How many times has Nevado del Ruiz erupted?

Nevado del Ruiz: A Volcano with a Fiery Past (and Present!)

Nevado del Ruiz. Just the name conjures up images of a towering, snow-capped giant. And that’s exactly what it is: a stratovolcano smack-dab in west-central Colombia. Locals also call it La Mesa de Herveo, but whatever you call it, this volcano means business. It’s not just any old mountain; it’s the highest active volcano in the Andes, scraping the sky at over 17,700 feet! Now, Ruiz might not erupt every other Tuesday, but when it does, history tells us to pay attention. We’re talking about a volcano with a history that stretches back a whopping two million years!

Think of it this way: Ruiz has been around for a long time, and its story is written in layers of ash and rock.

A Volcanic Timeline: From Ancient History to Modern Day

This volcano’s been busy over the millennia. Volcanic activity first stirred way back in the Early Pleistocene or Late Pliocene epochs. Fast forward to today, and the cone we see now? That bad boy started taking shape around 150,000 years ago. But let’s get to the good stuff: the eruptions. Over the last 10,000 years, Ruiz has blown its top at least 20 times. We know about 13 of those from historical records. The rest? Geologists have pieced them together from clues in the ground. Pretty cool, huh?

Here’s a little highlight reel of some of the big ones:

• Way Back When (Around 6660 BC): Ruiz’s earliest known Holocene eruption. Talk about ancient history!
• 1570: The oldest eruption we have a written record of.
• November 13, 1595: Boom! A major eruption sent three Plinian explosions echoing for miles – they say you could hear it 62 miles away! But it wasn’t just noise. Lahars, those nasty mudflows, roared down the valleys, claiming over 600 lives.
• February 19, 1845: Disaster struck again. A big earthquake triggered a massive mudflow that bulldozed down the Lagunillas River valley for 43 miles. The result? Over 1,000 lives lost and a town, Armero, eventually built right on top of the old mudflow. Talk about tempting fate…
• November 13, 1985: This is the one everyone remembers, and for good reason. A relatively small eruption – a VEI of 3, if you’re into the technical stuff – unleashed lahars that buried Armero. The death toll? A staggering 25,000 people. It’s one of the worst volcanic disasters ever, a stark reminder of nature’s power. The eruption shot ash and rock over 19 miles into the sky and released a massive amount of sulfur dioxide.
• 2012-2017: Even more recently, Ruiz has been puffing away, sending up ash plumes and sulfur dioxide. It’s like the volcano’s just reminding us it’s still there.

Lahars: The Silent Killers

Okay, let’s talk about lahars, because these are the real villains in the Nevado del Ruiz story. Imagine a river of mud, but supercharged with volcanic ash, rocks, and anything else the volcano throws in. Now, add water – lots of it, from melting glaciers. That’s a lahar. And because Ruiz is covered in ice, it’s a lahar-making machine. When an eruption happens, the heat melts the glaciers, creating a torrent of water that mixes with volcanic debris. The result? A fast-moving, incredibly destructive flow that can wipe out everything in its path.

The Armero tragedy? That was all about lahars. Even though scientists were raising the alarm about increased volcanic activity, the town wasn’t evacuated. The lahars, some over 100 feet thick and moving at 30 miles per hour, reached Armero in less than three hours. It was a catastrophe waiting to happen.

Keeping a Watchful Eye

So, what’s the deal now? Well, Nevado del Ruiz is still an active volcano, and scientists are keeping a close watch. They’re monitoring it constantly, looking for any signs of trouble. Back in March 2023, increased seismic activity prompted officials to raise the alert level, which means the risk of eruption is higher. And let’s not forget, there are around half a million people living in the valleys around the volcano. It’s a situation that demands respect and constant vigilance. Nevado del Ruiz is a powerful force of nature, and we need to be ready for whatever it throws our way.