IDS CONTRIBUTION TO ITRF2004
DISCONTINUITIES IN TIME SERIES OF STATION COORDINATES
IDS Analysis Coordination team
June 2005
1. STANDARD LIST OF DISCONTINUITIES
The following list of discontinuities was provided by the Analysis Centers and
used in the CATREF analysis. Click on the station name to visualize the time
series of N, E, U residual coordinates with respect to linear motion, derived
from the solutions of the the ign, ina, and lca analysis centers. When a new point
was defined by the Analysis Centers, a red line shows the corresponding date. Note
that the derivation of coordinates residuals by the CATREF software took those
declared discontinuity into account by estimating independent positions and
velocities before and after the break date. Therefore the corresponding sets
of residuals do not belong to the same set.
AREA: Arequipa 2nd point after the 2001, June Earthquake.
COLA: Colombo 2nd point after November 1994
DIOA: Dyonisos 2nd point after April 1, 1995
KRAB: Krasnoyarsk 2nd point after Nov 1999 (restart)
OTTA: Ottawa 1st point over Feb 1, 1990 - Jan 31, 1994
OTTA: Ottawa 2nd point over Feb 1, 1994 - Jan 31, 1998
SAKA: Sakhalin 2nd point after Oct 5, 1994 (earthquake on Oct 4, 1994)
SAKA: Sakhalin 3rd point after Dec 26, 1999 (restart)
SODB: Soccorro Is. 2nd point after Oct 3, 2002 (earthquake on Oct 3, 2002)
2.PROPOSED EXTENDED LIST OF DISCONTINUITIES
An additional list of station discontinuities is under discussion in June 2005.
The discontinuities that were discussed between ign and lca are listed hereafter,
with the Analysis Coordinator (ac) comments and a final proposal, using the
discontinuity qualifier proposed by R. Ferland. P: position change; V: velocity change.
For some proposed discontinuities in the case of a nearby earthquake, we propose to
wait until the expected effect is known. There are ongoing studies on this problem.
Links to the station motion residuals for ign, ina, and lca are provided under
the station name. A green line shows the proposed discontinuity dates. Links to the
station motion measured by ign and lca are provided under their columns.
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Sta Event Date Type Recommendations Comments
ign lca ac
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COLA Restart 01 Jul 2001 P yes yes YES
EASA Earthquake? 12 Feb 1998 V yes yes? NO Wait for effect evaluation
EVEB Restart 01 Jan 1997 P yes yes YES
EVEB Restart 01 Jan 2003 P yes yes YES
FAIA 01 Jan 1996 V yes? yes NO Wait for effect evaluation
FAIB Noisier in 2nd part of 2002 - - NO
KESB Restart 01 Jul 2004 P yes yes NO Wait for more data
KRAB Restart 01 Jan 2000 P yes yes NO Non linear motion mostly annual
MARB Restart 01 Apr 2003 P yes yes YES
ROTA ~ 1996-1997 V ? no NO Up motion non linear but smooth
STJB Restart 01 Sep 2002 V yes yes ?? No obvious date for a change
TRIB Earthquake? 31 Jul 2004 P yes ? NO Wait for more data
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