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Harris-Mann Climatology Article Archive

Title: A Brief Look At Some Explosive Volcanoes

Author: Meteorologist Randy Mann
Published: 11/26/2017

NASA’s Goddard Institute recently reported that October’s global temperature was the second highest on record. Based on the average readings from 1951 to 1980, October’s global temperature was about 1.62 degrees Fahrenheit above the normal.

According to scientists, 2017 will likely end up as the second warmest year on record. Although, we are heading toward the cooler sea-surface temperature event, La Nina, in the waters of the south-central Pacific Ocean, there is still plenty of warmer than average water temperatures in the northern Pacific Ocean and Arctic regions. This may account for some of the higher global temperatures.

I still receive many questions and opinions about this trend of warmer temperatures on a global scale. However, the readings from 1951 to 1980 include the very chilly 1970s when many scientists believed we were heading toward a new ice age. Our planet has definitely warmed up in recent years, but we’ll have to wait and see where we go from here. Cliff and I did update our long-term chart and discussion earlier this year at www.LongRangeWeather.com. And yes, we need to “go green.”

The one event that would halt this warming trend in its tracks is a major volcanic eruption. In June, 1991, Mount Pinatubo erupted which briefly led to about a degree drop in the Earth’s temperature for several years. Millions of tons of volcanic ash were ejected about 22 miles high up into the atmosphere and was dispersed tens of thousands of miles by the upper-level winds.

When we think of volcanic eruptions, most of us remember the Mount St. Helens eruption on May 18, 1980. Or, perhaps the most famous explosion in history, was Mount Vesuvius in 79 A.D. The Italian towns of Herculaneum and Pompeii were buried by dozens of feet of volcanic ash from the massive eruption. Based on eyewitness accounts, the event lasted for several days. Pompeii’s ruins have become a major attraction and it is a place I hope to visit very soon.

The most explosive and deadliest eruption since 1800 was Mount Tambora in April of 1815. The event was so massive that the mountain was reduced 4,000 feet to 9,000 feet. The following year, 1816, was known as the “year without a summer” in parts of Europe and North America due to the heavy ash thrown up into the atmosphere that reduced the Earth’s temperature at least several degrees. Historians believe that 60,000 to 90,000 people were killed from the initial eruption and an additional 100,000 people may have died from crop failures across the globe due to colder temperatures.

Scientists are working to better understand and predict volcanic eruptions. Currently, it’s estimated that there are over 1,500 active volcanoes on Earth. In the U.S., there are about 169 active volcanoes. Most of them are in Alaska where eruptions often occur every year. As of late last week, according to VolcanoDiscover.com, there are 36 erupting volcanoes, including Mt. Etna in Italy.

From a suggestion from a fellow meteorological friend, I watched Nova’s “Killer Volcanoes.” According to the program, around 1257 A.D., there was a huge eruption, about 10 times bigger than Mount Pinatubo and one of the biggest in recorded history. It was so large, that the Earth’s temperature cooled dramatically, nearly 4 degrees Fahrenheit, that led to widespread crop failures and very cold temperatures across the planet, including Europe and North America. Evidence of this huge explosion was based on written accounts, mass graves in London that date back to that time period, carbon dating of buried volcanic ash found across the world, and ice core samples from the North and South Poles.

From recent data and research, scientists discovered that the gigantic eruption came from a volcano once called Mount Samalas located in Indonesia, a region with a high number of active volcanoes. Today, a giant caldera, a large cauldron-like depression from the collapse of that specific mountain, resides where Mount Samalas once stood, right next to another active volcano, Mt. Rinjani. And, of course, Yellowstone has a large caldera from it’s massive explosion about 650,000 years ago.

According to the program, there have been 7 major eruptions the size of Mount Pinatubo or larger since 1257. So, it’s not the question of if there will be another blast near the Equatorial regions, but when.