Monday, February 11, 2019

Blowing in the Wind

     I was in the skid-steer when the aeolian processes blew in. Now, 
skid-steers are small worlds onto themselves. Strapped into a tiny cab, surrounded by diesel roar and hydraulic whine, view blocked by the 800# bale of hay the machine had in its grasp, it's a space capsule-like realm of isolation. Still, there was no denying something was happening. 

The view from my office

     It had been cold and calm when I started working. Now billowing curtains of snow were blowing across the field. Beyond the din of the machine I sensed a howl. The wind was that strong. When I had to get out to open a gate...WHOA! hit me with the force of an NFL linebacker. I could have been in the movie Alien, one of the Nostromo's crew called by a distress signal down to that spooky moon. I stepped out into a surface scouring maelstrom. My eyes watered, my face stung. I could barely stand up.
     I didn't appreciate it at the moment, but that was when the beauty was being created, when the sculpting was being done. Aeolian processes (such a lovely phrase) is simply a scientific term for wind and its effects. It's most often used to describe dune building. As in desert and beach sand dunes. Usually these are made of quartz mineral sand. But consider this: frozen water (ice) is also a mineral and in the form of snow it can be shaped by the wind much like sand. Most winters we get the conditions to observe this phenomenon: cold, dry snow followed by wind. That's what we had in late January.

     The classic dune shape is termed 'barchan'. It is a crescent with a low angled windward (stoss) side and a steeper downwind (lee) side. Other dunes may be transverse (perpendicular to the wind) or seifs (longitudinal to the wind). Some are even star-shaped. Processes of deposition and erosion work on dunes, moving them across the landscape and changing their shape. The sand grains sometimes slide along the surface and other times bounce in what's known as saltation.
     It would be a fascinating adventure to visit some of the world's great dune fields (if you need a travel companion I'm available for a small fee!). Namibia, in West Africa, may be the most popular dune destination. The desert near the Atlantic Skeleton Coast has stunning formations. In this country, Colorado's Great Sand Dunes National Park is the spot, while Zion National Park features lithified dunes that have been compacted and cemented into rock.

A sand dune reaching for heaven - Namibia

Great Sand Dunes National Park - Web image

     Closer to home, many people make a summer pilgrimage to Cape Cod with its coastal dunes. Regionally, I'ld recommend visiting Alburgh Dunes State Park on the shore of Lake Champlain in northwestern Vermont. The scale here is small but you can see the natural processes and efforts to stabilize and protect the beach/dune/wetland complex. Also consider a trip to Sandy Island Beach State Park on the east end of Lake Ontario in Oswego County, New York. The Nature Conservancy has worked with state and local government to conserve this unique beach and dune area.

The beach at Alburgh - Web image

Busy day at Sandy Island Beach - Web image

     Even closer to home, as in right out my back door, are dunes leftover from the last ice age. As glacial Lake Albany drained some 12,000 years ago it exposed beaches made of sand that had been eroded out of the Adirondack Mountains. This exposed sand was worked by the wind into a dune field across a broad swath of what is now Saratoga County. Eventually, vegetation became established and stabilized the area. With the arrival of Europeans the sand was mined, farmed, leveled and built upon. But you can still find remnant dunes with modest relief, including some in my hay fields. Maybe that explains my attraction to dunes...they've been the backdrop to my entire working life.

I use sand from the crest of this small dune

     When most of us think of sand dunes we think 'hot'. As in deserts and summer days at the shore. Ever the contrarian, I like to watch the same processes that shape sand work on cold snow. I remember a blizzard some 25 years ago. Bitter temps with sideways snow blown at near hurricane force. After the storm had spent itself I went out on skis to explore a molded world of drifts, gullies and corniced waves. A schuss thru winter's art gallery.
     I've often seen beautifully shaped snow up on the Lake George mountains. Buck, Pilot Knob, Sleeping Beauty and Shelving Rock  all have areas of wind swept open rock interspersed with wind blocking patches of low shrubby trees. Here, sometimes you can find mini snow dunes on mountaintops. Other times the frozen lake will itself be covered with snow. It's the bane of ice fishermen and skaters but gives the wind a big canvas to paint upon.

     And I have to mention 'sastrugi'. The first time I heard the word I imagined some yummy Italian dish. Maybe sausage smothered in marinara and melted cheese. That's the way my mind works. Of course, my mind is often mistaken. Sastrugi is actually from the Russian zastrugi, or 'small ridges'. It refers to parallel, wave-like undulations caused by winds on the surface of hard snow. It's  commonly seen in polar regions and would be fun to find around here. Sun cups, snow rollers and penitentes are other neat features most often seen at higher elevations.
     Whenever the snow flows in sheets across my fields I know it's time to wax the skis. Time to get out there and see what nature has wrought. Sculpted, sensual snow, like life itself, is ephemeral. Catch it while you can.

Also worth catching...
     Does drifting snow make you think of Dylan's Blowin in the Wind? Thankfully there are versions that don't try to sell you Budweiser. Here's one.


No comments:

Post a Comment