ROFFS� - schaudt.us OCEANOGRAPHIC ANALYSIS
FOR THE PGS Seismic Monitoring in the Gulf of Mexico

Due to scattered cloud cover today, we have used a combination of satellite imagery from the past 24-36 hours to complete today’s analysis. We have shown the seismic study work site in pink, the observed direction of surface currents from the sst° imagery in blue, observed direction and speed of surface currents from ADCP buoys and rigs in red, sea surface temperatures in black with white highlights, and water mass boundary zones in black. Arrows showing the direction of flow of the surface currents in blue indicate current direction only. There is no association between arrow length and current speed with the blue arrows.  The red arrows are ACTUAL measurements (speed and direction) of currents from ADCP buoys and rigs.  Sizes of the arrows are directly proportional to the speed of the currents in these areas.
Overall, we continue to observe a large counter-clockwise rotating eddy feature centered just southwest of the study area near 93°29’W & 26°30’N that appears to be pulling relatively warmer (73.4°F-74.3°F-75.3°F) water in a northwestward direction over the western portion of the study area. With the size and rotation of this eddy, we expect currents associated with it to be between 0.7-1.5 knots and we expect this motion to continue at least for the next three days; however due to a second counter-clockwise rotating eddy feature centered south of the study area and the chart area this eddy has moved approximately 7 miles southward over the past 48 hours.  We expect this southward motion to continue suggesting that currents may begin to ease within the study area 3-5 days in the future depending on what occurs with the feature located just to the southeast of the study area. Today, the small counter-clockwise rotating eddy that was forming near 92°30’W & 26°45’N on Friday appears to have blended with the surrounding waters due to its small size and the influence of the larger eddy located southwest of the study area.  The observed rig measurements have confirmed that there is a current division (northwestward to east/southeastward) along the survey line stretching from approximately 92°35’W & 26°30’N to 92°00’W & 27°08’N.  This division of currents is likely due to the combined influences of the large counter-clockwise rotating eddy centered southwest of the chart area and a third, clockwise rotating, eddy centered southeast of the chart area near 91°55’W & 26°33’N today.  This has been confirmed from BOTH the rig/ADCP measurements AND the actual high resolution satellite imagery.   Northwestward of these features (north/northwest of the study area) we observed a general west/northwestward flow of the relatively warmer (73.4°F-74.3°F) water west of approximately 92°30’W.  East of 92°30’W it appears as if another eddy located north/northeast of the study area and circulating in a clockwise direction is having an effect on the currents and we have observed westward and then northward motion of the currents towards the center of this feature.  This has been confirmed from the rig/ADCP measurements shown in red.
This analysis is updated Mon/Wed/Fri. We will continue to monitor these conditions daily and report any immediate change in circulation that will affect the work site.

Intermediate updates are issued when the situation warrants and if information is available.