have
recorded over the past years.
Q: Do you know why the GPS velocity vector data on the University of Utah’s web site hasn’t been updated since mid-2003? And can you provide us
an estimated date that it will be brought back online for the public?
A: High precision GPS data are collected and analyzed at the University of Utah. Data analysis of GPS data is not automated because information on
the position of the satellite orbits that contain the GPS satellites is not available for sometimes several weeks. Thus the coordinates of the
Yellowstone GPS sites are not finalized for a longer time than the seismic data that are analyzed daily by our seismic analysts. Also the ground
motion that GPS sensors are responsive to is much slower, moving at inches per year, compared to the signals of an earthquake that only last a few
seconds to minutes. Thus we process GPS data over long time periods, such as days, even though they are recorded at 15 second intervals. You can see
the finalized ground movement vectors at mines.utah.edu/velocity
time-series of (determined once per day) at
. These data are used for assessing
ground motion histories of the Yellowstone volcanic system and allow our scientists to identify ground motions that correspond to volcanic (magma and
hydrothermal fluids) fluid movement, earthquakes, etc. A USGS system interrogates many of the western U.S. GPS networks for data on a daily basis that
provides an automated but preliminary satellite orbit data. These are not as accurate nor checked for any errors or data glitches by an analyst, thus
it is more up-to-date but does not provide final solutions. You can see those data at:
Maps and technical information on the Yellowstone GPS network is available online at the University of Utah website
Q: Why was the Mt. Sheridan webicorder deactivated and will it be brought back on line? If so, when?
A: This station operates in one the most rigorous and exposed mountain climates in the Rocky Mountains. It is atop Mt. Sheridan, at 10,308 feet high,
in a remote wilderness of Yellowstone. This station frequently encounters winds of over 70 mph, ice of several feet thick can encase the antennas,
temperatures of – 40°F or lower in the winter, etc. This station is recognized for its noisy environment but it provides key data in the southern
side of the Yellowstone caldera for day-to-day surveillance and we choose to put more reliable seismic stations on the public web site. Also because
stations have intermittent technical difficulties we may remove or add stations as needed to our web site recordings.
Q: There have been no updates on the bulge in Yellowstone Lake in some
time. Could you please update us with whether this bulge has continued to grow, decreased, exhibited new behavior, etc.?
A: There is no continuous monitoring of ground movement of the lake bottom. In the last few years, the USGS researcher who has worked on studies of
Yellowstone Lake obtains data once per summer. This summer there were no changes observed to this area called the Weasel Creek/Storm Point Vent
System. As explained on our web site, we still have no evidence that this feature is either new or changing.
Q: Could you respond to whether the following activity criteria, as compiled by USGS, has been observed recently at Yellowstone? And what overall
activity level do you currently place Yellowstone at (Green, Yellow, Orange or Red)?
A: YVO has no color-code system at present, but may adapt one in the future to be consistent with the other USGS observatories. Yellowstone National
Park encompasses many different geyser basins and such a large area (over 8,500 square kilometers) that a single overall activity indicator may not be
feasible for the park.
Q: Have you seen a transition from high frequency earthquakes to volcanic earthquakes VLPs or harmonic tremors?
A: No. It’s worth noting, though that normal behavior of a hydrothermal system in other volcanic areas may include VLP and tremor, none have been
detected in Yellowstone. Such signals are caused by fluid motions rather than tectonic rock fracture. Also a more complete set of wider frequency
seismometers would be very useful to monitor such signals throughout the entire Yellowstone volcanic field. Currently, we do not have funds to
support such a network. We have recently applied for funds to support a postdoctoral researcher to look at the kinds of seismic and deformation
signals that are the day-to-day behavior of shallow geothermal systems.
Q: Have you seen rates of deformation anywhere in the caldera that have warranted an increased condition code? What level is the deformation
criteria at currently?
A: No. Upward and downward movement of the ground has been observed at Yellowstone using GPS and satellite interferometry measurement and many other
caldera systems. This has lead to the idea that the dynamics of caldera ground motions are a composite of magmatic and hydrothermal fluid movement,
but they have not led to eruptions in historic time at Yellowstone.
Q: Has there been an increase in emissions of CO2, SO2, H2S or 3He/4He fumarole gases? What criteria level would you place the gaseous emissions
A: There is no continuous gas monitoring in the park. We are still obtaining an accurate record of background compositions and overall fluxes of gas
from the park. Provided increased funding, we hope to improve our gas monitoring system in the future. YVO has not observed any dangerous change in
the emissions of gasses.
Q: Has there been a pronounced ground cracking with displacements across individual cracks of a few cm or more or distributed sets of tension
cracks and/or slip on opposing sets of normal faults bounding a graben?
A: No. Displacements along deforming ground have not been observed. The “cracks” in the ground that have been observed are in thermal basins and are
associated with water movement.
Q: Has there been new fumaroles and/or hot springs developing or a vigorous increase in output from existing fumaroles and/or hot springs?
A: Yes, some individual features have become more vigorous and new features have formed. However, other features have decreased in activity. YVO’s
best estimates indicate a relatively constant thermal water outflow both with respect to temperature and volume, in 2003. Changes in individual
thermal features are quite normal in Yellowstone.
Q: Has there been any instances of differential magnetic field changes of 5+ nT within a week to 10 days between 3 or more stations?
A: There is no continuous monitoring of the magnetic field in Yellowstone.
Q: Do you feel that there has been enough disclosure to the general populace, either through formal USGS press releases, or media coverage, on the
current conditions at Yellowstone to create an awareness level appropriate for the current situation?
A: Yes. The interest in Yellowstone’s volcanic aspects provided an excellent opportunity to educate people about Yellowstone National Park.
Inquires from the press were answered and the press were encouraged to travel to Yellowstone for first-hand observations. Local press agencies (such
as the Cody Enterprise, the Billings Gazette, the Bozeman Chronicle), regional agencies (such as the Kansas City Star) and national and international
media (such as the New York Times) all carried articles on Yellowstone’s highly dynamic geology. Discussions were also carried on the radio (such as
National Public Radio) and television (such as Salt Lake City, Utah; Denver, Colorado; Billings, Montana; Cheyenne, Wyoming). The Internet has also
carried a great deal of information. Unfortunately, many of the internet stories were based in fiction rather than fact. Rumors such as the reported
closure of Yellowstone Lake or the closure of all of Norris Geyser Basin could easily be checked and found to be false.
Q: Concerning the radius for damage if the supercaldera were to erupt, is there a contingency plan in place for a defined area around Yellowstone?
If so, what is it and what are the parameters of the defined area?
A: Our job at YVO is to provide adequate warning of volcanic activity at Yellowstone. The USGS Volcano Hazards Program has this responsibility at
Yellowstone and at all other US volcanoes, nationwide. We also provide information on the present state of seismicity, ground deformation and other
measurable parameters. We are not a civil defense agency. Such planning is left to the park and to the surrounding communities and states.
As an aside, Yellowstone has erupted about 30 times since the last caldera-forming eruption, 640,000 years ago. Nearly all these eruptions produced
relatively smaller lava flows than the notorious three giant eruptions that formed the calderas of Yellowstone. If this sort of eruption were to
occur today, as would be the most likely scenario for a Yellowstone eruption, there would be minimal effects outside the Park. Thus, the supposed
radius of damage you quote is only for an extremely unlikely kind of volcanic eruption.
[Edited on 11-3-2004 by SkepticOverlord]