Daily Report
Back to Expedition

July 19

Location at 2400 is 37° 56.3'N, 143° 54.8'E Weather: Fine but cloudy

Continue transit to Hachinohe Anchorage point. Arrive at 0830 hrs, anchor set at 0930 hrs. Co-Chief Scientist Jim Mori, science party representative Patrick Fulton, and CDEX observer Emily Brodsky disembarked by a boat around 1100 hrs. At midnight, IODP Exp. 343T was completed.

Here is a message from aboard Co-Chief Scientist Prof. Jim Mori;
Expedition 343T successfully completed the planned operations for drilling a borehole to the plate boundary fault zone and installing the temperature observatory. After being unable to deploy the observatory during the main expedition in April and May, it was a gratifying relief that this was accomplished on the second chance. There was excellent planning for the expedition by the engineering staff using the experiences gained a few months ago for this difficult deep water drilling, and this enabled completion ahead of schedule. We are fortunate that we were given the additional opportunity to complete one of the main goals of the project. Installation of the temperature sensors will enable measurement of the thermal properties of the fault zone to determine the friction levels for understanding the large slip during the 2011 Tohoku earthquake. A smooth transit to Hachinohe on a calm sunny day with a beautiful evening sunset was a relaxing finish to JFAST.

July 18

Location at 2400 is 37° 56.3'N, 143° 54.8'E Weather: Fine but cloudy

After pulling the running tool assembly out, transponders recovery was attempted. However none of the transponder had been recovered from 7000 meters seafloor. The vessel started moving to Hachinohe anchorage point from 1245 hrs.

July 17

Location at 2400 is 37° 56.3'N, 143° 54.8'E Weather: Cloudy

The underwater TV safely backed onboard 0545 hrs. Pulled out the running tool assembly to 5,000 meters below the ship took 8 hours and change Dual Elevator System to normal slip. Meanwhile, tried to recover transponders. Onboard science team was working hard to finalize the report.

July 16

Location at 2400 is 37° 56.3'N, 143° 54.8'E Weather: Fine but cloudy

In one day, we re-entered the of wellhead in 6,897.5 m water, ran 4.5 inch casing with the temperature sensors to 827.98 meters below seafloor, released the observatory string, and began pull out of hole. Sounds simple, but we were not able to accomplish this in over 40 days of operation a few months ago. Good weather, gained technical experience, and a lot of luck makes the difference. With installation of temperature monitoring, one of the main JFAST goals has finally been completed, and spirits of the onboard and onshore science party are high. Again, we appreciate the planning and operational efforts of the drilling engineers to achieve this great accomplishment.

July 15

Location at 2400 is 37° 56.3'N, 143° 54.8'E Weather: Overcast

Continue run completion assembly to the seafloor, filling up every 10 stands. Pick up and deploying UWTV from around 2200 hrs. Keep lowering UWTV to the casing shoe.

July 14

Location at 2400 is 37° 56.3'N, 143° 54.8'E Weather: Fine

Run 4.5 inch tubing started from 0130 hrs and running sensor assembly started from 1330 hrs. The final spacing of the 55 temperature sensors for the fault zone monitoring were set and placed in the casing for deployment into the borehole. For measuring the residual heat from the earthquake, the strategy is to have good spatial density near the fault zone (within about 50 meters) and then wider spacing of sensors farther away. Two of the sensors were also programmed to start recording later in October and February during the planned retrieval. These instruments will record a depth profile while the string is being pulled out of the hole. After a circulation test, the tubing with sensor assembly start running with drill pipe strings from 2145 hrs.

July 13

Location at 2400 is 37° 56.3'N, 143° 54.8'E Weather: Overcast

Continue pulling out the 8.5 inch drilling assembly to surface until around 2200 hrs. Lay down upper guide horn follows for make up 4.5 inch tubing for temperature observatory.

July 12

Location at 2400 is 37° 56.3'N, 143° 54.8'E Weather: Overcast

We reached the Total Depth of 854.81 meters below seafloor in the morning. We drill into the chert layer and comparison of ROP (rate of penetration) with the previous LWD hole (C0019B) shows a good correlation. Sea condition was getting bad but it was not bad as generate "wait on weather" situation. So we continue pulling the drill string out of the hole.

July 11

Location at 2400 is 37° 56.3'N, 143° 54.8'E Weather: Sunny but cloudy

Stab in the well head of C0019D hole around 0100 hrs and wash down 1 stand. Recover underwater TV took about nine hours and then resume drilling operation to 463 meters below seafloor till midnight.

July 10

Location at 2400 is 37° 56.3'N, 143° 54.8'E Weather: Sunny but cloudy

The 8.5 inch drilling assembly with mud motor ran to 6,900 meters below rig floor. After underwater TV cable function test, it lowered near the drill bit. After confirm the sea bed with underwater TV camera, searched the well head at C0019D with sonar. After few meter order vessel position adjustment, confirmed the well head.

July 9

Location at 2400 is 37° 56.3’N, 143° 54.8’E Weather: Cloudy

Installation of the guide horn took about 4.5 hours. From 0830 hrs made up the mud motor and connected to a drill collar stand and 8-1/2" drill bit. Function test of the mud motor went well and started running the drill string.

July 8

Location at 2400 is 37° 56.3’N, 143° 54.8’E Weather: Cloudy

The connection of UWTV cable to the both ends were finish and the TV working OK and ready to deploy. Move the vessel to C0019D location with DP mode. It is cloudy here but very calm sea condition, hope it continues.

July 7

Location at 2400 is 37° 56.3’N, 143° 54.8’E Weather: Rain

At 0530 hrs arrived UWTV cable free fall site (water depth 7,430 m). We did a function test of UWTV cable after cut off the broken end. As a result, 4 electric power supply lines and 3 fiber optic lines are effectively working. Once all the cable is wind up to the drum, connection to the UWTV takes place and further function test will conduct. Although no sunshine here, sea condition is not bad.

July 6

Location at 2400 is 37° 20.0’N, 143° 17.0’E Weather: Overcast

Smooth transit to the site, rendezvous with supply boat was made around 0200 hrs and a mud motor was loaded. Resume moving to underwater TV cable free fall operation point, 7,430 meters water depth.

July 5
(Exp. 343T)

Location at 2400 is 34° 35.9’N, 139° 20.6’E Weather: Cloudy

IODP expedition 343T "JFAST-2" officially started from 0200 hrs on 5 July 2012. This expedition is aimed to install the temperature observatory into C0019D hole where we set a well head during Exp. 343 but due to underwater TV cable failure we gave up of its installation. Due to a nature of this expedition, a technical leg, only small number of scientists onboard, currently the science party is Patrick Fulton and Nobu Eguchi. All the drill pipe stands are already made and ready for run. Prior to the pipe run, we need to fix Under Water TV cable, ETA of the location is early morning on 7th.


May 24

Location at 2400 is Helicopter meeting point, 38° 04' N, 142° 46' E Weather: Cloudy

Sampling from the most important core was continued until the last moment of disembarkation. All science party member safely flied from Chikyu to Sendai by helicopter. Remained measurements were being carried out by lab techs.

May 23

Location at 2400 is C0019E, 37° 56.3343 N, 143° 54.8084 E, Water depth 6889.5 mbsl Weather: Overcast

Pull out RCB coring assembly of the hole to the surface. The last full day on Chikyu was busy with splitting and sampling of important cores obtained over the last few days, as well as working on the last onboard measurements of physical properties. Report writing continued as preparations were made for the entire science party to depart by helicopter the following day. The science party thanks the laboratory staff, engineering and drilling staff, ship crew and shore support, for all the excellent work that made this expedition such a success.
We all look forward to our next Chikyu expedition!

May 22

Location at 2400 is C0019E, 37° 56.3343 N, 143° 54.8084 E, Water depth 6889.5 mbsl Weather: Rain

The coring operation was completed today with cores 19, 20, and 21 from depths of 826.5 to 844.5 meters below seafloor. The last core had poor recovery of only 6%, but successfully reached the targeted high resistivity layer, which had been identified in the LWD data. As anticipated, the material recovered from the layer was chert. Core 21 is the deepest ocean drilling research core below sea level ever retrieved (water depth 6889.5 m + 844.5 meters below seafloor = 7734.0 meters below sea level). The science party gathered on the cutting deck to watch the last core being processed, and expressed their thanks to the drilling engineers for all their efforts in maximizing the results of the drilling and coring operations.

May 21

Location at 2400 is C0019E, 37° 56.3343 N, 143° 54.8084 E, Water depth 6889.5 mbsl Weather: Fine but cloudy

Following a good view of the annular solar eclipse by almost everyone on the ship, the morning science meeting focused on updates of the paleomagnetic sampling, structural observations, and gas measurements from the recent cores. Logistics for leaving Chikyu were discussed as scientists prepare for the last few busy days of the expedition. Core continues to be retrieved from hole C0019E at depths of 816.5 to 826.5 meters below seafloor with recovery of about 40 to 50 percent. There was less than 1 meter of recovery from the Core 17, but it provided one the highlights of the expedition’s coring operations. Preliminary scans of the structural features appear to indicate we have sampled a major fault zone, and may have reached the top of the plate boundary.
The last few coring runs of Expedition 343 will end in morning of 22 May.

May 20

Location at 2400 is C0019E, 37° 56.3343 N, 143° 54.8084 E, Water depth 6889.5 mbsl Weather: Fine but cloudy

Four more cores were successfully retrieved from the depth interval 780.5 - 816.5 meters below seafloor. This sets the stage for coring through the second fault target on 21 May. Core recovery and quality are not fantastic, but in general there is sufficient material for visual core description, shipboard measurements, geochemical analysis of interstitial water, gas and solids, and discrete sampling for on-board and shore-based scientists. After the last weekly safety drill of our expedition, scientists celebrated two birthdays with a surprise party featuring cake, juice and tropical decorations.

May 19

Location at 2400 is C0019E, 37° 56.3343 N, 143° 54.8084 E, Water depth 6889.5 mbsl Weather: Fine but cloudy

At the morning science meeting Becky Cook described LWD and seismic data indicating possible structural changes near 780 meters below seafloor, which was being considered for the next coring target in C0019E. Coring continued with 3 cores (No. 7, 8, 9) retrieved from depths of 713 to 729 meters below seafloor, and there was varying recovery volumes of 14% to 71%. Drilling resumed from 729 to 770 m and core No. 10 was taken from 770 to 780.5 meters with a recovery of about 20%. Scientists have been busy carrying out the time sensitive analyses, core descriptions and other onboard analyses.

May 18

Location at 2400 is C0019E, 37° 56.3343 N, 143° 54.8084 E, Water depth 6889.5 mbsl Weather: Overcast

Cores No. 4, 5 and 6 were retrieved from depths of 690 to 714 meters below seafloor, with moderately good volumes of recovery. There was substantial improvement in the quality of the cores compared to the day before, with more intact samples. At the morning science meeting summaries were presented by Ken Takai on the gas sampling and Christie Rowe on the structural features observed in Cores No. 4 and 5.

May 17

Location at 2400 is C0019E, 37° 56.3343 N, 143° 54.8084 E, Water depth 6889.5 mbsl Weather: Overcast

It was a very exciting day for the science party because two cores with good recovery were acquired in the early- and late-morning hours.
After that, the center bit was inserted and the borehole was advanced 30 m to a depth of 688.5 meters below seafloor in order to begin coring through the upper fault zone target.

May 16

Location at 2400 is C0019E, 37° 56.3343 N, 143° 54.8084 E, Water depth 6889.5 mbsl Weather: Fine but cloudy

After the wait on weather ended this morning, drilling operations resumed at C0019E. Another successful test was done to drop MTLs down into the core barrel for measurement of downhole temperature and pressure. Coring was resumed during the late evening with the next core from about 650 meters below seafloor expected on deck early tomorrow. The official depth was reconsidered, and all parties agree that the water depth at Hole C0019E is 6918 meters below rotary table.
The expedition T-shirt was decided upon today with the Patrick Fulton's team providing the winning design.

May 15

Location at 2400 is C0019E, 37° 56.3343 N, 143° 54.8084 E, Water depth 6887.5 mbsl Weather: Rain

Drilling (without taking core) at hole C0019E continued to a depth of about 647.5 meters below seafloor until a wait on weather stopped drilling operations during the early evening. In the morning science meeting, Virginia Toy, Monica Wolfson and Christie Rowe described preliminary observations of lithologies, structures and microfossils seen in the core taken yesterday from a depth of about 175 meters below seafloor. In the afternoon, the split core was carefully examined and specific sampling locations were identified for the shipboard measurements of physical properties and for scientist's post expedition research.

May 14

Location at 2400 is C0019E, 37° 56.3343 N, 143° 54.8084 E, Water depth 6887.5 mbsl Weather: Overcast

After drilling to a depth of 170 meters below seafloor, the steady advance was halted to pull the center bit and run a de-plugger to prevent problems during later coring. In addition, the core barrel was sent down and a 9.5 m core was cut also for a test of the coring and wire-line retrieval systems. There was much excitement in the science party when it was reported that recovery was 90% of the drilled interval. The consensus is that the core is exciting and the science party wants more. The Ping-Pong championship was held, and the excellent play by the champion from China was just enough to overcome the skilled effort by the player from India.

May 13

Location at 2400 is C0019E, 37° 56.3343 N, 143° 54.8084 E, Water depth 6889.5 mbsl (tentative) Weather: Overcast

Running of the bit to the seafloor resumed in the morning after the wait on weather during the night. Spud in of the new hole C0019E occurred at 15:45 and the drilling reached about 130 meters below seafloor by the end of the day. Science party members discussed procedures for the time sensitive sampling in the core flow. The semifinals matches of the ping-pong tournament have been completed and the finals are planned for tomorrow before coring begins.

May 12

Location at 2400 is Next drilling site (5 m southwest of C0019B), 37° 56.3343 N, 143° 54.8084 E Weather: Overcast

Winds and a moderate swell continued throughout the day and evening; a few short breaks allowed more pipe to be run and by the end of the day the bit was at 5,532 meter below rig floor. In addition, scientists and engineers dropped an MTL temperature sensor down to the bottom of the drill string and recovered it with a wire-line, as a test of using the sensor to log the temperature across the fault after reaching target depth. The test was successful, so additional preparation of an MTL logging system will continue.

May 11

Location at 2400 is Upcoming drilling site (5 m southwest of C0019B),37° 56.3343 N, 143° 54.8084 E Weather: Overcast

Strong winds and high waves restricted some operations and canceled the helicopter flights. Preparations of the borehole assembly for the coring hole were completed and lowering of the drill string was begun.
After the bit reached a depth of about 4000 meters pipe-running operations were suspended to wait out the weather. Science party members continued to work on fine-tuning the core flow procedures.

May 10

Location at 2400 is C0019D, 37° 56.3224 N, 143° 54.8004 E, Water Depth 6,897.5 mbsl (tentative) Weather: Overcast

Pulling up of the drill pipe from the hole C0019D continued throughout the day. During the retrieval, there were some problems on the underwater TV system. Current plan is going to coring. So drillers have been started preparing RCB coring borehole assembly. Science party meetings were held about terminology for the expedition reports and improving details of the core flow procedures.

May 9

Location at 2400 is C0019D, 37° 56.3224 N, 143° 54.8004 E, Water Depth 6,897.5 mbsl (tentative) Weather: Overcast

The jetting in of the 20" casing and well head at C0019D took the better part of the day because of some resistant sediments and difficulty in detaching the running tool, but persistence paid off and the operation was completed successfully by about 20:00. Earlier in the day, the scientists and laboratory technicians finalized the core flow plan. Some additional training on instruments and instruction on laboratory procedures occurred during the day.

May 8

Location at 2400 is Upcoming drilling site (30 m southwest from C0019B), 37° 56.3224 N, 143° 54.8004 E, Water Depth 6,901 mbsl (tentative)Weather: Cloudy

The lowering of the wellhead and underwater TV at the hole C0019D continued and had reached a depth of over 5000 meters by the end of the day. There were practice (“dry”) runs in the core laboratory to examine the core flow for both the night and day shifts. Science party members and lab staff involved with core analyses were practicing and evaluating the many procedure involved in the immediate processing of core as it arrives on deck. Scientists are working to fine-tune the plans in anticipation of collecting delicate samples of the fault zone that will be analyzed in a number of ways.

May 7

Location at 2400 is C0019C, 37° 56.3033 N, 143° 54.7875 E, Water Depth 6,900 mbsl (tentative) Weather: Fine but cloudy

Analysis of logging while drilling data showed that the disconnection of the borehole assembly that occurred the previous day was not a result of any abnormal conditions of the borehole or the response of the formations being drilled. Once the pipe was returned to the ship, the engineering staff determined it was a mechanical failure of one section of the drill pipe. Extensive discussions were held on board about how to effectively use the remaining time for the expedition.
The remaining time in the original schedule would not permit continued attempt to take core samples of the fault and to place the temperature observatory in the borehole. At mid-day, however, a 4-day extension of operations became possible, which will allow continued effort to core and install a down hole observatory across the fault. Although the details of the planned operations are still being worked out, the extension provides one additional opportunity to achieve all the primary goals of the expedition. Preparation for 20” casing running commenced. At the morning meeting, visiting scientist Kuo-Fong Ma, from National Central University, Taiwan, presented an overview of scientific research associated with the Taiwan Chelungpu-fault Drilling Project.

May 6

Location at 2400 is C0019C, 37° 56.3033 N, 143° 54.7875 E, Water Depth 6,900 mbsl (tentative) Weather: Fine but cloudy

Drilling at the hole C0019C was restarted in the morning; however, there was an engineering problem in the early afternoon with a loss of the borehole assembly at a depth of about 120 meters below seafloor.The cause of the problem is being examined and future operational options are being considered. During the afternoon science meeting, the logging group presented a summary of the results from C0019B, including discussions about preliminary results and interpretations of drilling parameters, resistivity and borehole breakout data.

May 5

Location at 2400 is C0019C, 37° 56.3033 N, 143° 54.7875 E, Water Depth 6,900 mbsl (tentative) Weather: Fine but cloudy

Following two days of waiting on weather, resume running LWD assembly with underwater TV. Adjust vessel position and attempt re-entry into well head successfully. Preparations and training continued for routine measurements of physical properties of the anticipated core.
The science party thanks Nobu Eguchi for his very effective and friendly efforts as the Expedition Project Manager over the last 5 weeks.

May 4

Location at 2400 is C0019C, 37° 56.3033 N, 143° 54.7875 E, Water Depth 6,900 mbsl (tentative) Weather: Overcast

A wait on weather continued throughout the day. The logging scientists continued to work on hole C0019b summary, and other groups met concerning sampling, core flow, and measurements. Science party members also attended ship safety meetings.

May 3

Location at 2400 is C0019C, 37° 56.3033 N, 143° 54.7875 E, Water Depth 6,900 mbsl (tentative) Weather: Rain

Due to bad weather, the drill string was brought up to a depth of about 3000 m and secured for riding out the rough seas. Science party members had discussions about their research plans and discrete sampling of the anticipated core. During the wait on weather, some scientists entertained themselves in the evening hours by redecorating the library and lounge areas of the management deck.

May 2

Location at 2400 is C0019C, 37° 56.3033 N, 143° 54.7875 E, Water Depth 6,900 m (tentative) Weather: Continue running 8.5” logging while drilling assembly. Re-entry into the wellhead. Pull out LWD assembly to 3000 m for Wait on Weather.

Following the update of operations by the Expedition Project Manager at the general science meeting, a group of scientists presented their proposed research and associated needs for whole-round core samples.
Ensuing discussions amongst the participants focused on collaboration and maximizing efficient and equitable use of the limited core material that will be available. In the early evening, the science party watched the feed from the underwater TV as Chikyu was maneuvered to locate the well head. The speed and precision in which the drill string was placed into the 20" opening of the well head was truly amazing. After a wait on weather, Chikyu will need to repeat that operation at least two more times in order to finish the borehole and set the MTL observatory across the active plate boundary zone.

May 1

Location at 2400 is C0019C, 37° 56.30 N, 143° 54.79 E, Water Depth 6,900 mbsl (tentative) Weather: Fine but cloudy

Continue pulling out jetting borehole assembly. The running tool and underwater camera used in the setting of the wellhead at C0019C were retrieved. Logging While Drilling tools were prepared for the next drilling which is planned to start soon at C0019C. Between the busy times spent analyzing logging data, science party members had a break with a midnight dance party.


April 30

Location at 2400 is C0019C, 37° 56.30 N, 143° 54.79 E, Water Depth 6,900 m (tentative) Weather: Overcast

Pull out jetting assembly and recover underwater TV to the surface.
Analysis of the LWD data is ongoing to identify geological structures in hole C0019B. During the science meeting Patrick Fulton presented the current plan, which was updated on the basis of the LWD data, for the configuration of the temperature observatory that will be placed in the C0019C borehole. He explained that the new configuration will be capable of recording the anticipated temperature anomaly associated with the Tohoku earthquake if the rupture occurred on or in the vicinity of the structures located deep in the borehole.

April 29

Location at 2400 is C0019C, 37° 56.30 N, 143° 54.79 E, Water Depth 6,900 mbsl (tentative) Weather: Fog

Resume to running 20” casing pipe from 4,130 m with underwater TV till tag on seabed. 20” casing jetting from 6928.5 to 6957.5 m (29 meters below seafloor). Run Core Barrel Retrieving Tool with dart to release wellhead from drill pipe. Find hydraulic running tool unset wellhead by underwater TV.
During the morning a number of scientists presented results of preliminary analyses and interpretations of the LWD data collected from C0019B. Borehole breakouts, structural orientations, and geologic interpretations kept the long session active until lunchtime. In the afternoon there was a discussion among the entire science party about options for observatory installation and coring during the remainder of the expedition. The process of setting the well head for the observatory borehole progressed today. Jet in was done during the afternoon and there was a successful release of the wellhead from the running tool later in the evening. Also, Jim Sample and Christie Rowe appeared by internet at USA Science Festival in Washington DC.

April 28

Location at 2400 is Upcoming drilling site (70 m southwest from C0019B), 37° 56.30 N, 143° 54.78 E Weather: Overcast

Make up and run 20” casing with jetting borehole assembly to 4100 m, handle guide horn and lower underwater TV. Install Dual Elevator System and calibrate.
The morning science meeting focused on deciding the best location for the observatory borehole, C0019C. Knowledge of the strike of bedding at JFAST-3 from LWD data, and considerations of the trade-off between proximity to the LWD hole for ease of correlation and separation in order to minimize possible disturbance of the observatory by subsequent drilling, led to selecting a new site 70 m to the southwest of C0019B. Plans were made to wait until Sunday to discuss the geologic interpretation of the LWD data in order to continue data collection and analysis.

April 27

Location at 2400 is JFAST3b; 37° 56.2 N, 143° 54.5 E. Weather: Overcast

Continue to pull out the hole to the surface. Lay down LWD tools and drill bit. Move vessel to location JFAST 3b (130 m in the south from location 3a). Remove and check upper guide horn wear bushing. Prepare for 20” casing handling tool.
The morning meeting was spent discussing the next step in drilling operations. Various options regarding the order and time constraints on the observatory installation and coring operations were considered.
Also, prizes were given to the winners of the contest to predict the final drilling time and depth of C0019b. Parameter and resistivity image data from the LWD tools were made available by early evening.
Logging scientists began preliminary analyses of the results to identify borehole breakouts and geologic structures.

April 26

Location at 2400 is C0019B; 37° 56.34 N, 143° 54.8 E, Water depth; 6,883.5 mbsl Weather: Overcast

Continue to pull out of the hole with repeat logging.
After reaching the Total Depth of the LWD-MWD hole the night before, the science party identified three 50 m sections of the hole that would be logged again as the borehole assembly was being recovered.
The morning science meeting featured presentation of the real-time logging data and some preliminary analysis and interpretation. By the end of the day the borehole assembly was out of the borehole and well on the way back to the ship. Scientists talked to Japanese news media about the present operations.

April 25

Location at 2400 is C0019B; 37° 56.34 N, 143° 54.8 E, Water depth; 6,883.5 mbsl Weather: Fine but cloudy

Continue to Drill 8-1/2" LWD Hole to Total Depth. Pull out of the hole with repeat logging.
At the morning science meeting, there was discussion about the next steps in operations. Options for coring and observatory installation will depend on borehole stability and analysis of the LWD data. Louise Anderson and Tamara Jeppson presented updates on the realtime logging, which had reached about 700 meters below seafloor (mbsf) by the 10:30 meeting. Sanny Saito provided information about geologic interpretations of these data. The logging data were watched carefully throughout the day noting changes that may indicate structure and lithologic units. During the evening, the largest changes in resistivity and natural gamma ray were observed beginning at a depth of about 825 mbsf, and subsequently the rate of penetration dropped close to zero. The large changes in the logging parameters, along with the strong resistance to drilling, were interpreted to mean that the borehole had reached the hard chert layer, which was the designated target for this phase of drilling. At 21:43, the rate of penetration had dropped to near zero and the decision was made to stop drilling and begin repeat logging observations at designated depths while pulling out of the borehole. The borehole reached a final depth of 856 mbsf, for a total depth of 7740 meters below sea level. This extends the world record for total borehole length below sea level for a research borehole, which was set two days earlier. Spirits were high as this borehole reached the target depth without significant borehole stability problems.

April 24

Location at 2400 is C0019B; 37° 56.34 N, 143° 54.8 E, Water depth; 6,883.5 mbsl Weather: Overcast

Continue to Drill ahead 8-1/2" LWD Hole. Wait On Weather. Keep string moving, rotating and pumping. Resume drilling to 576.0 meters below seafloor at 2400.
The LWD drilling that had begun the previous day continued into the early hours of the morning before operations had to be suspended due to increasing rough weather conditions. The morning science party meeting began with the news the total depth of the borehole was at 424 meters below seafloor (wahoo!), and that the wait on weather would soon be lifted. The meeting was most enjoyable because we learned from the logging scientists that data collection was going well, and heard about preliminary determinations of porosity change with depth and identification of potential lithostratigraphic unit boundaries from the log data. Additional progress in deepening the borehole was made as drilling continued through the evening. Science party members also attend the ship's safety meeting.

April 23

Location at 2400 is C0019B; 37° 56.34 N, 143° 54.8 E, Water depth; 6,883.5 m Weather: Overcast

Spud C0019B. Jet in from 6912meters below rig floor and continue to drill 8-1/2" LWD Hole 7301m. Penetrate 389.0 meters below seafloor at 2400.
A new world record for scientific ocean drilling! Spud in for C0019B occurred at little past midnight on the LWD hole, and about an hour later we received confirmation that data were being received from the logging tools. Around 09:16 the LWD drilling passed the depth of 7049.5 meters below sea surface (166 meters below seafloor). This is the deepest total length from the ocean surface for a research borehole. The previous record was made during DSDP Leg 60, Hole 461A in the Marianas Trench in 1978 (water depth; 7034 meters below sea surface, 15.5 meters penetration below the seafloor). By 24:00, the LWD depth had reached 7300 meters below the sea surface (388 meters below seafloor) and geophysical logs were being continuously monitored. For access to the realtime logging data from the drill string, the pulse telemetry through the 7 km of mud and water has been working well.

April 22

Location at 2400 is C0019; 37° 56.34 N, 143° 54.8 E, Water depth; 6,883.5 m Weather: Overcast

Continue to run LWD Assembly to 6896m. Change to Duel Elevator System.
LWD Shallow test with seawater.
During the morning meeting of the science party, in anticipation of the start of logging operations, updated information was presented on the current pipe run and testing of tools. Also, Virginia Toy talked about similarities of lithologies and frictional properties of fault zone material from the Alpine and San Andreas faults. Recreational activities were planned for the afternoon, including a birthday party for the senior co-chief scientist. Later in the afternoon, there was a final test of the MWD pulse telemetry at a water depth of 6000 meters.

April 21

Location at 2400 is 37° 56.34 N, 143° 54.8 E, at JFAST3a, Seabed 6912 mbrt Weather: Cloudy

Continue lay down 20" casing and running tool at drill floor. Make up LWD borehole assembly. LWD shallow test with seawater. Troubleshooting of one of LWD tool failure. Decision made to lay out the failure tool and Run LWD without it. Perform shallow test. Continue to run LWD Assembly to 1120mbrt.
Scientists were able to watch the assembly of the LWD and MWD tools, the PDC drill bit, and various subs that make up the bottom hole assembly. Unfortunately, test of the logging and data transmission system revealed that one tool, the ProVISION tool, was not functioning properly. After some unsuccessful attempt at repair, the malfunctioning tool was removed and drillers began to run drill pipe, which brings us closer to drilling the LWD borehole.

April 20

Location at 2400 is 37° 56.34 N, 143° 54.8 E, at JFAST3a, Seabed 6912 mbrt Weather: Cloudy

Continue pulling out 20" Casing on drill pipe using Duel Elevator System. Investigation and test casing running tool. Break out and lay out well head joint.
The science party waited for completion of the drill pipe retrieval and prepared for the upcoming LWD drilling. Yasuyuki Nakamura presented the current interpretation of faults in the vicinity of the JFAST-3 site, from multi-channel seismic data, especially addressing the depths of the structures. The depth estimates are important for planning of the LWD. The LWD group then met to finalize watchdog schedules and responsibilities. The scheduled watchdog shifts for monitoring the LWD started in the evening.

April 19

Location at 2400 is 37° 56.34 N, 143° 54.8 E, at JFAST3a, Seabed 6912 mbrt Weather: Cloudy

Pull out 20” casing to 4392mbrt. Recover underwater TV. It was disappointing also for science party to learn that the running tool would not disconnect from the well head.. News that the underwater TV was successfully returned to the ship and the drill pipe and casing were being retrieved, and that a plan for LWD drilling was already in place, helped to raise spirits.
Patrick Fulton gave talk on a detailed analysis of frictional heating during earthquake slip as an explanation of the fault-related vitrinite reflectance anomalies documented in core samples from NanTroSEIZE drilling.
In addition, Patrick shared picturesque images of his field site in Texas where he collected samples of lignite deposits that are ideal for shearing experiments on vitrinite. The afternoon talk was delivered by Christine Regalla; she explained her ongoing studies of the evolution of the Tohoku forearc and implications for plate boundary dynamics in the region of the earthquake and our drill sites.

April 18

Location at 2400 is 37° 56.34 N, 143° 54.8 E, at JFAST3a Weather: Overcast

Break circulation for jetting successfully and pump sea water to clean inside pipe. Troubleshoot upper elevator oil leakage from signal line.
Make up 6-5/8" drill pipe stand and lower to seabed. Confirm sea water depth at 6912mBRT by Co-Chief Scientist.
Commence 20" casing jetting t spud and pushed to 6912 to 6940mBRT, 28.0 meters below seafloor. The science party was excited to watch the progress in the drilling operations on the monitor as the 20-inch diameter casing was jetted into the sea floor sediment and the shallow portion of the borehole was completed. Attempt to release casing running tool but no indication for releasing running tool. Decision made and attempt to recover dart of running tool by core barrel running tool with core line, unsuccessfully.
Tamara Jeppson talked about the relation of geophysical and rock properties in the SAFOD borehole, especially the association of the fault zone with low seismic velocity and low porosity. Christie Rowe talked about the fluid fault interactions in the Naukluft thrust, Namibia.

April 17

Location at 2400 is 37° 56.34 N, 143° 54.8 E, at JFAST3a Weather: Cloudy

Continue troubleshooting Dual Elevator System. Resume running 20" casing from 4845 mBRT to 6934mBRT with underwater TV. Survey site JFAST 3b and move vessel at 0.1knot to site JFAST 3a of LWD hole. As could be seen through the lens of the underwater TV system, the sea floor was flat and very uniform at both locations surveyed, so the drill sites were approved. Prepare spud in with 20" casing jetting.
Attempt to break circulation unsuccessfully due to plugging inside pipe.
The science party discussed with a talk by Jun Kameda about the differences in sediment diagenesis in cold and hot subduction margins, e.g., Japan Trench and Nankai Trough, respectively. Matt Ikari spoke on rate and state friction, focusing on the relationship between rate dependence and the absolute magnitude of friction. Personnel schedules and initial drilling parameters were set for the LWD operations that will hopefully begin in several days.

April 16

Location at 2400 is 37° 56.2 N, 143° 54.5 E, at JFAST3b Weather: Cloudy

Repairing underwater TV cable completed. Wait on Weather due to wave height. Dive underwater TV to well head housing at 4766m cable depth.
Rig up Dual Elevator System but troubleshoot its well center position sensor on the rail. In the morning, scientists heard about progress of the deployment of the underwater camera. They were not disappointed, as later that evening underwater scenes were viewed while the camera descended to 4700 meters. At the morning science meeting, plans were presented for the Logging While Drilling (LWD) which is scheduled to start in a few days. Logging resolution, drilling speed, and watchdog schedules were discussed. Becky Cook talked about her analysis of the structure of the Sumatra subduction margin using multi-channel seismic data. Monica Wolfson talked about relationships between seismicity and structure of the Discovery Transform fault. Science party members were taken on another ship tour to see seldom visited places on Chikyu.

April 15

Location at 2400 is 37° 56.2 N, 143° 54.5 E, at JFAST3b Weather: Fine but cloudy

Continue commissioning Dual Elevator System. Resume run 20” casing to 4843 meters below the drill floor. Pick up upper and middle guide horn. Repair underwater TV fiber cable communication. The morning meeting of the science party featured a presentation by Marianne Conin on the behavior of accretionary prisms that contain a large splay fault, as determined from Coulomb wedge theory and finite element analysis. She showed how model results could help explain the timing of the activity on the splay fault and development of extensional faulting that was documented along the NanTroSEIZE transect, as well as the stress and deformation states of the prism being drilled in the JFAST expedition. In the afternoon, science party members from all countries showed their skills in Japanese (Chinese) calligraphy.

April 14

Location at 2400 is 37° 56.2 N, 143° 54.5 E, at JFAST3b Weather: Cloudy

Continue running 20" casing from 2415m to 4074m below the drill floor.
Install upper guide horn. Rig down hydraulic elevator and install dual elevator system. After listening to the current information on encouraging progress and new problems in operations, the science party made plans for continued meetings and recreational activities during the weekend. Santanu Bose talked about sandbox models used to simulate deformation in an accretionary wedge which is similar to the setting of the JFAST-3 site. Christie Rowe talked about the Pofadder shear zone, which is a billion year old, deeply exhumed fault in Namibia, analogous to the San Andreas fault. The last tour of the LWD equipment was held today along with continued instrument training.

April 13

Location at 2400 is 37° 56.3 N, 143° 54.8 E, at JFAST3 Weather: Over cast

Pay out underwater TV cable. Install Guide Hone. Start running 20" casing with Jetting borehole assembly and 2,415 meters below the drill floor at 2400 hrs. The science party met with higher spirits after hearing of progress on operations and the initiation of preparation of the well head assembly for the first borehole. The morning talk was given by James Kirkpatrick about a fault that he is studying that may contain a geologic record of earthquake related dynamic weakening by silica gel formation. His observations of microcataclasite structures were very interesting, given that we expect to encounter some silica rich rocks in the borehole. These results together with experimental studies reported later by Takehiro Hirose on dynamic weakening mechanisms for dynamic slip rates, prompted much discussion among scientists. There was also continued planning for shipboard activities associated with the upcoming logging and core sampling.

April 12

Location at 2400 is 37° 57.0 N, 143° 59.0 E, UWTV free fall location(3.5 km East from JFAST3) Weather: Fine but cloudy

Continue to troubleshoot underwater TV cable loosening. Wind up cable.
The fastening of temperature sensors and their protective coverings onto the rope for the first borehole observatory has mainly been completed. Moderately rough weather continued so morning and afternoon science meetings were held as the room swayed. Jim Mori talked about earthquakes that occurred the previous night close to the 2004 Sumatra earthquake. Kohtaro Ujiie talked about results from seismic surveys, CT scans, logging, laboratory experiments, and core analyses of fault zones from the Nankai drilling. Data from both the plate boundary and splay faults were discussed. Ken Takai presented about post-earthquake disturbances in the chemical environments and microbial communities.
He emphasized the importance of hydrogen in stimulating growth of biological communities.

April 11

Location at 2400 is 37° 56.0 N, 143° 59.0 E, UWTV free fall location(3.5 km East from JFAST3) Weather: Rain

Pay out underwater TV cable to 7215 m, troubleshoot and wind up again.
Flanged up upper and lower section of the Guide Horn. Lab preparation continued, and two science meetings were held. The first meeting included a talk by Jan Behrmann on mechanical properties of the sediments likely to be encountered in upcoming drilling operations, based on past results from experimental deformation studies. During the afternoon meeting Tianhaozhe Sun spoke about pore-fluid pressure measurements from borehole observatories and using poroelasticity based analysis to characterize tectonic volumetric strains. Both speakers showed how these approaches can address expedition goals and expressed enthusiasm for installation of the observatories and collection of core samples.

April 10

Location at 2400 is 37° 56.0 N, 143° 59.0 E, UWTV free fall location(3.5km East from JFAST3) Weather: Fine but cloudy

Continue to troubleshoot on UWTV cable loosening, winch up underwater TV cable to the surface. Move vessel 3.5 km east to 7,500 m water depth area. Prepare to dive underwater TV cable with sinker. Make up drill pipe stands. Tsuyoshi Ishikawa, geochemist talked about co-seismic fluid-rock interactions at high temperatures. He showed temperature dependent changes of the fluid chemistry from the Chelungpu Fault, Taiwan, and locations in Japan. For the onboard ‘Science Cafe,’ co-chiefs presented talks to the staff of Chikyu, explaining science objectives and methods of JFAST. Training continues on the laboratory equipment for the science party.

April 9

Location at 2400 is 37° 56.0 N, 143° 57.0 E, Site JFAST3, Weather:Fine but cloudy

Continue to untwist underwater TV cable, troubleshoot on cable loosening. Prepare Middle and Lower Guide Horn. Make up drill pipe stands. Two science party meetings were held, and training on sampling protocol and the use of laboratory instruments continued. James Sample presented some of his recent work using isotopes from carbonate samples taken near faults in accretionary prisms, and the potential of clumped isotope analysis, to address questions of paleotemperature and fluid flow associated with faulting. The science party also discussed about the successful outcomes of the first stages of the Deep Fault Drilling Project on the Alpine fault in New Zealand, from lead principal investigator Virginia Toy.

April 8

Location at 2400 is 37° 56.0 N, 143° 57.0 E, Site JFAST3, Weather:Fine but cloudy

Continue to install wire line tool. Make up drill pipe stands.
Troubleshoot on underwater TV winch software and untwist its cable. As we wait for drilling operations to start, the science party had morning and afternoon meetings. Weirin Lin talked about stress orientation determined from boreholes drilled in the Tohoku region prior to the earthquake. Tao Yang presented results from a study of the changes in rock magnetic properties associated with faulting during the Wenchuan, China earthquake. Toshikaki Mishima talked about results of a similar study from the Chelungpu Fault, Taiwan.
Preparation on the laboratory equipment continues.

April 7

Location at 2400 is 37° 56.0 N, 143° 55.0 E, Site JFAST3, Weather:Fine but cloudy

Recover under water TV Cable to moon pool. Make up drill pipe stand and jetting borehole assembly, circulation test on hydraulic running tool. The science party had two meetings. In the morning Yasuyuki Nakamura reviewed findings of seismic and bathymetric surveys across the Japan Trench conducted prior to and after the Tohoku earthquake, as well as the findings from the high-resolution, pre-expedition survey that was used to select the drill sites. In the afternoon we had another interesting talk on the geology and structure of excavated Accretionary complex of the Kodiak Alaska from Christie Rowe.

April 6

Location at 2400 is 37° 56.0 N, 143° 57.0 E, Site JFAST3, Weather: Cloudy

Deploy and calibrate transponders. Make up drill pipe stands. Move and attempt to conduct free fall of underwater TV cable. The morning and afternoon meetings of the science party continued about some details of the various procedures in the laboratory including the core flow and publication procedures. Francesca Remitti presented her field research on the low-temperature deformation of an accretionary wedge from the Eocene in the Appenines, Italy. Yukari Kido provided clarification on the Logging While Drilling tools, parameters, and expected operations.

April 5

Location at 2400 is 37° 56.0 N, 143° 55.0 E, Site JFAST3, Weather:Fine but cloudy

Wait on weather. Transit to transponder deployment point, and deploy transponders. Make up drill pipe stands. With the break in the weather and resumption of operations, the science party was able to enjoy a tour of the ship, visiting many areas including the mud room, the bridge, and the drillers control room. In the afternoon, Co-Chief Scientist Prof. Jim Mori gave a comprehensive presentation on science findings and outstanding questions regarding the Tohoku earthquake and tsunami, which stimulated much discussion amongst participants. Other activities included beginning to write portions of the Expedition Report, and viewing the thousand or so seagulls that overwhelmed the ship.

April 4

Location at 2400 is 37° 43.0 N, 144° 20.0 E, Site JFAST3, Weather: Fine but cloudy

Wait on weather (WOW). We experienced a pretty bad sea condition yesterday but it is getting better now. Resume the rig work and transponder deployment will start soon. There were morning and afternoon meetings of the science party. In the morning, the plan for the locations of Hole A and Hole B was finalized. It was decided to choose two locations along strike that were spaced about 100 meters apart, in order to minimize fluid flow effects between the two boreholes. Sites slightly west of the initial JFAST3 location were designated since the bathymetry appeared to have less of a slope there. In the afternoon, there was also discussion about MWD/LWD operations.

April 3

Location at 2400 is 38° 00.0N, 143° 52.0E, Site JFAST3, Weather: Rain

We had arrived on the location at 0800, 3 April, but due to expected bad weather we have not done any scheduled operation, e.g., transponder deployment. Half of the science party member had a ship tour before the weather getting worse. We encounter maximum of 40m/s wind around midnight, and wave height was over 10m sometimes. The entire science party met for two meetings focused on observatories.

April 2

Location at 2400 is 37° 03.3N, 142° 54.5E, Weather Fine but cloudy

Transit to Under Water TV cable free-fall location, 3 km East of the first site JFAST3. Prepare for spud. Conducted emergency ship drill.
Held two general science-party meetings covering the principles for use of LWD/MWD data for locating the master thrust fault in Hole A, and the scientific motivation and requirements for establishing a temperature-measurement observatory across the master fault that slipped during the Tohoku earthquake.

April 1

Location at 2400 is 34° 35.6N, 139° 21.9E, off the coast of Katsuura,Chiba prefecture.
Weather Fine but cloudy

Left the Shimizu port on 1500, transit to the first drill site JFAST3.
Prepare for spud.
Hold a general science party meeting, self-introduction of each science party members, introduce schedule for next couple of days, publication policy and responsibility presentation by Publication Assistant. Science party members working in two shift from today.