EMSCOPE Data Portal:
Response functions and MT time series are available free of use and without restriction. These data are provided without warranty, and represent the best effort of EMScope to provide an accurate representation of the field data acquired and of unbiased response functions following data quality control provided by Oregon State University (OSU). EMScope, OSU, Incorporated Research Institutions for Seismology and the National Science Foundation are not responsible for unintended errors or deficiencies in the data sets or derived data products supplied, and will not be held liable for any loss, financial or otherwise, incurred as a result of using these data.
Authors of publications making use of these data are required to cite the source of the data as follows:
“The authors acknowledge the NSF-supported EMScope project and Incorporated Institutions for Seismology for the provision of magnetotelluric data and/or response functions used in our research/this publication.”
Response Functions-
MT response functions may be downloaded in EDI format directly from:
ftp://www.iris.washington.edu/pub/MT_EDI
Timeseries-
You can explore the collection of archived MT time series using IRIS’s database tools directly, or through the EarthScope.org web site data portal. Instructions for access to these resources are found immediately below.
(I) This Data Portal contains links to the IRIS Data Management Center, where all EMScope data are archived. All operational MT BB station data and metadata is archived through the IRIS DMC, and is available through the links provided below. Once you have selected the link, choose the Year the data were collected (2006, 2007, 2008, etc.) and the Network Name. All MT data collected by IRIS, including EMSCOPE data, use the network name “EM”. For instance, select “2007” and “EM” to see a calendar appear, where the dates on the calendar have active links to specific data sets, as seen in the picture below:
By then selecting a specific date from the calendar, a table of MT station availability will appear.
For a map of total MT station data availability, select:
http://www.iris.edu/SeismiQuery/station.htm
then select “EM” as the network name, and the start and end dates for the data query, select view results and then select Make Station Map. By selecting 2006/05/01 as the starting date, and 2007/11/01 as the ending date, the following map appears
Once you have identified the station i.d. of interest, a request for the data may be made from the IRIS DMC by using the IRIS BREQ_FAST Request Query Form
http://www.iris.edu/SeismiQuery/breq_fast.htm
Data may also be extracted from the IRIS DMC by way of an alternative data portal:
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OSU (pre)-BB MT Archived Data
(II) This portal also provides links to an archive maintained at Oregon State University, which contains magnetotelluric data sets collected at the sites of some of the EMScope BB MT stations, prior to their commissioning as operational MT BB stations. Some of these runs were collected in order to determine environmental noise levels at the then candidate MT BB sites, while others were collected as part of a continuing process of instrumentation comparison/calibration and electrode noise studies. At the OSU archive, the data are organized by station code, and comprise a unified zip archive for each station. The archive contains ASCII formatted MT data originating from the "readnims.f" program of Booker, modified by Park and Schultz, as well as associated metadata files, including Egbert .sp file. The archive also includes PDF format time series plot files in some cases.
The site at Soap Creek, near Corvallis Oregon Backbone station MTB02, was operated as a temporary site, and instrumentation test site, prior to its commissioning as an operational Backbone station. Three temporary sites were installed there in May 2006, designated SPC01, SPC02 and SPC03. In some cases, there was more than one run of MT data acquired from each site, hence the file naming convention of e.g. SPC0201 and SPC0202 designating the first and second run, respectively, at site SPC02.
Site SPC01 was located within 5 m of USArray seismic TA Site H03.a, while SPC02 and SPC03 were located approximately 80 m from that site. SPC02 made use of Pb-PbCl2 electrodes packed in KCl-supersaturated kaolin, while SPC01 and SPC03's electrodes were packed in NaCl-supersaturated kaolin.
The site at Parkfield, MTB01a, uses NaCl-supersaturated kaolin for its electrodes.
The site in Braden, MTB03a, uses NaCl-supersaturated kaolin, but in contrast to all other sites, the electrodes were pre-anodized with PbCl2. The others were built using bare lead wire.
Site code and name
MTB01a and MTB01b - Parkfield California - 17.8 MB file
MTB02a - Soap Creek Oregon - 371 MB file
MTB03a - Braden Missouri - 2.3 MB file
Other sites to be posted when available.
