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Showing posts from October, 2009

The Catskills: From Sea to Mountains

During the Devonian Period, 400-350 million years ago (MYA), the shallow Kaskaskia Sea covered much of eastern North America. When the Avalon subcontinent collided with the northeast edge of North America, about 380 MYA, the Acadian Mountains crumpled skyward, stretching from the mid Atlantic region to the Canadian Maritimes. In concert, downwarping of the crust to the west of this range created a deep bay (the Catskill Basin)in the Kaskaskia Sea; known as the Catskill Sea, this deeper water covered much of New York State and northeastern Pennsylvania.

Throughout the remainder of the Devonian and into the Mississippian Period, the Acadian Mountains eroded from lofty peaks to modest hills; much of the erosional debris was carried into the Catskill Sea, gradually filling its basin and pushing its shoreline further to the west (geologists refer to this process as the Catskill Delta formation). Elsewhere, the Kaskaskia Sea retreated to its component basins, which gradually filled with mari…

Song of the Season

Last evening and this morning, the distinctive song of the white-throated sparrow echoed through our neighborhood. These common sparrows, having bred and summered across the vast North Woods of Canada, winter in eastern and central regions of the U.S., arriving in the latter half of October.

While some move on to the balmy clime of Florida and the Gulf Coast States, our visitors are content to spend their winter in the bleak terrain and harsh conditions of America's Heartland, finding ample sustenance from a wide variety of seeds and berries. After all, they are Canadian natives, oblivious to frigid air and blowing snow. Throughout the colder months, they will be regular visitors to the backyard feeder, scratching for fallen seed during the early morning and late daylight hours.

The homesick song of the white-throated sparrow, translated by birders as "Oh my Canada, Canada, Canada," will fade as winter deepens but will build again during the lengthening days of February; t…

Raw Days

Characterized by chilly, damp and breezy weather, raw days most often occur in early spring or late autumn. During these periods, winter is battling with the milder seasons and frequent Pacific fronts, guided by an oscillating jet stream, bring unsettled conditions.

The raw days occur on the backside of these fronts, as winds shift from the north and "wrap around" precipitation falls under gray skies. The damp chill on these days, usually accentuated by a brisk, north wind, is generally more uncomfortable than the colder but drier days of mid winter. In addition, raw days occur on the heels of a warm, southerly flow (which develops ahead of the front), producing a dramatic, sudden shift to unpleasant weather.

Today is one of those raw days in Columbia. A chilly, morning drizzle has given way to partial afternoon clearing but a high overcast and northwest winds have prevented any significant warming. As the front continues to move eastward, our winds will shift from the south a…

The Nature of Teaching

Having spent most of my career in the private sector, I re-entered academic medicine several years ago and have enjoyed the opportunity to teach once again. After all, teachers are among the most influential people in our lives and it has been an honor to join their ranks.

A teacher does far more than impart factual information. In order to be effective, a good teacher guides students through the process of learning: how to acquire information, how to interpret it and how to apply it to their daily lives. The mechanism by which these goals are achieved is, of course, teacher dependent and some are more successful than others.

But the most vital aspect of teaching is the capacity to instill enthusiasm for a given field of knowledge. Looking back over my own education, I can easily name a handful of teachers who were especially effective in this regard and, it seems to me, it was their personal enthusiasm for the subject that infected me and other students. This quality, the essenc…

Homecoming

It is Homecoming Weekend in Columbia and, though I am not a graduate of the University of Missouri, it is fun to witness the pride and excitement of those who are or will be. Fortunately, mild, sunny weather is forecast for today's festivities and this evening's game.

Unlike our association with religions, political organizations or homelands, university life is an inclusive experience and, aside from alcohol-fueled scuffles at sporting events, is not a trigger for major conflict. Indeed, for many of us, college is our first significant exposure to individuals from other cultures and countries; as a result, our belief systems (religious, political and otherwise) are challenged, forcing us to actually think through the "truths" that were ingrained in our childhood. Since college is also often our first true experience with personal independence, we are free to absorb and consider these viewpoints without the overriding influence of parents and family (however well i…

Jim's Lost Season

Like star athletes whose season was cancelled, Jim Cantore and his fellow hurricane stuntmen have surely had a discouraging summer and fall. While global warming is expected to increase the strength and frequency of tropical storms and the annual shot-in-the-dark forecast from Colorado State predicted a fair amount of activity, the Atlantic hurricane season, with just a few weeks to go, has proved to be a dud.

Stripped of their opportunity to report amidst pounding surf and windblown rain, the Weather Channel crew was forced to settle for inland floods and tornado chasing; Jim visited sites of past glory and, in late summer, had the chance to report from a rowboat, gliding above submerged vehicles.

Almost all of this season's hurricane activity was in the Pacific, with several storms threatening the Baja and a series of massive typhoons creating havoc in Southeast Asia. Predicting the pattern and frequency of tropical cyclones is, obviously, still an inexact science. It will be a…

Sirius

This week, in the hour just before dawn, Sirius shines high in the southern sky, just southeast of the Orion constellation. The brightest star in the night sky, Sirius is "only" 8.6 light years from Earth; if it exploded 8 years ago, we won't know until next May.

Actually, Sirius is a binary star system, composed of a large, bright Sirius A star, twice the mass of our sun, and a small, faint Sirius B, only the size of Earth but possessing the mass of our sun. Astronomers believe that the duo formed about 250 million years ago (very recent in the history of the Universe) and that Sirius B, originally a red giant (five times the size of our sun), collapsed into a dense, white dwarf about 120 MYA. The two stars orbit each other every 50 years and are separated by a distance equal to the radius of Uranus' orbit around the sun; of course, from our vantage point, they appear close together.

Also known as the Dog Star, Sirius represented Orion's hunting companion to ea…

Maldivians & Polar Bears

This past week, the governing council of the Maldives, an island chain in the Indian Ocean, planned an undersea meeting to highlight the threat that global warming poses for their island nation. Located about 430 miles southwest of Sri Lanka, the Maldives have a mean elevation below 4 feet, making it the lowest country on Earth. As our planet's climate continues to warm, polar ice will melt and sea level will gradually rise; any low lying, coastal areas will be flooded and, as in the case of the Maldives, become uninhabitable. Furthermore, global warming may have a significant impact on precipitation patterns across the globe, posing a threat to agriculture, ranching and food production.

Like the polar bear of the Arctic, the Maldivian culture may be a victim of global warming, reinforcing the fact that man, like other species, is not immune to natural catastrophe. While current scientific evidence suggests that human activity has played a significant role in the current phase …

The Prairie Gull

Nesting in large colonies on prairie wetlands, Franklin's gulls summer across the Great Plains of North America, from central Canada to Montana, the Dakotas and Minnesota. There they feed primarily on insects and continue to do so on their migrations across America's Heartland, often hawking prey above plowed fields and ranchlands.

Those who travel across our vast plains in spring or fall are almost certain to see these gulls, which migrate in sizable flocks and often gather at favored staging areas. Their small size, buoyant flight and preference for grasslands make identification rather easy; Bonaparte's gulls, similar in size and appearance, are common visitors to the Great Lakes region but tend to migrate and winter along the Pacific and Atlantic coasts. By contrast, Franklin's gulls, once called "prairie doves," migrate through the center of our Continent and generally winter south of the United States.

Non-birders and amateur naturalists may be surpris…

Cranes over Kansas

Venus and a thumbnail moon beamed from the eastern sky as I left Denver early this morning and began a full day journey to Missouri; the first glow of dawn spread across the horizon, lighting a shelf of clouds far to the east. I caught up with those clouds near Flagler and would soon encounter one of nature's annual spectacles, the autumn migration of sandhill cranes.

The first flock crossed I-70 near Goodland and, over the next 60 miles, I observed many others. Nearing Oakley, I saw an especially large flock moving down from the north and I left the highway to observe the birds more closely and, more importantly, to listen to their distinctive calls as they circled southward on a northwest wind; as with the call of snow geese, the rattling bugle of sandhill cranes never fails to stir my soul.

Having summered and raised their young on tundra, marshy grasslands and open woodlands of Canada, these sandhills were headed for wintering areas in New Mexico, West Texas and Mexico; it was…

Front Range Fox Squirrels

Eastern fox squirrels are native to southeastern and central regions of North America, from southern Canada to the Gulf Coast. Over the years, these adaptable mammals have spread westward, crossing the Great Plains along wooded river valleys, and reached Colorado via the South Platte and Arkansas River corridors; small populations were also introduced in the State's larger cities.

In their native range, fox squirrels feed primarily on mast (acorns, walnuts, hickory nuts, etc.) but also consume a variety of fruits, seeds, buds and bird eggs. The pioneers that spread west did not find an environment rich in mast and have adjusted their diet accordingly, concentrating on alternative food sources (as above); they have also developed a taste for the cambium layer of tree bark and seem to be especially fond of Russian olive and Siberian elm trees (also introduced species). Needless to say, some of their dietary habits have not been well received by Front Range homeowners.

Faced with a …

The Paratethys Sea

During the Triassic Period, some 200 million years ago (MYA), the Tethys Sea opened across Pangea, rifting the northern Continents (Laurasia) from the southern Continents (Gondwana). Over the following Jurassic and Cretaceous Periods, the Atlantic Ocean, Indian Ocean and lesser seaways opened, splitting apart the components of these large land masses and leading to the continental geography that we find today.

During this process, the African Plate drifted northward and rotated counterclockwise, gradually compressing the Tethys Sea and cutting off its eastern connection with the Indian Ocean. In concert, a broad, relatively shallow arm of the Tethys, known as the Paratethys Sea, spread across central Europe and eastern Asia, initially forming a connection between the North Sea and the Mediterranean (the direct remnant of the closing Tethys). Beginning about 40 MYA, compression and subduction along the African-Eurasian margin forced up the Alps and other ranges across the northern edge …

October in the Valley

A cool but sunny afternoon coaxed me down to the South Platte Valley for a walk along the river and its wetlands. The recent hard freeze has taken a toll on the fall colors but, on the positive side, it eliminated most of the bothersome insects.

Still a bit early in the waterfowl migration season, the number and variety of ducks won't peak for a few more weeks but a fair mix was present on the river, lakes and marsh-lined ponds. Mallards and gadwall were most abundant, joined in the shallows by small flocks of pintail. wigeon and green-winged teal. Aside from a group of ring-necks, the deeper waters were left to the pied-billed grebes; double crested cormorants were noticeably absent, perhaps spooked south by the recent cold weather. Joining these water birds were great blue night herons, black-crowned night herons, belted kingfishers, killdeer and a lone beaver; cruising one of the larger lakes, the beaver looked more playful than industrious on this sunny afternoon.

Down from…

A Persistent Upslope

A shallow but persistent upslope flow has plagued Metro Denver for the past few days. Though the primary storm passed to our north and we were spared the heavy snow, Canadian high pressure, behind the front, has been sweeping cold, relatively humid air into our region; forced to rise across the High Plains, this flow has produced low clouds and fog along the base of the Front Range. Since this cold layer is shallow, a short trip into the mountains leads to clear skies and mild temperatures, offering a convenient escape from our chilly, gray weather.

Today, the wind has shifted from the northeast (the upslope direction for Metro Denver) to the east and the sun is breaking through our clouds and fog. The afternoon temperature should top out near 50 F but enough upslope remains to keep the hazy air in place. By tomorrow, the winds should be more from south and southeast; downsloping across the Palmer Divide, the air will heat up and our persistent fog should rapidly dissipate.

Denver&#…

Shooting the Moon

This past week, NASA bombarded the moon with a projectile, hoping to discover if water lay beneath its dusty, cratered surface. A minor project by NASA standards, the entire mission cost only 79 million dollars.

Not an expert in astronomy, physics or space exploration, I wonder whether the answer to their query, not yet revealed, will be of any significance to those of us on planet Earth. No doubt, the exploration of our solar system and galaxy has led to the development of a vast array of technologies and has given us insight into the evolution of our Universe. NASA advocates are quick to point out that the agency receives a small fraction of the federal budget and that, over the years, our investment has produced significant rewards.

While I cannot disagree with their argument, one hopes that we, as a species, keep our priorities in order. Faced with overwhelming deficits, worldwide famine, antiquated infrastructure and inadequate health care for the masses, the decision to spend …

Driving into Winter

It was chilly and clear in Columbia this morning, with the first frost of the season coating our lawns; the temperature was in the mid 30s (F). Driving west on I-70, the countryside was ablaze with fall colors, briefly obscured by dense fog in the Missouri River Valley. Entering Kansas, cloud cover began to build and the wind shifted out of the north, spinning the turbines west of Salina. Freezing drizzle appeared near Russell and a frosted landscape had developed by the time I reached Wakeeney, persisting to the crest of the Palmer Divide, in eastern Colorado. Approaching Denver, sheets of virga, some reaching the ground as snow, hung along the Front Range and a modest dusting whitened the roofs and lawns of the Mile High City; the temperature hovered in the upper 20s (F).

Despite the bleak landscape and winter-like conditions, I did manage to see an interesting mix of wildlife on my 11 hour journey. Dozens (if not a hundred) red-tailed hawks surfed the wind across Missouri and easter…

The Nature of Creativity

Creativity is the capacity to innovate: in the ways we express ourselves, interact with our environment, develop products or solve problems. While often associated with art and literature, this trait is important in all fields of human endeavor, including scientific research; indeed, inventors are among the most creative members of our species.

While most humans have some capacity for creativity, there is wide variability among the population. Having exceptional talent in a given area does not necessarily correlate with creativity; a world class musician, for example, may not be creative while the individuals who compose his music or conduct his performance are likely to be exceptionally creative. And, in my experience, creative people have a drive to express this trait in many aspects of their life; it is not unusual to find someone who is both a composer and a painter, both a designer and a photographer, both a chef and a choreographer.

Though a certain level of intelligence is imp…

Autumn Clash Zone

In America's Heartland, autumn usually provides a gradual shift from summer heat to winter's chill, offering plenty of sunny, dry weather along the way. But today, those contrasting seasons have been brought together and a clash zone, characterized by thunderstorms and heavy rain, stretches from central Texas to the Ohio Valley.

A broad dip in the jet stream, known as a trough, has produced winter-like conditions across the Intermountain West and Northern Plains while summer heat and humidity have developed across the Southeast. Meanwhile, low pressure, with its counterclockwise winds, sits over New Mexico and high pressure, with its clockwise winds, is camped over the Mid Atlantic region; this combination is pumping warm, humid air up from the Gulf of Mexico and across the Southern Plains and Lower Mississippi Valley. Near the edge of the cold front, this soupy air is lifted, producing the heavy rain and thunderstorms; up to 8 inches of rain is expected in some areas of easter…

Leaf Impressions

Back in the third or fourth grade, our teacher asked us to bring in leaves of various colors, shapes and sizes. She then dipped each in paraffin and created an autumn display for our classroom. But the key to this memory was her guide book, which let us identify and label our leaves.

Not having come from a nature-oriented family, this was one of my first introductions to the diversity of plants. At that stage in my life, a tree was a tree and leaves were those parts that shaded our tree house in summer, turned pretty colors in the fall and then cluttered the ground before we raked them into piles or burned them in my grandfather's backyard. And while I was familiar with a variety of wild creatures, primarily from trips to the zoo, I knew them more by category than by species. Backyard birds and butterflies were, in my mind, identified by color, not by family.

I will never know if my teacher anticipated the impact that her project and guidebook might have on her students. Perha…

Humans and Commitment

When humans first evolved, they surely had a strong commit-ment to their families, clans and tribes. After all, they were very dependent on others for their own survival; hunting, food gathering and protection from various environmental threats were all group efforts.

As human culture developed and evolved, these strong ties to family and community gradually loosened and individuals became more independent. Throughout the centuries, in concert with the rise of industry and technology, human commitment has been tested and, as one might expect, fracture lines have developed. Among the examples most often cited is the disintegration of the family, long the cornerstone of human society; one need only look at divorce rates and the growing number of fatherless children to acknowledge that trend.

The relatively recent focus on celebrity, extravagance and globalization has severed some of the last human bonds. Professionals, dedicated primarily to their personal success, change teams or compani…

Early Autumn Wetland

After a week of chilly nights and cool days, our local wetland reflects the seasonal change. The goldenrod and other late summer wildflowers are beginning to fade while splotches of olive and rust paint the woodlands. A decreasing variety of birds move about the preserve and, aside from the rant of killdeer, they are mostly quiet.

The water of the seasonal lake has retreated significantly and its resident amphibians, sluggish in the cooling environment, were slow to escape our approach. A lone green-backed heron haunted the wooded shoreline while an increasing number of ducks (primarily mallards and blue-winged teal) fed in the shallows; the latter were joined by a trio of pied-billed grebes, common migrants in our region. Though a squadron of swifts strafed the marsh, our resident swallows were noticeably absent, already off to the warm, buggy south. Out on the mudflats, a pair of yellowlegs joined the noisy killdeer, stopping to rest and feed on their way to southern shores.

A red-tai…

The Nature of Extinction

Mention extinction and most people think of dinosaurs, picturing them as hapless creatures who could not adapt to their environ-ment. In reality, they were a diverse and highly successful group of animals that inhabited the planet for 160 million years; by contrast, man has walked the Earth for only 125,000 years.

Ever since life evolved in the sea, some 3.6 billion years ago, extinction has played a vital role in our planet's natural history. Genetic mutations produce species diversification which, in turn, leads to competition; through the process of natural selection, those species that are best able to adapt to their environment will thrive while others become extinct. In the great majority of cases, this is a slow, gradual process that occurs over thousands (if not millions) of years. However, natural catastrophes, such as asteroid strikes, super volcano eruptions or other triggers of sudden climate change, can produce rapid and widespread extinctions; often associated with pe…

Man and his Planet

Earth coalesced from molten, interstellar debris about 4.6 billion years ago. Within 1 billion years, its crust had cooled into a puzzle of tectonic plates, a mosaic of continents and oceans covered its surface and life had appeared in its primordial seas. It would be another 3.2 billion years before primitive plants and animals colonized the land and almost 3.6 billion years before the first humans gazed upon their home planet.

Throughout that long history of evolution, the tectonic plates have been in constant motion, spreading apart, subducting, colliding and scraping against one another. In concert, oceans have opened and closed, continents have merged and rifted apart and the planet has witnessed an endless chain of tectonic activity, producing volcanism, earthquakes, tsunamis and climate change. All of these events have had an impact on Earth's landscape and on the life forms that inhabit this planet, including humans. Indeed, our species was nearly obliterated by the er…

October Blows In

It felt (and sounded) more like June than October this morning as thunderstorms rumbled across Missouri in the predawn hours. Igniting ahead of a cold front, these storms were racing off to the northeast as our recent, fair weather high slipped toward the mid Atlantic coast. The front itself was back in Kansas, its central low pumping humid air up through the Southern Plains and lower Mississippi Valley.

Tightly wound, the storm system should cross Missouri this evening and our southerly flow will give way to northwesterly winds, ushering in the cooler and drier air that we associate with October. Backside, "wrap-around" showers may persist tomorrow but the coming week promises sunny weather, with highs in the sixties (F) and lows in the forties.

This is, after all, the best month for outdoor exploration across America's Heartland. Mild, sunny days, colorful foliage, waves of waterfowl and energized mammals draw hikers, bird watchers and naturalists into the country. …