Guest Videos: What Is Lightning?

When thunder roars, go indoors! — words of wisdom from James Spann and other meteorologists.

Note that on Earth, lightning is most frequent in equatorial regions.

For almost 40 years–ever since Voyager passed the planet Jupiter–scientists have wondered why lightning is more frequent at Jupiter’s poles. It otherwise seems to work pretty much the same way as terrestrial lightning.

Thanks to data from the Juno mission, they may have figured it out now.

Meanwhile, back on Earth–
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Guest Video: The Falcon and Dragon Dance Begins

Update, July 11, 2018: I so enjoy the 21st-century luxury of having spacecraft tweet images from their latest position millions of miles away!

And here is the “Dragon Palace” in 3D!

Japan’s Hayabusa 2 spacecraft has arrived at Asteroid Ryugu!

Cesium–A Critical Mineral

Cesium (“caesium,” outside the US) is not just a ringtone. Nor is it simply the atom used in ultra-precise clocks that make everything from the Internet to GPS possible, thanks to accurate time stamps.

Yes, cesium defines time itself.

Although it can be hazardous in some forms, cesium also is extremely useful in a variety of niche applications ranging from things like catalyzing chemical processes to cleaning sulfur out of crude oil to making fiber optic and other specialty glasses to building cellphone motion sensor devices.

In its manmade radioactive form, Cs137 is used for treating cancer and sterilizing equipment in modern medicine; and as cesium formate, it is rented out as a reusable brine to companies drilling oil and gas wells in high-temperature, high-pressure formations.

The United States depends on imports, mainly from a mine in Canada. And that mine closed in 2015, although its cesium stock is still sufficient to meet US and worldwide demand for the near future.

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Guest Videos: Laguna del Maule Volcanic Complex

First off, here’s a skiing video, without a single mention of volcanoes. But everything they are travelling over, under, around and through is part of the Laguna del Maule volcano complex on the Chile-Argentina border.

Yes, it’s an active volcano. In fact, until last year it seemed the most likely candidate for the world’s next supereruption.

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Guest Video: The Salton Sea

A study at the end of June made headlines about earthquake hazard on the San Andreas Fault. The research looked at the area covered by the Salton Sea:

According to news reports, geologists found:

. . . a nearly 15.5-mile-long, sheared zone with two, nearly parallel master faults and hundreds of smaller, rung-like cross faults. . . The discovery . . . reveals the southern tip of the San Andreas Fault changes fairly gradually into the ladder-like Brawley Seismic zone. The structure trends northwest, extending from the well-known main trace of the San Andreas Fault along the Salton Sea’s northeastern shore, to the newly identified East Shoreline Fault Zone on the San Andreas’ opposite edge.

. . .

Future earthquakes in that zone or near the San Andreas Fault could potentially trigger a cascade of earthquakes leading to the overdue major quake scientists expect along the southern San Andreas fault zone . . .

So, perhaps it’s good that the “Riviera” scheme never worked out.

While seismologists scramble over the area to learn more about earthquake hazards, the USGS is monitoring the local volcano situation–which includes five vents discovered in 2013–through the California Volcano Observatory.

Again, not a good place for a resort!

Featured image: 12019, at Pixabay. Public domain.

Alaska’s Sitkin Volcanoes

You might already have heard of one of the two Alaskan “Sitkin” volcanoes, since headline writers at a few news websites are giving Great Sitkin Volcano the “about-to-explode” treatment.

Indeed, the Alaska Volcano Observatory (AVO) recently raised the aviation code on Great Sitkin Volcano to Yellow, since it is having a period of elevated seismicity.


Great Sitkin has been having swarms of small earthquakes off and on since 2016. There also was a small ash emission in early June.

Magma probably has moved into the volcano. But there is no sure way to predict exactly what Great Sitkin Volcano will do in coming weeks and months, as volcanologists told local journalists late last year.

Instead of going by the doom-and-gloom headlines, let’s get to know these volcanoes a little better.

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