Sean-Thomas Morrissey, 1942-2002

Morrissey spent all of his student and professional years at SLU. He obtained his bachelor's degree in philosophy with majors in mathematics, literature and education in 1964.

He joined the department of earth and atmospheric sciences in 1969. He was hired by William Stauder, S.J., to install a strain-meter intended to measure Earth tides in a mid-continent environment. The National Science Foundation funded the instrument, which through Morrissey's work, became the first of its kind to operate successfully in the central United States. Its sensitivity exceeded all other strain-meters that were operational at the time. The project was the first of many seismological and Earth-deformation instrumentation endeavors that Morrissey pursued during a 30-year period.

Later projects included the establishment of a telemetric prototype for stations of the worldwide network of seismographs operated by the U.S. Geological Survey; the creation of the first telemetered network to monitor micro-earthquakes in the New Madrid seismic zone; the development of workable instruments to measure small tilts of the Earth produced by earthquakes or volcanoes and their precursors; and the installation of the first fiber-optic broadband low-noise seismographic station at Cathedral Cave in Onondaga State Park in Leasburg, Mo.

Morrissey's skill with instruments in the field attracted much attention from both the seismological and geodetic communities, and he was invited to participate in several cooperative projects in the United States and abroad. These included the operations of seismographs and tilt-meters in Adak, Alaska; participation in a USA-USSR exchange program on earthquake prediction and induced seismicity in Soviet Asia where he helped install and operate various seismic instrument arrays; and the installation of a seismic network on Aegean Sea islands in cooperation with the University of Colorado. In California, he developed improved techniques for the installation of tilt- and strain-meters for the U.S. Geological Survey and in cooperation with the University of California at San Diego.

In recent years, Morrissey developed a new leaf-spring seismometer suspension system that allowed him to build seismometers from parts obtained at a local hardware store yet it rivaled state-of-the-art expensive high-precision instruments in their sensitivity. He also developed a new type of tilt-meter that is insensitive to lateral ground movement. This instrument holds the promise of significantly improving the quality of tilt data in places such as sides of volcanoes or tectonically active regions where lateral ground motion is also severe. The tilt-meters could be co-located with seismometers, allowing seismic data to be corrected for tilt, which often degrades long-period seismic data.

Morrissey was friendly and helpful and formed lasting friendships with many SLU graduate students and scientific colleagues. He was generous with his time when people needed help and often could be found patiently explaining difficult instrumentation concepts with clarity and enthusiasm.

Morrissey is survived by his mother, seven sisters, a brother, and nieces and nephews. He was talented, innovative, warm and broad in his interests -- a unique personality who will be sorely missed by many friends and colleagues.

A memorial Mass will be held at 3:30 p.m. Wednesday, April 10, at St. Francis Xavier College Church, 3628 Lindell Blvd. Memorials may be made to the Sean-Thomas Morrissey Research Fund In Earth Sciences at Saint Louis University.

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