Department of Physics, Engineering Physics & Astronomy

Department of Physics, Engineering Physics & Astronomy
Department of Physics, Engineering Physics & Astronomy

Departmental Colloquium - Spatio-temporal monitoring of gravity

Alexander Braun
Queen's Geology

Date: Friday September 28th, 2018
Time: 1:30 p.m. 
Location: 
Stirling A

Abstract:

Gravimetry is one of the classical geophysical exploration methods used to probe the subsurface of the Earth (or planets) for its density distribution. Gravimetry has been performed on platforms including people, terrestrial vehicles, ships, aircrafts, and satellites. This talk will feature a number of new developments in gravimetry which are enabled by either new platforms or new sensor technology. In the past, most of the applications of gravimetry were focused on static mapping gravity anomalies in an area of interest, however, with the launch of the GRACE satellite mission, temporal changes in gravity have become a new topic of interest. GRACE observations have shown details about the global water cycle, sea level change and even tectonic processes and earthqakes. However, the spatial resolution of GRACE products is limited to a few hundred kilometres, which only allows for  continental scale applications. In 2010, a new field operable superconducting gravimeter (iGrav) was developed, which superceeds the sensitivity of current field realtive gravimeters by 2 orders of magnitude. This instrument is sensitive to approximately 0.05 microGal (5*10^-10 m/s^2) which enables new applications including reservoir monitoring (oil, gas, water). We will present a number of new applications which exploit the new sensitivity level of those instruments. Of the ~30 instruments world-wide, Canada hosts two iGravs with one located at Queen's.