Saturday, February 22, 2014

Ice Cracks

Stress causes the cracks seen in exposed ice. New ice has fewer cracks compared to older ice since older ice has endured many warm-cold cycles. Warm and cold temperature cycles expand and contract ice.

Cracks in the frozen glacial meltwater of Lake Fryxell

Ice is not as resistant to thermal shocks as other solids. The expansion and contraction due to temperature changes creates a system of cracks.

Sometimes sinuous, sometimes rectilinear, these ribbon-like discontinuities form a graceful and intricate visual poetry on a frozen but ever-changing canvas.

We observe this intricate canvas of cracks as one might observe the last snapshot arriving from the past into the station of our sensory present.

A thundering pop summons us to sound.


The stresses causing ice cracks make somewhat expected snapping and popping sounds, but also make incongruous howling and screeching sounds.
The ice was here, the ice was there,
The ice was all around;
It cracked and growled, and roared and howled,
Like noises in a swound!

Samuel Taylor Coleridge, from Part I of The Rime of the Ancient Mariner
When ice warms and expands, sounds emanate along the stressed surfaces. Similarly when ice cools and contracts, sounds emanate from the source of the disturbance.


Saturday, February 15, 2014


Dunes by Jon Sullivan
Well-ordered distinguishable regularities of form appear everywhere in nature.

Early Greek philosophers considered order in nature in broad pursuit of a philosophy of nature that is a precursor to modern science.
“There is geometry in the humming of the strings. There is music in the spacing of the spheres.”
Pythagoras, Philosopher (570 – 495 BC)
Symmetry, spirals, meanders, waves, tessellations, and cracks are a few common patterns we observe in nature.

Symmetry is perhaps the most recognizable pattern since the human form has bilateral symmetry.


Many flora and fauna have n-fold mirror symmetry, a pattern that duplicates mirror-like across an axis or axes.
Symmetry can be bilateral, like a human face or a tiger's face when split down the bridge of the nose, five-fold like a starfish, or many-fold like a snowflake.


Many plants and animals have a spiral pattern. Each chamber of the nautilus mollusk has a shell that is a scaled copy of the next one, scaled by a constant factor and arranged in a logarithmic spiral.
Nautilus Mollusk
Red Cabbage
Red cabbage in cross-section has multiple, repeating spirals.


Sinuous curves in channels formed by water are meanders. Water movement causes erosion and deposition.
Flood Plain
When the path of a river begins to develop bends, the size and curvature of each bend increases as the flow carries sand and gravel to the inside of the curve. The outside of the bend is unprotected, accelerating erosion, and thereby increasing the meandering in a feedback loop.

Waves are disturbances that carry energy as it moves through a dynamic system. Wave patterns are also expressed in a steady state where energy driven motion has reached temporal equilibrium like a sand dune.
Sand Dunes
Ocean Wave
As energy is transformed to wave action in the ocean, or as wind passes over sand, dynamic and steady-state patterns emerge. Steady state patterns are essentially a snapshot since our perception of change is a matter of scale.
“From where we stand the rain seems random. If we could stand somewhere else, we would see the order in it.”
Tony Hillerman, Coyote Waits

Tessellations are repeating tile patterns. Tilings are common in living organism. Color patterns in flowers and the wax cells of honeycomb are examples of tessellation.
Fish, reptiles and fruits often have overlapping scales forming repeating units.
“Humans are pattern-seeking story-telling animals, and we are quite adept at telling stories about patterns, whether they exist or not.”
Michael Shermer

Cracks are openings that form to relieve stress. Crack patterns indicate whether the material is elastic or inelastic.
Inelastic, desiccated mud has a preponderance of straight and orthogonal 90° cracks. Cooled, elastic basalt can exhibit vertical 120° cracks that form hexagonal columns.
“There are only patterns, patterns on top of patterns, patterns that affect other patterns. Patterns hidden by patterns. Patterns within patterns. If you watch close, history does nothing but repeat itself. What we call chaos is just patterns we haven't recognized. What we call random is just patterns we can't decipher.”
Chuck Palahniuk, Survivor


Saturday, February 8, 2014

Where Life Dwells

Earth's biosphere is a band of rock (lithosphere), water (hydrosphere), and air (atmosphere) that harbors life. It is
"The place on Earth's surface where life dwells."
Eduard Suess (1875)
Earth is the only planet so far that supports and sustains living organisms.
There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.Carl Sagan
Earth is small planet compared to the vast cosmos where it resides. Approximately 80 minutes after sunset on Mars and about 99 million miles its home planet, NASA's Curiosity rover snapped an image of the Earth (below).

Earth in Mars' night sky.
Image from NASA's Curiosity rover, Jan. 31, 2014
"Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives."Carl Sagan


Saturday, February 1, 2014

Tectonic Fire

Observing Mount Vesuvius, Mount Etna, and other Volcanoes, Sir William Hamilton posited
May not subterraneous fire be considered as the great plough (if I may be allowed the expression) which Nature makes use of to turn up the bowels of the earth?Sir William Hamilton, 1774
Steam plume rising from Shishaldin.
28 January 2014.
A steam plume and elevated surface temperature were recently observed at Mount Shishaldin. The Shishaldin volcano is located on Unimak Island in the Aleutian Islands.

Mount Shishaldin is the highest peak in the Aleutian Islands. Shishaldin is distinguished as the most symmetrical cone-shaped glacier-clad mountain on earth.

Native Aleuts called the volcano Sisquk meaning:
Mountain which points the way when I am lost.
Unimak Island, and its highest peak, rise above one of the most active plate boundary zones on earth. The collision of the Pacific oceanic plate and the North American continental plate cause frequent earthquakes and volcanic activity.

Subduction of Pacific oceanic plate along the Aleutian Trench.

The oceanic plate is heavier than the continental plate, so it is forced below the edge of the continental plate. The ongoing process, called subduction, generates extreme stresses and heat.
And many a fire there burns beneath the ground.
Empedocles, 490 BC.

The Aleutian Trench

The subducting oceanic plate is marked by the Aleutian Trench which runs along the Aleutian Islands and the Alaska Peninsula. The Aleutian Trench is 22,638 feet deep south of Unimak Island.

Shishaldin and Isanotski Volcanoes, Unimak Island, Aleutian Islands