# Presentation: 779216

## Pops and PuffsParkfield and Mount St. Helens

- Pops and PuffsParkfield and Mount St. Helens

- Ken Hudnut, USGS
- Wednesday, 6 Oct. 2004
- Caltech Seismo Lab

- USGS photograph taken at 12:13:01 PDT
- Friday, October 1, 2004, by John Pallister

## A busy week - shake & bake

- Parkfield Mw6.0
- ruptured from southeast (near Gold Hill) to northwest (near Middle Mountain)
- normal aftershock sequence + triggered Bakersfield M5
- no evidence for southeastward migration of activity

- Mount St. Helens:
- vigorous and sustained phreatic activity
- indications of new magma (as of Monday)
- Sustained tremor
- Large deformations
- CO2 and SO2 emmissions

## Big News butnot very Big Ones (yet)Cholame - 1857?New Magma?

*Big News* butnot very *Big Ones* (yet)Cholame - 1857?New Magma?

## Slide 4

## Bakun & Lindh (1985), Science,6 August 1985, Volume 229, Number 4714 

**The Parkfield, California, Earthquake Prediction Experiment*****Summary**** *
*Five moderate (magnitude 6) earthquakes with similar features have occurred on the Parkfield section of the San Andreas fault in central California since 1857. The next moderate Parkfield earthquake is expected to occur before 1993. The Parkfield prediction experiment is designed to monitor the details of the final stages of the earthquake preparation process; observations and reports of seismicity and aseismic slip associated with the last moderate Parkfield earthquake in 1966 constitute much of the basis of the design of the experiment.*

***"Parkfield remains the best identified locale to trap an earthquake.”***
* **- National Earthquake Prediction Evaluation Council, 1994*

- Galitzin
- DeBilt (E-W)

## http://quake.wr.usgs.gov/research/parkfield/sciadv.html

## Slide 7

## Slide 8

## Courtesy of Mike Rymer, USGS

## Doug Dreger’s model (UCB)

- http://www.cisn.org/special/evt.04.09.28/finite.dreger.html

## Slide 11

## Chen Ji’s model (Caltech)

- http://www.gps.caltech.edu/~jichen/parkfield/parkfield.html

- Waveforms of 12 1-Hz GPS stations (Contributed by Kevin Choi, Andria Bilich and Prof. Kristine M. Larson of University of Colorado at Boulder) and a close strong motion station, Cholame 5W (CH5W, CISN). 15 GPS vectors distributed by Dr. Nancy King of USGS are also combined into this inversion

## Slide 13

## PBO instruments to study post-seismic deformation

- CSIRO GTS
- post-seismic
- strain evolution

- New PBO CGPS
- station installed

- Courtesy of Brian Coyle, UNAVCO

- Courtesy of Marie Mee, CSIRO

## Slide 15

## Cascades Volcanoes

**Information Statement**
-  Unusual events such as steam bursts (with or without minor ash fall)
**Notice of Volcanic Unrest - Alert Level ONE**
- anomalous conditions recognized, e.g., sustained, elevated seismicity
**Volcano Advisory - Alert Level TWO**
- significant likelihood of  culminating in hazardous volcanic activity
**Volcano Alert - Alert Level THREE**
-  volcanic event with attendant volcanologic or hydrologic hazards threatening to life and property appears imminent or is underway
-  Following the May 18, 1980, eruption of Mount St. Helens, accurate warnings were issued hours to weeks before 17 of 21 subsequent eruptions by scientists of the USGS Cascades Volcano Observatory (CVO) and University of Washington (UW) Geophysics Program. The most recent eruption occurred in 1986. Most of these warnings consisted of a series of information statements and staged alert levels. Future warnings at Mount St. Helens and other Cascade Volcanoes will follow a similar strategy.

## Timeline

- Sept. 23   (~2:00 a.m. PDT)
- Seismicity swarm begins

- now

- Oct. 1 (12:03 p.m. PDT)
- Initial steam emmission

- Oct. 2 (2:00 p.m. PDT)
- Tremor - Alert level 3

## Mount St. Helens Activity

- all is normal

## Slide 19

## Seismicity shallows

* **Graph showing relationship between time and depth of earthquakes beneath Mount St. Helens from August 2003 through August 2004. In this graph, 0 depth is referenced to 1.5 kilometers (about 1 mile) below the current summit of Mount St. Helens (8,363 feet above sea level).*

## USGS photograph taken on 30 September 2004 by Dan Dzurisin. 

- USGS scientist Michael Poland collects information from a GPS station on the east flank of Mount St. Helens (station Southeast Ridge). Mount Adams volcano is visible in the distance. More than a dozen GPS stations have been installed on or around Mount St. Helens to measure any deformation of the ground surface.
- USGS photograph taken on 30 September 2004 by Dan Dzurisin.

## Close-in view of south side of Mount St. Helens lava dome, showing the dome and part of the glacier forming at the base of the dome.

- USGS photograph taken on 30 September 2004 by Mike Poland and Dan Dzurisin.

## Installing gas monitoring equipment in helicopter, checking equipment, ready for takeoff to sample gases from the volcano. USGS photograph taken on 27 September 2004 by Steve Schilling.

## 12:03:32 PDT on October 1, 2004		Photo by John Pallister, USGS

- 12:03:32 PDT on October 1, 2004		Photo by John Pallister, USGS

## 12:16:01 PDT on October 1, 2004		Photo by John Pallister, USGS

- 12:16:01 PDT on October 1, 2004		Photo by John Pallister, USGS

## Plume from Johnston Ridge Observatory

- USGS photograph taken on October 1, 2004, by Gene Iwatsubo

## View of the south side of the dome from over the crater rim. USGS photograph taken on October 2, 2004, by Mike Lisowski.

## Data collection

- Seismicity
- GPS (including dome installations) & EDM
- Gas monitoring (CO2 and SO2)
- Thermal imaging
- LiDAR
- Video camera monitoring
- Microphones to detect explosions
- Visual and photographic monitoring

## Conclusions

- M6 Parkfield earthquake occurred in section of fault where it had been forecast & anticipated - many instruments in place
- Nucleated at SE instead of NW end, hence most dense concentration of instruments for precursors was 25 km away
- No precursors evidently were detected in borehole strain, surficial creep, GPS, 2-color laser, magnetometer, seismicity (no ‘17 min. foreshock’), or any other data
*But* on earthquake prediction; Rundle self-proclaimed ‘remarkable’ and ‘amazing’ success record of 15 for 16
- Normal aftershock sequence; triggered event near Bakersfield
- St. Helens phreatic activity was predicted because of anomalously shallow seismicity and related deformation causing fractures in glacier ice within the crater
- Next phase is developing - possibly new magma in edifice