- Also called:
- Bond cycle
- Related Topics:
- ice rafting
Bond event
-
What is a Bond event in climatology?
A Bond event is an ice-rafting event that carries rocky debris from Greenland and Iceland to the North Atlantic Ocean during the Holocene Epoch beginning about 11,700 years ago. Identified in deep-sea sediment cores, Bond events link to cyclic temperature fluctuations and abrupt climate warming, which result in icebergs from glaciers and ice sheets being released. These events are similar to Dansgaard-Oeschger cycles, which date back 45,000 years.
During the Holocene, cool, ice-bearing waters from north of Iceland periodically extended as far south as Great Britain. These events, named after American geologist Gerard Bond, are thought to be caused by cyclic changes in the circulation of North Atlantic waters, which occur on a cycle of 1,470 ± 500 years.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
Who discovered Bond events and how did they get their name?
Bond events are named for American geologist Gerard Bond. Bond and other researchers have posited that cyclic changes in the circulation of North Atlantic waters, occurring roughly every 1,470 years, have caused periodic cooling of surface waters and subsequent ice-rafting events. These events are any of nine ice-rafting incidents that carried coarse-grained rocky debris from Greenland and Iceland into the North Atlantic Ocean during the Holocene Epoch. Bond events are identified through analysis of deep-sea sediment cores from the North Atlantic Ocean and are associated with cyclic temperature fluctuations marked by abrupt climate warming, which culminate in massive releases of icebergs from glaciers and continental ice sheets.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
When did Bond events occur in Earth's history?
Bond events are ice-rafting incidents that transported rocky debris from Greenland and Iceland to the North Atlantic Ocean during the Holocene Epoch, starting about 11,700 years ago. Analysis of deep-sea sediment cores reveals these events are linked to cyclic temperature changes and abrupt climate warming, which lead to icebergs being released from glaciers and ice sheets. These events are similar to Dansgaard-Oeschger cycles from glacial periods up to 45,000 years ago. Eight primary Bond events have been identified based on ice-rafted debris variations in North Atlantic cores, starting approximately 1,400, 2,800, 4,200, 5,900, 8,100, 9,400, 10,300, and 11,100 years ago.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
How do scientists find evidence of Bond events?
Scientists find evidence of Bond events through analysis of deep-sea sediment cores from the North Atlantic Ocean. These events, marked by ice-rafting, carry rocky debris from Greenland and Iceland. Increases in grain size and concentrations of specific minerals, like hematite-stained quartz, feldspar, and volcanic glass, in sediment cores indicate episodes of ice rafting. Changes in grain composition suggest ice originating from different areas due to shifts in North Atlantic Ocean circulation. These ice-rafting episodes reflect a roughly 1,500-year cycle of global climate change.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What climate changes are linked to Bond events?
Bond events are Holocene ice-rafting incidents that involved rocky debris traveling from Greenland and Iceland to the North Atlantic Ocean. They are linked to cyclical temperature variations marked by sudden climate warming, which culminates in considerable iceberg releases from glaciers and continental ice sheets. Analysis of deep-sea sediment cores from the North Atlantic Ocean has identified these events, which mirror Dansgaard-Oeschger cycles from prior glacial periods. Evidence from sediment cores reveals that cool, ice-bearing waters periodically stretched as far south as Great Britain during the Holocene. These cooling and ice-rafting episodes are attributed to cyclical shifts in North Atlantic water circulation, occurring roughly every 1,470 years.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
Why is studying Bond events important for understanding Earth's climate history?
Bond events are important for understanding Earth's climate history because they are associated with cyclic temperature fluctuations and abrupt climate warming episodes. Identified through analysis of deep-sea sediment cores from the North Atlantic Ocean, Bond events show a roughly 1,500-year cycle of global climate change.
The analysis of ice-rafted debris in sediment cores indicates periodic cooling of surface waters, where ice-bearing waters from north of Iceland extended as far south as the latitude of Great Britain. These events help climatologists study changes in North Atlantic water circulation and their impact on global climate patterns during the Holocene Epoch.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
Bond event, any of nine ice-rafting events carrying coarse-grained rocky debris from Greenland and Iceland to the North Atlantic Ocean during the Holocene Epoch (beginning some 11,700 years ago and extending to the present day).
Bond events are known from the analysis of deep-sea sediment cores collected from the North Atlantic Ocean (see also core sampling). They are associated with cyclic temperature fluctuations punctuated by abrupt episodes of climate warming, which culminate in massive releases of icebergs from glaciers and continental ice sheets. Bond events (and their associated temperature cycles) appear to be similar to so-called Dansgaard-Oeschger cycles, or D-O cycles, which have been identified in ice cores from glacial periods dating back 45,000 years.
Icebergs calving from landed glaciers often contain rocks and other debris, which are eventually deposited on the ocean floor as the icebergs drift to warmer waters and melt. Episodes of Holocene ice rafting have been identified in the deep-sea sediment cores by increases in grain size and concentrations of hematite-stained quartz and feldspar. These minerals were derived from red beds in Greenland and concentrations of fresh volcanic glass from Iceland. The increase in coarse particles appears to be caused by increased ice rafting. The changes in grain composition, however, are thought to result from the rafting of ice from different source areas, a phenomenon brought about by changes in North Atlantic Ocean circulation. The ice-rafting episodes associated with Bond events appear to be Holocene expressions of a pervasive 1,500-year cycle of global climate change.
" height="20" alt="HEW Logo">
Changes in the amount of ice-rafted debris found in sediment cores along the ocean floor in the North Atlantic suggest that, during the Holocene, cool ice-bearing waters from north of Iceland have periodically extended as far south as the latitude of Great Britain. These phenomena have been named for American geologist Gerard Bond. Bond and others have argued that the periodic cooling of surface waters and subsequent ice-rafting events have been caused by cyclic changes in the circulation of North Atlantic waters, which occur on a cycle of 1,470 500 years. Eight primary Bond events have been identified, primarily from variations in ice-rafted debris in North Atlantic cores. Their approximate commencement times have been dated at 1,400, 2,800, 4,200, 5,900, 8,100, 9,400, 10,300, and 11,100 years ago. A ninth Bond event, which is a matter of some debate among paleoclimatologists, is thought to have occurred about 1500 ce, during the Little Ice Age.