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Data Set

Directory Name in the CD :   LDEO_USA 

DATA PARTICULARS

1. Lamont Doherty Earth Observatory [LDEO] of Columbia University provided these records covering :

1. the main-shock of November 12, 1999 Duzce earthquake and,

2. aftershocks of both the August 17, 1999 Izmit earthquake and the November 12, 1999 Duzce earthquakes. The period of recording extends from end of August 1999 until February 15, 2000.

2. The data sets are provided in two major directories: (a) 12 November 1999 Duzce earthquake main-shock records, and (b) all aftershocks � recorded following 17 August 1999 Izmit earthquake and beyond the Duzce earthquake into year 2000.

3. The recorders used in all stations are REFTEK-72A-08 (24 bit channels) operating in a triggered mode. The sensors used are TERRA TEK Model 320 (full scale = � 2 g). [Note: All stations also recorded high-gain three component L22 sensors. Stations MO (for the full deployment) and GE (only the first two months) recorded 3 broad-band components from Guralp CMG-40T. The complete data set from this experiment are expected to become available at the IRIS Data Center by May 2001].

4. The original data file names and formats have been preserved. These are also reflected in the original data summary Excel files. It is noted herein that all data are 100 samples per second.

5. General station information including (a) station names (and alternative numbers for LDEO data), (b) coordinates, and (c) geological/geotechnical descriptions are provided in station summary tables.

6. No corrections and selective criteria have been applied to the data. The user must go through the data set to determine its characteristics.

7. The Duzce main-shock data are given as integer values and should be multiplied by the scale factor (in each file) to get voltage from the FBA sensor. Then to get "g" that value should be multiplied by 0.8. The Duzce data is provided as 1 file per component per station per event.

8. The aftershocks are provided in original tar.gz format and can be unzipped with latest versions of Winzip. When unzipped, the data files are under original file names (e.g. 99.319007070375) indicating the (a) year [99], (b) Julian day [319], (c) time[070703], and station number [375]. Each record-file, has a short header that indicates the (a) station name [c375], (b) starting time of the record as also indicated from the file name, (c) total length of the record, (d) the sampling rate (100 sps), (e) scale or unit of motion [in g] and for each of the three components, (f) the component orientations [ in the order vertical, north and east] and (g) followed by three columns of acceleration data.