California’s Lassen Peak is sinking at a rate of about a centimeter per year for the past three decades. But volcanologists can’t figure out why. With no explosion in over a century, it might appear that California’s Lassen Peak hasn’t changed much.

But recent findings show the volcano has been slowly sinking for the past three decades. And volcanologists can’t figure out why. A recent study shows that there was a broad range of sinking measuring about 18 to 24 miles and progressing at the rate of about a centimeter per year on the peak. FULL REPORT