IRIS Knowledge Base

Category » USArray

There were 40 articles found in this category:

1. Are there infrasound sensors at Transportable Array stations?
   Beginning in 2011, infrasound sensors have been installed at all new TA sites and at some previously existing sites. As of April 2012, 370 sites have had Setra 278 and NCPA microbarometers co-located with the seismic sensors. The Setra instrument data is found in the BDO and LDO channels; NCPA d ...
2. Every now and then the data from a USArray TA station I am using look crazy. It looks like someone hit the sensor with hammer. What’s going on?
   There are numerous reasons a Transportable Array (TA) station, or any seismic station, might return data with a crazy signal including but not limited to: Field visit: an engineer being on site can introduce unexpected signals, especially if the vault is opened Vault settling: as the concrete ...
3. I requested some data and got a file back that I can't read. What do I do with this file?
   It is first necessary to identify what kind of file this is. Look for an extension or suffix Many times, a file will have a suffix on it, like .txt, to indicate the type of file. IRIS will typically send users these kinds of data: .seed, .dataless, .miniseed, .mseed, .dless = files in SEED form ...
4. How long do USArray TA stations stay in one spot?
   In general, Transportable Array stations record at a single site for approximately two years.
5. Are any of the USArray TA stations permanent?
   Yes. In general Transportable Array stations are removed after 2 years, but in a few cases stations are left operating as a permanent site. These include: Sites considered part of the permanent Reference Network Sites that have been adopted by local states, agencies or educational institutions ...
6. What happens after the USArray TA reaches the east coast?
   The USArray Transportable Array (TA) is a set of more than 400 stations traversing the United States from West to East over a 10 year time span. In 2013 when stations are installed in their East Coast locations they will be operated until 2015 such that each site will have recorded 2 years o ...
7. I requested some USArray TA data and received multiple copies of the same data. Why did this happen? 
   The IRIS DMC normally receives two copies of Transportable Array data, the real-time telemetered copy and a later "final" copy. In some cases a third copy of data is received that fills in gaps in the telemetered data. These different versions of the data are kept separate using SEED quality ...
8. I want to look at an earthquake that happened yesterday. How long do I have to wait for all the USArray TA data to arrive?
   The USArray Transportable Array data usually arrive at the DMC in near real-time, within seconds or minutes, and are immediately available via a number of request mechanisms. Continuous data are available in multiple ways: As real-time streams from the DMC's SeedLink server Using the DMC's Web ...
9. How do I obtain data from TA stations?
   Data from TA stations can be obtained by using any of the IRIS data request methods (see Requesting and Using IRIS Data). A few common request methods include: SeedLink server Web Services More information about USArray data access can be found at www.iris.edu/earthscope/usarray/#data.
10. Can I get USArray TA data in real time?
    The USArray Transportable Array data usually arrive at the DMC in near real-time, within seconds or minutes, and are immediately available from via request mechanisms such as: SeedLink server Web Services DHI Client (will be unavailable after June 30th, 2013) More information about data reques ...
11. How can I tell when a TA station was removed?
    One way to get information about the operational dates of a TA station is to use the IRIS DMC MetaData Aggregator (MDA). Choose the TA network, and then select the station name. The start and end dates of the station are listed in the 6th and 7th line from the top. An end date of 2599/12/31 (36 ...
12. Do you see Earth tides on the USArray TA stations?
    Earth tides can be seen at most of the TA stations using an appropriate filter. Very long period noise and/or vault instabilities at a site are possible reasons why Earth tides may not be observed.
13. Does anyone pick phase arrivals for USArray TA data? Is there an earthquake bulletin available?
    Phase picks on the USArray TA data are made by analysts at the Earthscope Array Network Facility (ANF). These ANF Event Bulletins are available as Searchable Product Depository (SPUD) products at the IRIS DMC or through the ANF website at Event Tables. Once the final phase picks arrive at the I ...
14. Do the USArray TA data contain calibration signals? If so, when and where are they? What do they look like?
    Calibrations on USArray TA data are run within a few days to weeks both after sensor installation and before sensor removal (if possible). The signal looks like large amplitude white noise with an abrupt start and end and lasts for about 2 hours. Two examples are illustrated in the attachments.
15. Is it possible to specify my own sample rate?
    USArray TA stations have several seismic channels available with different sample rates. The BH[ENZ] channels are 40 samples per second (sps or hz) and the LH[ENZ] channels are 1 sps. Some stations also have UH[ENZ] channels (0.01 sps) and VH[ENZ] channels (0.1 sps) available. If you want a dif ...
16. How do I obtain station latitude, longitude, sensor orientation and other metadata for the USArray TA?
    One method of obtaining station latitude, longitude, and sensor orientation metadata is to use the IRIS DMC Metadata Aggregator (MDA). From the network list, choose the TA network and then select the station and channel. Another option is to use the ws-station web service to return station met ...
17. What is a good place for a USArray TA station?
    There are many factors that go into selecting a successful Transportable Array site. The TA stations are laid out in a grid with ~70 km spacing. Proposed sites must be near these grid markers (you can find out whether a specific location is within the spacing limitations by using the Suggest a ...
18. How can I find out where future USArray TA sites will be located? 
    The USArray TA Status Map displays the current status of the TA network, including existing stations, initial sites, reconned sites, permitted sites, and constructed sites. This map is updated on a weekly basis. More station information can be found at Maps and Schedules.
19. Are there any other sensors besides seismometers at USArray TA stations?
    Yes, beginning in 2009 an Environmental Processor became part of the standard station design and records barometric pressure in addition to temperature inside the vault. These channels are identified with the SEED location ID of EP and channel codes of LDM for pressure and LKM for temperature. ...
20. I see curious transient signals in the data – what are they?
    There are many causes for transient signals. Long period transient signals can be caused by vault tilt (often resulting from weather systems or freezing/thawing ground), or local disturbances such as cattle, horses, or people. High frequency transient signals can be caused by fans, cars, or othe ...