Alaska residents are again being urged to brace themselves for a possible eruption of Mount Spurr.

Following up on last week’s warning, the Alaska Volcano Observatory reiterated in a series of posts on X Wednesday that the volcano, located 75 miles west of Anchorage, the state’s biggest city, could erupt within weeks or months and that residents should “familiarize themselves with any potential hazards.”

Additionally, the U.S. Geological Survey said it expects to see a continued increase in seismic activity, gas emission and surface heating in the coming weeks before a likely eruption. They plan to monitor, properly advise and warn the public well in advance of any eruption.

The Alaska Volcano Observatory says that if the more than 11,000-foot-tall, snowcapped volcano erupts, the impacts could include:

Damage to aircraft from ash, especially since 60,000 planes fly over Alaska daily.

A coating of ash on the ground that can hurt people’s eyes and lungs — and damage cars.

If ash falls, residents are urged to stay inside, wear a mask and follow official guidance on what to do next.

“The location, duration, and timing of the impacts would depend on the size and duration of the eruption as well as weather conditions during and afterwards,” the volcano observatory posted on X Wednesday.

Mount Spurr is one of a string of volcanos in the Aleutian Islands and is part of what’s known as the Ring of Fire, created by the Pacific plate sinking below the North American plate.

Last month, scientists estimated at least a 50% chance of Mount Spurr erupting. Since then, the Alaska Volcano Observatory and the USGS have recently reported “significantly elevated” volcanic activity from Mount Spurr. Experts have recorded increased gas emissions and newly reactive gas fissures (or fumaroles) at Crater Peek and increased earthquake activity and ground deformation.