International audienceRecent studies have proposed that millennial-scale reorganization of the ocean-atmosphere circulation drives increased upwelling in the Southern Ocean, leading to rising atmospheric carbon dioxide levels and ice age terminations. Southward migration of the global monsoon is thought to link the hemispheres during deglaciation, but vital evidence from the southern sector of the vast Australasian monsoon system is yet to emerge. Here we present a 230thorium-dated stalagmite oxygen isotope record of millennial-scale changes in Australian- Indonesian monsoon rainfall over the last 31,000 years. The record shows that abrupt southward shifts of the Australian-Indonesian monsoon were synchronous with North Atlantic cold intervals 17,600-11,500 years ago. The most prominent southward shift occurred in lock-step with Heinrich Stadial 1 (17,600-14,600 years ago), and rising atmospheric carbon dioxide. Our findings show that millennial-scale climate change was transmitted rapidly across Australasia and lend support to the idea that the 3,000-year-long Heinrich 1 interval could have been critical in driving the last deglaciation. DOI: 10.1038/ncomms3908

Diploastrea heliopora forms dense, robust, dome-shaped coral colonies throughout the reef ecosystems of the tropical Pacific and Indian Oceans. This slow-growing (2 to 6 mm/yr) coral has the potential to yield continuous paleoclimate records spanning up to 1000 yr for the warmest waters on Earth, the Indo-Pacific Warm Pool, and has a long fossil history as a single recognizable species. Despite the potential of Diploastrea to be an important new paleoclimate archive, little is known about the systematics of geochemical tracers incorporated into its skeleton. To fill this knowledge gap, we compared skeletal δ18O signatures in live Diploastrea and Porites colonies from Southwest Lagoon, near Amédée Lighthouse, New Caledonia (at the southern latitudinal limit for Diploastrea) and Alor, Indonesia (in the core area of the Indo-Pacific Warm Pool). We designed a new microsampling technique to minimize smoothing and distortion of the isotopic records due to the complex calyx architecture and slow growth of Diploastrea. High-resolution isotope profiles from the septal portion of the Diploastrea corallite are attenuated, whereas those restricted to the central columella are similar in quality to those extracted from the well-established Porites coral archive. The δ18O-temperature relationship for the columellar portion of Diploastrea (−0.18‰/°C) is in good agreement with that derived for a nearby Porites (−0.19‰/°C; Quinn et al., 1996), on the basis of comparison with an in situ sea surface temperature record from Amédée Lighthouse. There is a measurable difference of 0.3 ± 0.1‰ between the kinetic/biological disequilibrium offsets from seawater δ18O composition for Diploastrea and Porites. Despite this offset in mean δ18O, Diploastrea accurately records the regional differences in mean temperature and salinity between New Caledonia and the Indo-Pacific Warm Pool. Additional tests show that Diploastrea records El Niño–Southern Oscillation (ENSO) interannual variability in sea surface temperature and salinity across the southwestern Pacific, indicating that it should yield dependable paleo-ENSO records. Based on these results, we propose that D. heliopora has the potential to provide an important new coral archive of tropical paleoclimate

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[1] High-resolution measurements of Sr/Ca and 18 O/ 16 O in mid-Holocene and modern Porites corals were used to derive a history of freshwater fluxes to the Australian Great Barrier Reef (GBR). Interannual variations in dry-season seawater 18 O/ 16 O evident in the coral record for the late 20th century, but not 6200 years ago, correlate with variations in groundwater recharge of coastal aquifers. The results suggest that a delay in groundwater recharge following the post-glacial sea-level rise, and recent deforestation for agriculture, may have lead to higher land-sea hydraulic gradients and greater groundwater discharge to the GBR today. Oxygen-isotope mass balance calculations show that $3% in-mixing of CO 2 -enriched groundwater could raise the partial pressure of CO 2 in coastal seawater by $90 matm following strong summer monsoons. Consequently, modern nearshore corals in the GBR may now be subjected to lower aragonite saturation states, which could reduce coral calcification and contribute to recent reef degradation.

Four years have passed since Pole List XI11 was produced at which point some consideration was given to the discontinuing of these lists. However, the demand for an annual updating of world-wide palaeomagnetic results has been sufficient to justify continuing the lists. This list is exceptionally large representing four years of data. In the future, it is planned to continue these lists on an annual basis. This compilation includes most results up to the end of 1975. The compilation of results from the USSR by A. N. Khramov (Paleomagnetic directions and paleomagnetic poles, Leningrad 1971 -English version edited by M. W. McElhinny and translated by D. A. Brown, RSES Publication No. 99, 1973) has now been updated by Issues No. 2 (1973) and No. 3 (1975). A new copy of the English edited version including all data of Issues 1 , 2 and 3 is available on request from the authors.The results presented here are direct photographic reproductions of computer output. Column 1 gives the identification number and column 2 the age of the rock unit studied. The symbols used are: Quaternary Q, Tertiary T, Cretaceous K, Jurassic J, Triassic TR, Permian P, Carboniferous C, Devonian D, Ordovician 0, Cambrian CB, Precambrian PC.Subdivisions of periods from Cambrian to Cretaceous, where recognized, are denoted by U, M or L. Epochs within the Tertiary (Palaeocene, etc) are denoted TPA, TE, TO, TM and TP, and within the Quaternary (Pleistocene and Recent) are denoted by QP and QR. Subdivision of the Precambrian is not yet attempted.The heading Rock unit and accessory information covers two lines. The first line describes the rock unit sampled with a locality name. The second line summarizes subsidiary information. The numbers in brackets give the reference number(s) which may be referred to under the list of references. This is followed by a sequence of up to five letter symbols indicating the stability tests carried out on the rocks under investigation. They are as follows: Fold test F, igneous contact test C, conglomerate test G, reversals test R and alternating field A, steady field D, thermal T, and chemical H, demagnetization tests. These symbols are then followed by other information such as any isotopic ages for the rocks or whether the result is a combination of other separate entries on this or previous lists.The right-hand page summarizes all the basic data as follows: SLAT, SLONG are site latitude and longitude. B number of sites, N number of samples, TRT is the treatment applied indicated as A, T or H for magnetic, thermal or chemical cleaning and N for no treatments (NRM measurements only). REV indicates the proportion of reversely magnetized sites (or samples if sites unknown) expressed as a percentage (0 meaning all normal, 100 meaning all reversed). If the proportions are not known then the existence of both

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