PASSCAL Data Access

One of the functions of the IRIS Data Management System is to archive data from PASSCAL field experiments. Until recently, most if not all of the PASSCAL data sets have arrived at the IRIS Data Management Center in Seattle as assembled data sets in various formats (SEGY, SAC, etc.). However, a great number of the new data sets are now arriving at the DMC in SEED format while the experiments are still in the field. These data sets are available to the P.I.s of a project as soon as the data can be archived at the DMC.

There is a two year moratorium for all PASSCAL data sets but there is also a mechanism by which a user not associated with the experiment can get permission to request and use these data sets. If a P.I. chooses he/she may remove the two year restriction for all users or give permission to selected users to request these data sets. Permission comes from the PI in the form of a password. Users that have obtained the password may register for access to this restricted data over the internet: http://www.iris.edu/ Information on the availability of PASSCAL data (and other temporary network data at the DMC) and the format in which the data is archived, as well as the name(s) of the PI(s), can also be viewed on the DMC web site. The "Temporary Network Data" pages include mapped locations of past and present experiments, details of the experiments, station locations, data format and availability, and in some cases preliminary findings and publications. If the data set is an archived SEED volume a user can take advantage of an added "Map Stations" option - a web utility that allows the user to create a GMT map of all stations included in the experiment. Pre-assembled data sets usually arrive at the DMC after the two year restriction period and are therefor available as soon as they are received. To request an assembled set the user need only send email and include the name of the data set, the medium on which they would like to receive the data and their mailing address. Assembled sets can only be sent on tapes since the data is not stored on the DMC mass storage system. Data in SEED format is requested in the same manner as GSN data (using BREQ_FAST, WEED, etc.). Please view the DMC´s on-line Data Access Tutorial for more information about request mechanisms: /manuals/DATutorial.htm

Example of regional map on the Temporary Networks page for Greenland and Iceland PASSCAL Assembled data set 92-002 Status: Available ICELAND PASSCAL Data Set 92-002 South Iceland Seismic Refraction Experiment of 1990 William Menke Lamont-Doherty Earth Observatory of Columbia University Description: The experiment design was a linear profile of 210 receiver points and 11 shot points crossing the Western Volcanic Zone and South Iceland Seismic Zone of southern Iceland. The profile is oriented northwest-southeast and is about 170 km long. The main goals were to image the upper 10-15 km of the crust with a resolution of 1 km vertically and 5-10 km horizontally in the South Iceland Transform zone, and to measure crustal thickness through the measurement of moho reflection travel times. Status - ready for Shipment Format - AH Preferred Media - Exabyte Make request Example of entry on the Temporary Networks page for Greenland and Iceland