(Table 2) Revised stacked record on magnetic susceptibility of ODP Site 162-984 sediments

Magnetic field and susceptibility data were collected using the geological high-resolution magnetometer tool string (GHMT) at three sites during Ocean Drilling Program Leg 162. Postcruise processing of the magnetic field data yielded a polarity stratigraphy for Holes 986C and 987E. A magnetic susceptibility record was measured at Hole 984B. Detailed analysis of the core and log susceptibility records at Hole 984B yielded an empirical tool resolution of the susceptibility measurement tool (SUMT) of 53 cm. At Site 984, where sedimentation rates were typically >10 cm/k.y., this gave a resolution of at least ~5000 yr. This data report summarizes the GHMT postcruise processing, method of interpretation, and analysis of the SUMT resolution.

Sedimentologic and magnetic data of sediment cores on the western slope of the Mid-Atlantic Ridge

The relative paleointensity (RPI) method assumes that the intensity of post depositional remanent magnetization (PDRM) depends exclusively on the magnetic field strength and the concentration of the magnetic carriers. Sedimentary remanence is regarded as an equilibrium state between aligning geomagnetic and randomizing interparticle forces. Just how strong these mechanical and electrostatic forces are, depends on many petrophysical factors related to mineralogy, particle size and shape of the matrix constituents. We therefore test the hypothesis that variations in sediment lithology modulate RPI records. For 90 selected Late Quaternary sediment samples from the subtropical and subantarctic South Atlantic Ocean a combined paleomagnetic and sedimentological dataset was established. Misleading alterations of the magnetic mineral fraction were detected by a routine Fe/kappa test (Funk, J., von Dobeneck, T., Reitz, A., 2004. Integrated rock magnetic and geochemical quantification of redoxomorphic iron mineral diagenesis in Late Quaternary sediments from the Equatorial Atlantic. In: Wefer, G., Mulitza, S., Ratmeyer, V. (Eds.), The South Atlantic in the Late Quaternary: reconstruction of material budgets and current systems. Springer-Verlag, Berlin/Heidelberg/New York/Tokyo, pp. 239-262). Samples with any indication of suboxic magnetite dissolution were excluded from the dataset. The parameters under study include carbonate, opal and terrigenous content, grain size distribution and clay mineral composition. Their bi- and multivariate correlations with the RPI signal were statistically investigated using standard techniques and criteria. While several of the parameters did not yield significant results, clay grain size and chlorite correlate weakly and opal, illite and kaolinite correlate moderately to the NRM/ARM signal used here as a RPI measure. The most influential single sedimentological factor is the kaolinite/illite ratio with a Pearson's coefficient of 0.51 and 99.9% significance. A three-member regression model suggests that matrix effects can make up over 50% of the observed RPI dynamics.

Natural remanent magnetization of IODP Expedition 308, Holes U1319A, U1320A, U1322B, and U1324B from the northern Gulf of Mexico

Paleomagnetic analyses of the natural remanent magnetization of >1700 vertically oriented sediment samples from Integrated Ocean Drilling Program (IODP) Holes U1319A, U1320A, U1322B, and U1324B in the northern Gulf of Mexico reveal complex magnetostratographic signals for the Brazos-Trinity and Ursa region carried by detrital iron oxide minerals. Additionally, gyroremanent magnetization was observed to form during alternating-field demagnetization of samples containing an enhanced amount of magnetic iron sulfide minerals. Most characteristic remanent magnetization inclinations are reasonable for the site latitudes. Stable declinations allow for azimuth correction of the formerly unoriented drill cores.

Magnetostratigraphy of ODP Leg 108 sites

This paper presents the magnetostratigraphic results from Leg 108 of the Ocean Drilling Program. Measurements made with the shipboard "pass-through" cryogenic magnetometer on whole cores and archive halves are combined with those made on discrete samples; these measurements constitute the paleomagnetic data base for the Leg 108 cores. Polarity determination on unoriented, low-latitude cores is somewhat subjective; we rely heavily on the available biostratigraphic data and document our line of reasoning where appropriate. The interpretations presented here, therefore, are compatible with the available biostratigraphic information; they are also in substantial agreement with orientation information where available.

Polarity chron boundaries and interval sedimentation rates of ODP Leg 162 sites

Magnetic polarity stratigraphies for Sites 980-984 are based on shipboard measurements from the pass-through magnetometer after alternating field (AF) demagnetization at a peak field of 25 mT and shore-based stepwise AF demagnetization of discrete samples. The characteristic magnetization component was determined after AF demagnetization removed the steep downward drill-string-related magnetic overprint. Peak AF fields in the 20-30 mT range were required to resolve the component, carried by magnetite, that was used to produce unambiguous Pliocene-Pleistocene magnetic stratigraphies at all five sites. At Sites 980 and 983, magnetic stratigraphies were resolved to the base of the recovered advanced hydraulic piston corer (APC) section, which lies in the Matuyama Chron (1r.2r) and Olduvai Subchron (2n), respectively. At Sites 981 and 982, magnetization intensities decrease sharply in the normal polarity zone corresponding to the Gauss Chron (2An), and magnetic stratigraphies below this level could not be resolved. At Site 984, the resolution of magnetic stratigraphy was curtailed at ~250 meters below seafloor (Olduvai Subchron) by core deformation at the base of the APC section and in the underlying extended core barrel section. As the magnetic stratigraphies at all four sites are unequivocal, polarity chron interpretations can be made without aid from the biostratigraphy. Mean sedimentation rates within polarity chrons have been calculated and Pliocene-Pleistocene biomagnetostratigraphic correlations tested.

Data compilation on the biological response to ocean acidification: environmental and experimental context of data sets and related literature

The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.