Oklahoma Geological Survey annotated 24 hour low frequency seismograms for year 2002.

Four most recent days.

2002 DEC scroll   animated

2002 NOV scroll   animated

2002 OCT scroll   animated

2002 SEP scroll   animated

2002 AUG scroll   animated

2002 JUL scroll   animated

2002 JUN scroll   animated

2002 MAY scroll   animated

2002 APR scroll   animated

2002 MAR scroll   animated

2002 FEB scroll   animated

2002 JAN scroll     animated

Monthly seismogram statistics

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TAKE NOTICE: new format begins 2002 JAN01.
This index no longer has individual days. Click on a month, eg:
"2002 JAN SCROLL" to see the most recent gram for that month. You may
scroll that page down through the rest of the month. There is also a 
selection "four most recent days", to view the last four grams without
downloading the entire month.

Comments on the format change, or anything on this website will be
welcomed by jim@okgeosurvey1.gov.


These seismograms were produced by a broadband seismometer in the Leonard
walk-in vault. They show only vertical (ie, not East-West or North-South)
ground motion. The seismograms show 24 horizontal lines, one for each
hour of ground motion. The data is filtered so that it shows mainly
surface waves from distant earthquakes.

Some earthquakes are labeled (average 3.4 based on 2001 JAN through NOV)
to show the earthquake region, the distance from Leonard
in great circle degrees (eg. D=120), and magnitude (eg 5.1mb). Definite 
earthquake surface waves of earthquakes not located at the time the figure
was posted may be marked with a ?.

Some of the seismograms with large surface waves which may obscure other smaller
earthquakes are SIGNED ROOT COMPRESSED  This
consists of taking the root (from the 1.1 root to the 3.0 root) of each
number while keeping the original sign (plus or minus) of the number.

LONG EXPLANATION: hardware and software details. The epicenters used in annotation are from these two sources: 1.Swiss Seismological Service (Red Puma) seismo.ethz.ch/redpuma/redpuma_ami_list.html 2.U.S. Geological Survey, National Earthquake Information Center. neic.usgs.gov/neis/bulletin/ These web pages are processed by a NAWK program which calculates the distance to Leonard, Oklahoma U.S., and the expected arrival times of P/Pdif/PKP and LR. Source 1. tends to have lower magnitudes than source 2. If the type of magnitude was not labelled by the source, it is listed as simply "M" (eg 5.1M).

Seismogram Index For Year 2000

Seismogram Index For Year 2001

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