NOTE: In a sad coincidence, as I was writing this post, (a continuation of the last two posts—click here to go to the first in the series), a man in Florida was killed when a sinkhole opened up below his bedroom. Today’s post discusses the interpretive topics of the project I was working on in Southeast Alaska, including sinkholes.
Princes of Wales Island in Southeast Alaska is karst country. Karst is a landform that develops when water dissolves the carbonate bedrock, resulting in unusual features such as caves, sinkholes, shafts, disappearing streams and caves.
In limestone caves, features such as spires, pinnacles, soda straws, stalactites and stalagmites take thousands of years to form.
Muskeg, or peat bog wetlands above ground contain very wet, acidic soils that are a catalyst in cave development. As the water flows through the muskeg, it sometimes flows sideways across layers of hard clay until it finds a way down through the porous limestone.
Sinkholes are etched into the landscape as water trickles down from the surface. The second illustration in the sequence shows what happens when the “roof” wears thin and suddenly collapses.
Many animals use caves to escape harsh weather, find safe places to nest, give birth or hibernate. Some creatures spend their entire lives in the darkest interiors of caves.
To find out more about Prince of Wales Island and Beaver Falls Karst Interpretive Trail, check out:
The Pacific Northwest is not immune to sinkholes. In Shorelline, a city just north of Seattle, a giant sinkhole took out an intersection, just missing a nearby house. I designed some interpretive signs for the nearby park (written by Chuck Lennox). Check out the third sign in the series of project: Boeing Park