THE BURNED OVER DISTRICT

Rattlesnake Ridge like its namesake critter is in the process of shedding a large portion of the ridge. A 20 acre portion, about 4 million cubic yards. Currently it is moving at a rate of about 2 and a half inches a day but that may change.

The fissure was first spotted in October on Rattlesnake Ridge in south central Washington State, overlooking Interstate 82 and the Yakima River. Since then, a 20-acre chunk of mountainside — roughly four million cubic yards of rock, enough to fill 25 football stadiums to the top of the bleachers, eight stories up — has been sliding downhill. Geologists can measure its current speed — about two and a half inches a day — but they cannot say for certain when, or if, it might accelerate into a catastrophe. And they are powerless to stop it.

“The mountain is moving, and at some point this slide will happen — it’s just a matter of when,” said Arlene Fisher-Maurer, the city manager in Union Gap, population about 7,000, just north of the ridge.

The usual course of events when nature comes unhinged is for researchers and responders to look back in time, trying to understand what happened, as they assess and address the damage done. Here it is precisely the opposite: They are looking forward in time at a disaster in waiting, in which all is still potential and nothing is certain.

The worst-case scenarios — considered unlikely but possible — have the slide breaking loose suddenly and roaring down toward the Yakima River, blocking the channel and flooding the valley, or burying the interstate that runs along the river, carrying 30,000 vehicles a day. Either would mean big trouble for a rich agricultural district where apples and hops are king, about two and a half hours’ drive from Seattle.

By giving scientists, officials and the people who live nearby so much time to stew over what could be happening, the slow-motion nature of the slide — at least so far — has already created tensions. About 75 people have been evacuated from nearby houses that may or may not ever be damaged. The local road at the foot of the hillside has been closed. Irrigation canal operators stand ready to open dams and take water from the river if it is blocked by a rock slide. Alternate highway routes have been mapped out, in case the interstate becomes impassable.

Current projections, based on dozens of motion sensors that have been installed on the ridge, suggest that the collapse is most likely to happen sometime in late February.

“In a lot of disasters, you don’t have as much warning as months — hardly any,” said Jeff Emmons, the emergency management director for Yakima County. “It’s a unique thing.”

In the last few weeks, the main mass of rock has been moving toward a gravel quarry at the base of the ridge. The company that runs the quarry has stopped operations and has voluntarily offered to put up evacuated residents in nearby hotels for five weeks at its own expense, though the cause of the crack has yet to be formally determined.

Some things, though, are clear. The slide is occurring in a rumpled layer cake of volcanic rock, or basalt, laid down by eruptions that began about 17 million years ago, interspersed with thin deposits of silt and other sediments. Over time, the layers have folded upward, forming the ridge, and the topmost basalt layer is now sliding over the sedimentary layer beneath it.

Many landslides are caused by infiltration of rainwater or groundwater, but geologists think that water is not involved in this case at all, just gravity.

A slow motion disaster that can't be stopped, can only be watched. Like watching the Republicans in DC try to run a government. And despite the long lead time, it will be ignored by President Shithole when it happens.