July 28, 2021, 10:20pm
I just experienced my first earthquake!
I was lying in bed reading, when I heard a sort of scuttling noise in the roof, and felt some kind of rocking motion as if people were stomping through the cabin. But the sound of it didn’t seem right–not stomping, just weird sounds coming from the ceiling.
I looked up and saw my hanging lights and postcards and curtains beginning to sway. The rocking became more intense and I heard raised voices outside. My first thought was that drunk people were running around and somehow messing with the cabin, but when I heard my roommate’s door open, I realized something else was going on.
“So, I think that’s an earthquake,” she said, with a worried grin. “It’s still happening.”
By now, it felt like we were on a boat, rocking back and forth and side to side on tiny waves, the ground shifting slightly beneath us, perhaps like standing on a waterbed. We were holding onto our doorframes to steady ourselves. It lasted for minutes, long enough to make our way into the kitchen and open the window to see all our neighbors doing the same, or coming outside. “This is bigger than the one last year,” our neighbor across the street shouted through her window.
Behind her cabin, the white spruce were swaying dramatically as if in a heavy windstorm, but there was no wind. We all stood around and marveled at the earthquake until we felt like the shaking had ceased. I kept glancing at the calendar on the wall, watching its pages flap with the swaying of the cabin, until finally they stopped.
My roommate texted a friend about it, and a few minutes later her friend texted back and said that what we had felt was an 8.1 magnitude earthquake centered a little bit south of here near Chignik! My first earthquake, and big one, too. I kept hoping we’d get some aftershocks, but I haven’t felt any. As long as this doesn’t mean a volcano is about to blow, I’m pretty stoked about it!
Update since my original journal entry: That earthquake became known as the 2021 Chignik Earthquake, the largest earthquake in the US in 50 years! It was also the 7th largest in US history.
A little science: the earthquake happened as the result of thrust faulting on or near the subduction zone interface between the Pacific and North America plates. It happened about 20 miles deep, just off the coast of the Aleutians, and about 200 miles south of where I was at the time.
At first, it seemed like there had been no impacts besides some stuff sliding around, but the next day, we discovered the water supply had been damaged at the ranger cabins on Lake Brooks. Although these cabins were just a short walk from where I was living, the water came through a different system, and got infiltrated with sediment from the earthquake. For almost the whole rest of the season, park maintenance had to work to flush out the sediment and supply potable drinking water to the Lake Brooks residents with temporary tanks.
What a wild experience! It was a good reminder of how tectonically active this area is, located where are on the Ring of Fire. Historically, earthquakes like this can sometimes indicate that a volcano is about to erupt, but fortunately that didn’t happen this time. It did give me some extra respect for the natural forces of this land, and made me consider just how remote and dangerous this place can be.