Volcanic eruptions and flight delays

There are over 1,500 active volcanoes around the world with an average of 50-70 eruptions per year. According to VolcanoDiscovery.com, as of the weekend, there are 36 volcanoes that are currently erupting. There are also 34 volcanoes that are classified as “minor activity or in a warning” state.

Most of the eruptions are currently along the infamous “Ring of Fire.” This is an area that looks like a horseshoe that extends from New Zealand, Indonesia, Japan, southern Alaska and along the western U.S., Central American and the South American west coasts.

The Ring of Fire is the result of the movement and collisions of the tectonic plates that have led to the creation of over 450 volcanoes, especially along the U.S. West Coast. Approximately 90% of the world’s earthquakes are recorded in the Ring of Fire.

Erupting volcanoes have occasionally wrecked airline travel plans. Last week, flights to Bali, Indonesia, were canceled due to an ash cloud that originated from an erupting volcano in Indonesia. Flight cancellations were reported in Bali, South Korea, Singapore, India, Qatar and Australia. Thousands of travelers were left stranded for at least 24 hours.

Earlier this year, the Popocatepetl Volcano erupted in the middle of Mexico resulting in massive flight delays. Mount Etna in Italy has also been spewing hot ash, leading to numerous flight delays in July and August.

Back in 2010, Iceland’s Eyjafjallajokull (I still can’t pronounce this) volcanic eruption led to one the largest air traffic shutdowns in history. Millions of passengers all over the world were left stranded, especially in northern Europe from April 15-23. The ash cloud caused more disruptions May 4-5 in Scotland and Ireland. On May 9, airports in Spain, Portugal, northern Italy, Austria and southern Germany were closed. Most airspaces reopened later in May as the ash cloud dissipated.

Volcanic ash is primarily a mixture of rocks, minerals and tiny glass particles. These particles are specific enough to give geologists a history of previous eruptions. The composition of volcanic ash makes it extremely abrasive. Airlines will avoid them as they can permanently damage the windscreens pilots use to see out of the plane. The ash clouds can also clog or damage sensors.

Volcanic ash will also have a major impact on the airplane’s engines. Most jet engines suck in the air and then compress it. The air and gases flow through the engine, mixing with the fuel and then igniting it. This process makes it spin, then the high-pressure gases shoot out of the rear of the exhaust, pushing the plane forward.

When volcanic ash particles get inside the engines, they will melt and build up. This will result in the engine stalling as the airflow is disrupted.

One of the most famous incidents of an ash cloud coming into contact with a major airline was in 1982. A British Airways Boeing 747 was flying near Indonesia and intercepted an ash cloud from an erupting Mount Galunggung in Java. The event occurred at night and the pilots of the large aircraft lost all four engines. Miraculously, as the plane exited the ash cloud, the pilots were able to restart the engines and were soon redirected to Jakarta. It was a close call as the plane was losing altitude once it encountered the ash cloud. The mountains in Indonesia were as high as 11,500 feet, and it was decided that if the aircraft couldn’t maintain an altitude of 12,000 feet they would have to ditch the plane in the Indian Ocean. At around 13,500 feet, the pilots managed to get the engines to restart and finally got the plane to start climbing. The plane landed safely, but the pilot’s windscreen was heavily damaged, which severely limited their view.

In terms of our local weather, nearly 1.70 inches of rain have fallen this month. The normal November moisture for Coeur d’Alene is 3.07 inches. More rain has fallen this November at the Spokane International Airport as over 2.10 inches has been measured.

We’re still expecting a series of storms to move across the Inland Northwest this week with rain and snow. As of this weekend’s writing, chances were good that the lower elevations, especially in the outlying areas, would see more measurable snowfall.

Although many of these storms looked very promising to produce some significant rainfall earlier this month, they did weaken as they moved close to the strong ridge of high pressure over the center of the country. However, beneficial rains were reported down into California with more moisture on the way. Long-term dry patterns are hard to break, but when they do, our region will often receive much above-normal moisture, which looks like will happen this week. We still believe that this type of above-average rain and snow weather pattern will continue to evolve as we head into December.

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Contact Randy Mann at randy@longrangeweather.com.