Weather: Moving to Port of Nakagusuku, Okinawa
Location: Site C0016 (N 27° 47.45' E 126° 53.78', 998.8mMSL)
The transponders are up and the ship is moving to Okinawa. The lab is winding down and the Science Party is busy finalizing their shipboard reports. We will meet with the pilot in the early morning of October 4, ending the Expedition and leaving the ship by 09:00.
Weather: Fine but Cloudy
Location: Site C0016 (N 27° 47.45' E 126° 53.78', 998.8mMSL)
The final core from C0016B came back with little recovery, similar to the previous two cores. And similar to the previous cores, the material we got is quite interesting. The final core is subject for last-minute measurements and the final Sampling Party as the lab and rig operations are demobilizing.
The transponders used for the DP system was picked up by midnight, and we are ready to head to shore.
Weather: Cloudy
Location: Site C0016 (N 27° 47.45' E 126° 53.78', 998.8mMSL)
Some hard decisions had to be made today, the end result being that we are aiming for a total of 45 m penetration into Hole C0016B with the conventional coring system. The return of today’s effort was just 31 cm of core, but similar to yesterday, the material was quite interesting and could not have been recovered by other means. We are therefore returning for another 18 m of penetration tomorrow, reducing the planned casing operation to just planting a cap on the guide base for an ROV to land on in the future.
Weather: Cloudy
Location: Site C0016 (N 27° 47.45' E 126° 53.78', 998.8mMSL)
Last HPCS core from C0017D came up with very little sediment after just 1 m advance. But it brought the one thing we really were after: A temperature reading from the bottom of the Hole. We could therefore feel satisfied as we tripped pipe and left to return to the Guide Base at C0016. There, we ran into C0016B with the conventional coring assembly and recovered around 0.7 m of hard sulfides and sulfates from a 9-meter advance, after washing away the overlaying fine soft mud.
Weather: Fine but cloudy
Location: Site C0017 (N 27° 47.50' E 126° 54.72', 1129.5mMSL)
The formation in Hole C0017D has become sticky to the point where HPCS coring is getting problematic. Surprisingly, switching to ESCS gave very good recovery of the firm mud. Receiving a temperature measurement from the bottom of this hole was deemed important enough to attempt unguided reentry, which was done successfully. By midnight, we were ready to shoot a final HPCS core with APCT-3 and thermal stickers, after the reentry into C0017D.
Weather: Fine but cloudy
Location: Site C0017 (N 27° 47.50' E 126° 54.72', 1129.6mMSL)
First half of the day had great recovery from C0017D, coring dark silty muds with black and coarse volcanic layers, getting good temperature measurements as we cored with HPCS. However, halfway through the day recovery dropped to near zero as we encountered what seems to be a thick layer of loose volcanic rubble. We are now trying to continue with the ESCS assembly.
Weather: Fine but cloudy
Location: Site C0017 (N 27° 47.50' E 126° 54.71', 1129.6mMSL)
After tripping pipe from the INH-1C Guide Base, we moved to INH-6B to core the recharge zone for the hydrothermal system. The sediment there seems to be cool unaltered pelagic mud, and would be easy coring if it wasn’t for the current getting stronger. The current vibrations have given us some equipment issues, but nothing insurmountable.
Weather: Fine but cloudy
Location: Site C0016 (N 27° 47.45' E 126° 54.80', 982mMSL)
Coring at C0016A did not go well. The bit went into the mount we wanted to sample with ease, but must have turned as we cored. When we pulled out, the barrel snapped after a couple of spikes of overpull. We ended up with recovered no core. After that, we set the third and last Guide Base near the foot of the mount. We will return to that as the final site after coring recharge zone Site INH-6B.
Weather: Fine but cloudy
Location: Return to Site C0014 (N 27° 47.41' E 126° 54.04', 1060mMSL)
Since coring has paused while we do the capping and casing operations at C0014G, today has been a good time to discuss the plans after we core at INH-1D. We also began the third onboard Sampling Party, to clean out the core lockers before the large-diameter cores arrive.
Weather: Fine but cloudy
Location: Return to Site C0014 (N 27° 47.41' E 126° 54.04', 1060mMSL)
The last few cores from C0014G came up with no recovery and with no penetration, so we moved back to C0013 to use the last few aluminum liners to get some intact cores from there. Penetration was not good there either, and as we pulled out of the hole to prepare for the next casing run, we found the bit to be severely damaged. It is time to move to the final sites, and the Science Party will have a meeting to decide how to best fill the last week or so of the operation.
Weather: Fine but cloudy
Location: Return to Site C0014 (N 27° 47.41' E 126° 54.04', 1060mMSL)
We have cored about as deep as we can go in Hole C0014G in the time we have available, as the coring assembly is deteriorating in the hot and corrosive environment. We are getting back-flow through the bit, indicating that the seals are gone. Recovery is dropping, as there are no flow-control valves to stop drill-mud from washing the core out anymore. The formation is still indurated clays, volcanic material altered to a point where it is hard to tell whether we are drilling through sediment or basement. When we get done, we will return to C0013 and spend the last few 2-1/2-inch aluminum core liners getting another Hole there. Then we will case and cap C0014G.
Weather: Fine but cloudy
Location: Return to Site C0014 (N 27° 47.41' E 126° 54.04', 1060mMSL)
We have cored C0014G to about 100 m, by now through indurated grey clay hard enough to hinder the use of the HPCS assembly. Luckily, the punch coring system, EPCS, mostly works like a charm. We will continue using that until we run out of aluminum liner or the formation gets hard enough to switch to the industrial coring system.
Weather: Fine but cloudy
Location: Return to Site C0014 (N 27° 47.41' E 126° 54.04', 1060mMSL)
Returning to C0014 with Al liner for the IODP-sized coring systems has been a success. Core has been coming at a good rate, keeping the labs busy. Using Al liner does cause some issue for the labs, as we have no standards for MSCL measurements of that type. Also, minimizing non-circulation time for the ESCS coring system, which still needs plastic liner, have so far hindered melting even when temperatures in excess of 210 °C have been recorded. Progress is slow, but we are within schedule and core quality is good.
Weather: Fine but cloudy
Location: Return to Site C0014 (N 27° 47.41' E 126° 54.04', 1059mMSL)
Most the day was spent standing by for R/V Natsushima to finish operations on Site C0013 and INH-1. We took the opportunity to catch up on report writing and held a second sampling party, to relieve the inside core reefers and get core brought to the core containers. By evening time, we returned to coring operations. First hole was a test of the new aluminum liners at C0014F. After that, we entered the Guide Base at C0014 and began coring the main hole.
Weather: Fine but cloudy
Location: Crew change at Nago bay
Today we had crew change at Nago bay, three shuttles ferrying 66 people off the ship and 64 on. We also received a wider range of drill bits, aluminum liner for the IODP-size coring systems, and much needed lab supplies. This lull in operations is being used to catch up on sample processing and report writing.
Weather: Fine but cloudy
Location: Site C0015 (N 27° 47.66', E 126° 53.49', 885mMSL)
The weather today is expected to deteriorate, with maximum wave height of 3-4 m and strong winds. We are leaving anyway, heading for crew change and resupplying in Nago Bay, Okinawa. However, first we finished the drilling we wanted to do outside the Guide Base at Site C0014 and went to contingency site INH-11A to shoot a few cores nearer the hydrothermal vent system. However, there we encountered the hard, altered layer at only 9 mbsf. Our formation temperature tool, the APCT-3, has worked like a charm at C0014, recording a very steep temperature profile for the upper 20 meters or so below sea floor.
Weather: Fine but cloudy
Location: Site C0014(N 27° 47.41', E 126° 54.04', 1059mMSL)
Site C0014 is proving to be the site that may allow us to fulfill the objectives of this expedition. The coring has been going smoothly for the first 40 m or so, recovering very gassy pelagic mud before hitting the hot and altered zone much deeper than at C0013. This also means that with our very ambitious whole-round sampling plan for porewater geochemistry and microbiology, the lab is working frantically to keep up with the core flow. At the end of the day we decided we have done as much as we could outside the Guide Base, and started moving to contingency site INH-11A to get a few cores close to the hydrothermal vent area. Tomorrow we will finish coring there, and move to Nago Bay for crew change, storm shelter, and to pick up aluminum liner for the HPCS assembly.
Weather: Fine but cloudy
Location: Site C0014 (N 27° 47.41', E 126° 54.04', 1059mMSL)
We arrived at INH-5D and set guide base during the early hours. The sea floor is softer than Site C0013, with a nearby clam colony and some diffuse fluid flows suggesting hydrothermal activity. Breaching the mudline with HCPS at 10:57 today officially turned this site into C0014. Hole A came off to a poor start, however, with splintered core liner and technical issues that required a trip to recover the core.
Meanwhile, we have begun a series of lab tours for the crew, who will hopefully see labs with scientists busy processing samples. By night time, we began coring C0014B from the mudline, so far with more success.
Weather: Fine but cloudy
Location: Site C0013 (N 27° 47.41', E 126° 53.85', 1035mMSL)
Sea is still dead calm, although the sky is darkening. Today saw the completion of the casing and capping operation, and we are now moving to Site INH-5D - soon to become C0014. We are also keeping a watchful eye on a tropical depression to the south of us, which looks to be heading to Taiwan.
Weather: Fine but cloudy
Location: Site C0013 (N 27° 47.41', E 126° 53.85', 1035mMSL)
The last few coring runs came back with little or no core. We decided to finish this hole by casing and capping, and move on to next site.
The lab suffered a minor setback as our ball mill broke down. The Chief Mechanic and his team went straight on the case and had it checked over and back to working in very little time. We are now just waiting for a welder to make us a new cover plate for it. Meanwhile, powdered samples are being prepared the old fashion way: Hand-ground in mortars with pestles. Tonight we will begin the first onboard sampling party, laying out all cores from Site C0013 for flagging.
Sampling will happen tomorrow before noontime.
Weather: Fine but cloudy
Location: Site C0013 (N 27° 47.41', E 126° 53.85', 1035mMSL)
Today we switched to the conventional coring system with a diamond bit and 4-inch diameter aluminum casing. This required a switch of configurations, parameters and standards of relevant lab equipment. It also required a change of core cutting area from our regular station on the Lab Roof Deck to the temporary station set up aft of the derrick. This switch in core flow has been rehearsed and worked well.
Although we only recovered 2 meter of core, this was whisked off to the labs smoothly.
Weather: Fine but cloudy
Location: Site C0013 (N 27° 47.41', E 126° 53.85', 1035mMSL)
Run HPCS/ESCS/EPCS core, cut core at the main hole of C0013E. Pull out and run conventional coring assembly. Core has been flowing somewhat unevenly as we have had a hard time getting the liners out of the barrels, and recovery has been poor. But we are in the Guide Base now, coring Hole E which proves to be yet another different hole despite its closeness to the other hole. The Iheya hydrothermal system is proving to be very complex even here, 140 m from the nearest actual vent.
Weather: Fine but cloudy
Location: Site C0013 (N 27° 47.41', E 126° 53.86', 1034mMSL)
After the difficulties getting core yesterday, we are finally getting sediment back to surface. We are also getting H2S in copious amounts from below the hard layer that stopped us yesterday. While we have a lot of problems with warped and melted inner tubes, we are trying to bag H2S rich sections for fast-track sampling while the rest of the core is venting to safe levels. The issues getting core out of the barrels have at times made core flow quite difficult.
Weather: Fine but cloudy
Location: Site C0013 (N 27° 47.41', E 126° 53.85', 1035mMSL)
Make up and run HPCS/ESCS coring BHA. Position vessel east of Guide Base and confirm position with co-chief scientist. Take temperature survey at sea floor. Attempt to pressure up to fire core, unsuccessfully. Inner barrel slid to sea bed and start slow pumping to push inner barrel into sea bed, but inner barrel bent at 8.5 m marker on barrel and snapped. Pull out the core assembly, and run it again in the hole. Cut EPCS core to 9 meters below seafloor at C0013B successfully. Continues coring.
Weather: Fine but cloudy
Location: INH-4D (N 27° 47.4157', E 126° 53.8546', 1035mMSL)
Dive ROV and deploy transponders. Move vessel to the proposal site and sea bed survey. Find marker and decide INH-4D from seabed condition.
Position hard seabed guidebase to well center, move vessel 2 miles upstream of INH-4D. Set hard seabed guide base. A nice high pressure is keeping tropical depressions at bay while we are having the last ampling meetings before spud-in. The first samples are coming in already, of the drill mud for the microbiologists and geochemists to check contamination against.
Weather: Fine but cloudy
Location: Transit to Okinawa Trough, arrive at site.
Arrive at SW 1 mile from the site. Drift vessel and lower 1C Azimuth Thruster. Set DP mode. After that, we will set transponder, site survey by ROV, and set Guide Base.
Weather: Fine but cloudy
Location: Transit to Okinawa Trough
Transit to Okinawa. Weather is great with a nice breeze, scattered clouds and hardly any swell at all. We are doing good speed, almost 10 knots most of the time. Lab preparations are ramping up, keeping everybody busy for the upcoming arrival of core.
Weather: Fine but cloudy
Location: Transit to Okinawa Trough
We are in transit to Okinawa. Pick up and make up BHA and HPCS/ESCS outer core barrel. Weather is good with scattered clouds and a slight, long swell. The science party was taken on tours of the rig facilities and continued meetings and training for the upcoming core handling.
Weather: Fine but cloudy
Location: Port of Shimizu
Chikyu left Shimizu Port this morning at 0830hrs, heading towards Okinawa in great weather and a long swell. Meanwhile, prepare HPCS/ESCS inner barrels and large-diameter coring equipment. The
onboard curator and publication assistant held presentations for the science party as well.
Weather: Fine but cloudy
Location: Port of Shimizu
Today was taken up by many meetings of the discipline groups in the science party, as well as by the Pre-Spud Meeting. After the Pre-Spud Meeting, the discipline groups met with lab techs and Lab Officer to discuss more in detail about measurement procedures.
Weather: Cloudy
Location: Port of Shimizu
First general science meeting was held with talks by Ken Takai, Jun-ichiro Ishibashi and Gordon Southam. This lead to vigorous discussions about the upcoming science expectations. The make-up of
the four major science teams (Microbiology, Geochemistry, Sedimentology/Petrology and Physical Properties) was presented and shift schedule agreed upon. Over the next few days, we will discuss
within these groups the final details of the onboard measurement plan in consultation with Lab Officer and Curator.
Weather: Fine but cloudy
Location: Port of Shimizu
5 science party members received basic H2S contingency training, to be able to work on deck while the aluminum-lined 4-inch cores are being cut. CDEX staff introduced the onboard IT system, and the science party was given a tour of the lab decks, roughly following the planned core flow.
Weather: Fine but cloudy
Location: Port of Shimizu
After congregating in the port city of Shimizu the day before, the Expedition 331 Science Party boarded Chikyu at 14:00. Safety induction, cabin assignment, as well as generally getting settled in and getting familiarized with the ship, took up the rest of the day.
