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A gas hydrate assessment at International Ocean Discovery Program Expedition 400 drill sites was conducted using downhole logging and core data. Here, we calculate and present the base of gas hydrate stability zone at Expedition 400 drill sites in Baffin Bay, northwest Greenland. We used data from downhole logs and sediment cores from Sites U1603, U1604, U1607, and U1608 to assess hydrate and did not find evidence for the presence of hydrate. At Site U1606, only core data were acquired that showed a decrease in pore water salinity, potentially indicating the presence of hydrate; however, further confirmation was not possible due to the unavailability of downhole logging data. Because of the limitation of the acquired data at the drill sites, a further assessment to confirm the presence of hydrate was not possible. Although hydrate was not identified at any drill sites, hydrate might still be present in the region. 

Marine gateways play a critical role in the exchange of water, heat, salt, and nutrients between oceans and seas. Changes in gateway geometry can significantly alter both the pattern of global ocean circulation and climate. Today, the volume of dense water supplied by Atlantic–Mediterranean exchange through the Gibraltar Strait is among the largest in the global ocean. For the past 5 My, this overflow has generated a saline plume at intermediate depths in the Atlantic that deposits distinctive contouritic sediments and contributes to the formation of North Atlantic Deep Water. This single gateway configuration only developed in the Early Pliocene. During the Miocene, two narrow corridors linked the Mediterranean and Atlantic: one in northern Morocco and the other in southern Spain. Progressive restriction and closure of these corridors resulted in extreme salinity fluctuations in the Mediterranean and the precipitation of the Messinian Salinity Crisis salt giant. International Ocean Discovery Program (IODP) Expedition 401 is the offshore drilling component of a Land-2-Sea drilling proposal, Investigating Miocene Mediterranean–Atlantic Gateway Exchange (IMMAGE). Its aim is to recover a complete record of Atlantic–Mediterranean exchange from its Late Miocene inception to its current configuration by targeting Miocene offshore sediments on either side of the Gibraltar Strait. Miocene cores from the two precursor connections now exposed on land will be obtained by future International Continental Scientific Drilling Program (ICDP) campaigns. 

We present seismic two-way traveltime depth relationships for all sites drilled by the International Ocean Discovery Program Expedition 398, Hellenic Arc Volcanic Field, using high-resolution multichannel seismic and core data. First, we filter and interpolate P-wave velocity and density data taken from (1) whole-round cores and (2) discrete measurements on half-round cores. We establish the reliability of shipboard density measurements by comparing them with in situ logging data. Using these validated measurements, we estimate acoustic impedance and synthetic seismograms. By correlating synthetic seismograms with those extracted from multichannel seismic profiles at each site, we establish time-depth relationships. We assess the quality of these relationships by examining the alignment of major lithologic boundaries with prominent unconformities or correlated conformities in the reflection seismic data. The results of this report facilitate the mapping of core data onto the multichannel seismic profiles at each site, allowing for spatial tracing of core data across the Christiana-Santorini-Kolumbo volcanic field. 

We measured the natural remanent magnetization (NRM) and rock magnetic properties of 57 sediment samples and 38 basalt samples from Tūranganui Knoll on the Hikurangi Plateau collected at Site U1526 during International Ocean Discovery Program Expedition 375. NRM was measured on all samples before and after either progressive alternating field or thermal demagnetization. Principal component analysis was conducted to provide estimates of the characteristic remanent magnetization direction. Rock magnetic observations include measurements on select samples of the bulk magnetic susceptibility, susceptibility versus heating for Curie temperature assessment, magnetic hysteresis, backfield for coercivity of remanence determinations, isothermal remanent magnetization, and first-order reversal curves.