Gizmos

 

Our understanding of the how the Earth beneath our feet works is horribly limited by the meagre means we have to probe within the Earth. I have spent much of my career trying to develop better methods and instruments to investigate processes in the Earth ‘s interior beneath the vast ocean basins.  I first developed instruments for measuring electromagnetic fields in the oceans. Charles Cox and I also developed the first pressure sensor (DPG) capable of observing long period seismic waves (Rayleigh waves) on the seabed. Seismologists have long used the arrivals from large earthquakes to global seismic networks on land to investigate the Earths Interior, but until about 1994 ocean bottom seismometers OBSs were too limited in their capabilities. My group constructed one of the first fleets of OBSs capable of recording broad band seismic signals on the seafloor for deployments of a year or more. I developed the LDEO OBS fleet which is now part of a NSF funded OBS Pool which provides instruments for seafloor experiments for any US scientist with a successful proposal. (The ELSC experiment is one such experiment). Dr. Andrew Barclay now manages the LDEO OBS Pool. The strong demand for OBSs has produced a several lag between when experiments are funded and when the instruments go to sea, reflecting the importance of OBSs data to understanding the Earth’s interior.


The compliance technique and my recent ventures in marine geodesy are described on other pages in the site. The fidelity of OBS data remains a problem and my group is continuing to develop better means to shield the sensors from the effects of ocean currents, and better methods for measuring pressure and ground motion. Recent developments include the shielded OBS (TRM) for shallow water and the high resolution, high sampling rate absolute pressure gauge (APG)  There are always new instruments and devices (gizmos) under development in the OBS lab. I have had students who have spent much of career developing instrumentation. Such a program can produce a viable PhD, but it can be a long process.