6 resultados para Early Irish Literature
em Publishing Network for Geoscientific
Resumo:
DATED-1 comprises a compilation of dates related to the build-up and retreat of the Eurasian (British-Irish, Scandinavian, Svalbard-Barents-Kara Seas) Ice Sheets, and time-slice maps of the Eurasian Ice sheet margins. Dates are sourced from the published literature. Ice margins are based on published geological and chronological data and include uncertainty bounds (maximum, minimum) as well as what we consider to be the most-credible (mc) based on the available evidence. DATED-1 has a census date of 1 January 2013. Full description and caveats for use are given in: Hughes, A.L.C., Gyllencreutz, R., Lohne, Ø.S., Mangerud, J., Svendsen, J.I. (2015) The last Eurasian Ice Sheets - a chronological database and time-slice reconstruction, DATED-1.
Resumo:
The chronostratigraphy, the calcareous nannofossil biochronology, and the biostratigraphy of the Miocene and Pliocene sediments retrieved during Leg 115 in the equatorial western Indian Ocean are presented and discussed. Most of the zonal boundaries of the standard 1971 zonation of Martini and the 1973 zonation of Bukry are easily recognized in these low-latitude sediments. We also comment on the secondary events that are proposed in the literature to improve the biostratigraphic resolution provided by the standard zonations. The study of calcareous nannofossil biostratigraphy and taphonomy of sequences from the Northern Mascarene Plateau area, which was drilled to investigate the Neogene history of carbonate flux and dissolution, indicate that the accumulation of carbonates in this area results from a complex interplay among carbonate bioproductivity, carbonate removal by chemical dissolution and mechanical erosion, and carbonate addition by mass and current transport. In spite of these drawbacks, major changes and trends in carbonate accumulation can be recognized, most of which, if not all, correlate with major steps in the evolution of the Neogene climatic system.
Resumo:
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 By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived.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.
Effect of ocean warming and acidification on the early life stages of subtropical Acropora spicifera
Resumo:
This study investigated the impacts of acidified seawater (pCO2 900 µatm) and elevated water temperature (+3 °C) on the early life history stages of Acropora spicifera from the subtropical Houtman Abrolhos Islands (28°S) in Western Australia. Settlement rates were unaffected by high temperature (27 °C, 250 µatm), high pCO2 (24 °C, 900 µatm), or a combination of both high temperature and high pCO2 treatments (27 °C, 900 µatm). There were also no significant differences in rates of post-settlement survival after 4 weeks of exposure between any of the treatments, with survival ranging from 60 to 70 % regardless of treatment. Similarly, calcification, as determined by the skeletal weight of recruits, was unaffected by an increase in water temperature under both ambient and high pCO2 conditions. In contrast, high pCO2 significantly reduced early skeletal development, with mean skeletal weight in the high pCO2 and combined treatments reduced by 60 and 48 %, respectively, compared to control weights. Elevated temperature appeared to have a partially mitigative effect on calcification under high pCO2; however, this effect was not significant. Our results show that rates of settlement, post-settlement survival, and calcification in subtropical corals are relatively resilient to increases in temperature. This is in marked contrast to the sensitivity to temperature reported for the majority of tropical larvae and recruits in the literature. The subtropical corals in this study appear able to withstand an increase in temperature of 3 °C above ambient, indicating that they may have a wider thermal tolerance range and may not be adversely affected by initial increases in water temperature from subtropical 24 to 27 °C. However, the reduction in skeletal weight with high pCO2 indicates that early skeletal formation will be highly vulnerable to the changes in ocean pCO2 expected to occur over the twenty-first century, with implications for their longer-term growth and resilience.
Resumo:
This synthesis dataset contains records of freshwater peat and lake sediments from continental shelves and coastal areas. Information included is site location (when available), thickness and description of terrestrial sediments as well as underlying and overlying sediments, dates (when available), and references.