Appears to be an earthquake. Spike up to ~ .9 um/s in 0.03 - 0.1 Hz seismic band.

USGS:
5.2 magnitude 73km S of Isangel, Vanuatu 2015-10-17 21:02:32 UTC 59.0 km deep

SUS S_R_M saturating (Oct 17 21:32:20 UTC)
SUS E_T_M_Y saturating (Oct 17 21:32:20 UTC)
SUS B_S saturating (Oct 17 21:32:20 UTC)
SUS I_T_M_X saturating (Oct 17 21:32:20 UTC)
Intention Bit: Commissioning (Oct 17 21:32:20 UTC)
ISC_LOCK state: DOWN (Oct 17 21:32:30 UTC)
DRMI Unlocked (Oct 17 21:32:30 UTC)