AMS 14C dating points, isotopic compositions, Mg/Ca ratios and sea surface temperatures of sediment cores GeoB10029-4 and GeoB10038-4

Quantifying the spatial and temporal sea surface temperature (SST) and salinity changes of the Indo-Pacific Warm Pool is essential to understand the role of this region in connection with abrupt climate changes particularly during the last deglaciation. In this study we reconstruct SST and seawater d18O of the tropical eastern Indian Ocean for the past 40,000 years from two sediment cores (GeoB 10029-4, 1°30'S, 100°08'E, and GeoB 10038-4, 5°56'S, 103°15'E) retrieved offshore Sumatra. Our results show that annual mean SSTs increased about 2-3 °C at 19,000 years ago and exhibited southern hemisphere-like timing and pattern during the last deglaciation. Our SST records together with other Mg/Ca-based SST reconstructions around Indonesia do not track the monsoon variation since the last glacial period, as recorded by terrestrial monsoon archives. However, the spatial SST heterogeneity might be a result of changing monsoon intensity that shifts either the annual mean SSTs or the seasonality of G. ruber towards the warmer or the cooler season at different locations. Seawater d18O reconstructions north of the equator suggest fresher surface conditions during the last glacial and track the northern high-latitude climate change during the last deglaciation. In contrast, seawater ?18O records south of the equator do not show a significant difference between the last glacial period and the Holocene, and lack Bølling-Allerød and Younger Dryas periods suggestive of additional controls on annual mean surface hydrology in this part of the Indo-Pacific Warm Pool.

Tie points and goechemical analysis from different Holes of ODP Site 165-1002

The fine-grained sediments of the Cariaco Basin, Venezuela, of the last 130 ky, whose deposition history is well characterized, were analyzed geochemically in order to test the validity of sediment bulk geochemistry as an indicator of detrital provenance. Several binary and ternary diagrams as well as the chemical index of alteration (CIA) were tested for their capacity to discriminate the poorly contrasted detrital sources to the Cariaco Basin, and to describe the temporal evolution of the contributions of these different sources. Most of the diagrams tested did not allow a good discrimination of sources or, when sources were well discriminated, did not allow an interpretation of the temporal variations consistent with the known history. A relatively good discrimination of sources and a consistent interpretation of temporal variations were however obtained using Hf vs. Th and La/Yb vs. Gd/Yb binary diagrams, as well as Ti-Zr-Th, Ti-Zr-La, and Lu-Hf-Th ternary diagrams. Compared to the previous studies of the detrital content of the Cariaco Basin sediments, the geochemical approach permitted the recognition of a sediment contribution eroded from the Unare platform and Gulf of Cariaco during rapid sea level oscillations, and the contribution of Saharan eolian particles during the Younger Dryas-Preboreal and MIS6-5 transition. The choice of plotted elements was determined after considering carrier minerals, so that different elements may be informative in different sedimentary contexts. Overall, mineral sorting during transport appears as a major limit to quantitative estimation of the different contributions. In particular mineral sorting leads to the selective enrichment of elements associated with clays (Al, Rb, Th and LREE) in sediments deposited in the basin. Unless the geochemical effect of mineral sorting can be measured, it appears that quantitative provenance analysis should be performed on fractions of similar grain size instead of bulk sediment.

Barium intensities and tie points between holes of Leg 208

The Paleocene - Eocene thermal maximum (PETM) is one of the best known examples of a transient climate perturbation, associated with a brief, but intense, interval of global warming and a massive perturbation of the global carbon cycle from injection of isotopically light carbon into the ocean-atmosphere system. One key to quantifying the mass of carbon released, identifying the source(s), and understanding the ultimate fate of this carbon is to develop high-resolution age models. Two independent strategies have been employed, cycle stratigraphy and analysis of extraterrestrial Helium (HeET), both of which were first tested on Ocean Drilling Program (ODP) Site 690. Both methods are in agreement for the onset of the PETM and initial recovery, or the clay layer ("main body"), but seem to differ in the final recovery phase of the event above the clay layer, where the carbonate contents rise and carbon isotope values return toward background values. Here we present a state-of-the-art age model for the PETM derived from a new orbital chronology developed with cycle stratigraphic records from sites drilled during ODP Leg 208 (Walvis Ridge, Southeastern Atlantic) integrated with published records from Site 690 (Weddell Sea, Southern Ocean, ODP Leg 113). During Leg 208, five Paleocene - Eocene (P-E) boundary sections (Sites 1262 to 1267) were recovered in multiple holes over a depth transect of more than 2200 m at the Walvis Ridge yielding the first stratigraphically complete P-E deep-sea sequence with moderate to relatively high sedimentation rates (1 to 3 cm/kyr). A detailed chronology was developed with non-destructive X-ray fluorescence (XRF) core scanning records on the scale of precession cycles, with a total duration of the PETM now estimated to be ~ 170 kyr. The revised cycle stratigraphic record confirms original estimates for the duration of the onset and initial recovery, but suggests a new duration for the final recovery that is intermediate to the previous estimates by cycle stratigraphy and HeET.

(Table 1) Snow and ice thickness and layering at observation points of the North Pole 34 drifting station

Variability of total alkalinity in sea ice of the high-latitudinal Arctic from November 2005 to May 2006 is considered. For the bulk of one- and two-year sea ice, alkalinity dependence on salinity is described as TA = k x Sal, where k is salinity/alkalinity ratio in under-ice water. The given relationship is valid within a wide range of salinity from 0.1 psu in desalinated fraction of two-year ice to 36 psu in snow on the young ice surface. Geochemically significant deviations from the relationship noted were observed exclusively in snow and the upper layer of one-year ice. In the upper layer of one-year ice, deficiency of alkalinity is observed ( delta TA ~= -0.07 mEq/kg, or -15%). In snow on the surface of the one-year ice, alkalinity excess is formed under desalination ( delta TA is as high as 1.3 mEq/kg, or 380%). Deviations registered are caused by possibility of carbonate precipitation in form of CaCO3 x 6H2O under seawater freezing. It is shown that ice formation and the following melting might cause losses of atmospheric CO2 of up to 3 x 10**12 gC/year.

Tie points and log-adjusted depth scales for ODP Leg 207 Sites

Multiple copies of Cretaceous black shales extending from the early Cenomanian to the end of the Santonian were recovered at five sites on Demerara Rise during Leg 207 of the Ocean Drilling Program. These sediments are primarily composed of laminated organic-rich claystones interbedded with coarser, lightly laminated foraminferal-bearing packstones and wackestones. The black shales represent the local expression of widespread organic-rich sedimentation in the Atlantic during the mid-Cretaceous. However, incomplete recovery prevented construction of continuous composite sections, resulting in uncertainties concerning the correct stratigraphic placement of individual cores. By combining high-resolution measurements of bulk density collected shipboard on the multisensor track with continuous downhole measurements of formation resistivity using the Formation MicroScanner, an equivalent logging depth scale was constructed for black shales recovered from Sites 1258, 1260, and 1261. The integrated depths approach centimeter-scale resolution and are supported by comparisons of coarser resolution natural gamma ray emissions collected on cores and through downhole logging operations. The new depths highlight the extent of both intra- and intercore gaps and provide an opportunity to further constrain temporal and spatial paleoceanographic changes captured in proxy records from these sediments.

GPS raw data (control points and ground control points) from the Liguria Region, Borghetto Santo Spirito, Italy

Monitoring the impact of sea storms on coastal areas is fundamental to study beach evolution and the vulnerability of low-lying coasts to erosion and flooding. Modelling wave runup on a beach is possible, but it requires accurate topographic data and model tuning, that can be done comparing observed and modeled runup. In this study we collected aerial photos using an Unmanned Aerial Vehicle after two different swells on the same study area. We merged the point cloud obtained with photogrammetry with multibeam data, in order to obtain a complete beach topography. Then, on each set of rectified and georeferenced UAV orthophotos, we identified the maximum wave runup for both events recognizing the wet area left by the waves. We then used our topography and numerical models to simulate the wave runup and compare the model results to observed values during the two events. Our results highlight the potential of the methodology presented, which integrates UAV platforms, photogrammetry and Geographic Information Systems to provide faster and cheaper information on beach topography and geomorphology compared with traditional techniques without losing in accuracy. We use the results obtained from this technique as a topographic base for a model that calculates runup for the two swells. The observed and modeled runups are consistent, and open new directions for future research.

Common depth points and associated geographic coordinates

Fluids in subduction zones can influence seismogenic behaviour and prism morphology. The Eastern Makran subduction zone, offshore Pakistan, has a very thick incoming sediment section of up to 7.5 km, providing a large potential fluid source to the accretionary prism. A hydrate-related bottom simulating reflector (BSR), zones of high amplitude reflectivity, seafloor seep sites and reflective thrust faults are present across the accretionary prism, indicating the presence of fluids and suggesting active fluid migration. High amplitude free gas zones and seep sites are primarily associated with anticlinal hinge traps, and fluids here appear to be sourced from shallow biogenic sources and migrate to the seafloor along minor normal faults. There are no observed seep sites associated with the surface expression of the wedge thrust faults, potentially due to burial of the surface trace by failure of the steep thrust ridge slopes. Thrust fault reflectivity is restricted to the upper 3 km of sediment and the deeper décollement is non-reflective. We interpret that fluids and overpressure are not common in the deeper stratigraphic section. Thermal modelling of sediments at the deformation front suggests that the deeper sediment section is relatively dewatered and not currently contributing to fluid expulsion in the Makran accretionary prism.