Apr

6

 Egged on by arguments raised by the recent change in Administrations, and the white-hot debates generated by the "climate change" brouhaha, a glance at the field of geomorphism, the science of how the Earth changes over time, its forces and contributors, seems a plausible and worthwhile effort.

The average citizen pays little attention to the less sexy but commanding aspects of erosion, relying unfortunately on the headline tropism that provides little in the way of actual explanations or in-depth nuance. Icecaps melting! Shout the tabloid media. Island sinking by 2015, foretold a former Vice President, now proven comically overbloated in his prognostications, highly remunerated speeches and fizzled films.

But let us consider more than headlines in regard to geomorphism, which might reclaim some measure of moderation in thinking about the hubbub over change over the planet.

The geomorphologist has to consider multiple factors in trying to interpret how hills and valleys came to be. This includes the timing of these erosive elements, and what these geologic features look like over the march of years. Erosion as an umbrella overall is a key tab, but occurs at differing rates within a delicatessen of timescales based on rainfall, climate,, vegetation, , composition and homogeneity of rocks, fractures, fissures, landslides,

avalanches, riverine sedimentation and carrying capacity and, often overlooked but supremely important, slope. Nor can the geomorphologist ignore sunrises, sunsets, and even persistent shadows cast by crags and crests, blanking out sunlight for large swathes of day.

Remembering, too, the silent gnomes: Moon and tides, vestigial but vestal.

Instances of data are mobile, note, where the rate of erosion at the surface is offset by the never-ending fores of uplift/gradual upheaval ongoing as constantly, if incrementally, in many latitudes. For word lovers, this is denudational isostatic rebound. (For analogy and lingerie lovers, this can be likened to cunning covered underwires, for bosom support architecture.)

There are some 'easier' rules of gauge—with higher ascents and steeper mountain ridges eroding relatively swiftly: the East Himalayas erode at a whopping 2 to 3 mm per annum, for example. Such erosional rates, themselves, will evolve over time, as well, to meet new equilibrial homeostasis–depending on weather and wear forces noted above. (Such erosional rates hold steady for all earthly features except, one can posit, stubborn body fat, which defies discernible erosion for decades, seemingly.)

"Don't think we'll ever find the single smoking gun of erosion," according to pooh-bah Eric W. Portenga, bishop of Earth & Environmental Sciences at the University of Michigan. "The natural world is so complex, and there are so many factors that contribute to how landscapes change over time." As his measurement paradigm manages to gain foothold in the field of geomorphology, we will glean a better sense of what variables are vital, and which are not, in the erosion saga.

For decades, it has been a geology truism that rainfall is erosion's master driver. Semi-arid landscapes with sparse vegetation, yet the occasional major storm were thought to manifest the greatest grids of wear. But an important study challenges that 'bedrock' idea.

"It turns out the greatest control of erosion is not mean annual precipitation," notes theorist Paul R. Bierman, of the University of Vermont.

Instead, regardez slope.

"People always thought angle was a big deal," says Bierman. "But the data show slope is really important." Who would have thought?

(As with phalli, the angle is critical, for impregnation, as well, of course, as pleasuring.) So the land's angle, the naked scree and tree-root tangle, all fall to the mean—entropy flattening at the smallest suggestion, evolution's Zamboni edge.

Some of course prefer more direct and more calculable methodologies, ways of measuring the vales and hollows and their duration or extinction. Practitioners in this still-emerging field draw from the arenas of physics, biology, chemistry and math to arrive at a more graphic understanding of terrestrial surface processes and the evolution of topography over short-term and longer-term timescales.

We are clearly not yet at the certitude we seek. Needed is a Dionysian, geologic Dian Fossey, the recent Sam Pepys of primatology. Geologists and statisticians need rules of less-than-dumb thumb for figuring the whys, hows and whats of Earth's dynamic surface, translatable to our Earthly rocky past. And hopeful learned future.

Scant evidence, we propose (tongue in left cheek), of a gneiss Deity?


Comments

Name

Email

Website

Speak your mind

1 Comment so far

  1. marion dreyfus on June 7, 2017 5:26 am

    Until the list opens up again after unjust banning.

    MEGAN LEAVEY – Welcome, Warm-hearted Movie with A Woof

    Directed by Gabriela Cowperthwaite
    Written by Pamela Gray, Annie Mumolo
    Reviewed by Marion DS Dreyfus

    Take a plain-spoken heroine who decides for a variety of family reasons to sign up for the Marines. Add a positive take on the US Marine Corps, plus memorable and upstanding characters who ring true.

    Then add amazingly lovable (though not at first) German shepherds in the Marine Corps’ canine unit, “sniffers” who save lives by detecting landmines and Improvised explosive devices (IEDs).

    Full disclosure: Having been lucky enough to have been bivouacked in the US Air Force, as well as a sometime volunteer in the Israeli IDF–Army, Navy and Air force—there’s a huge tender spot for anything military. And as far as canines go, the heart melts with affection and amused marvelling, indulgence and love when there’s a dog in the picture. Who doesn’t love dogs?

    To this mix is the fact that “Megan Leavey” is a true story, portrayed with affecting simplicity and honesty by Kate Mara, and you have a winning combo. What’s maybe a little bit more amazing is that both sides of the current political divide, left and right, are charmed by this winning film—a contender in my estimation for one of the best of the year, easily in competition for the kind of praise rightly lavished on the outstanding—and somewhat parallel– “The Hurt Locker” (2008).

    In terms of combat canine training, personal exposure to a colleague’s canine training biz over a few years provides insights about what it takes. One thing that may not be evident, but should be, is that soldiers and their canine warrior companions must withstand huge noise assault. Dogs who buck or cower at explosions and sustained gunfire are automatically decommissioned and excluded from further training. I did not see this aspect of the training, which is crucial to the expert wrangling of such prized four-legged soldiers. But it is a point that most won’t think of in viewing this standout lenser.

    If you wonder why Kate Mara, as Marine Corporal Leavey, strokes her amazing sniffer, Rex, and murmurs ]ust “Good boy! Instead of feeding him food and treats, each dog has his/her own reward mechanism, and here, bonding with the trainer and getting embraced with love and encouragement is reward enough for the four-legged hero.

    In life, as shown in the film, Corporal Leavey saved hundreds of lives by ID’ing mines and explosives in unexpected loci in Iraq.
    Which is not to say there aren’t lethal surprises.

    The director cut new terrain, for this viewer at least, by filling the compassion chambers with affection for Mara as she slowly and painstakingly works with her ultra-aggressive Shepherd. You’re full of affection and joy for a while. Shortly thereafter, you are transported into maximal anxiety as the two, with hard-core soldier men in her company, encounter Iraqi irregulars, unknown snipers, seemingly innocent civilians and ground forces shooting at them, exploding ordnance mere feet from them—the suspense and anxiety is much more than the usual film, such as the current acceptable “Alien: Covenant,” which, for all its remarkable SFX, does not generate fear or anxiety, only attention and interest. Especially for the always-galvanizing Michael Fassbinder in a tour de force double role.

    You don’t really bond with the actors in “A: C” the way audiences do with “Leavey.”

    A small but not uninteresting note is that the excellent direction and writing, are all female. I’m not here claiming women can’t be every bit as dogged and accomplished as male directors and writers in describing military circumstances, but this film is a standout in having all the top-billed creatives being—female. Nice to see. Perhaps unexpected.

    For all the plot involves a female Marine, there is little unwanted sentimentality. Leavey seeks, and gets, no favors or extra consideration. That she serves with heroic distinction and physical injuries is all the more laudable. Furthermore, there seems to have been a sea-change in that, as portrayed in the film at least, the sexual harassment quotient seems at a blessed remove from this man’s Marines. Leavey faces her tasks and reg-related rejections and obstacles of all sorts with persistence and tenacity. It beats the likes of Ridley Scott-directed Demi Moore’s rugged but idealized “G.I. Jane” (1997). She was expected to fail. Twenty years on, we don’t expect Leavey to fail quite so automatically.

    A restrained, uncloying, unusually worthwhile and entertaining movie, this is one of the best we are likely to see in a special-effects-happy universe.

    And, no small miracle: Makes you proud to be—an American.

    Cast: Kate Mara, Ramon Rodriguez, Tom Felton, Edie Falco, Will Patton, Bradley Whitford
    marion ds dreyfus . . . 6 June 20©17

Archives

Resources & Links

Search