Friday, January 10, 2014

Where in the West: Dean and Burke Channels; Thunder Mountain and Tzeetsaytsul Peak, B.C.

Dean Channel on the left, Burke Channel on the right.
The January 2013 Where in the West was won by Ron Schott, not only for finding the names of the two major fjords shown in this photo, but also for identifying the mountain near the head of Burke Channel, which has two major peaks: Thunder Mountain, the highest, and Tzeetsaytsul Peak, somewhat lower. Ron also came up with the name of northern branch of Burke Channel, known as North Bentinck Arm.

I didn't know the location of this challenge when I posted it, but having seen it from the air, I knew it was between Anchorage and Seattle, that it was south of a more-or-less north-south-trending strait, and that it was much closer to Seattle than Anchorage and probably south of SE Alaska. This general knowledge gave me an advantage over anyone else trying to discover the location. I homed in on the location and found most of the names of the fjords and mountains on Google Earth (in labeled photos), but wasn't sure if the names were correct, so checked them on Wikipedia and GeoBC.
Google Earth image almost identical to my first photo. Dean Channel is on the left; Burke Channel is on the right.
It's true that the snow and clouds in the photos I shot complicated finding the location!
A photo zoomed in on Burke Channel.
Google Earth image with Burke Channel centered,
similar to the previous photo. 
Labouchere Channel splits to the left (north), connecting Burke and Dean Channels; the North Bentinck Arm heads straight away from us; and South Bentinck Arm goes off southward, barely visible in this view.
Zoomed in photo with the mountain in question in the distance.
It was  a little harder to get the right angle on Google Earth to zoom in on and identify the mountain that stood out in my view from the airplane, and it was hard from the photo to tell which side of the Burke Channel and North Bentinck Arm the mountain really was on.
Google Earth view, with the North Bentinck Arm of Burke Channel on the left and the South Bentinck Arm heading southward to the right.
The mountain really stands out in the Google Earth view (above). It's really on the north (left) side of North Bentinck Arm, and it has three smaller mountains nearly centered in front of it (west of it).
Google Earth image: Thunder Mountain is the highest peak in the center; Tzeetsaytsul Peak is the next highest peak to the left (north).
And there we have it: several fjords carved by glaciers, now partly (mostly) inundated with water, and one mountain with two main peaks. Thunder Mountain is highest at 2664 m (8740 ft); Tzeetsaytsul Peak comes in at 2575 m (8448 ft). Apparently, both Thunder Mountain and Tzeetsaytsul Peak were named for the thundering sound created by the movement of Tzeetsaytsul glacier.
Google Earth view of Tzeetsaytsul Glacier on the east side of Tzeetsaytsul Peak and Thunder Mountain; north is to the right.
Read about the Bella Coola area (Bella Coola is at the head of North Bentinck Arm) at the Bella Coola Blog.

A few Geological References:
Gehrels, George E., and Nevine D. Boghossian, 2000, Reconnaissance geology and U-Pb geochronology of the west flank of the Coast Mountains between Bella Coola and Prince Rupert, coastal British Columbia: Geological Soc America, Special Papers, v. 343, p. 61-76. Abstract at Refdoc.fr.

Mahoney, J. B., et al, 2002, Structural geology of eastern Bella Coola map area, southwest British Columbia: Geological Survey of Canada, Current Research, 2002-A10, 9 p.

Smith, D. J., and Desloges, J. R., 2000, Little Ice Age history of Tzeetsaytsul Glacier, Tweedsmuir Provincial Park, British Columbia: GĂ©ographie physique et Quaternaire, v. 54, no. 2, p. 135-141.

Stowell, Harold Hilton, and William C. MacClelland, eds., 2000, Tectonics of the Coast Mountains, Southeastern Alaska and British Columbia: Geological Society of America, Special Papers v. 343, 389 p.

A few Geographical Links:
Dean Channel location - at GeoBC

Fitz Hugh Sound - Wikipedia

Fitz Hugh sound location - at GeoBC

Labouchere Channel location - at GeoBC

North Bentinck Arm location - at GeoBC

South Bentinck Arm location - at GeoBC

Thunder Mountain location - at GeoBC

Tzeetsaytsul Peak location - at GeoBC

2 comments:

Ron Schott said...

Interesting! I didn't think to look for an online source of BC Geographical names. Instead, I sought out a KML file of BC topographic maps (http://geobc.gov.bc.ca/base-mapping/imagery/topographic.html) that I could overlay in Google Earth, where I pulled up the relevant topo maps as PDF files.

Silver Fox said...

Well, you found the same basic site (geobc.gov) -- I happened on a link to the geographical names on Wikipedia.