Thirteen days before Christmas, somewhere in the frigid waters of the Bering Sea, a massive volcano unexpectedly rumbled back to life.
Just like that, Bogoslof volcano began its first continuous eruption since 1992, belching great plumes of ash tens of thousands of feet into the cold sky over the Aleutian islands, generating volcanic lightning, and disrupting air travel—though not much else.
The volcano is on a tiny island about 60 miles west of Unalaska, which is the largest city in the Aleutians. It has a population of about 5,000 people.
Bogoslof hasn’t quieted yet. One explosion, in early January, sent ash 33,000 feet into the air. Weeks later, another eruption lasted for hours, eventually sprinkling enough ash on the nearby city to collect on car windshields and dust the snow-white ground with a sulfurous layer of gray. Over the course of two months, Bogoslof’s intermittent eruptions have caused the island to triple in size so far, as fragments of rock and ash continue to pile atop one another.
Geologists don’t know how long the eruption will last. In 1992, the activity at Bogoslof began and ended within weeks. But more than a century ago, it erupted continuously for years. In the 1880s, volcano observers in the Aleutians had little but their own senses to track what was happening. Today, scientists use satellite data and thermal imagery to watch Bogoslof—signs of elevated temperatures in satellite data indicate that lava has bubbled to the surface, for example. But monitoring efforts are nowhere near what they could be. For the relatively remote Bogoslof, the absence of ground-level sensors is inconvenient, perhaps, but not necessarily alarming. Elsewhere, the dearth of volcano sensors poses a deadly problem.