Horizontal Electrometer Pressure Inverted Echosounder V16

HPIES on seafloor at Axial Base
HPIES on the Deck of the RV Thompson

The HPIES instrument awaits deployment on the aft deck of the R/V Thompson during Leg 2 of the VISIONS'15 cruise. Credit: Alex Jamsedi, Western Washington University; V15.

HPIES Deployed At Axial Seamount

The HPIES instrument is being lowered over the side of the R/V Thompson for installation at the base of Axial Seamount. The HPIES (Horizontal Electrometer Pressure Inverted Echosounder) measures the horizontal electrical field, the bottom pressure, and the acoustic travel time from the seafloor to the sea surface to characterize the properties of the water column.

The Horizontal Electrometer-Pressure-Inverted Echosounder (HPIES) is an instrument that utilizes a bottom pressure sensor, a 12-kHz inverted echosounder and a horizontal electrometer to measure the horizontal electrical field, the bottom pressure, and the vertical acoustic travel time from the sea floor to the sea surface. These properties provide insights into the vertical structure of current fields and water properties including temperature, salinity, and specific volume anomaly, separation of sea surface height variation and temperature, and near-bottom water currents.

During VISIONS '14, two HPIES were installed, one at Axial Base (LJ03A) and one at Slope Base (LJ01A).