Plate Boundary Observatory (PBO)
The Plate Boundary Observatory (PBO) component of EarthScope is a geodetic observatory designed to study the three-dimensional strain field resulting from deformation across the active boundary zone between the Pacific and North American plates in the western United States. The observatory consists of arrays of Global Positioning System (GPS) receivers and strainmeters which will be used to deduce the strain field on timescales of days to decades and geologic and paleoseismic investigations to examine the strain field over longer time scales. PBO also plans to have 79 borehole stations with seismic instrumentation installed. All seismic and strain data generated by PBO are available through the IRIS DMC.
PBO Seismic Data Handling
In the newly approved PBO project baseline, PBO requested funding to take over collection, downloading, and quality checking of seismic data from PBO borehole strainmeter stations, as well as delivering these data to the IRIS DMC for archiving and distribution.
Overview of PBO Data Handling
PBO seismic stations generate 3 components of data at 100 samples/second. These data will flow from the Q330 installed at each station to a Marmot external buffer installed at each station. The Marmot will run an Antelope ORB that splits the data at the station. One stream will flow to Boulder, via Antelope ORB-to-ORB transfer, and the other will be archived at the station as an on-site buffer, potentially for triggered data. In Boulder, PBO will use the Antelope suite to monitor the seismic network, perform command/control, and the like. Data will flow to the archive at the IRIS DMC for permanent storage.
PBO Strain Data Handling
PBO Borehole Strain & Laser Strain Data at IRIS DMC
Data from borehole and laser strain components of the PBO have been accessible since August 2005. These data are managed as network code PB. One unusual aspect of these data are that they are available in both SEED format, through regular request mechanisms, and the raw datalogger format called
Ice9 for laser strain, and
bottle format from the Gladwin borehole tensor strain instruments. One reason for this is that strain data require substantial QC and validation, and access to these raw data is important.
To Access PBO Data from the DMC
Before requesting data for the first time, we recommend that you:
- Learn about the various tools IRIS Data Services offers
- Read the IRIS Data Services manuals
- View the IRIS Data Services software that is available
- Learn about using IRIS Web Services
IRIS distributes near-real time miniSEED data via BUD. Click here to access real time data via BUD »?
SEED Data Requests
Waveform data from the PB network are available in SEED format. Several tools provide access to SEED format data at IRIS for querying the archives and allowing data requests.
The table below shows typical
Location Identifiers and
|Network Code||Station Code||Location Identifier||Channel||Sample Rate||Details|
||100 samples/s||Borehole Seismic|
||LS[1, 2, 3, 4]
RS[1, 2, 3, 4]
* = wildcard
Two Analysis Centers process all PBO strainmeter data. The Borehole Strainmeter Analysis Center is operated by UNAVCO at the PASSCAL Instrument Center in Socorro, NM, and the Laser Strainmeter Analysis Center is operated by UC San Diego. These centers create cleaned and calibrated strain time series that are stored in XML format at the PBO strainmeter archives.
Processed strain data
All PBO borehole strain data , laser strain data, and their associated environmental data are available in a “processed XML” format at 300 second (5 minute) sample interval. All data for one station year are contained in a single XML file. The XML file names contain the SEED station name, the year of the data, and the date and time that the data was created.
Raw strain data
As of August 2010, the PBO strainmeter network consists of 75 borehole strainmeter stations and five laser strainmeters. Raw data are available in both the native logger format (bottle for the BSM stations and Ice-Nine for the LSM stations) and in standard SEED format. All these data are available from the PBO strainmeter archives at the IRIS Data Management Center.
If you want to download the “raw” data (in tar files), you can access these via the link below, where the two types are referred to as either
bsm for borehole, or
lsm for laser strain.
For further updates and information related to this growing network, please visit the PBO: