Thursday, March 28, 2024
46.0°F

We are seeing an increase in volcanic activity worldwide

| September 20, 2010 9:00 PM

On Aug. 29, thousands of people were evacuated after a volcano on the Indo-nesian island of Sumatra erupted for the first time in 400 years. Earlier this month, Mount Sinabung spewed hot ash more than a mile into the air along with volcanic earthquakes. Two people died and more than 30,000 were evacuated.

Indonesia has the highest density of volcanoes in the world. There are nearly 500 in what is called the 'Belt of Fire,' or the 'Ring of Fire.' Approximately 130 of the volcanoes are active and 68 are currently listed as dangerous.

The 'Ring of Fire' was formed from the collision of large tectonic plates that are either slamming into one another or sliding past each other. Along this division, there are major fault lines, like the San Andreas fault in California, and major volcanoes. The 'Ring of Fire' stretches for approximately 25,000 miles in a horseshoe shape from eastern Asia to the western shores of North and South America. It has 452 volcanoes and is home to 75 percent of the world's active and dormant volcanoes.

This region is also responsible for about 90 percent of the world's earthquakes and 80 percent of the world's largest quakes. Although many of us are noticing the increase in volcanic activity, there is no known correlation, at least right now, of one volcanic eruption triggering another volcanic explosion along the 'Ring of Fire.'

However, there may be an exception to this rule. In Iceland, the eruption of Eyjafjallajokull, which caused widespread flight cancellations in Europe because of the giant ash cloud, has produced a lot of speculation concerning the neighboring volcano Katla. In the past, when Eyjafjallajokull has erupted, Katla has often followed within a short period of time. These volcanoes are not located along the "Ring of Fire," but still quite active.

On Aug. 25, Italy's Etna volcano and Columbia's Galeros volcano, both erupted. The explosions were not huge, but new and perhaps bigger eruptions are expected at anytime.

If volcanic activity continues to increase, and there is an eruption big enough to send millions of tons of ash and dust into the upper layers of the atmosphere, then the Earth's temperature would likely drop at least a degree or two from present levels. This happened in June of 1991 when Mount Pinatubo exploded in the Philippines. For the following year, the Earth's temperature dropped about 1-2 degrees before recovering several years later.

As requested by another Coeur d'Alene Press subscriber, here are the 20 most deadly volcanic eruptions in the past 500 years worldwide and their approximately death tolls:

Kelut, Indonesia, 1586: 10,000

Vesuvius, Italy, 1631: 4,000

Oshima, Japan, 1741: 1,481

Papadanyan, Indonesia, 1772: 2,960

Lakagigar, Iceland, 1783: 9,340

Unze, Japan, 1792: 15,000

Tambora, Indonesia, 1815: 92,000

Galunggung, Indonesia, 1822: 4,000

Nevado del Ruiz, Columbia, 1845: 36,417

Krakatau, Indonesia, 1883: 36,417

Ritter, Paupa New Guinea, 1888: 3,000

Mount Pelee, Martinique, 1902: 29,000

Kelut, Indonesia, 1919: 5,110

Lamington, Papua New Guinea, 1951: 2,942

Hibok-Hibok, Philippines, 1951: 500

Agung, Indonesia, 1963: 1,148

NORTH IDAHO WEATHER REVIEW AND LONG-RANGE OUTLOOK

Following the seventh-driest first half of September in Coeur d'Alene since at least the inception of regular weather record-keeping in 1895, we finally began seeing some much-needed showers early this past Thursday morning in the area as I wrote this weekly update.

Only a scant .19 inches of precipitation was gauged on Player Drive in town through Sept. 15. Spokane had even less moisture at just .09 inches.

Our recent streak of four straight 80-degree-plus afternoons, that helped ripen our tomatoes in the backyard garden, likewise ended on Thursday.

Cooler temperatures and on-and-off shower activity will continue locally for much of the rest of the month. Our final September rainfall total could approach the 115-year normal of 1.58 inches. Last September, as the storm track went to the south of us during the warm 'El Nino' event, we gauged just .45 inches of rain, more than a full inch below normal.

We had a near-record six 'Sholeh Days' at or above 90 degrees last September, including a near-record high of 90 degrees on the first day of autumn on Sept. 23.

Longer-term, despite some brief mild 'Indian Summer'-type weather conditions expected in early October, I see a wet and cool fall followed by a colder and snowier than normal winter season, thanks to the new 'La Nina' gaining strength in the cooling waters of the Pacific Ocean.

Remember, I still see at least 80 inches of snow this winter in Coeur d'Alene. More than 100 inches of the white stuff may be gauged in some of the typically snowier locations to the north of the Lake City from Rathdrum to Priest Lake.

Last winter, during the warm El Nino event, we only measured a puny 18.4 inches of snow all season. I didn't use my snowblower even once! Our normal Coeur d'Alene snowfall in an average winter since 1895 is 66.7 inches.

But, even with the new La Nina, I don't foresee the return of the all-time record snowy winters of 2007-08 and 2008-09 during the global cooling period associated with our 'Silent Sun.'

No other two winters back-to-back ever produced even close to the 318.5 inches of snow that the 2007-09 period gauged locally in town. The recent winters beat the 1915-17 seasons by more than 100 inches.

I doubt that we'll see the type of harsh winters that we saw in 2007-09, at least in my lifetime. We certainly don't need anymore collapsed buildings or heart attacks or broken backs, from shoveling such heavy, wet snows. Remember, this is 'Camelot,' not Lake Tahoe!

Cliff Harris is a climatologist who writes a weekly column for The Press. His opinions are his own. E-mail sfharris@roadrunner.com