| Subj: | yc... |
| Date: | 1/9/01 12:56:20 PM Pacific Standard Time |
| From: Goble David To: bardsquill@aol.com ('bardsquill@aol.com') |
|
hi Kent...
Yellowstone Caldera experienced a moderate high frequency tectonic seismic
event at about 1700 UTC today...9 January 2001...
as can be clearly seen at the urls...the pressure wave hit the Pelican Cone
and Joseph Coat stations at about 1706 UTC...
and...the shear wave hit about 1707 UTC...
Old Faithful and Norris Junction stations both showed low-level Long Period
(LP) harmonic events just prior to the high frequency event...
but...both stations showed increased and continuous LP events for the next
hour following the high frequency event...
this can be interpreted as magma movement triggering a tectonic event which
then allowed much more magma movement...
once again...hells-a-poppin'...
UUSS Webicorder (Seismogram) Displays...
http://www.seis.utah.edu/helicorder/
Old Faithful...
http://www.seis.utah.edu/helicorder/ut.YFT_EHZ_WY.2001010900.gif
Pelican Cone...
http://www.seis.utah.edu/helicorder/ut.YPC_EHZ_WY.2001010900.gif
Norris Junction...
http://www.seis.utah.edu/helicorder/ut.YNR_EHZ_WY.2001010900.gif
Joseph Coat...
http://www.seis.utah.edu/helicorder/ut.YJC_EHZ_WY.2001010900.gif
the following papers...though written about events at Long Valley
Caldera...are also pertinent to Yellowstone Caldera...
that is...the following excerpts from these paper...suggest an apparent
correlation between long period (LP) non-double-couple (NDC) seismic events
and magma movement...
from the relationship...period is inversely proportional to frequency...T
=
1/f...note that...
if...the frequency of long period events are in the range of 0.02 to 0.05
cycles per second...or...0.02 to 0.05 Hertz...
then...the period of these events are in the range of 50 to 20 seconds per
cycle...
which is what we are seeing at Old Faithful and Norris Junction stations...
clearly...we are seeing long period seismic events...magma movement...at
Yellowstone Caldera...
Volcanic Seismic Sources...
http://www.seismo.berkeley.edu/seismo/annual_report/ar98_99/node17.html
"...seismic unrest culminated on November 22 [1997] with a series of four
magnitude 4.6-4.9 earthquakes located in the south moat of the caldera.
Preliminary moment tensor analysis of these events revealed anomalous
seismic radiation. Deviatoric moment tensors have large
non-double-couple(NDC) components, and full moment tensor inversions reveal
a component of coseismic volumetric expansion in all four events..."
"...complete, three-component, long-period (0.02 to 0.05 Hz) displacement
waveforms..."
"The combined isotropic-CLVD solutions and anomalously long source
durations
apparent in the P-waveforms of these events together with the observation
of
a compressional strain transient...suggest that fluids were involved in the
source process..."
"The seismic moment tensor observations and the strain transient suggest
that seismicity was triggered by the injection of high pressure fluid or
possibly by pressurization of water saturated faults in the south moat by
a
pressure pulse generated by magmatic heating."
Structure and Volcanic Earthquakes at the Long Valley Volcano,
California...
http://www.dur.ac.uk/~dgl0grf/mammoth.html
"...long-period (LP) earthquakes...are thought to be associated with
underground magma movements..."
"...activity culminated in 1980 when a seismic crisis occurred that
involved
4 earthquakes with magnitudes of ~ 6. These earthquakes had
non-double-couple focal mechanisms, and were attributed to dyke
injections...Subsequent investigation revealed that the resurgent dome had
inflated by ~ 25 cm since the previous year..."
"The resurgent dome has inflated progressively and is now ~ 70 cm higher
than it was in 1979."
"...magma body may have a total volume of 500-1,000...[cubic
kilometers]...and the amount of new magma added is calculated to be ~
0.25...[cubic kilometers]."
"Most recently it has been discovered that unusually long-period (LP)
earthquakes occur regularly at depths of ~ 15 km beneath Mammoth Mtn.
Earthquakes of this type are poorly understood as yet, but are thought to
be
associated with magma movements at depth..."
| Subj: | fyi |
| Date: | 1/11/01 12:34:22 PM Pacific Standard Time |
| From: (Goble David L) |
|
triggered "excitation" at Yellowstone Caldera...
it has become apparent from the seismograms of 1/10/2001 MST that the
inflated magma chamber beneath Yellowstone Caldera is being "excited" or
"stimulated" by the large energy waves being propagated by earthquakes in
the Eastern Pacific...
the incoming energy from the 6.7 magnitude Kodiak Island event is clearly
seen on the Pelican Cone station seismogram at 16:08:50 UTC...which is
consistent with a travel time of approximately seven minutes to Golden,
Colorado...and...the resultant "excitation" of large magitude long period
tremors in the inflated magma chamber is seen on the Old Faithful
seismogram
by 1613 UTC...
likewise...the incoming energy from the 5.8 magnitude Vancouver event is
clearly seen on the Pelican Cone station seismogram at 00:00:30
UTC...and...again...the resultant building "excitation" of the inflated
magma chamber is seen on the Old Faithful seismogram by 00:12 UTC...
i'm beginning to wonder how much "excitement" the pressure cooker at
Yellowstone Caldera can take...
01/01/10 16:02:42 UTC 57.09N 153.62W Depth: 33.0 km 6.7Ms KODIAK ISLAND
REGION, ALASKA
City
Distance (degrees) Travel Time (min:secs) Arrival
Time UTC Phase
Anchorage, Alaska
4.56
1:06.7
16:03:48.7 Pn
Golden, Colorado
35.62
6:54.5
16:09:36.5 P
01/01/11 00:04:06 UTC 49.24N 128.92W Depth: 10.0 km 5.8Ms VANCOUVER ISL,
CANADA REGION
City
Distance (degrees) Travel Time (min:secs) Arrival
Time UTC Phase
Anchorage, Alaska
16.85
3:55.9
0:08:01.9 Pn
Golden, Colorado
19.33
4:25.4
0:08:31.4 P
Pelican Cone...
http://www.seis.utah.edu/helicorder/heli/yellowstone/Uuss.YPC_EHZ_WY.2001011
000.gif
Old Faithful...
http://www.seis.utah.edu/helicorder/heli/yellowstone/Uuss.YFT_EHZ_WY.2001011
000.gif
| Subj: | Yellowstone is going nuts...!... |
| Date: | 1/13/01 12:14:00 PM Pacific Standard Time |
| From: (David Goble) To: bardsquill@aol.com |
|
hi Kent...
i sent the first part of this e-mail earlier today using my home.com
address...
but...i'm not too sure how well it works lately...
anyway...this is what is sent earlier...
**********************************
another triggered LP seismic event at YC...
this Mendocino Fracture Zone tectonic earthquake...
5.2 2001/01/13 05:08:41 40.739N 125.334W 4.8 85 km (53 mi) WNW of Ferndale,
CA
see the link...
Recent Earthquakes in California and Nevada...
http://pasadena.wr.usgs.gov/recenteqs/
triggered long period tremors at Yellowstone Caldera...
see the link...
Old Faithful Seismic Station...
http://www.seis.utah.edu/helicorder/heli/yellowstone/Uuss.YFT_EHZ_WY.2001011300.gif
**************************************
but...now the situation has changed drastically...!...
**************************************
all Yellowstone seismic stations are off line...
Old Faithful at 1705 UTC...
Pelican Cone...Norris Junction...Pitchstone Plateau at 1820 UTC...
Joseph Coat...Denny Creek at 1825 UTC...
and...here is what triggered the long period tremors at Yellowstone...
01/01/13 17:33:31 UTC 12.77N 88.83W Depth: 60.0 km 7.6Mw OFF COAST OF
CENTRAL AMERICA
http://neic.usgs.gov/neis/bulletin/010113173331.HTML
City Distance (degrees) Travel Time (min:secs) Arrival Time UTC Phase
Mexico City, Mexico 11.93 2:47.2 17:36:18.2 Pn
San Juan, Puerto Rico 22.57 4:55.2 17:38:26.2 P
Lima, Peru 27.33 5:39.1 17:39:10.1 P
Golden, Colorado 30.51 6:07.4 17:39:38.4 P
Norris Junction Seismic Station
http://www.seis.utah.edu/helicorder/heli/yellowstone/Uuss.YNR_EHZ_WY.2001011300.gif
i will keep you updated as more information comes in...
_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com
| Subj: | yc update... |
| Date: | 1/18/01 1:52:38 PM Pacific Standard Time |
| From: (Goble David
) To: bardsquill@aol.com ('bardsquill@aol.com') |
|
hi Kent...
moderate to large earthquakes continue to "trigger" long period tremors
in
the caldera at Yellowstone...
cause ... 01/01/16 13:25:00 3.97S 101.66E 33.0 6.8Mw A
SOUTHERN SUMATRA,
INDONESIA
effect
...
http://www.seis.utah.edu/helicorder/heli/yellowstone/Uuss.YFT_EHZ_WY.2001011
600.gif
cause ... 01/01/18 01:40:48 UTC 25.88N 110.38W Depth: 10.0 km 5.0Mb GULF
OF
CALIFORNIA
effect
...
http://www.seis.utah.edu/helicorder/heli/yellowstone/Uuss.YFT_EHZ_WY.2001011
700.gif
also...long period tremors seem to be occurring
"spontaneously"...
http://www.seis.utah.edu/helicorder/heli/yellowstone/Uuss.YFT_EHZ_WY.2001011
500.gif
the "triggered" LP tremors are indicative of "excitation" of the
magma
chamber...
and...possibly...the injection of additional magma at depth from the
"hot
spot" plume beneath the caldera...
when queried regarding the seismic waveforms from the Old Faithful
station
from 1329 to 1430 UTC on 1/16/2001...an individual responding to my
"appeal
to professional earth scientists" posted the following information
via
on-line communication...
"It appears to me that you have first a local event, very small, followed
by
a large distant quake."
"The duration of the 15-20 second waves gives me pause; I'm not sure
what
causes that."
"The P-wave doesn't seem large enough to cause such long lasting
energy."
to me...the reaction...
"...gives me pause; I'm not sure what causes that."
to the evidence of long duration LP seismic waves at Yellowstone
Caldera
speaks volumes...
also telling is the quote regarding the long duration response to such
small
input of seismic energy...
"...P-wave doesn't seem large enough to cause such lasting energy"
the individual did not respond to my "response post" that included
my
analysis suggesting the injection of fresh magma from the hot spot
plume...
perhaps i'm getting too close to the truth for
comfort...because...the
"spontaneous" LP tremors have to have some source...
from these observations...it is "likely" that the "spontaneous" LP
tremors
are indicative of the injection of additional magma at depth from the
"hot
spot" plume beneath the caldera...
the other Yellowstone Caldera seismic stations show no tectonic
"trigger"
events...local or distant...during the time frame of the "spontaneous"
LP
tremors on 1/15/2001...
UUSS Webicorder (Seismogram) Displays, Yellowstone
Region
http://www.seis.utah.edu/helicorder/heli/yellowstone/index.html