Robin George Andrews

A slightly misleading title; nevertheless, an exuberant exploration of what we know about volcanoes.

The book's title may suggest it is about supervolcanoes, and the author does speak of Yellowstone but proves dismissive of the idea of the "supervolcano." Instead, the author is enamored with volcanoes in general. One travels with him across the world and explores all kinds of different types of volcanoes. Great detail is given about Kilauea in Hawaii; what may happen at Yellowstone; interesting volcanoes in the Great Rift Valley; and undersea volcanoes.

The author then explores what we know of volcanism in our solar system: the previous history of volcanism on the Moon; the volcanic activity of Mars in the past, possibly the present; questions about Venus; and much about the volcanism we have seen on moons of Jupiter and Saturn.

The author's enthusiasm for the subject is infectious but we could have done without the attempts at verbal memes and cliches. A great read if you are interested in geology or volcanism.… (altro)

I would have preferred to have *much* more detail about terrestrial volcanoes and volcanologists. Still, I enjoyed what Andrews gave us.

> Around 252 million years ago, a planet already suffering from ecological turmoil was also baking thanks to the ~2-million-year-long eruption of lava gushing out of what is now Siberia. This continental-scale volcanism, unleashing climate-perturbing gases of its own, also ignited a huge reservoir of coal, triggering a global warming offensive. When all was said and done, this Murder on the Orient Express–style apocalypse killed more than nine out of every ten marine species and seven out of ten terrestrial vertebrate species—birds, amphibians, reptiles, mammals, and so forth—on the planet. This event, aptly known as the Great Dying, was easily the worst mass extinction in Earth’s history and its darkest chapter.

> that heat isn’t extreme enough at present to keep both [Yellowstone] reservoirs completely molten. Get a fresh injection of hot molten rock from below, say, and sure, more of the reservoir cooks and melts. But what you have for the most part is solid rock, with a network of molten ponds, pools, and slivers. Sometimes more of it is molten, sometimes less. Think of it as a strange sponge, with the holes filled with a hellish gelatin. That gelatin, being hotter than the cooler, frozen volcanic crystals around it, is naturally buoyant, and the laws of physics demand that it rise as best as it can. It exploits zones of structural weakness, like big holes in the sponge, as it makes its ascent. Magma chambers aren’t really cavernous gaps in the crust at all, but reservoirs of mush, serpents of partially molten rock confined within a labyrinth of crystals. They are Beelzebub’s sponges. … Yellowstone’s sponges may be gigantic, but they are mostly frozen right now. Seismic data suggest that the upper reservoir is between 5 and 15 percent molten. The lower reservoir is only 2 percent molten

> The crust being thicker on the farside could be explained by a really cool idea from 2014 named Earthshine. Back when the Moon formed, it was much closer to Earth, perhaps only 8,000 miles away, compared with today’s distance of nearly 240,000 miles

> Several thermometers were buried in the lunar soil by the Apollo 15 and Apollo 17 missions and kept running from 1971 to 1977. It was hoped they would take the Moon’s internal temperature, but as they only went a few feet into the ground, they were affected by whatever was happening at the surface. Scientists found that they registered a curious uptick in temperature during the duration of the heat-flow experiment. This was found to be the astronauts’ fault: as they bounded about, they kicked up a lot of lunar soil. This made the surface rougher, making it less able to reflect sunlight, and causing the surface to warm up

> Mars, like the Moon, also has two hemispheres that are vastly different from each other: a southern, highly cratered highlands section with crust up to 62 miles thick, and a northern, smooth lowlands section with a paltry 19-mile-thick crust

> Mars, like Earth, also has mud volcanoes. They are exactly what they sound like: buoyant or pressurized mud bubbles up out of holes in the ground. Terrestrial mud is fairly runny. But Mars’s thin atmosphere means that the average surface temperature is –81 degrees Fahrenheit. This quickly freezes the tops of these mud flows, insulating the mud below and letting it flow over long distances like gloopy lava in tunnels in Hawai‘i.

> The trapped gases within martian meteorites, when compared with present-day measurements by robots suggest that most of Mars’s early atmosphere had been obliterated just 500 million years or so after Mars was born. If true, that implies Mars was almost always an acutely frigid place with a very low atmospheric pressure. It would have been incredibly difficult, if not impossible, to have long-lived river systems, lakes, and oceans much later in its history—and yet the once wet valleys and basins suggest otherwise. So did the planet dry up or didn’t it? Most researchers I spoke to are coming around to the idea that Mars was never warm and wet, but icy and damp. The ancient martian atmosphere would have had so little carbon dioxide that it would be impossible to get the global Mars temperature above freezing and keep it there. Fortunately, that’s no problem for liquid water. In Antarctica’s McMurdo Dry Valleys, you still have substantial lakes trapped beneath ice. The mercury only rises above freezing for a couple of days per year, but that’s enough to melt glaciers and snow to supply meltwater to underground lakes

> Mantle plumes, aiming at tectonic plates on Earth, have moving targets to hit. On Mars, their targets are stationary.

> on Io, so much new magma keeps gushing up through massive, diabolical esophaguses and onto the surface that the crust gets squashed down. This, says Davies, sometimes snaps the crust upward, forming sudden mountains 12 miles high.

> what are the odds that you have a planet like the Earth in the Goldilocks zone—not too hot, not too cold, where all the conditions are just right—versus having moons around the larger planets we know, like Neptune-size and up … there’s a lot of these bigger planets and they might have moons where tidal heating may be a factor. You may have more ocean worlds with frozen icy crusts than Goldilocks worlds like the Earth.”… (altro)

I found this interesting. He starts with the recent Hawaiian volcano and works his way across Earth then into space and the other planets explaining how volcanoes have affected the Earth and the other planets. He also delves into what make other planets uninhabitable using their volcanoes as the point of reference. Mr. Andrews gets into some of the debates between scientists and volcanologists.

There were times I did not understand what he was saying (not a big science person) but as I read more I understood more. By the time I got to the last chapters with Venus, Jupiter, and Saturn I did understand what was happening and why in the world of volcanoes. Worth the read.… (altro)