Antarctic Icebergs Caused Huge Sea Level Rise 14,600 Years Ago
A new study reports icebergs breaking off Antarctica caused rapid sea level rise 14,600 years ago.
A study published May 28 in the journal Nature reports that the Antarctic icebergs may have caused rapid sea level increases. The researchers identify eight events of increased iceberg numbers from the Antarctic ice sheet, happening between 20,000 and 9,000 years ago. The largest influx of icebergs, which happened 14,600 years ago, resulted in a sea level rise of 6.5 feet over 100 years. The study provides the first direct evidence for historical, significant melting of the Antarctic ice sheet.
Oregan State University climate scientist and study co-author Peter Clark says, "The Antarctic ice sheet had been considered to be fairly stable and kind of boring in how it retreated. This shows the ice sheet is much more dynamic and episodic, and contributes to rapid sea-level rise." The researchers used marine records of iceberg-rafted debris, various objects and sediments embedded in the ice that are deposited after the iceberg melts, to understand changes in Southern Hemisphere ice sheets. This technique has previously been widely used to understand variability in Northern Hemisphere ice sheets.
Antarctica's glaciers have been shrinking since the end of the last great ice age, and the study reports that the last large release of icebergs was 9,000 years ago. Those melting events were caused by natural climate warming. Scientists have pointed to 0.4 inches per year [http://www.escapistmagazine.com/news/view/134294-Climate-Change-Worse-Than-We-Predicted-Says-New-Report]. Comparatively, the melting event 14,600 years ago resulted in a rise of approximately 0.8 inches per year over 100 years.
Source: Discovery News [http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13397.html]
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A new study reports icebergs breaking off Antarctica caused rapid sea level rise 14,600 years ago.
A study published May 28 in the journal Nature reports that the Antarctic icebergs may have caused rapid sea level increases. The researchers identify eight events of increased iceberg numbers from the Antarctic ice sheet, happening between 20,000 and 9,000 years ago. The largest influx of icebergs, which happened 14,600 years ago, resulted in a sea level rise of 6.5 feet over 100 years. The study provides the first direct evidence for historical, significant melting of the Antarctic ice sheet.
Oregan State University climate scientist and study co-author Peter Clark says, "The Antarctic ice sheet had been considered to be fairly stable and kind of boring in how it retreated. This shows the ice sheet is much more dynamic and episodic, and contributes to rapid sea-level rise." The researchers used marine records of iceberg-rafted debris, various objects and sediments embedded in the ice that are deposited after the iceberg melts, to understand changes in Southern Hemisphere ice sheets. This technique has previously been widely used to understand variability in Northern Hemisphere ice sheets.
Antarctica's glaciers have been shrinking since the end of the last great ice age, and the study reports that the last large release of icebergs was 9,000 years ago. Those melting events were caused by natural climate warming. Scientists have pointed to 0.4 inches per year [http://www.escapistmagazine.com/news/view/134294-Climate-Change-Worse-Than-We-Predicted-Says-New-Report]. Comparatively, the melting event 14,600 years ago resulted in a rise of approximately 0.8 inches per year over 100 years.
Source: Discovery News [http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13397.html]
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