Nov
7

Natural Disasters in Focus: Volcanoes

Natural Disasters in Focus: Volcanoes

November 7
By

In each edition of Natural Disasters in Focus, we take you inside some of the most terrifying natural disasters the world has to offer.

For this edition, we’ll be discussing one of the most destructive forces on earth: volcanoes. Volcanic eruptions are some of the most spectacular cataclysms Mother Nature has in her arsenal. They can be massive events that cause destruction in vast swaths, or they can be relatively minor, only spewing limited amounts of gas and lava that affects the surrounding area minimally. While some volcanoes erupt without warning, some have a number of geological warning signs. Even still, it can be tough to determine when they’ll actually go off. But when they do, it can be catastrophic.

Historically, some massive eruptions have wiped out huge populations of people and animals—some even think one of these “super eruptions” will happen soon. But will it? What are some other things to know about volcanoes?

How many volcanoes are there?

The Universe Today reports that there have been 505 volcanoes active in recorded history. The report also notes that geologists have discovered an additional 1300 in that have been active in the last 10,000 years. Put simply, there are lots of volcanoes in the world. In the US alone there are 169 active volcanoes, and 57 of those are a high threat. In Europe there are around 69 active volcanoes. You can see which volcanoes are erupting or might be near eruption in real time at VolcanoDiscovery.com.

Volcano Map

Map of select active volcanoes

What was the biggest volcanic eruption in history?

The most deaths attributed to a single volcanic eruption in modern times happened at Iceland’s Laki, which took an estimated 10,000 lives following its eruption in 1783. The most destructive eruption in all of history happened at present-day Lake Toba in Indonesia. Hypotheses suggest that this eruption occurred over 70,000 years ago and caused a 10-year volcanic winter that destroyed vegetation and other food sources, eventually leaving a mere 3,000-10,000 humans alive on the planet.

What types of volcanic structure are there?

Lava landforms can be tubes, domes, fountains, volcanoes, lava lakes, and more. There’s a variety of structures with volcanic properties, some of which are also underwater.

A lava dome structure. Photo courtesy of USGS.

A lava dome structure. Photo courtesy of USGS.

Are there different types of eruption?

There are many types of volcanic eruption. They range from the common Hawaiian eruption, characterized by slower lava flows issued from a volcanic structure, all the way to Peléaneruptions, noted for their massively explosive characteristics that involve heavy lava flow, expulsion of volcanic debris, as well as gas, dust, and ash. There are also underwater eruptions with varying characteristics.

Are there different types of lava?

Lava is molten rock and comes in a variety of types depending on its chemical composition, but is classified into three types: felsic, intermediate, and mafic. Depending on the lava’s temperature and composition, it can flow in a few different ways, such as an ʻAʻā flow or a Pāhoehoe flow.

ʻAʻā flow front advancing over pāhoehoe. Photo by USGS.

ʻAʻā flow front advancing over pāhoehoe. Photo by USGS.

What else do we need to know about volcanoes?

They can be insanely loud.

When a volcano on Krakatoa (near Java in Indonesia) erupted in 1883, it produced a noise so loud that the sound circled the earth four times. The captain of a British ship nearby wrote in his log that half the crewmen’s eardrums burst as a result of the blast. More recently, a volcano in Papua New Guinea erupted, producing a formidable report as well:

The lava they spew is extremely hot.

Lava temperatures can be up to 2012 Fahrenheit (1000 degrees Celsius). Here’s a video of a hot lava flow consuming a can:

Earth is not the only planet with volcanoes.

According to a report by PBS, volcanoes helped shape a number of the planets in our solar-system, including our neighbor Mars. NASA has found as many as 500 volcanic centers that may have been active in the last 100 years.

There will not be a super eruption any time soon.

Maybe you’ve seen the articles about the caldera floor in Yellowstone National Park. Supposedly, if this floor collapses it will set off a “super eruption” that may have the power to extinguish human life on earth. Well, despite fear-mongering media reports about it, the Yellowstone Volcano Observatory issued this statement, “Although fascinating, the new findings do not imply increased geologic hazards at Yellowstone, and certainly do not increase the chances of a ‘super eruption’ in the near future. Contrary to some media reports, Yellowstone is not ‘overdue’ for a super eruption.”

Sure, an eruption probably will happen in Yellowstone at some point in the distant future, but it’s nothing to worry about today. If it did happen, however, this video imagines what it might look like:

So that’s about it for volcanoes, if you’ve got any interesting volcano experiences, please share in the comments. And remember, volcanoes certainly are neat, but they’re also dangerous. Look for our article about how to survive a volcanic eruption so you know what to do if you live near one or if you’re just visiting.

Top photo credit: J.D. Griggs via Wikimedia