Special Event
Basic Information
Time of Occurrence (GMT): Tuesday August 31, 1999 at 23:03:7.08 Z
Time of Occurrence (PDT): Tuesday August 31, 1999 at 04:03:7.08 PM
Time of Occurrence (PST): Tuesday August 31, 1999 at 03:03:7.08 PM
Depth (km) 3.55
Magnitude (Mc) 3.5
Location 45.1863N 120.0908W
77.8 km E of Maupin, OR
96.2 km ESE of The Dalles, OR
202.0 km E of Portland, OR
Name of data file: 99083123030o
This is an automated web page produced after a
significant earthquake to give essential information about the
earthquake and previous earthquake activity
in the region. This information will be updated as needed.
Detailed Information and Graphics about the Earthquake
Our data base of earthquake hypocenters contains information
from the 19th century to the present.
Included are:
- A map of the Pacific Northwest
showing the location of the earthquake (in red) plus prior earthquakes M > 3.5.
Shallow events are black. Events deeper than 35 km are green.
- A map showing a closer view
of the earthquake and prior historical earthquakes
with magnitude 3.5 or greater.
Shallow events are black. Events deeper than 35 km are green.
- A list of 10 big earthquakes
preceding the mainshock that are closest to it and have a
magnitude greater than 3.5. These are the most significant
historical earthquakes in the vicinity of the mainshock
(see the closer view map above).
- A map showing
the location of the earthquake relative to cities.
- A map showing
the location of the earthquake relative to the nearest
seismograph stations that recorded it.
- A detailed list of all earthquakes
(M > 1.0) that occurred in the vicinity of the special earthquake
in the previous two years. For the locations of these events see
the next map.
- A map of all earthquakes
(M > 1.0) that occurred in the two years prior to the special earthquake.
Detailed area shown is just few kilometers around the mainshock.
- A List of the nearest 20 strong motion sites
Earthquake Mechanism
If sufficient P-wave first motion data are available,
a fault plane determination for the earthquake
will be available in the form of
Moment Tensor Estimates of the Earthquake size may also be available. To see,
check at Oregon State U.
Preliminary Strong Motion Information
Related Information: Most Up-to-Date Local, National, and Global Earthquake Summaries
