The first sample of data from the MOBB seismometer was downloaded through the ROV serial connection on 22 April 2002. This was 10 days after the sensor was completely installed (Julian day 101). The first few days, the temperature within the sensor housing rose several degrees, but then stabilized. Then the sensor began to settle and the mass weights slowly shifted over time (See Figures 1-3).
From the horizontal component mass position drift behavior, it appeared that the pressure vessel was settling and tilting toward the southwest. The sensor was recentered during our second visit to the site (April 22, 1997).
Figure 1: Vertical component mass position
Figure 2: North component mass position
Figure 3: East component mass position
Figure 4: Local earthquake data
Figure 5: Earthquake data off the coast of Mexico