2 December 2019
Ice – Information
Ice Flowers (b)
There’s much to marvel about as low temperature changes the state of water from liquid to solid. Ice is amazing! My purpose here is to encourage you to look more closely at the ice that appears at the edges of marsh waterways and with enough cold, the entirety of Spring Lake as well as the various nearby marsh and tidal areas. Look, too, at puddles that form when snow melts and nights are cold. Regardless of where you look, timing is key. Get out before the sun warms the ground and causes the ice to melt.
In my experience, the best time to see tidal ice is when high tide occurs between 2-4 a.m. Ice likely forms during slack tide, the time before the tide changes from incoming to ebbing and there is the least water movement. Then when the tide ebbs, the ice is gently deposited on the marsh surface and is there when the sun is up and you’re there to see it. (This is my suggestion regarding tidal ice formation, but I’ve not done a systematic study, and haven’t run across any information about this). Check the marsh website www.abbottmarshlands.org for the link to current tides.
On any given day ‘good’ ice, ice that has photographic possibilities, can be challenging to find. There are no guarantees. It depends on, most obviously, low temperatures, available water, and good light. These conditions may be quite transitory. Frost and thin ice can be changed back to liquid water by midmorning. Snow, even a dusting, can cover details and fuse with ice destroying interesting features. Yet interesting ice patterns can be found along stream edges even when the ground is snow covered. Following rain or snowmelt, water can accumulate and freeze in shallow puddles. High winds can create waves that reach tree branches, transforming them, but once freeze-up occurs, splash ice no longer forms.
Part of the magic is finding what nature has unpredictably arranged, and adding to the allure are sounds of ice cracking and moaning, and the challenge of avoiding missteps.
Tidal Ice – with unusual crystals on the bottom.
I first really saw ice on a Christmas bird count on Duck Island near the Delaware River on January 1, 1995; that was my first three-dimensional ice. Since then, most ice sightings have been within 20 miles of home – our patio, Plainsboro Preserve, the Millstone floodplain near Griggstown, and the Abbott Marshlands, including the banks of the Delaware River, and Crosswicks and Watson’s creeks. I have ventured farther afield with a few forays along the Wickecheoke Creek near Stockton, NJ, the cliffs near Frenchtown, NJ and Easton, PA, and streams in the Pinelands.
ICE — At the Interface of Life and Art
The molecular composition of water, two atoms of hydrogen and one of oxygen (H2O), is known to virtually everyone. Key to its properties that make life as we know it possible is the bonding between hydrogen and oxygen atoms. While the actual molecular arrangement of liquid water is unknown to scientists, that of ice is.
The special properties of water that affect the Earth’s biosphere include:
–water is transparent to light, allowing light to penetrate, for example, our eye for vision and plant cells for photosynthetic .
–a great amount of heat is involved in changing state – 80 calories per gram of water must be gained or lost for the transition from ice to / from liquid at 32ºF (0ºC) and 540 calories from liquid to / from steam at 212ºF (100ºC). This ability to absorb and give up energy is important in moderating the Earth’s temperature.
-the greatest density of water is at 39ºF (4ºC); as water cools below that point it expands and floats. Freezing of a lake, therefore, is a top down process, permitting organisms to survive at the unfrozen bottom.
What happens to water to create ice?
Loss of heat energy with cooling results in an increase in the number of hydrogen bonds between molecules. In water at 32ºF only 15% of molecules will be bonded together, while in ice at 32ºF, 100% will be. As the temperature falls below 32ºF, the bonds between the hydrogen atoms of one molecule and the oxygen of another molecules become ‘stronger’, locking molecules together. In ice, the attraction of molecules causes a lattice to form.
To begin the freezing process, water needs to collect around a nucleus to ‘learn how’ to position its molecules in the crystal lattice. The nucleating material can be a foreign particle, a bit of dust, vegetation, or bacteria, or a salt grain. These cause orderliness to occur amid the randomness of molecules found in liquid.
As water freezes, crystals form. They may take the form of needles or plates and both may occur at the same time. Crystals one to two feet long and three feet wide (!) have been observed in lakes.
Effects of ice on organisms
Damage
The damaging effect on tissue is the rupture of cell organelles and membranes by enlarging ice crystals or by the unwinding of enzymes that then lose their ability to catalyze metabolic reactions.
Ice in soil, e.g., needle ice, can dislodge seedlings and tear plants apart.
Survival
For organisms in bodies of water, ice may insulate, preventing too low temperatures from developing.
Among plants and animals there are tolerators and avoiders. Avoiders may migrate (vertically into the soil or to more moderate climates) or, in the case of plants, produce seeds with low moisture content that are not affected by low winter temperatures. Tolerators may change cell contents, e.g, by increasing the amount of sugars and other materials that act like antifreeze, or by producing nucleating proteins that reduce the size of ice crystals that develop.
Kinds of ice
Ice may be called, for example, fraizel slush, candle ice, needle ice, segregation ice, or splash ice. Each has its own characteristics and method of formation. Eskimos have more than a dozen words for ice.
Spring Lake Bubbles – Bubbles are likely of methane gas produced by anaerobic methanogenic bacteria that live in the lake bottom sediments
Ice as art
If water freezes slowly, ice is clear, the air having had time to diffuse away into the surrounding water. If it freezes quickly, air bubbles can be trapped. Ice with few bubbles is clear; that with many is white. The patterns that develop in ice are likely related to what triggers ice formation (air, impurity within the water, a twig), but under apparently identical conditions of temperature, air pressure, environment, etc., many diverse types of ice crystals can form and grow (witness snowflakes) at the same time in a given body of water.
Water can also freeze when it splashes onto trees, rocks, or other cold objects along the sides of ponds, lakes, or waterfalls or when it drips off a roof. It can condense out of the air to create frost feathers and lace on windows, or roses on the surface of ice.
Splash ice – edge of Delaware River.
Pancake ice, Delaware River.
Ice jam, Delaware River at Trenton Boat Launch
The beauty of ice is related to random and varied crystal forms, to bubbles, and to the way light is dispersed, reflected, and transmitted through it.
Suggested Reading / References:
Ball, P. 2001. Life’s Matrix: A Biography of Water. University of California Press, Berkeley.
Gosell, M. 2005. Ice: The Nature, the History, and the Uses of an Astonishing Substance. Alfred A. Knopf, New York.
Pielou, E.C. 1998. Fresh Water, University of Chicago Press, Chicago.
The web: search for ‘ice forms’. Physorg.com reports (from Physics Mar 24, 06) discovery of two new ice forms at –160ºC.
Exploring Ice Flowers
DEC
Stems function as wicks for soil water; the water freezes when exposed to cold air.
