Station Information |
Data access |
Over the past 25 years the USGS and its collaborators have collected
an extensive set of fault monitoring data.
The dataset consists of 9 different experiment types and contains
over 1300 channels of strain, creep, magnetic field, tilt, well water
level, differential lake level, electric field, pore pressure and
associated environmental measurements such as rainfall, barometric
pressure, wind speed, snow depth and crustal temperature at various
depths. These data are often called "low-frequency data" because
the typical sample rate of once every 10 minutes is low in comparison
to typical seismic sample rates. The largest volume of data come from
sites located near the San Andreas fault system in California, but the
dataset also includes sites in Oregon, Alaska and the South Pacific.
We are actively loading these data onto the NCEDC, and are working
with the USGS to assemble the requisite information for instrument
In addition to archiving the "raw" data, the USGS is providing a
cleaned version of the USGS data at its web site.
||Primary data channels
||Auxiliary data channels
|Creep||creep(1-n channels)||rainfall, temp, voltages
|Magnetometer||magnetic field (1-3 channels)||temp, voltages
|Tensor strain||strain (3 channels)||pore pressure, rainfall, voltages
|Volumetric strain||dilatation strain||pore pressure, barometric pressure, temp, voltages, water level
|Wire strain||strain (3 channels)||temp, voltages
|Tilt||tilt (2 channels)|| temp, rainfall, voltage
|Lake level tilt||water tilt level||barometric pressure, temp, voltages, wind speed, wind direction
|Long baseline tilt||interferometer tilt||temp, voltages
|Well water||water levels||gravity, barometric pressure, rainfall, temp, voltages
|Electric potential||electric potential||
Typical Recorded Channels
These documents describe how the SEED convention for channel naming is
being applied to the UL network and show the mapping of the USGS channel
names to the SEED channel names.
Station and Channel Information
Waveform data from the UL network are available in SEED format.
Several tools provide access to SEED format data at the
NCEDC, both in terms of querying the archives and
allowing data requests.
- Querying the archives
- Requesting data by channel and time
- Requesting data by event
Help on using these
tools is available.
A cleaned version of the data
is available from the USGS.
Use the SeismiQuery program
to check on the availability of UL digital waveform data.
Use the NetDC Data Request Form
to request digital waveforms from the NCEDC in SEED format
or to check the availability of the UL digital waveforms.
- Use the
program to read the resulting SEED files.
timing accuracy of the UL data
is limited by characteristics of the data acquisition system system.
Please read the description of the data timing carefully before
you use the data.
Some of the UL waveforms have been archived, but their instrument responses
are not yet complete. These waveforms will show up on waveform queries,
but the data will not be available in SEED format until the instrument responses
are complete. The list
UL SEED channel names, locations, and operational times (year/month/day format)
reflects the channels for which we have complete responses.