Mt Rainier from the Puyallup Valley down from Bonney Lake, WA.
"One of the natural hazards facing residents of Pierce County is volcanic activity from Mt. Rainier.
"The Mt. Rainier Lahar Warning System consists of two separate components, operating in tandem: Acoustic Flow Monitors (AFM) and the All Hazard Alert Broadcast (AHAB) sirens.
"The sirens are made for outdoor warning and used to alert residents in the Puyallup River Valley of the need to evacuate due to a lahar or other volcanic event. ... The outdoor sirens wail for approximately five minutes during the testing. During a real event, the outdoor sirens will continuously wail until the batteries die or they are destroyed."
""The world is full of obvious things which nobody by any chance ever observes…""
— Arthur Conan Doyle
“The Hound of the Baskervilles”
""Mathematics...
