Our
first surprise destination was a hidden waterfall. Captain
Crabough put the bow of Emerald Sea within 100 feet of this magnificent
feature. The engines were cut and we drifted in place for about
10 minutes while all passengers were encouraged to make their way to
the bow and take pictures. This waterfall appeared to be fresh
water only without glacial silt.
Continuing
our journey to the
Blackstone complex, we passed several "rafts" of otters. Captain
Crabough gave more narration regarding the otters, who are called the
"old man of the sea" due to their white faces. Otters bodies
contain no blubber, so their beautiful coats keep them warm. The
Exxon Valdez oil spill ruined the local otters waterproofing.
Next
we passed by Willard Island, known for camping and kyaking
adventures. Other local tour companies offer this type of trip
from this beautiful spot. Blackstone Bay features 8 glaciers, 6
on the sides of the bay and 2 tidewater glaciers at the head end
separated by a point of land.
We
visted Blackstone Glacier first
and Beloit Glacier second. Other glaciers in the Blackstone
compex include Ribbon, Lawrence, Marquette, Concordia, Ripon, Burns and
others. Early in the cruise, Captain Crabough announced that
passengers were welcome to visit the bridge after lunch. As I was
in the well equiped bridge, the Emerald Sea was about to pass over the
Blackstone terminal moraine. Having spent many a weekend in the
Sierra Nevada mountains in California before discovering and falling in
love with Alaska, I learned a few facts about glaciation.
As a
glacier moves down its valley, it scrapes and scours valley sides and
bottoms. As it reaches its terminus, it deposits this
material. In the mountains, a terminal moraine looks like a pile
of rocks, usually at the mouth of a valley. In Prince William
Sound, the ocean covers the terminal moraine, sometimes by only 10's of
feet of water. It always amazes me to watch the depth sounder
while creeping over an underwater terminal moraine. The tides
always must be factored in in such a cruise. The depth sounder
screen moves from nearly hundreds of feet in depth to a spike and then
goes back down to deeper bay bottom. Considering the June 24th
2005 tide at Blackstone Bay, the terminal moraine was only 18 feet
below the water surface. It helps that the Emerald Sea has a
shallow draft. While there was a major period of glaciation about
10,000 years ago, there have been minor ice ages as well. Around
the time of Columbus, glacier ice covered much of the land above the
60th parallel of latitude. The Prince William Sound area was
likely iced over in the last minor ice age.
On our
way to
Blackstone Glacier, Captain Crabough stopped the Emerald Sea and the
crew brought some glacial ice onboard. There are a number of
names for glacial ice in the ocean or lake water. An "iceberg" on
a piece of ice which rises 15 feet or more above the water
surface. Other names include brash ice with 0 to 3 feet of ice
exposed, growler ice with 3 to 7 feet of ice exposed and bergy bits
with 7 to 15 feet of ice exposed. Careful observers may notice
locations where silty fresh water seems to stay separate from salty
ocean water. The ocean water looks cloudy because the fresh silty
water has a different specific gravity than ocean saltwater.
Captain Crabough mentioned that many ocean locations in Alaska stay ice
free in wintertime due to the warm Japan current flowing nearby.
Next, we were educated about the different kinds of glaciers.
Blacktsone and Beloit are fjord or tidewater glaciers due to the ice
terminus being below sea level and feature almost vertical faces of
ice. Valley glaciers such as Billings glacier terminate in a
valley above sea level. Hanging glaciers terminate above
valleys. When you take the Alaska Railroad Glacier Discovery
train to Grandview, Deadman glacier is visible and pointed out on the
nature walk.
We
arrived at Blackstone Glacier and Captain
Crabough silenced the engines once again and we waited for something to
happen. Nothing happened and Captain Crabough recited the ways to
cause a glacier to calve off some ice. One way is for everyone to
put their cameras down. Next is to blow the horn which the Forest
Service frowns upon. Next, the boat must leave the glacier and
surely the glacier will calve ice when nobody is watching.
Captain Crabough entertained questions from the passengers and I asked
if anyone has ever dropped their cell phone off the Emerald Sea.
He replied no, but only since there is no cell phone service at
Blackstone Bay. In the past, one passenger dropped her digital
camera, which then found its way through a drain opening off the deck
and into the bay. I have a few items on the bottom of Long
Beach Harbor from my sailboat.
