Younger Dryas transgression in western Norway: a modelling approach

Meltwater routing and the Younger Dryas.

The Younger Dryas--the last major cold episode on Earth--is generally considered to have been triggered by a meltwater flood into the North Atlantic. The prevailing hypothesis, proposed by Broecker et al. [1989 Nature 341:318-321] more than two decades ago, suggests that an abrupt rerouting of Lake Agassiz overflow through the Great Lakes and St. Lawrence Valley inhibited deep water formation i...

Inconsistent impact hypotheses for the Younger Dryas.

Israde-Alcántara et al. (1) presented evidence from Lake Cuitzeo sediments and argued that it supports the Younger Dryas (YD) impact hypothesis of Firestone et al. (2) for a major extraterrestrial impact event “involving multiple airburst(s) and/or ground impact(s) at 12.9 ka.” Firestone et al. (2) did not specify the details of the impact but proposed that it had “continentwide effects” and wa...

Modelling the concentration of atmospheric CO2 during the Younger Dryas climate event

The Younger Dryas (YD, dated between 12.7}11.6 ky BP in the GRIP ice core, Central Greenland) is a distinct cold period in the North Atlantic region during the last deglaciation. A popular, but controversial hypothesis to explain the cooling is a reduction of the Atlantic thermohaline circulation (THC) and associated northward heat #ux as triggered by glacial meltwater. Recently, a CH 4 -based ...

Geology. Was the Younger Dryas triggered by a flood?

A Blind Test of the Younger Dryas Impact Hypothesis

The Younger Dryas Impact Hypothesis (YDIH) states that North America was devastated by some sort of extraterrestrial event ~12,800 calendar years before present. Two fundamental questions persist in the debate over the YDIH: Can the results of analyses for purported impact indicators be reproduced? And are the indicators unique to the lower YD boundary (YDB), i.e., ~12.8k cal yrs BP? A test rep...