IODP Expedition 346

Asian Monsoon

Daily Science Report for 31 August 2013

LOCATION: Hole U1425D (39°29.4392′N, 134°26.5395′E, 1920 m water depth)

SCIENCE UPDATE: Downhole logging operations in Hole U1425B were completed successfully with the second pass of the FMS-sonic tool string at 0100 h. The FMS-sonic suite collected good resistivity images of the borehole, sonic velocities, and natural gamma radiation data. These downhole measurements are very helpful for planning coring operations and stratigraphic correlation for the next deep hole at this site (Hole U1425D), as they enabled us to identify and estimate the depth and size of drilling gaps and the dolomite and siliceous claystone horizons. Hole U1425C was started at 0355 h, 15 m south of Hole U1425B. Only three cores (Cores U1425C-1H to ‑3H, from 0 to 25 m) were taken in this hole for the purpose of post-expedition optically stimulated luminescence (OSL) dating. As in the previous site, the cores were sampled directly on the drill floor during the night to minimize exposure to light. Once we pulled out of the hole and cleared the seafloor, the ship was offset 15 m west of Hole U1425A and Hole U1425D was started at 0605 h establishing a seafloor depth of 1919.6 m. Cores U1425D-1H to ‑29H extended from the seafloor to 237 m with a recovery of 240.5 m (102%). All cores from Hole U1425B have been sampled, measured for physical and chemical properties, and described. The Opal A/CT transition was observed in Core U1425B-52H, at ~340 m. The cored interval between ~340 m and the bottom of Hole U1425B (407 m) consists of siliceous claystone, with porcelanite found in the deepest core (Core U1425B-61X).

Daily Science Report for 30 August 2013

LOCATION: Hole U1425B (39°29.4476′N, 134°26.5502′E, 1919 m water depth)

SCIENCE UPDATE: We started the day with an education and outreach event with Colorado State University while XCB coring Hole U1425B. XCB Cores U1425B-55X to ‑59X extended from 350.7 to 397.5 m with a recovery of only 25.3 m of core (54%). In an attempt to improve core recovery as the formation was becoming increasingly silicified with depth, the next core, U1425B-60H, was cut with the half-length APC system yielding a full core (5 m). However, the liner got jammed in the core barrel and we decided to cut one more XCB core before terminating the hole after APC/XCB refusal at 407.2 m. Total recovery for Hole U1425B was 397.3 m (98%). Following the end of coring operations in Hole U1423B, the hole was conditioned for downhole logging and the bit was pulled up to a logging depth of 80 m. The same Paleo-combo tool string configuration used at Site U1423 was deployed to the bottom of Hole U1425B. It recorded spectral gamma ray, caliper, magnetic susceptibility, resistivity, and lithologic density logs over the entire interval. Following the deployment of the Paleo-combo, we lowered the FMS-sonic tool string and it reached 396 m. The day ended during the initial pass of the FMS-sonic, while recording resistivity images of the borehole, sonic velocities, and natural gamma radiation. In the laboratories, the geochemistry team finished processing all interstitial water samples and completed headspace analyses for Hole U1425B. Solid samples were prepared for C/N and carbonate analyses and interstitial water samples were measured for sulfate, alkalinity, and minor elements. The sediment interval recovered in Cores U1425B-24H through ‑61X predominantly consists of moderately bioturbated brownish gray biosiliceous clay, above 341 m (Core U1425A-52H), and biosiliceous claystone below. Calcareous microfossils are absent or rare below ~195 m. The age at the base of the record is estimated to be greater than 11.8 Ma based on radiolarian bioevents.

Daily Science Report for 29 August 2013

LOCATION: Hole U1425B (39°29.4476′N, 134°26.5502′E, 1919 m water depth)

SCIENCE UPDATE: Coring continued in Hole U1425B with the recovery of Cores 19H to 54H (127.2 to 350.7 m), alternating between the APC (full and half length) and XCB systems due to the firmness of the formation and the presence of dolomite layers. Cores U1425B-19H to ‑20H, ‑36H to ‑39H, and ‑41H to ‑54H were half-length APC cores. Cores U1425B-32X and ‑40X were taken with the XCB core barrel. The interval recovered in Cores U1425B-4H through ‑23H consists predominantly of dark grayish brown homogenous diatom ooze. Biostratigraphic analyses provide an age greater than 9.1 Ma for the base of Core U1425B-48H (322.5 m). We held a meeting to present the scientific and operations objectives for Site U1425 and proposed sites YB-1 and YB-2.

Daily Science Report for 28 August 2013

LOCATION: Hole U1425B (39°29.44′N, 134°26.55′E, 1919 m water depth)

SCIENCE UPDATE: We arrived at Site U1425 at 0230 h. The thrusters and hydrophones were lowered, the APC/XCB bottom-hole assembly was made up, and the positioning beacon was deployed while lowering the drill string to the seafloor. The first attempt to start Hole U1425A failed after the first core barrel came back empty (water core). A second attempt recovered a full core barrel (9.81 m), so Hole U1425A was terminated after Core U1425A-1H narrowly failed to recover the desired sediment/​​water interface. The bit was raised 3 m and the vessel offset 15 m north of Hole U1425A. Hole U1425B was started at 1005 h establishing a seafloor depth of 1919 m.

Cores U1425B-1H to ‑18H extended from the seafloor to 127.2 m and recovered 129.5 m of core (103%). APC Cores U1425B-1H to ‑12H (0–104.6 m) were recovered using full length core barrels. Hard dolomite layers interspersed through formation led to the use of a mixture of coring systems below that point. Core U1425B-13X was cut using the extended core barrel (XCB) coring system. Cores U1425B-14H and ‑15H used full length APC barrels. Core U1425B-16X was cut using the XCB coring system. Cores U1425B-17H and ‑18H were then taken using half-length APC cores. Successful temperature measurements were taken on Cores U1425B-4H, ‑7H, and ‑10H (37.3, 65.8, and 94.3 m, respectively). High resolution Rhizon sampling for interstitial water chemistry was conducted in Cores U1425B-1H and ‑2H. The interval recovered in Cores U1425B-1H to ‑3H consists of greenish gray clay and olive green silty clay and corresponds to the same Lithologic Unit I found at the previous sites. Preliminary biostratigraphic analyses provide an estimated age of 3.4 Ma for the base of Core U1425B-12H (104.6 m). We held the Site U1424 science summary meeting.

Daily Science Report for 27 August 2013

LOCATION: Sea of Japan/​​East Sea, in transit to Site U1425 (YR-1)

SCIENCE UPDATE: We completed coring operations at Site U1424 with the recovery of Cores U1424C-5H through ‑7H extending from 35.4 to 63.9 m. Total recovery for Hole U1424C was 64.35 m of core (101%). The drill string was pulled back clearing the sea floor by 0320 h. By 0854 h the rig floor was secured for transit, the vessel control transferred from dynamic positioning mode back to the bridge, and the thrusters were raised to begin our transit to Site U1425 (proposed site YR-1). By midnight we had covered 153 nmi at an average speed of 10.2 kt.

The operations plan for Site U1425 is to APC/XCB core two holes to ~450 m, one hole to ~30 m for optically stimulated luminescence (OSL) sampling, and a fourth hole may be APC cored to ~200 m depending upon results from stratigraphic correlation obtained from the first two holes. In addition, we will carry out downhole logging measurements in the deepest hole.

The sedimentary succession recovered at Site U1424 extends from Pliocene to Holocene and is dominated by clays and diatomaceous ooze. Volcaniclastic material represents a minor component throughout the sediment succession, except in tephra layers.

Daily Science Report for 26 August 2013

LOCATION: Hole U1424C (40°11.3914′N, 138°13.8998′E, 2819 m water depth)

SCIENCE UPDATE: Today we completed coring operations in Holes U1424A and U1424B and started to APC core Hole U1424C. We cut and recovered Cores U1424A-12H to ‑17H from 101.8 to 158.8 m. The total recovery for Hole U1424A was 161 m of core (101%). The drill string was pulled up and cleared the seafloor at 0645 h, ending Hole U1424A. The ship was offset 15 m north of Hole U1424A, and Hole U1424B was started at 0740 h with the bit positioned 3 m lower than in the previous hole. Hole U1424B was cored continuously to 154.7 m (Cores U1424B-1H to ‑17H) recovering 155.3 m of core (100%). The drill string was pulled up to the seafloor, the ship offset 15 m south of Hole U1424A, and Hole U1424C was started at 2125 h. By midnight, we had recovered APC Cores U1424C-1H to ‑4H extending from the seafloor to 35.4 m. Cores U1424C-1H to ‑3H were sampled directly on the drill floor for the purpose of post-expedition optically stimulated luminescence (OSL) dating. OSL dating is a critical objective of Expedition 346 because precise dating of the Pleistocene section of the sedimentary sequence is of primary importance to examine the timing of the intensification of the East Asian summer monsoon, northward shift of westerly jet axis, reduction of ventilation in the Sea of Japan/​East Sea, and weakening of the East Asian winter monsoon on millennial time scales. OSL sampling involved special core handling procedures and was conducted during the night to minimize exposure to light. The cores were cut into the routine 1.5 m whole-round sections as the core was pulled out of the core barrel. The sections were slipped into opaque aluminum-lined pouches, labeled, sealed and stored. Description and measurements of physical and chemical properties of the cores collected at Site U1424 continue. High-resolution interstitial water samples were collected from Hole U1424A and from Cores 4H to 7H in Hole U1424C. We are also measuring inorganic carbon and total organic carbon across the color banded bedding observed in the uppermost part of the stratigraphic sequence (Lithologic Unit IA).

Daily Science Report for 25 August 2013

LOCATION: Hole U1424A (40°11.4001′N, 130°13.9003′E, 2819 m water depth)

SCIENCE UPDATE: We completed the ~98 nmi transit to Site U1424 (proposed site JB-1) at 0736 h.

Description and measurements of sediment physical properties of all cores from Site U1423 were completed. The sedimentary succession at Site U1423 extends from the Pliocene to the Holocene and is dominated by clays, silty clays and diatomaceous ooze with discrete foraminifer-bearing clay beds. Volcaniclastic material represents a minor component throughout the sedimentary sequence, except in tephra layers where it is the dominant component. We held the Site U1423 science summary meeting at noon and by midnight scientists began turning in the Site U1423 reports for review.

Hole U1424A was started at 1525 h. We recovered Cores U1424A-1H through ‑11H extending from the seafloor down to 101.8 mbsf and yielding 102.4 m of core (101%). The geochemistry team conducted high resolution Rhizon pore water sampling of the uppermost five cores from Hole U1424A for shipboard and post expedition geochemical analyses. Paleomagnetic measurements identified the Brunhes/​Matuyama polarity transition (0.781 Ma) near the base of Core U1424A-3H. The age at the base of Core U1424A-9H (~83 mbsf) is estimated at ~2.7 Ma based on biostratigraphic markers.

Daily Science Report for 24 August 2013

LOCATION: Northeast Sea of Japan/​East Sea, in transit to Site U1424 (JB-1A)

SCIENCE UPDATE: Following the successful deployment of the modified paleo-combo downhole logging tool string, we lowered the FMS-Sonic tool string to the bottom of Hole U1423B (249 m) and recorded resistivity images of the borehole, sonic velocities, and natural gamma ray data over the entire interval. The downhole logging experiment was completed and the drill string pulled out of the hole by 0515 h. Subsequently, the ship was moved 15 m south of Hole U1423A and Hole U1423C was started at 0655 h. Hole U1423C was drilled without coring to 114 m. From this depth down to 180 m, we cut and recovered seven cores in a series of alternating drilled and cored intervals with the objective of filling gaps in APC cores recovered from the previous two holes at Site U1423. Real-time stratigraphic correlation indicated that the carefully orchestrated coring operation appeared to be successful. The drill string was pulled out of the hole and the rig prepared for transit to the next site, U1424 (proposed site JB-1A). Description and measurement of physical and magnetic properties have been completed for all cores from Hole U1423B and are ongoing for Hole U1423C.

Daily Science Report for 23 August 2013

LOCATION: Site U1423 (41°41.95′N, 139°4.98′E, 1797 m water depth)

SCIENCE UPDATE: The ship was offset 15 m north of Hole U1423A, and Hole U1423B was spudded at 0050 h. Cores U1423B-1H through ‑28H extended from the seafloor to 249.1 m, recovering 250 m (100%). As in Hole U1423A, the interval recovered in Hole U1423B consists of alternating biosiliceous greenish gray clay, dark brown silty clay, and olive green silty clay in the upper ~100 m (Lithostratigraphic Unit I), and relatively homogenous diatom ooze to total depth (Unit II). A remarkable feature of Unit I is the alternating, decimeter scale color banded bedding that characterizes most of the sequence. An age of 4.8 to 5.1 Ma is estimated for the bottom of Hole U1423B based on biostratigraphic markers. Sulfate analyses of interstitial water samples from Site U1422, and phosphate, ammonia, and minor elements from porewater samples from Site U1423, have been completed. Sediment samples from Site U1423 are being measured for carbonate, total carbon, and total nitrogen content. Following the end of coring operations in Hole U1423B, the hole was conditioned for downhole logging. By 2000 h the first logging tool string was being deployed to the bottom of the hole. The modified paleo-combo tool string recorded spectral gamma ray, caliper, magnetic susceptibility, resistivity, and lithologic density logs over the entire interval.

Daily Science Report for 22 August 2013

LOCATION: Site U1423 (41°41.95′N, 139°4.98′E, 1797 m water depth)

SCIENCE UPDATE: Hole U1423A was completed with Cores U1423A-1H through ‑22H extending from the seafloor to 206.6 m and recovering 212.9 m (103%). The interval from 0 to ~93 m (Cores U1423A-1H through ‑10H) described today consists of brown and dark green biosiliceous silty clay equivalent to stratigraphic Unit I at Site U1422. Early Pleistocene to late Pliocene (2.2 to <3.4 Ma) age indicators were found in Cores U1423A-10H to ‑14H. Geochemical analyses of samples from Site U1422 are being finalized and sampling for interstitial water and solid phase geochemistry was completed at Hole U1423A. Expedition scientists submitted the initial drafts of the Site U1422 science reports.

Daily Science Report for 21 August 2013

LOCATION: Site U1423 (41°41.95′N, 139°4.98′E, 1796 m water depth)

SCIENCE UPDATE: Our final activity at Site U1422 was to recover the drill string and secure the rig for transit. The vessel initiated its transit to Site U1423 (proposed site JB-2A) at 1142 h. We plan to drill two holes, one to ~200 m and one to ~250 m, although the depth and number of holes may be adjusted based on the age and quality of the sediment recovered. In addition to coring, we plan to conduct downhole logging in the deepest hole. We continue to describe and analyze samples from the cores recovered at Site U1422. Cores U1422E-3H and ‑4H were rhizon sampled for pore water analysis. We held the science summary meeting for Site U1422 and scientists began working on their site reports. By 2342 h, we were maneuvering the ship over the location of Site U1423, about 16 nmi northwest of Ōshima Island.

Daily Science Report for 20 August 2013

LOCATION: Hole U1422E (43°45.9897′N, 138°50.0002′E, 3440 m water depth)

SCIENCE UPDATE: Coring in Hole U1422D concluded with Cores U1422D-4H through ‑16H (21.6 to 141.8 m) after reaching 90,000 lbs of overpull with Core U1422D-16H. The total recovery for Hole U1422D was 152.83 m (108%). The drill string was pulled up to the sea floor, the ship offset 15 m east of Hole U1422A, and Hole U1422E was spudded at 1320 h. Hole U1422E was cored to APC refusal, which occurred at Core U1422E-14H (111.6 m). The total recovery for Hole U1422E was 114.34 m (103%). The drill string was pulled out of the hole ending coring operations at Site U1422. Two major lithologic units are recognized at Site U1422. Unit I (0 to ~90 m) consists of alternating greenish gray clay, dark brown silty clay and olive green silty clay. Unit II (~90 to 205.2 m) consists of diatomaceous silty clay and silty sand. Ash beds from a few mm thick up to 25 cm thick occur throughout the entire interval, but are most abundant in the lower part of Unit I and the uppermost part of Unit II. The base of the cored interval is older than ~3 Ma, but younger than 3.9 Ma based on biostratigraphic markers. The geochemistry laboratory is running samples on the IC and ICP, and carbonate and CHNS analyses are ongoing. Core description and stratigraphic correlation of Holes U1422A, U1422B, U1422C, U1422D and U1422E continues.

Daily Science Report for 19 August 2013

LOCATION: Hole U1422D (43°45.99′N, 138°49.99′E, 3440 m water depth)

SCIENCE UPDATE: Hole U1422C was completed with Cores U1422C-14H through ‑31H, from 115.8 to 205.2 m, with recovery of 96.15 m (108%). The interval consists of Pleistocene to late Pliocene biosiliceous greenish gray clay to brownish or olive green silty clay, with sparse thin carbonate laminae. An increasing number of sandy beds occur with increasing depth below Core U1422C-12H (~100 m) and are interpreted to be turbidite layers. An age of less than 3.9 Ma is estimated for the bottom of Hole U1422C based on radiolarian biostratigraphy and magnetostratigraphy. Coring switched from the full-length advanced piston corer (APC) to the half-length APC system at Core U1422C-15H after reaching 90,000 lbs of overpull with Core U1422C-14H. At 1950 h, the drill pipe was pulled out of the seafloor, ending Hole U1422C. The ship was offset 15 m west and Hole U1422D was initiated at 2120 h. Cores U1422D-1H to ‑3H (0–21.6 m) have been retrieved with recovery of 27.9 m (129%).

Daily Science Report for 18 August 2013

LOCATION: Hole U1422C (43°45.99′N, 138°49.99′E, 3440 m water depth)

SCIENCE UPDATE: Today we completed APC coring Holes U1422A (1 core), U1422B (1 core), and started coring operations in Hole U1422C. Holes U1422A and U1422B were ended after the first core at each hole failed to recover the desired sediment/​water interface. Direct comparison of the magnetic susceptibility measured in the mudline cores from the first two holes with the magnetic susceptibility record from ODP Site 795 showed that Core U1422A-1H and Core U1422B-1H were taken from ~8 and ~3 m below the seafloor, respectively. Hole U1422C was spudded at 0640 h on 18 August. By midnight, Cores U1422C-1H through ‑13H (0–115.8 mbsf) were recovered, yielding 119.6 m of sediment. All cores from Holes U1422A and U1422B, and Cores U1422C-1H to ‑11H have been measured for physical properties. Cores U1422A-1H, U1422B-1H, and U1422C-1H to ‑3H consist of alternating light greenish gray clay to brown and olive green silty clay. Bioturbation ranges from sparse to moderate. An age of ~2.2 m.y. is estimated for the bottom of Core U1422C-10H based on radiolarians. The biostratigraphic data are consistent with that from ODP Site 795 drilled ~30 km northeast of Site U1422.

Daily Science Report for 17 August 2013

LOCATION: Hole U1422A (43°45.99′N, 138°49.99′E, 3446 m water depth)

SCIENCE UPDATE: The ship arrived at Site U1422 at 1448 h on 17 August, after a 3556 nmi voyage across the North Pacific. The thrusters were lowered and the ship switched to full dynamic positioning (DP) control at 1528 h. After making up the bottom hole assembly (BHA), the rest of the day was spent lowering the drill string to the seafloor.

A pre-site meeting was held to discuss the geologic background and objectives of proposed sites JB-3 (Site U1422), JB-2 and JB-1, in the northern part of the Sea of Japan/​East Sea, as well as to give an overview of drilling operations. The main scientific objectives at these sites are to:

• Reconstruct the behaviors of the Westerly Jet (WJ), East Asian Winter Monsoon (EAWM), and the Tsushima Warm Current (TWC);
• Identify ice-rafted debris (IRD) events and reconstruct temporal variation in their southern limit; and
• Reconstruct the ventilation history of the Sea of Japan/​East Sea.

Daily Science Report for 16 August 2013

LOCATION: Northeast Sea of Japan/​East Sea, in transit to Site U1422 (JB-3)

SCIENCE UPDATE: Today we passed through the Tsugaru Strait, which separates the Japanese island of Hokkaido, to the north, from Honshu, to the south. A four knot opposing current in the strait impacted the ship’s speed considerably as we crossed from the North Pacific Ocean into the Sea of Japan/​East Sea. Scientists attended presentations on “Pleistocene megafloods in the northeast Pacific,” and “Putting the early deglaciation of the Scandinavian ice-sheet in a global context.” Core describers underwent further training on the Section Half Imaging Logger (SHIL), and the Physical Properties and Stratigraphic Correlation groups practiced core flow procedures and data acquisition on the whole-round loggers. Estimated time of arrival at Site U1422 is 1500 h on 17 August.

Daily Science Report for 15 August 2013

LOCATION: In transit to the Sea of Japan/​East Sea

SCIENCE UPDATE: Senior shipboard personnel held the operational “pre-spud” meeting for the northernmost sites in our coring program—proposed Sites JB-3 (Site U1422), JB-2 and JB-1. Scientists are now on their assigned work shifts and eagerly awaiting core. Clocks were turned back one hour. Ship will be at UTC + 9 hours for the duration of the expedition. Estimated time of arrival at Site U1422 is between 1200 h and 1800 h on 17 August.

Daily Science Report for 14 August 2013

LOCATION: In transit to the Sea of Japan/​East Sea

SCIENCE UPDATE: All science teams remain busy practicing their laboratory procedures and familiarizing themselves with their instruments and applications. The geochemistry group refined the methods for interstitial water sampling and analyses and did initial training on the spectrophotometer (ammonium, biogenic silica, and total phosphorous), ion chromatograph (IC), and the ICP-ES (major and minor elements). They also discussed a sediment budget for the squeeze cakes and potential sampling for total organic and inorganic carbon for the upcoming core recovery. We attended presentations “The characters of dust in the East Asia and its evolution,” and “History of Asian eolian input to the west Philippine Sea over the last one million years.” The distance remaining to Site U1422 (JB-3) is 637 nmi. The estimated arrival time is 1800 h on 17 August.

Daily Science Report for 13 August 2013

LOCATION: In transit to the Sea of Japan/​East Sea

SCIENCE UPDATE: Today, all laboratory teams continued training on their laboratory instruments and procedures. The sedimentology team underwent training on the Section Half Multisensor Logger (SHMSL), which measures sediment color reflectance and magnetic susceptibility, and the Section Half Imaging Logger (SHIL), which had been offline due to software maintenance. We attended the presentations “High resolution optical dating for marine sediments from North Pacific Ocean,” and “Middle to late Miocene stepwise climate cooling: Evidence from high-resolution deep-water isotopes.” The USIO technical staff and the Siem Offshore crew attended a presentation on the expedition objectives given by the chief scientists.

Daily Science Report for 12 August 2013

LOCATION: In transit to the Sea of Japan/​East Sea

SCIENCE UPDATE: We have traveled 2352 nmi since we left Alaska on 2 August. The distance remaining to the first site of the expedition is 1184 nmi and we anticipate arriving at Site U1422 (JB-3) in the afternoon of 17 August. Expedition scientists continue to test and familiarize themselves with all laboratory instruments and core description application. In the afternoon, the Sample Allocation Committee met to review and refine the shipboard sampling plan. In addition, scientists attended presentations “Variation in the freshwater discharge of the Yangtze River and associated surface water change in the northern East China Sea,” as well as “Anthopogenic influence and extreme climate events in Rhone pro-delta sediments (Gulf of Lions, NW Mediterranean).”

Daily Science Report for 11 August 2013

LOCATION: In transit to the Sea of Japan/​East Sea

SCIENCE UPDATE: Expedition scientists continued training on their laboratory instruments and perfecting methods and procedures while in transit to Site U1422 (JB-3). We attended the presentations “Nature of periodicities in the color and major element composition of the Japan Sea/​East Sea sediment” and “Dispersed volcanic ash in marine sediment.” A fire and abandon ship safety drill was conducted in the morning.

Daily Science Report for 10 August 2013

LOCATION: In transit to the Sea of Japan/​East Sea

SCIENCE UPDATE: Scientists continue to practice core description, collection of physical and chemical properties, and to discuss postcruise research studies. Members of the “Day shift” scientific team were led on a ship tour by the Operations Superintendent. In addition, we attended the presentations “Forget about anoxia: the early anthropocene in the Black Sea” and “Sediment and pore water chemistry across shallow sulfate-methane transitions: the anaerobic oxidation of methane.” The estimated time of arrival at Site U1422 (JB-3) is 1800 h on 17 August.

Daily Science Report for 8 (and 9) August 2013

LOCATION: In transit to the Sea of Japan/​East Sea

SCIENCE UPDATE: Scientists started to process a “play core” taken by Expedition 341 in the Gulf of Alaska for practicing routine physical properties measurements, geochemical and micropaleontological analyses, and core description. In addition, scientists received training on the use of light microscopes and the new scanning electron microscope. They also attended presentations “Dating South Pacific Gyre pelagic clays with constant cosmogenic cobalt,” as well as “Ostracods in Cenozoic Paleoceanography: from regions of deep water formation to ultra-oligotrophic environments.” Clocks were advanced 24 h at midnight as we crossed the dateline.

Daily Science Report for 7 August 2013

LOCATION: In transit to the Sea of Japan/​East Sea

SCIENCE UPDATE: Today the ship traveled 234 nmi at 9.8 kt in moderate seas. The expedition management team and the stratigraphic correlators met with the Siem Offshore drilling crew to discuss coring operations. Scientists attended presentations on “Ocean circulation in the Sea of Japan/​East Sea based on radiolarian studies,” as well as “Oxygenation changes in the Cariaco Basin and their linkage to abrupt climate change.” All science laboratory groups completed their drafts of the methods descriptions and submitted their reports to the Co-Chiefs’ office. We held meetings with the sedimentology and micropaleontology teams to review shipboard laboratory procedures.

Daily Science Report for 6 August 2013

LOCATION: In transit to the Sea of Japan/​East Sea

SCIENCE UPDATE: Expedition 346 scientists continue to work on their method descriptions. We held a meeting to talk about proposed post-expedition micropaleontological, isotope geochemistry, and trace element studies, and held two science seminars by members of the science party. Clocks were turned back one hour to UTC – 11.

Daily Science Report for 5 August 2013

LOCATION: In transit to the Sea of Japan/​East Sea

SCIENCE UPDATE: Due to severe weather, the ship tour scheduled for today was canceled. Scientists assigned to the “Night Shift” underwent a detailed core flow overview by the shipboard curator. The rest of the scientists continued to work out the shipboard sampling plan and to write their method descriptions. In the afternoon, we held a meeting to discuss postcruise provenance studies and the Sample Allocation Committee met to review shipboard procedures for shorebased sample requests for microbiological studies. In addition, we held two science seminars by members of the science party. Clocks have been turned back one hour every twelve hours as we transit west across the North Pacific.

Daily Science Report for 4 August 2013

LOCATION: In transit to the Sea of Japan/​East Sea

SCIENCE UPDATE: Today, the science party received an overview presentation on IODP sample policy, scientists obligations, and further information on tasks at sea from the Expedition Project Manager. The scientists assigned to the “Night Shift” were led on a ship tour by the Operations Superintendent, while the “Day Shift” underwent a detailed core flow overview. Tomorrow we planned to conduct the same activities for the opposite shifts. Science teams continued to work out laboratory procedures and on their method descriptions. In the afternoon, the science party received a presentation on downhole logging operations, and we held meetings to discuss the shipboard sampling plan and procedures for geochemistry, microbiology, optically stimulated luminescence (OSL) dating, and paleomagnetism.

Daily Science Report for 3 August 2013

LOCATION: In transit to the Sea of Japan/​East Sea

SCIENCE UPDATE: The science party received a presentation on how to prepare and write the expedition reports from the Expedition Project Manager, and an overview of the sampling and core description applications by the IODP-USIO technical support team. The sedimentology and biostratigraphy teams received DESClogik training. Other lab teams continued their review of laboratory procedures and tools and worked on their method descriptions. In the afternoon, the science party received a presentation on the Lithostratigraphy of the Sea of Japan/East Sea, and we held meetings to discuss stratigraphic correlation and post-expedition plans for XRF scanning of the cores. The estimated date of arrival at our first site, JB-3, is 17 August.

Daily Science Report for 2 August 2013

LOCATION: In transit to the Sea of Japan/​East Sea

SCIENCE UPDATE: We departed the Valdez Container Terminal at 0718 h and began our ~2 week transit to Site JB-3 in the Sea of Japan/​East Sea. Building on yesterdays orientation activities, today the Expedition 346 scientists received an introduction to the shipboard computing environment and started discussing laboratory methods and protocols. Our first fire and abandon ship safety drill was conducted in the afternoon.

Daily Science Report for 1 August 2013

LOCATION: Valdez, Alaska Container Terminal

SCIENCE UPDATE: Following Expedition 346 scientists and USIO technical staff introductions, the captain of the JOIDES Resolution, Physician and Offshore Installation Manager delivered the ship’s safety rules and regulations to the science party and new technical staff; the chief scientists and staff scientist presented an overview of the expedition project, scientific objectives and operations plan. Scientists were given a tour of the laboratories and also underwent orientation to laboratory safety and life at sea. The estimated time of departure was revised to 0700 hours on 2 August.