Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 2342

Statistical analysis of factors affecting landslide distribution in the new Madrid seismic zone, Tennessee and Kentucky Statistical analysis of factors affecting landslide distribution in the new Madrid seismic zone, Tennessee and Kentucky

More than 220 large landslides along the bluffs bordering the Mississippi alluvial plain between Cairo, Ill., and Memphis, Tenn., are analyzed by discriminant analysis and multiple linear regression to determine the relative effects of slope height and steepness, stratigraphic variation, slope aspect, and proximity to the hypocenters of the 1811-12 New Madrid, Mo., earthquakes on the...
Authors
R.W. Jibson, D. K. Keefer

A direct method for calculating instrument noise levels in side-by-side seismometer evaluations A direct method for calculating instrument noise levels in side-by-side seismometer evaluations

The subject of determining the inherent system noise levels present in modem broadband closed loop seismic sensors has been an evolving topic ever since closed loop systems became available. Closed loop systems are unique in that the system noise can not be determined via a blocked mass test as in older conventional open loop seismic sensors. Instead, most investigators have resorted to...
Authors
L. Gary Holcomb

An introduction to quiet daily geomagnetic fields An introduction to quiet daily geomagnetic fields

On days that are quiet with respect to solar-terrestrial activity phenomena, the geomagnetic field has variations, tens of gamma in size, with major spectral components at about 24, 12, 8, and 6 hr in period. These quiet daily field variations are primarily due to the dynamo currents flowing in the E region of the earth's ionosphere, are driven by the global thermotidal wind systems, and...
Authors
W.H. Campbell
Was this page helpful?