Here are some photos that may help you get a better idea of various glacial features


This tidewater glacier is a popular stop for tour boats from Seward, AK. It is one of several
outlet glaciers from the Harding Ice field.
 


The margin of Bear Glacier discharges into a lake. Because of the low profile of the glacier, it
breaks apart (calves) along the crevasses and makes icebergs. Debris carried in the medial
moraine on the left side of the image decorates some of the icebergs.  Color differences in the
water are due to different sediment concentrations.
 


Hanging Glacier, Jasper National Park, Canada  This small hanging glacier fills the col, or saddle, between
Mount Andromeda and Mount Athabasca. Notice the highly fractured nature of the ice in the lower part
and compare it to the smoother appearing ice at the upper part. Most of this glacier is fed by drifting snow.
 


The ELA of Exit Glacier, Alaska.  The ice on the left and in the center is old and crevassed,
whereas the snow on the right lies above the seasonal melting line (or equilibrium line
altitude (ELA)). Further to the right lies the snow field of the Harding Ice Cap.
The debris in the foreground also marks the ELA.
 


Nunataks and medial moraine, Grewingk Glacier, AK  Notice the dirty icebergs from the small medial
moraine on the right side. Brown colored snow in the upper reaches of glacier are ash cover.
 


Crevasses, Exit Glacier, Alaska
Good examples of extensional crevasses. Note that they have the same shape as normal fault blocks.
 


Orgives, Juno Ice field, AK.  The orgives have a regular spacing and the relief can trap water and snow.
Notice the location of the medial moraine just below the bedrock peak the photo was taken from.
 


Close view, Medial Moraine, Bryn Mawr Glacier, AK, 1997
Here the various bands can be traced from nearly horizontal to vertical orientations.
 


Mount McClintock, Antarctica.  Several glaciers stream down the side of the mountain. The rough surfaces of the
ice are due to highs in the bed that the ice must flow up over. As the it flows over these highs, crevasses open up.
The beginnings of medial moraines (the dark bands) mark the junction of glaciers.
 


Molded Wall, New Zealand.  Lateral glacial abrasion has smoothed this metamorphic rock along
the valley side. The flowlines indicate a downward direction.
 


Striated Graywacke, Yale Glacier, AK 1997.  Nice parallel striations. Bedrock fracture trends across the left
side of the image. Field of view about 1 m. Why the scattered pits? Which way was the glacier flowing?
 


Strained lee cavity, Amherst Glacier, AK, 1997.  On this sloping surface a small cavity has been
protected from erosion. Some striations can be seen inside the cavity indicating that the glacier at times
eroded the bottom of the cavity. What do you make of the staining (from iron)?  Why does it have a
distribution just on the inside of the cavity?  What age is it relative to the other striations
is the cavity? Relative to the striations outside the cavity?
 


Chatter Marks, Mount Desert Island, Maine.  This series of fractures lies on the crest of a granite
stoss and lee form. The fractures are essentially a series of percussion marks formed as
an englacial rock was dragged over the ridge. Notice how the width of the
fractures increases in the down-flow direction until an abrupt termination.
 


Plucking, New Zealand.  This small stoss and lee form shows how the plucking
process works. The block on the right is scheduled next for erosion.  This is the
beginning of a roche mountonÈe.
 


Kelley's Island Grooves, Ohio.  The grooves on Kelley's Island have been the source of debate for
over 100 years.  Some say they were cut by glacier ice, others say by jets of subglacial water. Note
the curved forms suggesting fluid flow. The smaller grooves lie inside a larger one framed by the fence.
You are looking in the direction that the glacier flowed. Note the texture line about 1/2 way up the
grooves.  Above this line the limestone bedrock is more weathered than below the line
because till was more recently removed, exposing the grooves.
 


Delta, Lake Pukaki, New Zealand.  The extreme limit of the outwash of the Tasman River. Note the
numerous channels, sediment rich water, and the smaller fan/delta on the upper right. Roads for scale.
 


Thin delta, Baker Lake, Quebec.  The topset beds do not show distinct layering, but the contact is sharp.
The grain size variation in the foreset beds is from fine sand to pebble-cobble, which suggests a
proximal source.
 


Double Moraines, Exit Glacier, AK.  Two moraines, a nice pair.  What would cause such a thing?  Note the
rope fence running down the middle of the channel between the two moraines.  People in lower left for scale
 


Loess in the Wind, Matanuska Valley, Alaska.  Winds moving across the outwash of the
Matanuska River valley entrain the silt fraction to produce loess.  Photo by Warren Huff.
 


Chatermark Group, Mt. Sirius, Antarctica, 1986.  Ice flow from left. Note the general alignment
of these.  Is there any significance to the larger striae that traces across the top?
 


Glacial Imprint, Downeast Maine.  On this Landsat image the alignment of lakes reflects glacial erosion cutting the local
bedrock. Note the lakes on Mount Desert Island (cutting through granite) have a slightly different orientation.
Some of the light colored areas directly up from the word "Mount" are blueberry fields on gravel glacial marine deposits.
 


What's that Ridge?  Part 1.  Glacier deposits are funny things. Is the ridge shown in this image of the
same or different origin as the ridge in the next image?
 


What's that Ridge?  Part 2.  They look the same, but are they? One is an esker and contains gravel,
the other is a moraine and contains till.
 


Flutes, Bear Glacier, Alaska.  These linear ridges formed below the Bear Glacier as it moved
from upper right to lower left. Notice that they trace over sinuous ridges.  Can you spot
the start of any single flute?  Bonus: What are the sinuous ridges?


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Please direct comments about this page to John Stimac
URL http://www.ux1.eiu.edu/~cfjps/1300/glacier_photos.html
Revised 9/6/99
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