Etna’s Changing Landscape
Boris and Alfio, geologists at Sicily’s National Institute of Geophyscis and Volcanology picked us up in their four-wheel drive jeeps. Etna is a stunning image. She rises 3,300 meters right from the seafloor, towering over the towns located around her flanks, providing fertile land for farming and beautiful hiking and skiing. Alfio calls her their “Sicilian Mother”: bountiful and beautiful, but able to flare up at a moments notice.
We drive up the base of Etna studying the lava flows visible on the road cuts. Lava from a 1690 eruption traveled 45 km to Catania, destroying much of the city, before pouring into the Ionian Sea. As we make our way up the lava gets younger: 1700s, 1983, 1991-2, until we finally reach the tourist center where lavas in 2001 and 2002 lavas destroyed several buildings. There is a cable car that takes people from the tourist camp to 2,500 meters. The cable car was first built in the 1970s so people could more easily reach the summit. Periodic lava flows have destroyed it four times in 40 years. The current one was rebuilt after the 2002 eruption.
At base camp, we stop to pick up Doug and Diane, two videographers accompanying us up the mountain. Boris and Alfio also grab a caffé (an Italian staple). We pass through the gates for authorized personnel only, getting annoyed looks from the tourists who have to pay to ride the cable car or trudge up themselves.
We’ve driven about halfway up, when we notice two large hills covered with ash towering over us. In 2000, the area was a flat expanse of ash without these features. Within a year, magma beneath Etna had generated these two massive cones.
Boris says that every time he comes up to Etna he takes dozens of photos and that in the seven years has accumulated hundreds of photos of features that are no longer part the landscape. We so often think of mountains as slowly growing features that may set off an earthquake every few decades, but rarely change within our lifetime. And here is Etna that, like all active volcanoes, changes completely every few years, even without a major eruption.
We park the jeeps around 2,800 meters and begin to hike across thick deposits of windblown ash. We can see traces of snow that fell this year or several years ago, preserved under the ash. The walking gets tough as the ground turns to lava called A’a (for its Hawaiian counterpart).
A’a is crumbly, sharp, and painful to grab onto if you lose your balance.
Further up we start to see rocks of hydrothermal origin. These are composed of minerals that crystallize from water heated inside Etna (sulfur is the most common mineral). We’re still far from Etna’s active caldera, so these are rocks that were ejected from the caldera during Etna’s numerous explosions, or burps as Nano calls them.
We make the last scramble across a 40 degree slope to edge of the Etna’s most active caldera, where enormous fountains of lava erupted in 2008.
Over a period of eight months, 66 lava fountains gushed into the air. (Compare this to Mauna Loa’s 46 lava fountains in three years.)
So here we are, standing right next to it.
The rocks are coated in soft ash from explosions earlier this year, in April. They are warm to the touch from the magma just beneath the surface. Walking around, we come across vents of hydrogen sulfide under our feet. If the breeze blows the wrong way for too long, the smell of rotten eggs is overwhelming, burning your eyes, nose, and throat. Boris said he’s breathed in so much hydrogen sulfide, he has destroyed much of his sense of smell.
The trek back down Etna is treacherous, but beautiful. It’s a relief to finally make it back to the soft ash and our jeeps. Those of us here for the first time – myself, my parents who are visiting from Massachusetts, Doug, and Diane are nearly speechless with awe and wonder.
The next morning Boris calls to tell us that the caldera edge we were hiking along had collapsed into the caldera. The powerful, scary Etna had changed the landscape once again. I agree with Alfio: a Sicilian Mother after all.