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 the mountains, white-crowned sparrows moved along the wood borders, where a variety of regulars (magpies, flickers, chickadees, song sparrows) made their appearance; American kestrels and a red-tailed hawk rounded out the bird observations. All in all, it was an unremarkable, October afternoon in the South Platte Valley.... just what I needed!
Tuesday, October 13, 2009
Monday, October 12, 2009
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's weather is all about wind direction, which explains both the spring-like outbreaks in winter (brought by downsloping chinooks) and the winter-like conditions in spring (when Pacific storms produce uplsope snow along the Front Range). For now, I anticipate a break in the chilly haze and look forward to a few mild, sunny days before I return to Missouri.
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's weather is all about wind direction, which explains both the spring-like outbreaks in winter (brought by downsloping chinooks) and the winter-like conditions in spring (when Pacific storms produce uplsope snow along the Front Range). For now, I anticipate a break in the chilly haze and look forward to a few mild, sunny days before I return to Missouri.
Sunday, October 11, 2009
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 79 million dollars to shoot the moon, though a paltry sum by government standards, seems both unwise and arrogant. Then there's the "defense" budget.
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 79 million dollars to shoot the moon, though a paltry sum by government standards, seems both unwise and arrogant. Then there's the "defense" budget.
Saturday, October 10, 2009
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 eastern Kansas while northern harriers hunted low across the icy fields of the High Plains. A flock of white pelicans drifted to the south just west of Hayes, a mix of teal and shorebirds covered many of the farm ponds and a herd of pronghorn browsed the windswept plains near Agate, Colorado. But the highlight of the trip was a large flock of sandhill cranes; numbering 100 or more, they circled across the highway just north of Limon.
I'll spend the rest of the week at our farm in Littleton and, no doubt, we'll be back in mild, autumn weather within a few days. For now, a taste of winter is in order, a common occurrence in October along the Colorado Front Range.
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 eastern Kansas while northern harriers hunted low across the icy fields of the High Plains. A flock of white pelicans drifted to the south just west of Hayes, a mix of teal and shorebirds covered many of the farm ponds and a herd of pronghorn browsed the windswept plains near Agate, Colorado. But the highlight of the trip was a large flock of sandhill cranes; numbering 100 or more, they circled across the highway just north of Limon.
I'll spend the rest of the week at our farm in Littleton and, no doubt, we'll be back in mild, autumn weather within a few days. For now, a taste of winter is in order, a common occurrence in October along the Colorado Front Range.
Friday, October 9, 2009
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 imperative, one's creativity does not necessarily correlate with his or her IQ; a genius may not be creative while very creative people may be of average intelligence. In fact, there is evidence that creativity is not limited to the human species; some chimpanzees, for example, use natural tools, presumably having learned this behavior from creative members of their clan.
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 imperative, one's creativity does not necessarily correlate with his or her IQ; a genius may not be creative while very creative people may be of average intelligence. In fact, there is evidence that creativity is not limited to the human species; some chimpanzees, for example, use natural tools, presumably having learned this behavior from creative members of their clan.
Thursday, October 8, 2009
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 eastern Oklahoma, southern Missouri and southern Illinois.
Our image of the seasons is based on our observation of weather patterns over many years. We generally picture October as a month of sunny days, colorful foliage and crisp, clear nights. But nature does not always comply with our expectations and this day will look and feel more like April.
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 eastern Oklahoma, southern Missouri and southern Illinois.
Our image of the seasons is based on our observation of weather patterns over many years. We generally picture October as a month of sunny days, colorful foliage and crisp, clear nights. But nature does not always comply with our expectations and this day will look and feel more like April.
Wednesday, October 7, 2009
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. Perhaps, for her, it was just another seasonal recommendation in the instructor's manual. But, for me, it was a memorable and significant event, one of only a handful that I can clearly associate with igniting my interest in nature. For that, I am sincerely grateful and hope that others entrusted with the education of children will recognize their opportunity to instill passion in young minds.
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. Perhaps, for her, it was just another seasonal recommendation in the instructor's manual. But, for me, it was a memorable and significant event, one of only a handful that I can clearly associate with igniting my interest in nature. For that, I am sincerely grateful and hope that others entrusted with the education of children will recognize their opportunity to instill passion in young minds.
Tuesday, October 6, 2009
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 companies with no sense of commitment to their original organization. Financial gurus no longer invest in corporations or small businesses; rather, they trade or buy stocks, puts and options, moving in and out of positions to maximize their personal wealth. Politicians, focused primarily on staying in office, are less concerned about the welfare of the general public than they are about appeasing influential lobbyists; eschewing "socialism," they protect the power brokers of our society. Corporations, uncommitted to the workers that built them, outsource their labor, laying off dedicated employees in order to maximize profits. The commitment of many modern humans is primarily to themselves.
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 companies with no sense of commitment to their original organization. Financial gurus no longer invest in corporations or small businesses; rather, they trade or buy stocks, puts and options, moving in and out of positions to maximize their personal wealth. Politicians, focused primarily on staying in office, are less concerned about the welfare of the general public than they are about appeasing influential lobbyists; eschewing "socialism," they protect the power brokers of our society. Corporations, uncommitted to the workers that built them, outsource their labor, laying off dedicated employees in order to maximize profits. The commitment of many modern humans is primarily to themselves.
Monday, October 5, 2009
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-tailed hawk circled overhead and a flock of vultures, like kites on a breezy day, dipped and tilted above the creekside ridge. In the coming weeks, the foliage of the marsh and grassland will continue to fade as the surrounding woodlands take on their October splendor; by then, winter songbirds will claim the thickets and the cold, quiet season will settle across this Missouri wetland.
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-tailed hawk circled overhead and a flock of vultures, like kites on a breezy day, dipped and tilted above the creekside ridge. In the coming weeks, the foliage of the marsh and grassland will continue to fade as the surrounding woodlands take on their October splendor; by then, winter songbirds will claim the thickets and the cold, quiet season will settle across this Missouri wetland.
Saturday, October 3, 2009
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 periods of glaciation, these mass extinctions are spaced throughout the history of our planet.
Humans, equipped with superior brain power, have imposed a new wave of extinction. Having directly out-competed Homo erectus and the Neanderthals, we now threaten the survival of other species through destruction of natural habitat, pollution of the environment, over hunting and over fishing. Recent global warming, to which we have clearly contributed, may lead to the extinction of many species and will surely have a negative effect on humans as well. By reducing our impact on natural ecosystems, we should be able to minimize man-induced extinction; nevertheless, natural extinction, essential to the balance of life on Earth, will continue and, at some point in the future, it will claim our own species.
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 periods of glaciation, these mass extinctions are spaced throughout the history of our planet.
Humans, equipped with superior brain power, have imposed a new wave of extinction. Having directly out-competed Homo erectus and the Neanderthals, we now threaten the survival of other species through destruction of natural habitat, pollution of the environment, over hunting and over fishing. Recent global warming, to which we have clearly contributed, may lead to the extinction of many species and will surely have a negative effect on humans as well. By reducing our impact on natural ecosystems, we should be able to minimize man-induced extinction; nevertheless, natural extinction, essential to the balance of life on Earth, will continue and, at some point in the future, it will claim our own species.
Friday, October 2, 2009
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 eruption of the Toba supervolcano, on Sumatra, 74 thousand years ago.
Contrary to the views instilled by various religions, the Earth was not created in preparation for human occupation. We, like other species, evolved in concert with our planet and this evolutionary process, governed by tectonic forces and natural selection, continues today. The log of recent earthquakes, tsunamis and volcanic eruptions clarifies this point and warns us that natural cataclysms, whether along the San Andrea Fault, at Yellowstone or via a wayward meteor, will continue to mold the future of both our planet and our species.
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 eruption of the Toba supervolcano, on Sumatra, 74 thousand years ago.
Contrary to the views instilled by various religions, the Earth was not created in preparation for human occupation. We, like other species, evolved in concert with our planet and this evolutionary process, governed by tectonic forces and natural selection, continues today. The log of recent earthquakes, tsunamis and volcanic eruptions clarifies this point and warns us that natural cataclysms, whether along the San Andrea Fault, at Yellowstone or via a wayward meteor, will continue to mold the future of both our planet and our species.
Thursday, October 1, 2009
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. It's the season for adventure, with all its expected sights and unexpected discoveries.
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. It's the season for adventure, with all its expected sights and unexpected discoveries.
Wednesday, September 30, 2009
Samoa & Sumatra
Over the past 24 hours, powerful earthquakes have occurred along the west coasts of Samoa and Sumatra. A secondary tsunami has caused significant damage in Samoa but it is too early to know if the Sumatran quake will result in a tsunami across the Indian Ocean.
The Sumatran quake occurred south of the epicenter of the devastating earthquake and tsunami that shocked the planet earlier this decade but, like its many predecessors, it surely developed along the west Sumatran subduction trench, where the Australian Plate is dipping below the Eurasian Plate. In such regions, the overlying plate is pulled downward by friction with the subducting plate; this building pressure is intermittently released, producing an earthquake and, by lifting the overlying ocean water, often triggering a tsunami.
The Samoan quake is less easy to explain. Not lying along a plate margin, the Samoan Islands have long been characterized as volcanic hotspots, produced by the movement of the Pacific plate over a mantle plume; in this respect they would be similar to the Hawaiian Ridge and other mid-plate island chains. However, geologists who have studied the age of volcanic rocks on the Samoan Islands and other regional archipelagos, have not found the age progression that typifies a hot spot chain. Some believe that these islands have developed above a fracture in the Pacific plate, which may have resulted from stress within the ocean crust; such a fracture would permit mantle intrusion, leading to volcanism and island formation. Yesterday's earthquake seems to lend support for that theory.
The Sumatran quake occurred south of the epicenter of the devastating earthquake and tsunami that shocked the planet earlier this decade but, like its many predecessors, it surely developed along the west Sumatran subduction trench, where the Australian Plate is dipping below the Eurasian Plate. In such regions, the overlying plate is pulled downward by friction with the subducting plate; this building pressure is intermittently released, producing an earthquake and, by lifting the overlying ocean water, often triggering a tsunami.
The Samoan quake is less easy to explain. Not lying along a plate margin, the Samoan Islands have long been characterized as volcanic hotspots, produced by the movement of the Pacific plate over a mantle plume; in this respect they would be similar to the Hawaiian Ridge and other mid-plate island chains. However, geologists who have studied the age of volcanic rocks on the Samoan Islands and other regional archipelagos, have not found the age progression that typifies a hot spot chain. Some believe that these islands have developed above a fracture in the Pacific plate, which may have resulted from stress within the ocean crust; such a fracture would permit mantle intrusion, leading to volcanism and island formation. Yesterday's earthquake seems to lend support for that theory.
Tuesday, September 29, 2009
Waterpocket Fold
The Waterpocket Fold is a 100-mile long warp of Earth's crust in southern Utah. Trending SSE to NNW, the Fold extends from the Colorado River valley to the area of Thousand Lake Mountain; most of the scenic terrain created by this geologic formation is now protected within Capitol Reef National Park.
Before the Waterpocket Fold developed, rock layers of this region were stacked horizontally, with older sediments below younger ones. Then, about 70 million years ago, pressure within the North American plate crumpled up the Rocky Mountains; in concert, the rock layers of southern Utah warped downward to the east. Subsequent erosion, augmented by uplift of the Colorado Plateau about 15-20 million years ago, has uncovered the various strata of this tilted layer cake, with older sedimentary rocks (Permian; 270 million years old) exposed on the west edge of the fold and younger deposits (Cretaceous; 80 million years old) on the east. Since some layers are more resistant to erosion than others, the Waterpocket Fold is characterized by an alternating pattern of ridges and basins, interspersed with geologic domes and spires.
The landscape that we observe across our globe today is a product of geology, tectonic activity and erosion; it is but a snapshot in the 4.6 billion-year history of our planet and will continue to change over the coming millenia. Few places on Earth offer a better illustration of these natural, terrain-sculpting processes than does the Waterpocket Fold.
Before the Waterpocket Fold developed, rock layers of this region were stacked horizontally, with older sediments below younger ones. Then, about 70 million years ago, pressure within the North American plate crumpled up the Rocky Mountains; in concert, the rock layers of southern Utah warped downward to the east. Subsequent erosion, augmented by uplift of the Colorado Plateau about 15-20 million years ago, has uncovered the various strata of this tilted layer cake, with older sedimentary rocks (Permian; 270 million years old) exposed on the west edge of the fold and younger deposits (Cretaceous; 80 million years old) on the east. Since some layers are more resistant to erosion than others, the Waterpocket Fold is characterized by an alternating pattern of ridges and basins, interspersed with geologic domes and spires.
The landscape that we observe across our globe today is a product of geology, tectonic activity and erosion; it is but a snapshot in the 4.6 billion-year history of our planet and will continue to change over the coming millenia. Few places on Earth offer a better illustration of these natural, terrain-sculpting processes than does the Waterpocket Fold.
Monday, September 28, 2009
The Bird of Autumn
Birders tend to associate certain species with specific times of the year. Of course, this is especially true for those birds that inhabit our area for limited periods of time and the identity of these seasonal species varies widely from one region to another.
Here in the Midwest, most birders likely associate warblers with mid spring, when these colorful and active species move through our region, challenging identification by even the most experienced naturalists. In summer, many of us are especially aware of avian residents that seem undaunted by the heat and humidity; chimney swifts and house wrens come to mind. Winter brings seasonal residents from the north; just the sight or sound of juncos and white-throated sparrows can produce a chilling effect and we come to admire the hardiness of these Canadian visitors.
For me, the white-breasted nuthatch is the bird of autumn. Though this common acrobat inhabits our area throughout the year, I have long associated his distinctive call with cool, sunny days and bright autumn foliage. Perhaps this hearkens back to my earliest days as a birder, when I first identified this amusing bird on a glorious October afternoon. Whatever the cause, the yank of a nuthatch is, for me, a sound of the season, as much a part of autumn as falling leaves, frosty nights and the nostalgic scent of wood smoke.
Here in the Midwest, most birders likely associate warblers with mid spring, when these colorful and active species move through our region, challenging identification by even the most experienced naturalists. In summer, many of us are especially aware of avian residents that seem undaunted by the heat and humidity; chimney swifts and house wrens come to mind. Winter brings seasonal residents from the north; just the sight or sound of juncos and white-throated sparrows can produce a chilling effect and we come to admire the hardiness of these Canadian visitors.
For me, the white-breasted nuthatch is the bird of autumn. Though this common acrobat inhabits our area throughout the year, I have long associated his distinctive call with cool, sunny days and bright autumn foliage. Perhaps this hearkens back to my earliest days as a birder, when I first identified this amusing bird on a glorious October afternoon. Whatever the cause, the yank of a nuthatch is, for me, a sound of the season, as much a part of autumn as falling leaves, frosty nights and the nostalgic scent of wood smoke.
Sunday, September 27, 2009
Between Seasons
In Missouri, late September is a time of transition. The oppressive summer heat has moved to our south but the deep autumn chill has yet to arrive. Some color dapples the forest but late summer wildflowers still adorn the grasslands and, for the most part, greenery dominates the landscape.
Though a few summer birds have left with the heat, most linger in our woods and winter visitors have yet to leave their Canadian homeland. Frogs, snakes and aquatic turtles still haunt the wetlands, fiddlers still sing through the night and the hoot of the great horned owl is but a distant memory. Here in the Heartland, we are suspended between summer and fall.
But all will change within a few weeks. Autumn splendor will paint the countryside, a hard freeze will silence the insects, waterfowl will reclaim the wetlands and the culling season will begin. Nature may not always obey the human calendar but we can count on her cycle to endure.
Though a few summer birds have left with the heat, most linger in our woods and winter visitors have yet to leave their Canadian homeland. Frogs, snakes and aquatic turtles still haunt the wetlands, fiddlers still sing through the night and the hoot of the great horned owl is but a distant memory. Here in the Heartland, we are suspended between summer and fall.
But all will change within a few weeks. Autumn splendor will paint the countryside, a hard freeze will silence the insects, waterfowl will reclaim the wetlands and the culling season will begin. Nature may not always obey the human calendar but we can count on her cycle to endure.
Friday, September 25, 2009
The Champlain Basin
When the last of the Pleistocene Glaciers plowed through New England, it molded the landscape, sculpting the mountains and eroding broad valleys. One of the latter, stretching between the Adirondacks of New York and the Green Mountains of Vermont, would become the basin for Lake Champlain.
After peaking in its coverage, some 20,000 years ago, the Wisconsin Glacier began to melt back to the north, opening the newly formed basins. Some of these drained to the south or east, while others, including the Champlain Basin, drained northward. Blocked by the retreating glacier, the north flowing rivers gave rise to valley lakes, filled by mountain streams and by meltwater from the glacier itself. By 15,000 years ago, Lake Vermont, more extensive than today's remnant, spread across the Champlain Basin. Then, as the ice sheet retreated further into Canada, the rising ocean spilled through the St. Lawrence Valley and southward into the basin of Lake Vermont. Turning brackish, the latter became the Champlain Sea, an arm of the North Atlantic, and, for a thousand years or more, harbored a wide variety of marine life; fossils of these sea creatures are found across the basin today.
Finally, as New England rebounded from the weight of the glacier, the Sea slowly drained back toward the Gulf of St. Lawrence and freshwater reclaimed the basin, giving rise to Lake Champlain. Sustained by snowmelt and rainwater from the flanking mountains, the Lake drains northward via the Richelieu and St. Lawrence Rivers, flowing through a glacial valley that once admitted the sea.
After peaking in its coverage, some 20,000 years ago, the Wisconsin Glacier began to melt back to the north, opening the newly formed basins. Some of these drained to the south or east, while others, including the Champlain Basin, drained northward. Blocked by the retreating glacier, the north flowing rivers gave rise to valley lakes, filled by mountain streams and by meltwater from the glacier itself. By 15,000 years ago, Lake Vermont, more extensive than today's remnant, spread across the Champlain Basin. Then, as the ice sheet retreated further into Canada, the rising ocean spilled through the St. Lawrence Valley and southward into the basin of Lake Vermont. Turning brackish, the latter became the Champlain Sea, an arm of the North Atlantic, and, for a thousand years or more, harbored a wide variety of marine life; fossils of these sea creatures are found across the basin today.
Finally, as New England rebounded from the weight of the glacier, the Sea slowly drained back toward the Gulf of St. Lawrence and freshwater reclaimed the basin, giving rise to Lake Champlain. Sustained by snowmelt and rainwater from the flanking mountains, the Lake drains northward via the Richelieu and St. Lawrence Rivers, flowing through a glacial valley that once admitted the sea.
Thursday, September 24, 2009
Columbia River Country
On our recent trip to Oregon, we spent some time along the Columbia River, the grand waterway of the Pacific Northwest. Rising in southeast British Columbia, it makes a curve to the north and then heads south, picking up flow from the Kootenay and Pend Oreille Rivers before entering the U.S. In eastern Washington, it is joined by the Spokane, Snake and Yakima Rivers and then heads westward along the Oregon border, taking in flow from the John Day, Deschutes, Williamette, Lewis and Cowlitz Rivers before entering the Pacific west of Astoria. Completing a journey of 1245 miles and collecting flow from a watershed of 258,000 square miles, the Columbia is the fourth largest river in the country and the largest west of the Continental Divide.
The current course of the Columbia has been molded since the rise of the Rocky Mountains, 65 million years ago. Once inundated by shallow seas, the region has experienced periodic volcanism over the past 40 million years and Pleistocene floods eroded the landscape 12-20 thousand years ago; the latter carved the famous Channeled Scablands of eastern Washington. Today, erosion continues, fed by heavy snows across the Rockies and Cascades, and, as many of us witnessed in 1980, regional volcanism continues to sculpt this rugged terrain.
Though beautiful and powerful, the Columbia has been used and abused by those who have settled across its vast watershed. Fourteen dams disrupt its flow, providing hydroelectric power, flood control and water for consumption and irrigation; however, these same structures have had a significant impact on the welfare of salmon populations, a threat only partially mitigated by the construction of "fish ladders." In addition, channelization of the river has augmented industrial development throughout its valley, offering a vital route of transportation; of course, this has resulted in significant water pollution, including material from nuclear plants. As is common across the globe, any attempt to balance conservation and resource exploitation tends to tip against the natural environment.
The current course of the Columbia has been molded since the rise of the Rocky Mountains, 65 million years ago. Once inundated by shallow seas, the region has experienced periodic volcanism over the past 40 million years and Pleistocene floods eroded the landscape 12-20 thousand years ago; the latter carved the famous Channeled Scablands of eastern Washington. Today, erosion continues, fed by heavy snows across the Rockies and Cascades, and, as many of us witnessed in 1980, regional volcanism continues to sculpt this rugged terrain.
Though beautiful and powerful, the Columbia has been used and abused by those who have settled across its vast watershed. Fourteen dams disrupt its flow, providing hydroelectric power, flood control and water for consumption and irrigation; however, these same structures have had a significant impact on the welfare of salmon populations, a threat only partially mitigated by the construction of "fish ladders." In addition, channelization of the river has augmented industrial development throughout its valley, offering a vital route of transportation; of course, this has resulted in significant water pollution, including material from nuclear plants. As is common across the globe, any attempt to balance conservation and resource exploitation tends to tip against the natural environment.
Tuesday, September 22, 2009
A Perfect Deluge
After enduring more than a year of severe drought, the residents of northern Georgia and bordering States had been hoping for a tropical storm that might restore the vegetation, recharge the streams and fill their reservoirs. Alas, in the middle of a lackluster hurricane season, relief came not in the form of a powerful storm but as the effects of a plodding cold front. Unfortunately, it was a gift that kept on giving, drenching the region with 10-20 inches of rain and producing catastrophic floods throughout the area.
The cold front, curving from the eastern Great Lakes to central Texas, established a clash zone, with warm, humid air to its southeast and cool, dry air to its northwest. As the front inched to the east, a southerly flow of Gulf air invaded the Southeastern States, priming the region for thunderstorms. The front and its low pressure center provided lift, pulling the soupy air up and over the invading wedge of cool air; the terrain of northern Georgia and its border areas, higher than the Gulf Plain to the south and east, augmented this lift as the warm, moist air streamed up from the south. All of these factors ignited thunderstorms along the edge of the front, which, lacking a potent shove from the jet stream, lounged over these uplands, dropping heavy rain before redeveloping and training over the same areas.
In effect, a Perfect Deluge was established and continued to intensify until the front moved further to the east. Despite a respite today, more precipitation is expected throughout the week as another cold front drops from the Midwest. Hopefully, that rainmaker won't linger over this flood zone which has no capacity to absorb additional moisture; any rain that falls will quickly move to the swollen streams and rivers.
The cold front, curving from the eastern Great Lakes to central Texas, established a clash zone, with warm, humid air to its southeast and cool, dry air to its northwest. As the front inched to the east, a southerly flow of Gulf air invaded the Southeastern States, priming the region for thunderstorms. The front and its low pressure center provided lift, pulling the soupy air up and over the invading wedge of cool air; the terrain of northern Georgia and its border areas, higher than the Gulf Plain to the south and east, augmented this lift as the warm, moist air streamed up from the south. All of these factors ignited thunderstorms along the edge of the front, which, lacking a potent shove from the jet stream, lounged over these uplands, dropping heavy rain before redeveloping and training over the same areas.
In effect, a Perfect Deluge was established and continued to intensify until the front moved further to the east. Despite a respite today, more precipitation is expected throughout the week as another cold front drops from the Midwest. Hopefully, that rainmaker won't linger over this flood zone which has no capacity to absorb additional moisture; any rain that falls will quickly move to the swollen streams and rivers.
Subscribe to:
Posts (Atom)