Axial volcano and NeMO Net, click for full size map

The NeMO Net system uses acoustic modems to relay data from seafloor instruments to a buoy at the surface, which in turn sends the data to NOAA's Pacific Marine Environmental Laboratory via satellite. In 2004-5, two instruments on the seafloor will be linked into NeMO Net: a Remote Access Sampler (RAS) in the ASHES vent field, and a Bottom Pressure Recorder (BPR) near the center of the caldera. The map above shows the locations of the instruments and the NeMO Net buoy. The plots below show some of the latest data that has been transmitted from the seafloor.

UPDATE: A NEW NEMO NET BUOY WAS DEPLOYED ON SEPTEMBER 26, 2004, AND IS NOW COMMUNICATING WITH A NEW RAS INSTRUMENT ON THE SEAFLOOR. A REPLACEMENT BPR WAS ALSO DEPLOYED, BUT HAD TO BE RECOVERED AFTER DATA TRANSMISSION PROBLEMS WERE DISCOVERED. THE BPR WILL BE REPAIRED AND REDEPLOYED AS SOON AS POSSIBLE.

3-days with tides |  All Data with tides 3-days without tides |  All Data without tides

2003-2004 BPR was located near the center of Axial caldera, and precisely measured the pressure of the overlying ocean, as a way to monitor for inflation or deflation of the volcano. The raw BPR data (purple) closely follows predicted ocean tides (black). But after subtracting the tides from the BPR data, the difference (red) shows any sudden changes in seafloor height which may signal the onset of an eruption at the volcano. Three days of pressure data and the cumulative data are displayed in separate plots, with and without tides.