News Details

December 2, 2012
San Francisco-Palomar Hotel

An IRIS PASSCAL data-archiving workshop will be offered prior to the 2012 Fall AGU meeting in San Francisco. This workshop will serve as an opportunity to help PIs and archivers familiarize themselves with the data group, the support provided by the data group, and the software utilized in the archival process.

FlexArray Experiment: Western Idaho Shear Zone

If this photo (below) of a 6' 1" tall individual looking up at the top of the solar panel mast doesn't cause one to wonder how much snow the mountains near Cornucopia, Oregon receive, a Snow Cat (below left) at a nearby lodge certain makes it's clear - lots of it. This temporary seismic station installed in the mountains of eastern Oregon is part of Dr. Ray Russo's Western Idaho Shear Zone Earthscope Flexible Array experiment. Spanning eastern Oregon to eastern Idaho, the seismic network covers arguably some of the most remote and rugged mountains of the contiguous United States.

Three engineers from the Escuela Politecnica Nacional Ecuador, Instituto Geofísico, spent the first two weeks of May here at PASSCAL. They are planning a network of 63 permanent broadband stations, 25 emergency sites, and 70 accelerometer stations in Ecuador. These stations will be used to monitor volcanic activity and seismic events. Ecuador is home to more than 20 volcanoes, so this is an important undertaking not only for the scientific knowledge it will provide, but also for the safety of the Ecuadoran people.

 

 

SEIS-UK Director Dr. Alex Brisbourne accompanies the staff of the PASSCAL Instrument Center  to gain experience working in polar environments while supporting the POLENET and Whillans Ice Sheet projects for a month and a half during this year's field season.

In July 2009, several IRIS/PASSCAL scientists assisted with the Batholiths Onland project. This large group effort involved over 50 scientists and grad students, for the purpose of making "a seismic refraction and wide-angle reflection survey across the Coast Mountains batholith of British Columbia, Canada."

Number of SiRFs Exp. Number Experiment Name 4 200551 Costa Rica Subduction (Nicoya) 2 200559 HLP-lite (aka pre-HLP) 2 200604 Anatahan Volcanoes 1 200609 CAFE 3 200611 CRB-Wallowa 2 200617 PIRE 1 200622 Carpathians 1 200655 Mexico ETS

Example of LOGPEEK display of a recent RT130 logfile with a SiRF clock attached, illustrating the timing problem. Note the DSP-CLK DIFF and JERKS/DSP SETS points.

DSP CLOCK DIFFERENCE -1 SECS and 0 MSECS messages mark the beginning of timing errors in the RT130 data, due to the SiRF clock’s erroneous time shift. The SiRF goes back and forth between correct and incorrect time over periods of hours or days. The RT130, and hence your data, will follow suit, generally with a lag of 4 hours.

 

‘POSSIBLE DISCREPANCY’ messages will be produced whenever the SiRF and the RT130 are not in sync. Four consecutive ‘POSSIBLE DISCREPANCY’ messages will reset (JERK) the RT130 time.

If the clock is being power cycled, the clock is locking and the RT130 is phase locking with the SiRF each time it is powered, the 4-hour lag is produced.