Escaping from Typhoon Saomai, the JOIDES Resolution sailed southwest past Guam beginning 1015 hr (UTC + 10 hr) on 5 September. The destination was an unnamed seamount located at 12°57´N, 143°37´E near the Mariana Trough spreading center axis. Arriving near the site at 1950 hr, we conducted a short survey of the volcano using the 3.5- and 12.0-kHz echo sounders and magnetometer. The survey was completed at 0000 hr on 6 September, and the ship was positioned over the volcano summit, the thrusters were lowered, and a beacon was dropped to establish Site 1182.
A bottom-hole assembly (BHA) with the hammer drill was made up and run down to the seafloor with the VIT/subsea TV camera. By 0745 hr, the seafloor was in view on the TV screen and a short survey of the seafloor was done. The bottom appeared to be the rough surface of a submarine lava flow with typical pillow structures and debris. Roughness appeared to be on the order of 1 m in most places.
Hole 1182A was initiated at 0845 hr at a depth of 2878 mbrf and drilled to 2 mbsf (Table T2). The drill string was pulled clear of the seafloor 15 min later and moved 5 m. From 0915 to 0930 hr, Hole 1182B was drilled to 1.5 mbsf, also beginning at 2878 mbrf. Both holes were drilled with the VIT camera in place to observe the progress of the drill bit, but this meant that no rotation was possible. The VIT/subsea TV camera was recovered and Hole 1182C was drilled from 1045 to 1345 hr, beginning at 2878 mbrf and penetrating to 5 mbsf. The VIT/subsea TV camera was again lowered to check the drilling results. After offsetting 20 m north, Hole 1182D was spudded at 1530 hr and drilled to 1 mbsf, beginning at 2877 mbrf. The VIT/subsea TV camera was recovered and drilling in Hole 1182D was continued. Soon rotation was lost and increasingly more weight was required to cause the hammer to actuate. The BHA was worked free at 1825 hr and tripped back to the rig floor to check the hammer.
By 0030 hr on 7 September, the hammer was back on the rig floor and found to be in good condition. The bit was changed, and the drill string, along with the pulsation sub, was tripped back to the seafloor with the VIT/subsea TV camera. After another short reconnoiter of the seafloor, Hole 1182E was spudded at 1030 hr and was drilled to 4.5 mbsf, from 2870 mbrf. Moving 5 m north, Hole 1182F was started at 2872 mbsf and drilled to 7 mbsf, from 1130 to 1345 hr. Following another 5-m offset, Hole 1182G, the final spud test, was started at 1530, from 2873 mbrf. Penetration was 5 mbsf.
The drill string was tripped back to the seafloor; the BHA cleared the rotary table at 0215 hr on 8 September. After cleaning up the rig, thrusters were raised and the JOIDES Resolution made way to Guam, arriving at 1400 hr on 8 September, bringing Leg 191 to a close.