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Freezing and Heaving · Street Smart Naturalist

• 0:01
  SPEAKER_00: Greetings.
• 0:01
  SPEAKER_00: This is David B.
• 0:02
  SPEAKER_00: Williams and the podcast of my newsletter,
• 0:05
  SPEAKER_00: The Street Smart Naturalist,
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  SPEAKER_00: Explorations of the Urban Kind.
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  Every week I share my observations and adventures with the
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  human and natural world
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  SPEAKER_00: around Seattle,
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  SPEAKER_00: Puget Sound,
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  SPEAKER_00: and the Pacific Northwest.
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  SPEAKER_00: Today's episode highlights my recent adventures in the cryosphere.
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  SPEAKER_00: To learn more about my work, please go to my website, geologywriter.com.
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  You will also find a link to my Substack newsletter and my
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  previous four years of newsletters,
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  SPEAKER_00: as well as images tied to this week's episode.
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  SPEAKER_00: Thanks again for joining me on this adventure,
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  SPEAKER_00: and welcome to Podcast 14 of the Street Smart Naturalist,
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  SPEAKER_00: Frosting and Heaving,
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  SPEAKER_00: March 6,
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  SPEAKER_00: 2025.
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  SPEAKER_00: Recently,
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  SPEAKER_00: on a walk at Dungeness Spit on the Olympic Peninsula,
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  SPEAKER_00: my wife and I saw a curious phenomenon.
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  If you haven't been out to this five-mile finger of sand and driftwood,
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  you are missing out.
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  SPEAKER_00: It's pretty darned amazing.
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  SPEAKER_00: That being written, we didn't actually walk the spit.
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  SPEAKER_00: Unlike we usually did at the spit,
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  we turned left and walked away from the sand along the bluff
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  that rises out of the
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  SPEAKER_00: water and runs west toward Port Angeles.
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  SPEAKER_00: I have long liked this spot.
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  SPEAKER_00: The bluff is geology in motion.
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  SPEAKER_00: As waves undercut the face,
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  sand and cobbles and boulders constantly cascade to the sea in
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  a steady state of
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  SPEAKER_00: status change from bluff to beach.
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  SPEAKER_00: But that's not what intrigued us this time.
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  SPEAKER_00: Instead, we were excited by the ice.
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  SPEAKER_00: It occurred only in a short stretch of bluff,
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  SPEAKER_00: perhaps 100 yards in extent,
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  SPEAKER_00: about a mile into our walk.
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  SPEAKER_00: I noticed it from up the beach,
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  SPEAKER_00: attracted by the white blotches and a landscape of gray and khaki.
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  SPEAKER_00: Although we had seen ice and snow on the ground atop the bluff,
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  SPEAKER_00: I didn't think the white was ice at first.
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  SPEAKER_00: It seemed too incongruous here at the beach.
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  SPEAKER_00: Not until I touched the ice was I really sure.
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  SPEAKER_00: What was ice doing here, and why only here?
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  The main feature we noticed that was different was the layer of
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  gray sediment in the bluff.
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  SPEAKER_00: We hadn't seen it before.
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  Unlike the previous sections we had passed,
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  which consisted of beds of sand and conglomerates,
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  SPEAKER_00: The gray was very fine-grained, basically clay.
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  SPEAKER_00: If it had been warmer, I could easily imagine a nice mud facial.
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  SPEAKER_00: But I digress.
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  Packed tightly together,
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  the clay particles had prevented water penetration.
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  This had forced water that had percolated down through the
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  overlying sand layers to
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  SPEAKER_00: flow out to the surface,
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  SPEAKER_00: in this case,
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  SPEAKER_00: the bluff face.
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  SPEAKER_00: Here,
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  the water had encountered the freezing temperatures that had
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  caused the snow and
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  SPEAKER_00: ice atop the bluff.
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  SPEAKER_00: The result was the ice that had attracted our attention.
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  At the bottom of the bluff,
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  the water had spread out and frozen into small alluvial fans.
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  Where it encountered boulders,
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  it created small islands of rock surrounded by a sheet of ice.
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  SPEAKER_00: When I walked up to the base of the bluff,
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  I realized that what I thought was mud was actually mud-covered
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  ice with water
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  SPEAKER_00: flowing underneath.
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  The mud was insulating the ice at the surface and preventing it
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  from melting.
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  Underneath,
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  the temperature had warmed enough so the water flowed instead
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  of froze.
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  SPEAKER_00: At least, that's my speculation.
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  SPEAKER_00: I'm open to other suggestions.
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  Even if I'm wrong,
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  my wife and I still had fun trying to figure out what we saw.
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  A few days before this exciting moment,
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  I had another cryogenic scene of wonder.
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  I was walking on the Centennial Trail,
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  north of Arlington with my pal Scott.
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  SPEAKER_00: I had stepped off the pavement onto a dirt path paralleling the trail.
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  SPEAKER_00: At my feet,
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  SPEAKER_00: it looked like the earth was eating itself,
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  SPEAKER_00: or at least sucking pebbles back into its innards.
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  SPEAKER_00: This was an optical illusion.
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  SPEAKER_00: What I was seeing was frost heaving.
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  SPEAKER_00: As the name implies, freezing water was expanding and moving the ground.
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  because it's easier to push up against the minimally resistant
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  atmosphere versus
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  SPEAKER_00: down against the entire planet,
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  SPEAKER_00: the ice heaved up.
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  SPEAKER_00: The pebble,
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  SPEAKER_00: though,
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  appears to be sinking because the surrounding soil gets heaved
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  up more and more
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  SPEAKER_00: easily than the pebble.
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  SPEAKER_00: The pebble was moving, but ever so slightly.
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  SPEAKER_00: During each freeze, the pebble rose a wee tad.
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  SPEAKER_00: During the thaw,
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  SPEAKER_00: perhaps some sediment filled the nascent open space under the pebble,
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  SPEAKER_00: causing it to rise.
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  SPEAKER_00: Out here in the Puget Lowlands,
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  SPEAKER_00: we tend not to have serious freeze-saw cycles,
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  SPEAKER_00: so this part of the cryosphere occurs relatively infrequently.
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  SPEAKER_00: In contrast,
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  SPEAKER_00: on the East Coast,
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  frost heaving is common and was more so back in the 1700s and
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  1800s at the end of
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  SPEAKER_00: the Little Ice Age.
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  SPEAKER_00: The result was the regular upchucking in fields of boulders and cobbles,
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  SPEAKER_00: which farmers called New England potatoes.
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  SPEAKER_00: In his splendid book,
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  SPEAKER_00: Stone by Stone,
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  SPEAKER_00: Robert Thorson adds that some people thought,
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  SPEAKER_00: quote,
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  SPEAKER_00: the stones grew from Satan's seeds,
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  SPEAKER_00: unquote.
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  SPEAKER_00: Despite the supposed connection to the Prince of Darkness,
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  people used the stones to build the extensive stone walls that
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  graced the east.
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  SPEAKER_00: Two weeks after my ride with Scott, we were again on the trail.
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  SPEAKER_00: Winter was beginning to close down.
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  SPEAKER_00: The day was warm and sunny.
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  SPEAKER_00: Buds were starting to appear on branches.
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  SPEAKER_00: Birds were singing of their virtues.
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  SPEAKER_00: Crocuses were smiling in purple and orange.
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  SPEAKER_00: Spring was in the air.
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  SPEAKER_00: I'll miss the ice and the story it creates.
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  SPEAKER_00: I'm returning today to a former feature, the word of the week.
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  SPEAKER_00: Cryogenic basically refers to freezing.
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  SPEAKER_00: The cryosphere is the realm where water exists as ice,
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  SPEAKER_00: such as glaciers,
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  SPEAKER_00: hair ice,
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  SPEAKER_00: needle ice,
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  SPEAKER_00: and frost evening.
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  Cryo,
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  by the way,
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  comes from an ancient Greek word meaning frost or icy cold.
• 5:46
  SPEAKER_00: Once again,
• 5:46
  SPEAKER_00: this is David B.
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  SPEAKER_00: Williams,
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  SPEAKER_00: author and voice of The Street Smart Naturalist,
• 5:51
  SPEAKER_00: Explorations of the Urban Kind,
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  a weekly newsletter and podcast focusing on the human and
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  natural world around Seattle,
• 5:58
  SPEAKER_00: Puget Sound,
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  SPEAKER_00: and the Pacific Northwest.
• 6:01
  SPEAKER_00: If you'd like more details about my books,
• 6:03
  SPEAKER_00: walks,
• 6:03
  SPEAKER_00: and talks,
• 6:04
  SPEAKER_00: and a link to sign up for my newsletter and podcast,
• 6:07
  SPEAKER_00: check out my website,
• 6:08
  SPEAKER_00: geologywriter.com.
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  And don't forget to slow down,
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  pay attention,
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  and enjoy the world around you.