Anoxic Event

Oceanic anoxic events or anoxic events occur when the Earth's oceans become completely depleted of oxygen (O2) below the surface levels. Although anoxic events have not happened for millions of years, the geological record shows that they happened many times in the past. Anoxic events may have caused mass extinctions. These mass extinctions were so characteristic they include some of those which geobiologists employ to serve as a time marker in biostratigraphic dating. It is believed oceanic anoxic events are strongly linked to lapses in key oceanic current circulations, to climate warming and greenhouse gases. What is clear from careful analysis of the geologic records occurring before and after the affected ages is that onsets are rapid and so are recoveries. Both sets of data suggests that a sudden climate threshold or tipping point occurs at about four times the Earth's mean carbon dioxide levels relative to the baseline concentrations of circa 1750. This date is significant in that it is regarded as the beginning of the Industrial age.

Klappentext

Oceanic anoxic events or anoxic events occur when the Earth's oceans become completely depleted of oxygen (O2) below the surface levels. Although anoxic events have not happened for millions of years, the geological record shows that they happened many times in the past. Anoxic events may have caused mass extinctions. These mass extinctions were so characteristic they include some of those which geobiologists employ to serve as a time marker in biostratigraphic dating. It is believed oceanic anoxic events are strongly linked to lapses in key oceanic current circulations, to climate warming and greenhouse gases. What is clear from careful analysis of the geologic records occurring before and after the affected ages is that onsets are rapid and so are recoveries. Both sets of data suggests that a sudden climate threshold or tipping point occurs at about four times the Earth's mean carbon dioxide levels relative to the baseline concentrations of circa 1750. This date is significant in that it is regarded as the beginning of the Industrial age.