West Coast/Alaska Tsunami Warning
Center
Operations Manual
NOAA/NWS/WCATWC
Palmer,
http://wcatwc.arh.noaa.gov
Section 4.3:
EarthVu Geographic Display
Last Updated: 5/2007
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EarthVu is displayed on the
upper four monitors
EarthVu is geographic
display software developed at the WC/ATWC. Its main functions are to:
·
Display epicenters on various scale maps,
·
Overlay pertinent information such as historic
tsunamis and earthquakes, volcanoes, elevation contours, roads, pipelines,
tsunami watch/warning areas, etc.,
·
Provide a graphical platform for computing tsunami
models,
·
Display results of previously computed models for
calibration during tsunami warnings,
·
Compute and display tsunami travel times,
·
Interface with earthquake and tsunami data bases,
and
·
Create maps to link to tsunami messages issued by
the center.
EarthVu runs in parallel with the
EarlyBird seismic processing system and normally uses
four monitors. EarthVu is sent automatic
and interactively computed earthquake locations. As these locations are acquired, appropriate
maps are shown on the monitors.
EarthVu can be run in one
of four modes:
1) Display large-scale maps and overlays,
2) Interface for tsunami
travel time maps,
3) Display small scale maps, and
4) Display regional maps which show the last seven
day’s events.
Overlays
Several overlays are available in EarthVu.
·
Major Cities
·
Tsunamis - all known Pacific
basin tsunamis, from NOAA/NGDC
·
Earthquakes - all known
quakes magnitude > 5, 1900-present, from USGS/NEIC
·
Volcanoes - from Global
Volcanism Program
·
Seismometers - seismometer
data processed at WC/ATWC
·
Tide Gages - tide gage sites
recorded at WC/ATWC
·
Watch/Warning Areas -
present tsunami watch/warning status
·
Lat/Lon Grids - meridians
and parallels at specifiable intervals
·
Cities - from DOD Digital
Chart of the World
·
Contours - from DOD
Digital Chart of the World
·
Geographic Names - from
DOD Digital Chart of the World
·
Airports, roads, pipelines,
power lines, trails, railroads - from DOD Digital Chart of the World
Other interactive options
available in EarthVu are: display detailed data on a tsunami,
volcano, tide gage, or seismometer with a mouse click, re-draw map with color
coded elevations/bathymetries, turn on/off voice option (says location as
displayed), call historic data bases, and specify an area of the map to expand
in the small scale map program.
Historic tsunami and earthquake data are queried with program HISTORY
which is called from EARTHVU. HISTORY retrieves information from the data bases
by date, location, and magnitude. The output can be in summary form or in great
detail, and is written to the screen and/or printer. The earthquake data base
is from the USGS/National Earthquake Information Center. It contains all
earthquakes between 1900 and present over magnitude 5 (over 70,000 quakes). The
tsunami data base is taken mostly from NOAA/National Geophysical Data Center
studies (e.g. Lander et al., 1993; Lander, 1996). It contains over 1000 Pacific
basin tsunamis dating back to 47BC. The same information accessed by program
HISTORY is also used by EARTHVU and the other programs when displaying tsunamis
and earthquake data on maps.
Tsunami
Travel Times and Models
Tsunami travel time and tsunami model computations can also be performed
and displayed through the EarthVu interface. Tsunami travel time results are displayed on an EarthVu map. The tsunami model computation technique
is described in Kowalik and Whitmore (1990). EarthVu acts as a graphic
interface where model areas are specified and results are displayed. EarthVu also displays pre-computed model results and
provides a method to scale the results based on recorded tsunamis during a
warning. This technique is discussed
further in Section 4.3.1.
References
Kowalik, Z. and P.M. Whitmore (1991). An investigation of two tsunamis
recorded at
Lander, J.F. (1996). Tsunamis Affecting
Lander, J.F., P.A. Lockridge, and M.J. Kozuch (1993). Tsunamis Affecting
the West Coast of the United States 1806-1992, NGDC Key to Geophysical
Record Documentation No. 29, NOAA, NESDIS, NGDC, 242 pp.