Musings: 2025 (current posts)

Recent craters in Siberia due to methane release from hydrates in the permafrost

January 15, 2025

Methane hydrate is a complex of methane and water. It is an ice-like solid at conditions where methane itself would be a gas. There is a lot of methane underground in cold regions, where the methane hydrate is effectively part of the permafrost. There is a concern that warming of the permafrost could lead to release of the methane, which is a potent greenhouse gas and also flammable.

Concern that it might happen is being replaced by study of how it happened.

A crater on the Yamal Peninsula in Siberia.

The crater core is about 30 meters across.

This crater was first noticed in 2014. There are now about 20 such craters in Siberia, all new since about that time and many in the same region. From the time of the initial observations, it seemed likely that the craters were due to methane release, probably stimulated by climate change, but the details have been debated.

This is trimmed and reduced from the top figure on the Wikipedia page listed below; credit is given there to the scientists who provided it. There are other views of such craters in Figure 1 of the article and in the news stories.

So, what happens? The simplest model might be that the hydrate warms, releasing methane, which escapes. That model does not necessarily lead to a crater. A more complex model might postulate that the methane builds up inside a closed region, until the pressure is high enough to break it open -- explosively. A new article offers support for an even more complex process. It involves the migration and mixing of water layers of different salinities (salt content) and temperatures. That flow of differing liquid phases promotes heat transfer, and puts physical stress on the subsurface structures. The article is based largely on mathematical modeling, with some lab work that supports the idea. The model depends on the geological details of the area. Thus it helps to explain the limited geographical distribution as well as the nature of the craters.

Of course, it is reasonable that there are various processes that can lead to methane release. The current work is just an example of one way it might happen. The work serves to remind us of the likely importance of methane hydrates.

* News stories:
- Massive exploding methane craters are tearing Siberia apart and scientists finally know why -- Scientists uncover the mechanics behind Siberia's explosive craters as warming drives methane release. (Tibi Puiu, ZME Science, November 11, 2024.)
- New explanation for Siberia's permafrost craters -- The region's unique geology, not only warming and permafrost thaw, caused the methane explosions. (AGU, September 26, 2024.)
* Wikipedia page referred to above as source for the figure: Gas emission crater. (Wikipedia.) Useful overview. The current article is noted there. It is now reference #11; search the page for the lead author (Morgado) if needed.
* The article, which is open access: Osmosis Drives Explosions and Methane Release in Siberian Permafrost. (Ana M O Morgado et al, Geophysical Research Letters 51:e2024GL108987, September 26, 2024.)

Among posts about methane and its hydrate:
* Methane hydrate: a model for pingo eruption (August 4, 2017).
* Climate change: Should we focus on methane? (March 24, 2012).
* Ice on fire (August 28, 2009).

Photosynthetic hamster cells

Scientists have added chloroplasts to hamster cells growing in lab culture. The chloroplasts functioned for at least two days; there is at least a hint that they contributed fuel to the cell economy. This appears to be the first example of free chloroplasts (that is, not within their own host cell) functioning in animal cells. What will it take to get good chloroplast function over an extended period? We'll see.

The authors suggest an interesting lab use for such photosynthetic animal cells. In tissue culture, they could be a useful source of oxygen for the cells.

Happy 45²

January 6, 2025

A once in a lifetime event for most of us. But it is extra special for anyone who was around in 1936.

This post is listed on my page Internet resources: Miscellaneous in the section Mathematics; statistics.

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