News! February 2009. gPhones measure anomalously large seismic noise, even when physically separated by over 1000 km. Click here for details.
News! July 2008. Two gPhones demonstrate high corrleation even during quiet periods. Click here for details.
News! May 2008. Six Micro-g Lacoste gPhone Gravity Meters capture the 12 May 2008 Sichuan, China Earthquake with extremely high correlation.
News! January 2007. Micro-g
LaCoste gPhones capture two different Japanese earthquakes
in Colorado, USA and Walferdange, Luxembourg.
Micro-g LaCoste is proud to introduce the gPhone
gravity meter (previously known as the Portable Earth Tide, or
"PET" meter) as the latest member of its land gravity
meters. The gPhone gravity meter is based upon the LaCoste and
Romberg technology that has dominated land gravity meters
since 1939. The gPhone gravity meter has a low drift so that
it can be used to integrate periodic signals (like earth
tides) for very long time periods (years). The gPhone also has
excellent high frequency response so that they can be used to
monitor higher frequency non-periodic events such as
earthquakes. The gPhone can be coarse-ranged over
7000milliGals (worldwide), and has a ±50 milliGal dynamic
range during measurement.
The versatile gPhone gravity meter has a
sophisticated data acquisition system synchronized by a
rubidium clock that can be locked to GPS so that arrays of
gPhones can be used to give a wider area picture of seismic or
long period gravity changes due to subsurface density
changes. The instrument can be monitored and controlled via
the internet for remote operation.
The principle behind Micro-g LaCoste's gPhone is the
patented L&R zero-length spring suspension system. The gPhone
is based upon the G-Meter, but with significant upgrades: It
has an improved thermal system - a double-oven - for more
precise temperature stability. The instrument also has a true
vacuum seal so that it is completely insensitive to buoyancy
changes due to atmospheric changes. Full force feedback on the
sensor allows for 0.1 microGal resolution.