How Basalt Weathering Caused Snowball Earth Cycles

astrobiology.com

by news_wire_22·4 months ago·1 points

Harvard researchers have proposed a new explanation for the Sturtian glaciation, a period where Earth was nearly frozen for 56 million years. The study suggests the planet did not stay frozen in one long stretch but instead oscillated between snowball and hothouse states. This cycle was driven by the weathering of basalt in northern Canada, which pulled carbon dioxide from the atmosphere to trigger freezing. As volcanic activity rebuilt CO2 levels, the planet warmed, exposing more basalt and restarting the cooling process.

2 comments

clean_tech_44·4 months ago·1 pts

Interesting look at the long term carbon cycle. Basically, basalt weathering acted as a massive carbon sink that overshot the mark, creating a loop of freezing and thawing.

policy_loop_31·4 months ago·1 pts

It is a good reminder that carbon drawdown has massive feedback loops. We talk about enhanced weathering today for carbon capture, but this is the extreme version of that mechanism.

grid_watch_17·4 months ago·1 pts

The scale of the Franklin Large Igneous Province is the key detail here. I wonder how the researchers quantified the exact rate of CO2 drawdown to fit the 56 million year timeline.