International Ocean Drilling Program Research Articles

Reef growth history at intermediate to mesophotic depths since the end of the Last Glacial period along the Great Barrier Reef shelf edge

Reef communities at intermediate (10 to 30 m) and mesophotic (~ 30 to 150 m) depths occupy large areas of sea floor but little is known about their potential to accrete vertically, their response to sea-level change and other environmental perturbations. In this study, the authors have examined cores from two holes, M0040A and M0041A, drilled by the International Ocean Drilling Program Expedition 325 along the shelf edge of the modern GBR at 131 m water depth. The objective was to investigate reef growth history at palaeo-water depths > 20 m over a time period spanning 30,000 years, from the end of the Last Glacial period through the last deglaciation. Based on changes in lithologies and biotic components, and a robust chronostratigraphic framework supported by 47 radiometric ages, the authors have identified two episodes of reef growth, one during Marine Isotope Stage (MIS) 2 and the other at the onset of the deglaciation, both characterised by abundant microbialite crusts and distinct coral assemblages. Palaeo-water depths range from 30 to 60 m and from 20 to 30 m for the MIS 2 and early deglacial reef sections, respectively. The first episode of reef growth documented in the cores initiated at 27 to 25 ka, possibly in response to increased light availability and change in sedimentation resulting from falling sea-level between 32 and 29 ka from MIS 3 and also to low atmospheric pCO2 at the end of the Last Glacial period. Reef accretion was reduced or ceased sometime between 24 and 19 ka, coinciding with the rapid 20 m sea-level fall of the peak Last Glacial Maximum and minima of SSTs. Reef growth resumed at 19.5 to 18.5 ka, influenced by a period of moderate sea-level rise and increasing sea surface temperatures at the onset of the deglaciation. Reef growth termination at ca. 17 ka correlates with a major episode of reef demise previously identified in adjacent mid and outer terrace cores and linked to reduced water quality combined with rapid deglacial sea-level rise. Vertical accretion (VA) rates were calculated based on two methods: linear visual fitting and Bayesian modelling. The findings show that the highest VA rates are associated with microbialite boundstone. Reef ecosystems dominated by microbialite and corals developed at intermediate and mesophotic depths, and grew vertically at maximum rates of 2 to 5 mm yr-1 depending on the method used, over a period of rapid environmental change during the transition from MIS 3 to MIS 1. Further study needs to explore the potential of modern-type deep coralgal communities to cope with higher rates of sea-level rise predicted this century.

Pinxian Wang: no place for a 'gold rush' in the exploration of the deep sea.

Prof. Pinxian Wang () of Tongji University, born in 1936, is one of the leading deep-sea scientists in China. As the first co-chief scientist of Chinese nationality in the international Ocean Drilling Program (ODP), he co-led ODP Leg 184 in 1999; and in 2018, at 82 years old, he dived to a depth of 1400 meters in the South China Sea (SCS) in China's manned submersible 'Deep Sea Warrior'. In recent years, he has also become a star of science popularization in China-he has more than 1.7 million followers on China's video-sharing platform bilibili, and his popular science book Deep Sea in Simple Words is a best seller. In September 2022, Prof. Wang was interviewed by NSR's Associate Editor-in-Chief, Zhonghe Zhou. In this interview, Prof. Wang summarized his six-decade-long scientific career, talked about the past and future of China's deep-sea research efforts, and explained his opinion on how to promote scientific culture in China.

The impact of clay fraction on the strength and stress ratio ( K 0 ) in Gulf of Mexico mudrocks and quartz silt mixtures: implications for borehole stability and fracture gradient

Mudrock strength parameters are required to improve the prediction of fracture gradient during drilling in poorly consolidated formations. Understanding the influence that mineral composition and consolidation stress have on the mechanical properties of mudrocks aids safe well design. Small changes in the mudrock clay content are shown to have significant effects on two important engineering parameters: the lateral stress ratio at rest, K 0 , and the critical state effective friction angle, ϕ ′ cs . A laboratory-testing programme using quartz silt and a Gulf of Mexico clay mixture investigates the effects of mudrock clay content on K 0 and ϕ ′ cs at two stress levels: 1 and 10 MPa. Values of K 0 and ϕ ′ cs were obtained by subjecting composition-controlled clay–silt specimens to a drained uniaxial vertical strain ( K 0 consolidation) phase, followed by an undrained compression triaxial shear phase. Triaxial tests illustrate consistent and systematic increases in K 0 and decreases in ϕ ′ cs , with increases in clay content at both stress levels. Stress dependence is observed through increases in K 0 and decreases in ϕ ′ cs with increases in stress level. Stress-dependent behaviour is shown to be more pronounced in mudrocks of high clay content. A predictive model is presented for K 0 in normally consolidated mudrocks, as a function of clay content and effective stress. The model is used to calculate the fracture gradient (least horizontal stress) profile at the International Ocean Drilling Program (IODP) Expedition 308 Site 1324. The estimated fracture gradient illustrates the effects of clay content and consolidation stress on safe mud weight design. Thematic collection: This article is part of the Geopressure collection available at: https://www.lyellcollection.org/cc/geopressure

Iron isotope constraints on the lithological heterogeneity of the upper mantle in the South China Sea

The South China Sea is located at the junction of the Eurasian, Indian, Australian, and Pacific plates, and thus its evolution is complex and the nature of its sub-ridge mantle remains unclear. Here we present new iron (Fe) isotopic data for mid-ocean ridge and intraplate basalts from the South China Sea region, in order to examine the origins of compositional heterogeneity in the sub-ridge mantle beneath the South China Sea. The investigated mid-ocean ridge basalts are from International Ocean Drilling Program Sites U1431 and U1433 in the eastern and southwestern sub-basins of the South China Sea, respectively. The primary melts of the Site U1431 and U1433 basalts have mean δ56Feprim = +0.06‰ ± 0.04‰ (2SD; n = 10) and +0.02‰ ± 0.02‰ (2SD; n = 3), respectively. The primary melts of the intraplate rocks have highly variable δ56Feprim (+0.04‰ to +0.22‰). Our new and previously published data show that the δ56Feprim values and Fe/Mn ratios of the Site U1431 and U1433 basalts are positively correlated (r2 = 0.42). This result indicates that the heterogeneous Fe isotopic compositions of the studied basalts reflect distinct mantle source lithologies (i.e. pyroxenite and peridotite) that have also been identified from the chemistry of olivine phenocrysts. Co-variations between δ56Feprim values and Mg–Sr–Nd isotopes for the South China Sea basalts suggest that the end-member components in the sub-ridge mantle include an enriched recycling-related pyroxenitic component with high δ56Fe and low δ26Mg, and a ubiquitous depleted subduction-modified peridotitic component with low δ56Fe and high δ26Mg.

Coexistence of Hainan Plume and Stagnant Slab in the Mantle Transition Zone beneath the South China Sea Spreading Ridge: Constraints from Volcanic Glasses and Seismic Tomography

Abstract The influence of Hainan mantle plume and subducting recycled oceanic crust beneath the spreading ridge of the South China Sea (SCS) have been widely proposed recently, but still controversial and ambiguous. Here, we present seismic tomographic evidence, new major and trace element, and Pb isotopic compositions of volcanic glasses from one International Ocean Drilling Program drill core (Site U1434) in the SCS spreading ridge. The volcanic glasses are relatively enriched in alkalis and light rare earth elements (LREEs) and depleted in heavy REEs (HREEs), exhibit slightly positive anomalies in Nb, Ta, Zr, and Hf as well as a positive Nb relative to La and Th, and show relatively high 207Pb/206Pb and 208Pb/206Pb isotopic ratios, suggesting ocean island basalt- (OIB-) type and enriched mantle 2- (EM2-) type geochemical features likely related to a mantle plume. These geochemical features are consistent with those of late Cenozoic volcanic rocks in Hainan and surrounding areas associated with a mantle plume, likely providing the influence of Hainan mantle plume beneath the spreading ridge of the SCS. The SCS primary-melt and volcanic glasses indicate that the source mantle involved 18.5% eclogite (dense, recycled oceanic crust from the stagnant subducted slab) and 46.1% garnet pyroxenite (produced by the reaction between the peridotite melt and recycled oceanic crust). The existence of Hainan mantle plume and stagnant subducted slab is further supported by geophysical evidence from a recent three-dimensional P-wave seismic tomographic model.

A new database structure for the IHFC Global Heat Flow Database

Periodic revisions of the Global Heat Flow Database (GHFD) take place under the auspices of the International Heat Flow Commission (IHFC) of the International Association of Seismology and Physics of the Earth's Interior (IASPEI). A growing number of heat-flow values, advances in scientific methods, digitization, and improvements in database technologies all warrant a revision of the structure of the GHFD that was last amended in 1976. We present a new structure for the GHFD, which will provide a basis for a reassessment and revision of the existing global heat-flow data set. The database fields within the new structure are described in detail to ensure a common understanding of the respective database entries. The new structure of the database takes advantage of today's possibilities for data management. It supports FAIR and open data principles, including interoperability with external data services, and links to DOI and IGSN numbers and other data resources (e.g., world geological map, world stratigraphic system, and International Ocean Drilling Program data). Aligned with this publication, a restructured version of the existing database is published, which provides a starting point for the upcoming collaborative process of data screening, quality control and revision. In parallel, the IHFC will work on criteria for a new quality scheme that will allow future users of the database to evaluate the quality of the collated heat-flow data based on specific criteria.

Early-Middle Pleistocene productivity changes of the Northern Cascadia Margin, Pacific Ocean

A total of 362 marine core samples from 200 meters below the sea-floor (mbsf) were examined through the International Ocean Drilling Program (IODP), Hole U1325B, Northern Cascadia Margin. The diversity parameters increased at ~200 mbsf during the Early Middle Pleistocene Transition (EMPT) period and gradually decreased towards ~165 mbsf. The diversity pattern is also notable, which projects the termination of EMPT due to increased orbital cyclicity (~41,000 to ~100,000 years). The δ18O (Uvigerina peregrina) at regular intervals ~150 mbsf, ~110 mbsf, ~50 mbsf and ~20 mbsf certainly agrees with the abundance of Cibicides wuellerstorfi, indicating the intrusion of California Cold Current in the region. The relative abundance rate of Cassidulina laevigata inversely proportional to the peaks of C. wuellerstorfi strongly indicating the circulation of Alaskan warm current in the Cascadia Margin. The paleoproductivity and oxygenation proxies strongly suggest the maximum primary productivity throughout ~85 mbsf towards the recent interval and the study region are showing oxic to suboxic environment further, the correlation matrix and the principal component phenomenon also strongly mirror the relationship and driving factors of the paleoceanographic condition. The present study aimed to understand the connections between each proxy liable to the paleoceanographic and paleoproductivity changes during the Early-Middle Pleistocene, Northern Cascadia Margin.

Contourite characterization and its discrimination from other deep‐water deposits in the Gulf of Cadiz contourite depositional system

AbstractDespite numerous efforts to properly differentiate between contourites and other deep‐water deposits in cores and outcrops, reliable diagnostic criteria are still lacking. The co‐occurrence of downslope and along‐slope sedimentary processes makes it particularly difficult to differentiate these relatively homogeneous deposits. The main aim of this paper is to identify differences in deep‐water sediments based on Principal Component Analysis of grain size and geochemistry, sedimentary facies, and reinforced by microfacies and ichnofacies. The sediments studied were obtained from two International Ocean Drilling Program Expedition 339 sites in mounded and sheeted drifts in the Gulf of Cadiz. The statistical approach led to the discernment of hemipelagites, silty contourites, sandy contourites, bottom current reworked sands, fine‐grained turbidites and debrites over a range of depositional and physiographic elements. These elements are linked to contourite drifts, the drift‐channel transition, the contourite channel and distal upper slope. When bottom currents or gravity‐driven flows are not the dominant depositional process, marine productivity and continental input settling forms the main depositional mechanism in deep‐water environments. This is reflected by a high variability of the first principal component in hemipelagic deposits. The stacked principal component variability of these deposits evidences that the contourite drift and the adjacent contourite channel were influenced by the interrelation of hemipelagic, gravitational and bottom current induced depositional processes. This interrelation questions the paradigm that a drift is made up solely of muddy sediments. The interrelation of sedimentary processes is a consequence of the precession‐driven changes in the intensity of the Mediterranean Outflow Water related to Mediterranean climate variability, which are punctuated by millennial‐scale variability. Associated vertical and lateral shifts of the Mediterranean Outflow Water, and therefore of its interface with the East North Atlantic Central Water, controlled sediment input and favoured turbulent sediment transport in the middle slope. During the interglacial precession maxima/insolation minima, a more vigorous upper core of the Mediterranean Outflow Water and the enhanced impact of the East North Atlantic Central Water – Mediterranean Outflow Water interface allowed for the development of the sandier contourite deposits.

Planktonic Foraminiferal Endemism at Southern High Latitudes Following the Terminal Cretaceous Extinction

AbstractAustral planktonic foraminiferal assemblages from immediately above the Cretaceous/Paleogene (K/Pg) boundary at Ocean Drilling Program Hole 690C (Maud Rise, Weddell Sea) and International Ocean Drilling Program Hole U1514C (southeast Indian Ocean) show a much different record of post-extinction recovery than anywhere outside the circum-Antarctic region. Species of Woodringina and Parvularugoglobigerina, genera with well-documented evolutionary successions within the early Danian P0 and Pα biozones at tropical/subtropical and mid-latitude localities, are absent from southern high latitude sequences. This study proposes new criteria for biostratigraphic correlation of the lowermost Danian Antarctic Paleocene AP0 and AP1 Zones using stratophenetic observations from Scanning Electron Microscope images of lower Danian planktonic foraminifera at deep-sea sites in the southern South Atlantic and southern Indian Ocean. The small but distinctive species Turborotalita nikolasi (Koutsoukos) is a highly reliable index species for the lowermost Danian as it consistently occurs immediately above the K/Pg boundary at multiple southern high latitude sites, which is consistent with its distribution at middle and low latitudes. Also useful for cross-latitude correlation is Parasubbotina neanika n. sp., which first appears within the lowermost Danian worldwide. The geographic distribution of the New Zealand species Antarcticella pauciloculata (Jenkins) and Zeauvigerina waiparaensis (Jenkins), as well as Eoglobigerina maudrisensis n. sp. from just above the K/Pg in the southern South Atlantic and southern Indian Ocean, helps define the extent of the Austral Biogeographic Province and provides evidence for marine communication via marine seaways across Antarctica. While An. pauciloculata was previously considered a benthic species, new stable isotope evidence demonstrates that it lived a planktonic mode of life. It is possible this species evolved from a benthic ancestor and that the benthic to planktonic transition occurred through an intermediate tychopelagic lifestyle at a time when calcareous plankton were less abundant as a result of the terminal Cretaceous mass extinction.

A high‐resolution diatom‐based Middle and Late Holocene environmental history of the Little Belt region, Baltic Sea

The large‐scale shifts in the salinity of the Baltic Sea over the Holocene are well understood and have been comprehensively documented using sedimentary proxy records. More recent work has focused on understanding how past salinity fluctuations have affected other ecological parameters (e.g. primary productivity, nutrient content) of the Baltic basin, and salinity changes over key events and over short time scales are still not well understood. The International Ocean Drilling Program Expedition 347 cored the Baltic basin in order to collect basin‐wide environmental records through a glacial–interglacial cycle. Site M0059 is located in the Little Belt between the Baltic Sea and the Atlantic Ocean. A composite splice section from Site M0059 was analysed at a decadal resolution to study changes in salinity, nutrient conditions and other surface water column parameters based on changes in diatom assemblages and on quantitative diatom‐based salinity inferences. A mesotrophic slightly brackish assemblage is seen in the lowermost analysed depths, corresponding to 7800–7500 cal. a BP. An increase in salinity and nutrient content of the water column leads into a meso‐eutrophic brackish phase. The observed salinity increase is rapid, lasting from 7500 to 7150 cal. a BP. Subsequently, the Little Belt becomes oligotrophic and is dominated by tychopelagic diatoms from c. 7100 to c. 3900 cal. a BP. This interval contains some of the highest salinities observed followed by diatom assemblages similar to those of the Northern Atlantic Ocean, composed primarily of cosmopolitan open ocean marine diatoms. A return to tychopelagic productivity is seen from 3850 to 980 cal. a BP. Anthropogenic eutrophication is detected in the last 300 years of the record, which intensifies in the uppermost sediments. These results represent the first decadally resolved record in the region and provide new insight into the transition to a brackish basin and subsequent ecological development.

Holocene environmental history of the Ångermanälven Estuary, northern Baltic Sea

The Baltic Sea has experienced a complex geological history, with notable swings in salinity driven by changes to its connection with the Atlantic and glacio‐isostatic rebound. Sediments obtained during International Ocean Drilling Program Expedition 347 allow the study of the effects of these changes on the ecology of the Baltic in high resolution through the Holocene in areas where continuous records had not always been available. Sites M0061 and M0062, drilled in the Ångermanälven Estuary (northern Baltic Sea), contain records of Holocene‐aged sediments and microfossils. Here we present detailed records of palaeoecological and palaeoenvironmental changes to the Ångermanälven Estuary inferred from diatom, palynomorph and organic‐geochemical data. Based on diatom assemblages, the record is divided into four zones that comprise the Ancylus Lake, Littorina Sea, Post‐Littorina Sea and Recent Baltic Sea stages. The Ancylus Lake phase is initially characterized as oligotrophic, with the majority of primary productivity in the upper water column. This transition to a eutrophic state continues into the Initial Littorina Sea stage. The Initial Littorina Sea stage contains the most marine phase recorded here, as well as low surface water temperatures. These conditions end before the Littorina Sea stage, which is marked by a return to oligotrophic conditions and warmer waters of the Holocene Thermal Maximum. Glacio‐isostatic rebound leads to a shallowing of the water column, allowing for increased benthic primary productivity and stratification of the water column. The Medieval Climate Anomaly is also identified within Post‐Littorina Sea sediments. Modern Baltic sediments and evidence of human‐induced eutrophication are seen. Human influence upon the Baltic Sea begins c. 1700 cal. a BP and becomes more intense c. 215 cal. a BP.

The use of amino acid indices for assessing organic matter quality and microbial abundance in deep-sea Antarctic sediments of IODP Expedition 318

The Adélie Basin, located offshore of the Wilkes Land margin, experiences unusually high sedimentation rates (~2cmyr−1) for the Antarctic coast. This study sought to compare depthwise changes in organic matter (OM) quantity and quality with changes in microbial biomass with depth at this high-deposition site and an offshore continental margin site. Sediments from both sites were collected during the International Ocean Drilling (IODP) Program Expedition 318. Viable microbial biomass was estimated from concentrations of bacterial-derived phospholipid fatty acids, while OM quality was assessed using four different amino acid degradation proxies. Concentrations of total hydrolysable amino acids (THAA) measured from the continental margin suggest an oligotrophic environment, with THAA concentrations representing only 2% of total organic carbon with relative proportions of non-protein amino acids β-alanine and γ-aminobutyric acid as high as 40%. In contrast, THAA concentrations from the near-shore Adélie Basin represent 40%–60% of total organic carbon. Concentrations of β-alanine and γ-aminobutyric acid were often below the detection limit and suggest that the OM of the basin as labile. DI values in surface sediments at the Adélie and margin sites were measured to be +0.78 and −0.76, reflecting labile and more recalcitrant OM, respectively. Greater DI values in deeper and more anoxic portions of both cores correlated positively with increased relative concentrations of phenylalanine plus tyrosine and may represent a change of redox conditions, rather than OM quality. This suggests that DI values calculated along chemical profiles should be interpreted with caution. THAA concentrations, the percentage of organic carbon (CAA%) and total nitrogen (NAA%) represented by amino acids at both sites demonstrated a significant positive correlation with bacterial abundance estimates. These data suggest that the selective degradation of amino acids, as indicated by THAA concentrations, CAA% or NAA% values may be a better proxy for describing the general changes in sedimentary bacterial abundances than total organic matter or bulk sedimentation rates.

Oceanic mantle gravimetric response to the seafloor spreading of the Southwest Sub‐basin, South China Sea

AbstractThe residual mantle gravity anomaly (RMA) is a straightforward response of the deep mantle structure of the lithosphere. We acquired RMA from newly updated free‐air gravity anomaly by incorporating abundant geophysical evidences, such as the International Ocean Drilling Program expedition 349, the interpretation of 10 seismic profiles and the bathymetric data in the Southwest Sub‐basin (SWSB) of the South China Sea. By inverting the crustal thickness by the application of the isostatic flexure analysis, comparing with ocean bottom seismic tomography result, then determining a detail crustal thickness of the study region, we calculated the RMA of the oceanic basin in the SWSB. The main features of the RMA and their relation to the palaeo‐spreading pattern are discussed, and the implications of the asymmetric lithospheric deformation due to variations in melt extraction are proposed. In the light of the asymmetric RMA at the north and south sides of the fossil spreading centre in the SWSB, we preferred asymmetric melt retention depth and extraction rate changes during the oceanic lithosphere creation of the South China Sea. Copyright © 2016 John Wiley & Sons, Ltd.

A recent phase of accretion along the southern Costa Rican subduction zone

Abstract In 2011 we acquired a 3D seismic reflection volume across the Costa Rica margin NW of the Osa Peninsula to investigate the complex structure and the development of the seismogenic zone within the Costa Rican subduction zone in the vicinity of recent International Ocean Drilling Program (IODP) drilling. In contrast to previous interpretations, these newly acquired seismic images show that the margin wedge is composed of a layered fabric that is consistent with clastic sediments, similar to materials recovered from IODP drilling, that have been thrust and thickened into thrust-bounded folded sequences. These structures are consistent with a balanced sequence that has been frontally accreted in the context of an accretionary model. We interpret these sequences as sediment originally deposited on the subducting crust in a trench basin created by the southward migration of the Cocos–Nazca–Caribbean triple junction, and accreted during recent margin subduction that also accelerated with passage of the triple junction. The margin is composed of relatively rapidly accreted sediment that was added to the margin during a phase of accretion within the last ∼5 Ma that was probably preceded throughout the Neogene by periods of non-accretion or erosion.

Evaluating climatic response to external radiative forcing during the late Miocene to early Pliocene: New perspectives from eastern equatorial Pacific (IODP U1338) and North Atlantic (ODP 982) locations

Orbital-scale climate variability during the latest Miocene-early Pliocene is poorly understood due to a lack of high-resolution records spanning 8.0–3.5 Ma, which resolve all orbital cycles. Assessing this variability improves understanding of how Earth's system sensitivity to insolation evolves and provides insight into the factors driving the Messinian Salinity Crisis (MSC) and the Late Miocene Carbon Isotope Shift (LMCIS). New high-resolution benthic foraminiferal Cibicidoides mundulus δ18O and δ13C records from equatorial Pacific International Ocean Drilling Program Site U1338 are correlated to North Atlantic Ocean Drilling Program Site 982 to obtain a global perspective. Four long-term benthic δ18O variations are identified: the Tortonian-Messinian, Miocene-Pliocene, and Early-Pliocene Oxygen Isotope Lows (8–7, 5.9–4.9, and 4.8–3.5 Ma) and the Messinian Oxygen Isotope High (MOH; 7–5.9 Ma). Obliquity-paced variability dominates throughout, except during the MOH. Eleven new orbital-scale isotopic stages are identified between 7.4 and 7.1 Ma. Cryosphere and carbon cycle sensitivities, estimated from δ18O and δ13C variability, suggest a weak cryosphere-carbon cycle coupling. The MSC termination coincided with moderate cryosphere sensitivity and reduced global ice sheets. The LMCIS coincided with reduced carbon cycle sensitivity, suggesting a driving force independent of insolation changes. The response of the cryosphere and carbon cycle to obliquity forcing is established, defined as Earth System Response (ESR). Observations reveal that two late Miocene-early Pliocene climate states existed. The first is a prevailing dynamic state with moderate ESR and obliquity-driven Antarctic ice variations, associated with reduced global ice volumes. The second is a stable state, which occurred during the MOH, with reduced ESR and lower obliquity-driven variability, associated with expanded global ice volumes.

IODP New Ventures in Exploring Scientific Targets (INVEST): Defining the New Goals of an International Drilling Program

The INVEST conference, an international meeting to define the scientific goals and required technology for a new ocean drilling program, was held at the University of Bremen on 22–25 September 2009. Based on the large attendance and vigorous engagement of scientists in the discussion of new science/technology ideas, INVEST was extremely successful. Initially 400 participants were expected, but the INVEST steering and organization committees were thrilled to see a much larger number of scientists flock to Bremen to demonstrate their support and enthusiasm for the continuation of an international scientific ocean drilling program. In all, 584 participants, including sixty-four students, from twenty-one nations and >200 institutions and agencies attended the INVEST conference. Contributions to INVEST included 103 submitted white papers that were posted on the INVEST webpage (http://www.marum.de/iodp-invest. html), and breakout discussions in fifty working groups that focused on a range of topics during the course of the conference. In addition, students and early career scientists, as well as national funding agency managers and platform providers, presented a total of eighty-six posters. Interspersed with the working group and plenary sessions were twelve keynote lectures, chosen to highlight overarching themes and new directions in research and technology.

Determining Priorities for a New International Ocean Drilling Program: Integrated Ocean Drilling Program New Ventures in Exploring Scientific Targets (INVEST); Bremen, Germany, 23–25 September 2009

A multidisciplinary, international community meeting was held in Germany to define the research goals of the new Integrated Ocean Drilling Program (IODP) New Ventures in Exploring Scientific Targets (INVEST) program. The meeting, attended by 584 participants from 21 countries and more than 200 institutions and agencies, featured 12 keynote lectures and 50 working groups. Participants defined five innovative research directions that are central to the study of the Earth system and that require ocean drilling.First, climate change impacts can be studied through ocean drilling. The study of long‐term climate change impacts on the environment is only possible through examination of the geologic record. Meeting attendees agreed that future ocean drilling is essential to the study of cryosphere dynamics and sea level change. Drilled ocean sediments will provide critical high‐fidelity records of marine and terrestrial ecosystem responses and feedbacks to climate change. Ocean drilling is vital to studies of long‐term changes in the hydrologic cycle as they relate to greenhouse gas and other forcings and to studies of the processes that account for abrupt climate changes and climate extremes.

Deep sea drilling in the oceans: History and potentials (to 40th anniversary of the International Ocean Drilling Program)

Deep sea drilling in the oceans: History and potentials (to 40th anniversary of the International Ocean Drilling Program)

Fred Noel Spiess

Fred Noel Spiess

海洋掘削と今後の古地磁気研究

Paleomagnetism and rock magnetism have played roles of great importance in various aspects of the ocean drilling projects like IPOD, DSDP, and ODP for over 40 years. This article reviews the major contributions of paleomagnetism, and introduces what is aniticipated for paleo-and rock magnetism in IODP, a new phase of international ocean drilling program begun in 2003.