The Tracker’s nose for news must be broken. Less then two weeks ago I was with a naturalist and traditional Northwest artist and carver, David Stephens, in a coastal woods near Glacier Bay in Southeast Alaska. He asked, “do you see what’s wrong with this forest?” Getting a blank look in reply he explained that the old growth Sitka spruce and western hemlock sort of peter out close to shore. A subtle bluff near the wood’s edge, he went on, is an old beach step. Post-glacial isostatic rebound is lifting the land so fast that the forest hasn’t kept up, its shrubby rim revealing where it is invading what had been below high tide just a century ago. I asked a cheerful geology professor who is nuts about the region’s glacially-carved gneiss and diorite, Harold Stowell of the University of Alabama, if the rebound is outpacing global sea level rise. He said sure, several places around here.
That was while cruising around in the little ship Lindblad National Geographic Sea Bird (exactly what Nat’l Geo Soc’y has to do with the ship is very unclear). Stephens and Stowell were among the vessel’s fine naturalists. I suppose I figured, not quite consciously, that’s interesting as can be but if these guys know it well enough to tell cruise passengers about it, ‘must not be news. Wrong.
Cue the front page of today’s NYTimes and Cornelia Dean‘s story “As Alaska Glaciers Melt, It’s Land That’s Rising.” She explains it all in considerable detail (‘tho I would have rephrased that hed to say “….Its Land Is Rising” just to avoid two apostrophes). Dean alertly smelled news where I merely smelled mossy woods. She keeps it moving fast with plenty of local color. Her main example is Juneau’s local, rapid uplift, tying the rapid retreat of the Mendenhall Glacier (and by inference its feeder, the huge Juneau Ice Field above the capital) to the shallowing of an important shipping channel and to coastal landowners’ acreage gains. Dean does not explain how much of the uplift is due to recent acceleration beyond its slow rise since the last glacial maximum 13,000 years ago or whenever the ice around there was an astonishing mile or two thick. But the land really is popping up, and the glaciers really are galloping back. Wonder how long before Alaska’s last tidewater glacier kisses the sea a last goodbye and pulls its nose back up into the high country?
Pic: From a float plane out of Petersburg AK and the nearby, retreating LeConte glacier, its bergs floating past, May 4. Most of the flats are due to low tide. But the small trees on the forest edge at the points of land and the stepped shoreline are evidences of uplift. So I heard.