منابع مشابه
Atmospheric depletion of mercury over Antarctica during glacial periods
Mercury is a globally dispersed toxic metal that affects even remote polar areas. During seasonal atmospheric mercury depletion events in polar areas, mercury is removed from the atmosphere1,2 and subsequently deposited in the surface snows3. However, it is unknown whether these events, which have been documented for the past two decades, have occurred in the past. Here we show that over the pa...
متن کاملGlacial Geology of Cape Bird, Ross Island, Antarctica
Located on the northwest coast of Ross Island in McMurdo Sound, Cape Bird features virtually unweathered surface drift with erratics from the Transantarctic Mountains (TAM) and with enclosed marine shell fragments. This Cape Bird drift is cut by Holocene beaches. The chronology of drift deposition and beach formation comes from AMS radiocarbon dates of associated marine shells, and of penguin b...
متن کاملTiming of millennial-scale climate change in Antarctica and Greenland during the last glacial period.
A precise relative chronology for Greenland and West Antarctic paleotemperature is extended to 90,000 years ago, based on correlation of atmospheric methane records from the Greenland Ice Sheet Project 2 and Byrd ice cores. Over this period, the onset of seven major millennial-scale warmings in Antarctica preceded the onset of Greenland warmings by 1500 to 3000 years. In general, Antarctic temp...
متن کاملDenitrification and hydrologic transient storage in a glacial meltwater stream, McMurdo Dry Valleys, Antarctica
In extreme environments, retention of nutrients within stream ecosystems contributes to the persistence of aquatic biota and continuity of ecosystem function. In the McMurdo Dry Valleys, Antarctica, many glacial meltwater streams flow for only 5–12 weeks a year and yet support extensive benthic microbial communities. We investigated NO3 uptake and denitrification in Green Creek by analyzing sma...
متن کاملMite dispersal among the Southern Ocean Islands and Antarctica before the last glacial maximum.
It has long been maintained that the majority of terrestrial Antarctic species are relatively recent, post last glacial maximum, arrivals with perhaps a few microbial or protozoan taxa being substantially older. Recent studies have questioned this 'recolonization hypothesis', though the range of taxa examined has been limited. Here, we present the first large-scale study for mites, one of two d...
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ژورنال
عنوان ژورنال: Nature
سال: 1938
ISSN: 0028-0836,1476-4687
DOI: 10.1038/142097a0