IODP Expedition 340T

Atlantis Massif Oceanic Core Complex APL

Daily Science Report for 2 March 2012

LOCATION: San Juan, Puerto Rico

SCIENCE UPDATE: Arrived San Juan, Puerto Rico at 1150 hrs. All science reports are completed. Successfully completed IODP Atlantis Massif APL Expedition 340T. We completed the logging program at Hole U1309D, carried out a camera survey of the surrounding seafloor, and collected a seafloor sample at nearby Hole U1392A.

Daily Science Report for 1 March 2012

LOCATION: In transit to San Juan, Puerto Rico

SCIENCE UPDATE: The science party met to discuss the full set of preliminary results from downhole logging operations at Hole U1309D and the final expedition report is near completion. Sample and data requests based on the data collected at Sites U1309 and U1392 have been refined and submitted. Lab cleaning is completed. Estimated time of arrival at the pilot station is 0900 hours tomorrow, 2 March.

Daily Science Report for 29 February 2012

LOCATION: In transit to San Juan, Puerto Rico

SCIENCE UPDATE: Today, scientists are preparing text and figures documenting the preliminary results from Sites U1309 and U1392 for the final expedition report. Live videoconferences featuring the ship’s scientists and technical staff are continuing throughout the days of transit. Our transit speed has been favorable since departing Site U1309, with an average daily speed greater than 12 knots.

Daily Science Report for 28 February 2012

LOCATION: In transit to San Juan, Puerto Rico

SCIENCE UPDATE: Scientists are continuing to review results and develop final expedition reports. The technical staff is preparing laboratory instruments and cleaning labs prior to the San Juan port call.

Daily Science Report for 27 February 2012

LOCATION: In transit to San Juan, Puerto Rico

SCIENCE UPDATE: Today, scientists continued to process logging data, discuss results from Holes U1309D and U1392A, and prepare final expedition reports. A live videoconference was conducted with environmental science students from Bonneville High School in Idaho Falls, Idaho. Our transit speed has been faster than expected and the current ETA in San Juan, Puerto Rico is 2 March.

Daily Science Report for 26 February 2012

LOCATION: In transit to San Juan, Puerto Rico

SCIENCE UPDATE: After completing all logging operations at Hole U1309D yesterday, we deployed the camera system for a bottom survey around the site. The survey was designed as a 5-km offset spiral around Hole U1309D that would allow scientists to document the sea floor environment. Following the survey, the ship navigated back to a distinctive mound-like feature that was imaged very close to Hole U1309D. The drill pipe was lowered to the seafloor and a modified Advanced Piston Core (APC) core barrel was run to the bottom in an attempt to collect a sample. Material was recovered in the core catcher and the site was officially designated Site U1392. A magnetometer survey was completed over Hole U1309D and by the early morning of 26 February, we were underway to San Juan, Puerto Rico. Today, scientists began processing the logging data from Hole U1309D and the science party met to discuss preparing results for the final science report.

Daily Science Report for 25 February 2012

LOCATION: Hole U1309D, Atlantis Massif (30°10.12'N, 42°7.11'W, water depth 1656 mbrf)

SCIENCE UPDATE: The sonic tool string that was run into Hole U1309D yesterday evening completed a pass of the deep section of the hole, between 700 mbsf and the bottom of the hole ~1400 mbsf. A full set of sonic data were obtained, including borehole compressional, shear, and Stoneley slownesses (the reciprocal of velocity). The Magnetic Susceptibility Sonde (MSS) tool string, the last run of the logging program for Hole U1309D, was run into the hole this morning. The MSS measures the magnetic susceptibility of the borehole wallrock, which depends on the concentration and composition of magnetic minerals, such as magnetite. This tool is temperature-limited, so the logging run sampled only the cooler, upper interval of the hole down to ~800 mbsf. A repeat pass over ~200 m was also run, to check repeatability in the measurements, and the MSS tool string was run back up to the rig floor. Logging operations for Expedition 340T were complete by 11 am. The drill pipe was pulled back to seafloor and the camera system was deployed for a bottom survey around the reentry cone. We should be performing a crossing magnetometer run over Hole U1309D and then we will get under way to San Juan.

Daily Science Report for 24 February 2012

LOCATION: Hole U1309D, Atlantis Massif (30°10.12'N, 42°7.11'W, water depth 1656 mbrf)

SCIENCE UPDATE: The sonic tool string, which measures acoustic velocity, was run into Hole U1309D shortly before midnight on 23 February. The target interval was the deep section of the hole (>800 mbsf) that was not logged with the sonic tool during IODP Expedition 305. The tool string was unable to pass through the logging bit at ~700 mbsf and was brought back up to the rig floor. The VSI (Versatile Seismic Imager) was run into the hole around dawn for the second phase of a vertical seismic profile (VSP) experiment, which is always carried out during daylight hours. We recorded seismic stations throughout the entire open hole interval, including the deep section where no VSP was carried out during previous expeditions. After modifying a section of the sonic tool string to help it pass through the bottom hole assembly, we tripped pipe back down to ~700 mbsf. The sonic tool string was successfully run into the hole and through the bit in the evening and the run should be complete by early morning on 25 February.

Daily Science Report for 23 February 2012

LOCATION: Hole U1309D, Atlantis Massif (30°10.12'N, 42°7.11'W, water depth 1656 mbrf)

SCIENCE UPDATE: This morning, the camera system was deployed and Hole U1309D was reentered for the second time during the expedition. The first logging run of the day was a vertical seismic profile (VSP) experiment using the Versatile Seismic Imager (VSI). The tool was successfully clamped to the borehole wall at the first testing station, ~100 m below the drill bit, but subsequent attempts to clamp were not successful. We suspected that the caliper arm had been damaged and this was confirmed when the tool returned to the rig floor. A back-up VSI shuttle was substituted into the tool string to replace the damaged one, and the tool was run back into the hole to continue logging. Five stations were recorded before the end of daylight operating hours, when all seismic work must cease. The tool string was brought back up to the rig floor and we are currently tripping pipe to place the bit at ~700 mbsf, in preparation for an overnight logging run with the sonic tool string.

Daily Science Report for 22 February 2012

LOCATION: Hole U1309D, Atlantis Massif (30°10.12'N, 42°7.11'W, water depth 1656 mbrf)

SCIENCE UPDATE: The Triple Combination tool string successfully reached the bottom of Hole U1309D at 3060 mbrf (1404 mbsf), after recording an in situ temperature profile on the way down. A good repeat temperature profile was recorded as the tool string was pulled up from the bottom of the hole at a speed of 1500 ft/hr. Hole size, density, gamma ray, and resistivity were also recorded, showing good agreement with measurements made during IODP Expedition 305 in 2005, the last time this hole was occupied. When the tool string was brought back into the drill pipe to complete the run, it became stuck in the bottom hole assembly (BHA), neither able to exit or to be pulled up completely through the pipe. Unfortunately, it could not be retrieved with the logging wireline and cutting procedures were initiated. The drill string and tool string were successfully recovered, revealing that two sets of centralizers had been damaged during logging and/or pipe reentry. We will continue the logging program in Hole U1309D with the deployment of the Versatile Seismic Imager (VSI).

Daily Science Report for 21 February 2012

LOCATION: Arrived at Hole U1309D, Atlantis Massif

SCIENCE UPDATE: Last night we began positioning over Site U1309. We spent the morning hours making up the drill pipe and running it down toward the seafloor, more than 1600 m below sea level. The camera system was deployed so that we could locate the reentry cone at Hole U1309D, carrying with it the J/aRt "Art Under Pressure" styrofoam sculptures. After surveying along a small grid with the camera down, we identified the U1309D reentry cone and successfully reentered the hole. In the afternoon we began logging with the first tool string, the Triple Combination, measuring density, gamma ray, resistivity, and an in situ temperature profile. We anticipate completing the first tool run by early tomorrow (22 Feb) morning.

Daily Science Report for 20 February 2012

LOCATION: In transit to Site U1309

SCIENCE UPDATE: Scientists, technical and shipboard staff attended a pre-site meeting to, to review the operations plan for Hole U1309D and, if time allows, a short coring program that will follow. Laboratory Officer gave a presentation to scientists and to the technical staff who will be acting as Protected Species Observers (PSOs) during vertical seismic profile (VSP) experiments. We currently anticipate arriving at Hole U1309D tonight, ~2200 h on 20 February, and we hope to begin logging by dawn tomorrow.

Daily Science Report for 19 February 2012

LOCATION: In transit to Site U1309

SCIENCE UPDATE: Scientists completed Part 2 of the ship's tour today, visiting the core tech shop, the engine room, the underway geophysics lab, and the fantail, where the ship's towed magnetometer is tethered. As we rapidly approach Site U1309, the science party continued writing introductory sections of the final science report. In the afternoon, scientists and technical staff met to discuss the potential short coring program that could follow logging operations at Site U1309.

Daily Science Report for 18 February 2012

LOCATION: In transit to Site U1309

SCIENCE UPDATE: Today, scientists were given Part 1 of a ship's tour, including the bridge deck and a visit to the rig floor. The science party met to discuss the format of the final scientific report for the expedition. The ship has been making better time than expected as we transit to our site, traveling at an average speed of more than 12.5 knots. We are exploring the possibility of adding a short coring program to planned work at Site U1309, if we still have time after completing logging operations.

Daily Science Report for 17 February 2012

LOCATION: In transit to Site U1309

SCIENCE UPDATE: Scientists attended a presentation on plans for education and outreach during the expedition, which include live videoconferences with a variety of classrooms and the Art Under Pressure contest. Later in the day, scientists and technical staff participated in the first videoconference of the expedition. Science party and engineers discussed detailed plans for logging operations at Site U1309.

Daily Science Report for 16 February 2012

LOCATION: In transit to Site U1309

SCIENCE UPDATE: Today, the chief scientist presented background and scientific objectives of Expedition 340T to scientists and technical staff. Scientists also received an introduction to the ins and outs of an expedition, including the strategy for producing a detailed scientific report. The science party continued to refine the logging plan for Site U1309, reviewing operational reports from IODP Expeditions 304 and 305 during which the site was initially drilled.

Daily Science Report for 15 February 2012

LOCATION: In transit to Site U1309

SCIENCE UPDATE: The IODP Atlantis Massif Expedition (340T) officially began when we departed Lisbon at 0638 h and began the transit to Site U1309 on the Mid-Atlantic Ridge. We anticipate a ~6.5 day transit to Site U1309. The captain held the first fire and boat drill. Expedition 340T scientists went through introductions and several orientation presentations, including HSE training and a ship tour, while still in port. The science party met to discuss upcoming logging operations.