IODP Expedition 398
Hellenic Arc Volcanic Field
Daily Science Report for 10 February 2023
Location: Berth 5, Port of Heraklion, Crete
Science Update: The vessel arrived at the pilot station at 0700 h, with the pilot onboard at 0706 h. Tugboats connected at 0715 h. The first line ashore was at 0736 h, ending Expedition 398 Hellenic Arc Volcanic Field. The science party disembarked at 1200 h.
In total, Expedition 398 drilled 7.34 km, cored an interval of 5.72 km, and recovered 3.35 km of sediments and basement rock.
Daily Science Report for 9 February 2023
Location:
- Hole U1599C (proposed Site CSK-23A); 36°26.9389′N, 25°46.7762′E; water depth 592.7 m
- Underway to Heraklion, Crete: 36°10.22′N, 25°36.00′E
Science Update: Cores U1599C-45R to 50R were retrieved from 639.8 to 697.8 mbsf. The average recovery for today’s cored interval is 51% (0%–90%). The bit cleared the seafloor at 1740 h and the rotary table at 2030 h. Hole U1599C reached a maximum penetration of 697.8 mbsf with a cored interval of 474.8 m and a recovery of 244.18 m. The average recovery for the hole was 51%. The vessel was under bridge control and started the sea passage to Heraklion, Crete at 2130 h, ending Site U1599.
Cores U1599C-42R to 50R were run through the whole-round physical properties track systems, split, and described. The cores consist of calcareous sandstone, gravelly sandstone, micrite, matrix-supported sandy conglomerate, and dolostone. Microscopic analyses showed transparent glass, authigenic dolomite and calcite, and altered volcaniclastics.
All laboratory groups finished their site reports and the Preliminary Report.
Daily Science Report for 8 February 2023
Location: Hole U1599C (proposed Site CSK-23A); 36°26.9389′N, 25°46.7762′E; water depth 592.7 m
Science Update: Cores U1599C-32R to 44R were retrieved from 513.7 to 639.8 mbsf. The average recovery for today’s cored interval is 51% (0%–90%).
Cores U1599C-31R to 41R were run through the whole-round physical properties track systems. Cores U1599C-31R to 41R were split and described. The cores consist of dolomitic sandstone, organic-rich dolomitic sandstone, sandstone, calcareous mudstone, tuff, calcareous tuffaceous mudstone, tuffaceous sandstone, and micrite. Microscopic analyses showed transparent glass, authigenic dolomite and calcite, and altered volcaniclastics.
Daily Science Report for 7 February 2023
Location: Hole U1599C (proposed Site CSK-23A); 36°26.9389′N, 25°46.7762′E; water depth 592.7 m
Science Update: Hole U1599C was reentered at 0230 h. Cores U1599C-26R to 31R were retrieved from 455.5 to 513.7 mbsf. The average recovery for today’s cored interval is 45% (34%–60%).
Cores U1599C-26R to 30R were run through the whole-round physical properties track systems. Cores U1599C-26R to 30R were split and described. The cores consist of dolomitic marl, organic-rich marl, dolomitic sandstone, and organic-rich dolomitic sandstone. Microscopic analyses showed transparent and brown glass, authigenic dolomite and calcite, iron and manganese oxides, volcanic lithics, foraminifers, and calcareous nannofossils.
Daily Science Report for 6 February 2023
Location: Waiting on weather 5.5 nmi west of Hole U1599C; 36°27.00′N, 25°42.00′E
Science Update: Throughout the day, the vessel was waiting on weather (WOW). The weather forecast showed an improvement throughout the evening and into the night. The 5.5 nmi move from the WOW station to Site U1599 in DP mode began at 1640 h and continued throughout the night.
All groups worked on their Site U1600 reports and finalized their methods chapters.
Daily Science Report for 5 February 2023
Locations:
- Hole U1600C (proposed Site CSK-24A); 36°32.5890′N, 25°39.0067′E; water depth 326.3 m
- Waiting on Weather 5.5 nmi west of Hole U1599C; 36°27.00′N, 25°42.00′E
Science Update: Cores U1600C-13R and 14R were retrieved from 179.7 to 188.5 mbsf, the final depth of the hole. Hole U1600C reached a maximum penetration of 188.5 mbsf with a cored interval of 113.5 m and a recovery of 36.78 m. The average recovery for the hole was 32%. The drill string was tripped up and the bit cleared the rotary table at 0525 h. The 8.4 nmi sea passage to Site U1599C began at 0600 h, ending Site U1600. The vessel was on location and under DP control at 0708 h. The rig floor crew began assembling the RCB BHA and the drill string was tripped down to 200 m above the seafloor. Weather conditions were predicted to deteriorate and exceed operational limits. The vessel was offset 5.5 nmi to the west of Hole U1599C in DP mode, on the leeward side of Anafi Island. Throughout the night the vessel was waiting on weather (WOW).
Cores U1600C-12R to 14R were run through the whole-round physical properties track systems. Cores U1600C-10R to 14R were split and described. The cores consist of organic-rich calcareous mud, sandstone, and ultramafic rocks marking the basement.
Daily Science Report for 4 February 2023
Locations:
- Hole U1596B (proposed Site CSK-06B); 36°26.5568′N, 25°22.4875′E; water depth 381.9 m
- Hole U1600C (proposed Site CSK-24A); 36°32.5890′N, 25°39.0067′E; water depth 326.3 m
Science Update: The bit cleared the rotary table at 0105 h. The 17.8 nmi sea passage to Site U1600 began at 0154 h, ending Site U1596. The vessel arrived on location at 0336 h and was under full DP control at 0400 h, restarting Site U1600. Hole U1600C was spudded at 0655 h in a water depth of 326.3 mbsl (by offset), followed by a drilled interval without recovery to 75 mbsf. Cores U1600C-2R to 12R were retrieved from 75 mbsf to 179.7 mbsf. The average recovery for today’s cored interval is 33% (0%–97%).
Cores U1600C-3R to 11R were run through the whole-round physical properties track systems. Cores U1596B-1H to 11F and U1600C-3R to 9R were split and described. The cores consist of mud, tuffaceous mud, ash, lapilli, lapilli ash, organic-rich calcareous sand, calcareous sand, and organic-rich calcareous mud.
Daily Science Report for 3 February 2023
Locations:
- Hole U1595C (proposed Site CSK-08A); 36°22.8674′N, 25°24.3062′E; water depth 291.31 m
- Hole U1596B (proposed Site CSK-06B); 36°26.5568′N, 25°22.4875′E; water depth 381.9 m
Science Update: Hole U1595C was spudded at 0005 h with Core U1595C-1H recovering 3.8 m, establishing seafloor depth at 291.31 m. Following Core 1H, the hole was drilled without recovery to 53 mbsf. The HLAPC was deployed for Cores U1595C-3F to 11F at 95.3 m. A launch pulled up alongside with the mayor and deputy mayor of Santorini, the commander of the port police authority, two eminent scientists, a Siem Offshore crew member, and 9 journalists boarding the vessel at 0910 h. High torque indicated a collapsing hole was observed. After ~45 min and an overpull of 100,000 lb, rotation could be reestablished, and the decision was made to abandon the hole. The bit cleared the seafloor at 1115 h. Hole U1595C reached a maximum penetration of 95.3 mbsf with a cored interval of 46.1 m and a recovery of 21.37 m. The average recovery for the hole was 46%. The drill string was tripped out of the hole and the bit cleared the rotary table at 1347 h. The launch with dignitaries and media departed the vessel at 1430 h, and the vessel began its 4.8 nmi passage to Site U1596 at the same time, ending Site U1595. The ship arrived on location, 50 m from Hole U1596A, at 1615 h. Hole U1596B was spudded at 1915 h with Core U1596B-1H retrieving 4.2 m, establishing seafloor depth at 381.9 mbsl. APC coring continued to Core U1596B-5H at 42.2 m, the final depth of this hole. The bit cleared the seafloor at 2300 h. Hole U1596B reached a maximum penetration of 42.2 mbsf with a cored interval of 42.2 m and a recovery of 36.63 m. The average recovery for the hole was 87%. The pipe trip up to the vessel continued throughout the night.
Cores U1595C-1H to 11F, and U1596B-1H were run through the whole-round physical properties track systems. Cores U1595B-10H to 15F and U1595C-1H to 11F were split and described. The cores consist of tuffaceous mud, ash, lapilli, lapilli ash, lithic lapilli, lithic crystal lapilli, and organic-rich mud.
Daily Science Report for 2 February 2023
Locations:
- Hole U1599C (proposed Site CSK-23A); 36°26.9389′N, 25°46.7762′E; water depth 592.7 m
- Hole U1595B (proposed Site CSK-08A); 36°22.8819′N, 25°24.3358′E, water depth 294.42 m
Science Update: The 28.2 nmi sea passage to Site U1595 began at 0142 h, ending Hole U1599C. The vessel arrived on location, 50 m from Hole U1595A, at 0415 h. The rig floor crew began assembling the APC/XCB BHA. A launch pulled up alongside with the mayor and deputy mayor of Santorini, the commander of the port police authority, two eminent scientists, and 8 journalists boarding the vessel at 0915 h. Hole U1595B was spudded at 1010 h with Core U1595B-1H retrieving 3.7 m, establishing the seafloor depth at 291.42 m. Cores U1595B-2H to 13H were retrieved from 3.7 to 108.2 mbsf. The HLAPC was deployed for Cores U1595B-14F and 15F, to a final hole depth of 127.1 mbsf. Cores from Hole U1595B recovered of 74.02 m over the 127.1 m interval (74%). The drill string was tripped out of the hole and the bit cleared the seafloor at 2320 h, ending Hole U1595B. The vessel was offset 50 m along the seismic line in preparation for Hole U1595C.
Cores U1595B-1H to 15F were run through the whole-round physical properties track systems. Cores U1595B-1H to 8H were split and described. The cores consist of tuffaceous mud, ash, lapilli, lapilli ash, and lithic lapilli.
Daily Science Report for 1 February 2023
Location: Hole U1599C (proposed Site CSK-23A); 36°26.9389′N, 25°46.7762′E; water depth 592.7 m
Science Update: Cores U1599C-15R to 25R were retrieved from 348.8 to 455.5 mbsf. The average recovery for today’s cored interval is 52% (0%–96%). Following Core U1599C-25R, the drill string was pulled up to 55 mbsf. A free-fall funnel (FFF) was assembled and deployed at 2005 h, followed with the vibration isolated television (VIT). The bit cleared the FFF at 2117 h. The VIT was back on board at 2209 h, and the rig crew began disassembling the RCB BHA in preparation for APC operations at the next site.
Cores U1599C-14R to 25R were run through the whole-round physical properties track systems. Cores U1599C-13R to 25R were split and described. The cores consist of dolomitic marl, organic-rich marl, marl, tuff, organic-rich sandstone, and bioclastic marl. Microscopic analyses showed transparent glass, authigenic dolomite, and calcareous nannofossils.