8 resultados para André, Yves Marie, 1675-1764.

em Publishing Network for Geoscientific


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During Leg 67, the Middle-America Trench transect off Guatemala was drilled across the convergent margin of southern Mexico and Central America south of the Tehuantepec Ridge. The data of Leg 66, north of the Tehuantepec Ridge, and that of Leg 67 provided the opportunity to establish a continuous chronology of airborne volcanic ashes intercalated within the sediments (Aubouin et al., 1979; von Huene et al., 1980). Sites of both expeditions are favorably located for obtaining a good record of the explosive volcanicity of these areas, given the proximity of the volcanic sources and the position of the sites under the prevailing winds.

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Deep Sea Drilling Project Leg 66 drilled eight sites along a transect across the Middle America Trench off Mexico, including continental (Sites 493 and 489), oceanic (Site 487), and trench (Site 486) reference sites and four sites (490, 492, 491, 488) in the trench inner wall. Because of their location - close to volcanic sources and subject to prevailing winds and marine currents (N to S, NW to SE) - analysis of airborne ashes intercalated within the sediments at these sites provides a reliable record of explosive volcanism in the area. Intense onshore volcanic activity in Mexico during the Oligo-Miocene has been well documented by the andesites and ignimbrites of the Sierra Madre Occidental and Sierra Madre del Sur and in the Plio-Quaternary by the andesites and basalts from the Trans-Mexican Neovolcanic Belt and the eastern border of Baja California.

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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 By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived.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.