During the North Pacific cruise of the R/V Yaquina in 1966,
total magnetic field intensity was measured in the Andreanof group
of the Aleutian Islands. Three north-south track lines were made
across the Aleutian Trench and ridge between longitudes 175° W
and 180°.
Three small scale magnetic profiles across the trench and
ridge and one large scale profile over the crest of the ridge were
constructed from the data. Total field and anomaly contour maps
were drawn from the profiles. The data reveal:
1. A strong east-west trend of the contours present south of
the ridge but absent north of the ridge which suggests
that the Aleutian ridge is the boundary of two different
magnetic provinces.
2. Large anomalies south of the trench which appear to be
continuous for a distance of about 500 miles. The
anomalies result from shallow structures and are considered
to be ocean floor magnetic lineations.
3. Large anomalies north of the trench which result from
deep-seated structures, probably strongly magnetic intrusions.
4. Short wavelength anomalies on the crest of the ridge which
may result from dike intrusions parallel to the trend of the
ridge.
5. A local magnetic gradient of about 800 gammas after removal
of the regional geomagnetic field. The residual
gradient is "low" over the trench and "high" over the ridge.
The magnetic variation may be related to changes in the
depth of the Curie temperature isotherm. / Graduation date: 1968
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28141 |
| Date | 09 October 1967 |
| Creators | Skorpen, Allan Jerome |
| Contributors | Heinrichs, Donald F. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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