|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Science-Pacific Region-Ocean Sciences-Research Activities |
Tsunamis and Tsunami Research |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
December
26, 2004 and March 28, 2005
Indian Ocean Tsunami Events
The highly dispersive waves of the Indian
Ocean tsunami (Evgueni Kulikov)
PDF March 28, 2005 Indian Ocean tsunami Information about the December 26, 2004 Indian Ocean tsunami is provided by Alexander Rabinovich for these four areas:
Indian Ocean
* Digital 3-minute data from 8 stations on the coast of South Africa Ruth Farre, Superintendent Tidal information, Republic of South Africa 
Pacific Ocean Stations 
Aleutian Islands tsunami records
Pacific Ocean
Pacific Ocean Tsunami Data The following table presents the results of the preliminary analysis of the tsunami data for the Pacific Ocean, including Hawaii, Alaska, Washington, California, Mexico, Salvador, Peru and Chile. All these data were provided by the WC/ATWC (thanks a lot to Paul Whitmore and his staff!). The records had 1-minute, 2-minute or 6-minute sampling intervals. The main problem with the data were repeating 1-hour segments. Almost all series had 4-5 such segments. Some series also had erroneous spikes and gaps. The data was corrected except for Puerto Williams, Chile: this series had too many problems, so it was excluded from the further analysis. Tides were calculated and subtracted from the original series. The residual series were used for analysis of tsunami waves. Actually, this is the first global-scale tsunami occurring in the "instrumental era". This tsunami was recorded all over the world ocean, from Antarctida in the south to the far North Pacific and the North Atlantic, including most of the sites in Chile, Peru, Mexico, California, British Columbia, Alaska, Hawaii, the Aleutian Islands, and the Kuril Islands. The exceptions are only the stations located deeply inside straits and inlets and sheltered from the open-ocean arriving waves (like Seattle, Tacoma, Vancouver, and Queen Charlotte City) or open-coast stations strongly affected by wind waves and swell and consequently having very high noise level (e.g. Langara, and Shemya). Tsunami waves in the Pacific Ocean (as well as in the North Atlantic Ocean) had very clear "train-structure". This "train structure" is such that the parameters
for both the first and
the "main" train are included separately (for some sites the parameters
are included for three trains). The complicated "train
structure" of the recorded tsunami waves at various sites in the Pacific Ocean creates significant problems in estimating
"true" arrival time and comparison with numerical
models.
North Pacific Ocean Tsunami Data
Tide gauge records for the instruments located on the oceanic side of
Vancouver Island (Tofino, Bamfield, Winter Harbour) or relatively
open to the oceanic influence (Victoria, Port Hardy, Bella Bella)
indicate evident tsunami signals. Tsunami arrival times are quite clear at most
sites and could be estimated only approximately. Tsunami signatures
have not been found in the records of Queen Charlotte City and Prince
Rupert. The trough-to-crest
wave heights, duration of tsunami "ringing" and observed
periods are the following:
29 (2nd) The estimated tsunami parameters indicate that:
Quite long ringing of tsunami oscillations in Winter Harbour, Tofino,
Bella Bella, and Victoria
also indicates that there were several sources of incoming waves.
Tsunami oscillations in Winter Harbour are
stable and clear. This
record is similar to the record in Severo Kurilsk, North Kuril
(Russia) and have two trains of arriving waves. The
main difference is
that the arrival times of the observed trains in SK were ~ four
hours later.
The maximum wave (21 cm) was observed in Winter Harbour at 03:00
GMT of 28-12. Apparently, the arriving tsunami waves were low
frequency waves (probable
periods are 40-55 min) in accordance with the large main shock source
area.
This explains why the recorded oscillations were so evident in Winter
Harbour, Tofino and Victoria but weak in Bamfield and Port Hardy: the resonant
periods of the
first three sites are 20-57 min, while in Bamfield they are 2.4, 3.7
and 4.1 min in PH
and 11 and 5.6 min in Bam (see Figure 7 in Rabinovich, A.B. and
Stephenson, F.E.:
2004, Longwave measurements for the coast of British Columbia and
improvements
to the tsunami warning capability, Natural Hazards, 32, 313-343).
Top of Page
Top of Page
Pacific
Ocean Atlantic
Ocean South
Africa Indian
Ocean
Here are results of the preliminary analysis for
the Antarctic record:
Syowa Station, Antarctica
Hydrographic and Oceanographic Dept., Japan Coast Guard. The sampling interval
is 30 seconds.
The data is provided by
Dr. S. I. Iwasaki,
National Research Institute for Earth Science and Disaster
Prevention,
Tsukuba, Japan.
The record shown is detided and high-pass filtered (Kaiser-Bessel
window = 6rs).
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
