HR: 0800h
AN: ED31B-1208 [Abstracts]
TI: Gravity and Magnetic Survey of Southern Oklahoma Alcugen in Texas Panhandle, Near the 2000 earthquake
swarm North of Amarillo
AU: * Manns, S
ED31B-1208
AF: Texas Tech University, Dept of Geosciences
Texas Tech University, Lubbock, Tx 79409
United States
AU: Gurrola, H
EM: Harold.Gurrola@ttu.edu
AF: Texas Tech University, Dept of Geosciences
Texas Tech University, Lubbock, Tx 79409
United States
AU: Robinson, R
ED31B-1208
AF: Texas Tech University, Dept of Geosciences
Texas Tech University, Lubbock, Tx 79409
United States
AU: Horton, M
ED31B-1208
AF: Texas Tech University, Dept of Geosciences
Texas Tech University, Lubbock, Tx 79409
United States
AU: Herrmann, M
ED31B-1208
AF: Texas Tech University, Dept of Geosciences
Texas Tech University, Lubbock, Tx 79409
United States
AU: Seshhadri, S
ED31B-1208
AF: Texas Tech University, Dept of Geosciences
Texas Tech University, Lubbock, Tx 79409
United States
AU: Anderson, H
ED31B-1208
AF: Texas Tech University, Dept of Geosciences
Texas Tech University, Lubbock, Tx 79409
United States
AU: Bribiesca, E
ED31B-1208
AF: Texas Tech University, Dept of Geosciences
Texas Tech University, Lubbock, Tx 79409
United States
AU: Lindsey, C
ED31B-1208
AF: Texas Tech University, Dept of Geosciences
Texas Tech University, Lubbock, Tx 79409
United States
AU: Montalvo, R
ED31B-1208
AF: Texas Tech University, Dept of Geosciences
Texas Tech University, Lubbock, Tx 79409
United States
AU: Cyrek, C
ED31B-1208
AF: Texas Tech University, Dept of Geosciences
Texas Tech University, Lubbock, Tx 79409
United States
AU: Allen, T
ED31B-1208
AF: Texas Tech University, Dept of Geosciences
Texas Tech University, Lubbock, Tx 79409
United States
AU: Hoemberg, J
ED31B-1208
AF: Texas Tech University, Dept of Geosciences
Texas Tech University, Lubbock, Tx 79409
United States
AU: Hassan, A
ED31B-1208
AF: Texas Tech University, Dept of Geosciences
Texas Tech University, Lubbock, Tx 79409
United States
AB:
The Texas panhandle is not a region normally thought of as being prone to seismic activity. Earthquakes with magnitudes of 3
to 4 do however occur in this region every year or so and are felt by residents in the area. There are historical reports
of earthquakes of magnitude 5 during the early twentieth century. The earthquakes in this region are most likely associated
with displacement on old faults related to the Southern Oklahoma Aulacogen (SOA, 600 Ma) which was deformed during the
Ouachita orogeny to form the Wichita Mts.
During the summer of 2000 there were an unusually large number of earthquakes for this region, five, all from the same
location a few kilometers north of Amarillo Texas, 35.39 degrees north latitude and 101.81 degrees west longitude according
to the NEIC catalogue. The non-seismic exploration class at Texas Tech University collected and interpreted gravity and
magnetic data along a dirt road crossing the location of this earthquake "swarm" (yes in Texas 5 is a swarm) to determine if
the old faults of the SOA coincide with the location of these earthquakes.
The survey was conducted along a service road of the Santa Fe Railroad that crosses US 87 approximately 20 miles north of
Amarillo, Texas trending in a south-southwest direction. Gravity data were collected every 100m along a 5 km profile using
Warden and Lacoste gravity meters with elevation control provided by leveling survey tied to elevation markers on the map.
Gravity data were colleted, using GPS elevation location and elevation, on roads over more than 20 km surrounding the local
survey to provide regional control. Magnetic data were collected along the 5 km profile.
Models derived from these data indicate a 200 m thick layer of poorly consolidated sediments with densities of 2.0 g/cc that
can be interpreted as the Ogallala aquifer overlaying a layer with density of 2.6 g/cc. The interface between these layers
is very structured and has at least three sharp ridges that we interpret as faults with as much as 50 meters of offset along
this interface that could only be interpreted as offset on faults in the Wichita prior to their erosion and burial. We are
planning additional work related to this project to use electrical methods (EM34 and GPR) to determine if there is offset in
shallower layers that would indicate more recent seismicity.
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DE: 0800 EDUCATION
DE: 0810 Post-secondary education
DE: 0825 Teaching methods
DE: 0840 Evaluation and assessment
DE: 0845 Instructional tools
SC: Education and Human Resources [ED]
MN: Fall Meeting 2005