Typhoon Merbok & Climate Change

Tropical storm Merbok formed in the Western Pacific Ocean on September 11 and was moving north as it intensified into a typhoon over the following days.  Forecast to weaken in the cooler waters of the Bering Sea, the storm defied expectations.

Crossing relatively warm ocean waters west of Alaska, Merbok retained tropical storm winds which, at times, reached hurricane-force intensity.  Massive waves developed north of the Aleutian Island Chain and, over the past two days, high winds, torrential rain and a storm surge approaching 12 feet lashed the West Coast of Alaska.  Extensive damage has been reported from small towns spaced along that rugged coastline.

Once again, global warming is primarily responsible for this tragic weather event.  Warm seawater fueled the power of this storm as the remnants of Merbok churned eastward.  No doubt, fewer tropical storms will die in sub-polar seas as climate change progresses.

Ward Lake

On the north side of Ketchikan, not far from the cruise ship crowds, Ward Creek tumbles down through a glacial valley, headed for the Tongass Narrows.  Gathering the outflow of several glacial lakes along the way, it eventually flows through Ward Lake before beginning its final stretch to the sea.

Surrounded by a rich Temperate Rainforest of western cedar and hemlock and hosting rustic shelters built by the Civilian Conservation Corps, Ward Lake is encircled by a pleasant, well-engineered trail.  Educational plaques, spaced along the route, introduce visitors to the ecology of the valley and fine wooden bridges ford the creek and its tributaries.  Though a campgrounds borders the lake, we encountered less than a dozen fellow hikers on our two-mile circuit.

In this land of spectacular scenery and untamed wilderness, relative solitude and tranquility are never far away.  While those de-boarding the cruise ships head for craft shops, historic sites, tour buses and taverns, those of us interested in the landscape and wildlife have endless places to explore, often quite close to town.

Misty Fjords National Monument

On this mild, sunny morning in Southeast Alaska, we took a cruise from Ketchikan to Misty Fjords National Monument.  Established in 1978 by the Carter Administration, this refuge protects two steep-walled fjords and their numerous coves within 2 million acres of the Tongass National Forest along the western edge of the North American mainland.

These fjords feed into Behm Canal, a broad channel that borders the northern and eastern sides of Revillagigedo Island.  Known for their spectacular landscape, scenic waterfalls and sea bird rookeries, Rudyerd and Smeaton Bays (the two primary fjords) are accessed by boat or float plane.  While it was a bit late in the summer for peak activity at the rookeries, I did observe a fair number of pigeon guillemots and glaucous-winged gulls on the cliffs and bald eagles were common along the waterways.  Brown and black bears, wolves and Sitka deer are among other wildlife that inhabit the Monument.

Also of interest was New Eddystone Rock, rising in the middle of Behm Canal near the entrance to Rudyerd Bay.  Named by the British explorer, Captain George Vancouver, in 1793, this erosional remnant of volcanic basalt towers above a small island where a dozen or so harbor seals lounged in the mid-morning sun.  Though hump-backed whales often visit Behm Canal during the warmer months, none were observed today. 

To Margaret Bay

Ketchikan spreads along the southwest coast of Revillagigedo Island but most of the island is uninhabited.  Today, we enjoyed a boat ride to Margaret Bay, one of several that indent the northwest coast of Revillagigedo.

The purpose was to set a couple of crab traps in Traitor's Cove and to take a hike to a bear-watching site in the Margaret Creek Valley; the latter is managed by the National Forest Service.  A two-mile, roundtrip hike takes visitors to an overlook blind above the creek, where black bear fish for spawning salmon.  During our stay, we were fortunate to observe two young bears, fishing at a waterfall along the creek.

The trapping effort produced one Dungeness crab and we stopped to check several shrimp traps on our way back to Ketchikan; those traps were highly productive though an octopus and several large starfish had eaten some of the catch.  Beyond these highlights, the trip provided spectacular views of the waterways, mountainous islands and rugged peninsulas north of Ketchikan; our thanks to Steve and Gary for the seven-hour tour.

Lunch Creek Trail

At the north end of the Tongass Highway, the only major road through Ketchikan, is a small parking area that provides access to the Lunch Creek Trail.  The latter, winding through rich Pacific rainforest, soon reaches Lunch Creek Falls and then follows the stream down to a scenic bay.

Far from the cruise ships and the tourist throngs in downtown Ketchikan, the rocky beach offers spectacular views of distant islands and their forested mountains, rising above the cold blue water.  We enjoyed a peaceful visit for an hour or so, disturbed only by an occasional fishing boat or float plane; indeed, even the wildlife was relatively scarce, represented by a lone ruddy duck and a flock of black scoters.

This was the Alaska that I had pictured in my mind's eye before flying up from Seattle: tranquility, solitude and an abundance of natural beauty; my thanks to Patty and Sam for their hospitality and for directing us to this beautiful and inspiring refuge.  More excursions are planned over the next few days.

Northwest to Ketchikan

Escaping the latest heat wave along the Colorado Front Range, my wife and I will be visiting friends in Ketchikan, Alaska, over the next several days.  There we will enjoy afternoon highs in the 60s (F) and overnight lows in the 50s; of course, rain showers are also in the forecast, as one might expect in Southeast Alaska.

As I discussed in Alaska's Collage of Terranes, most of the State is a mosaic of exotic terranes and volcanic island arcs, later molded by glaciers, earthquakes, volcanic eruptions, torrents of meltwater and fluctuating sea levels.  Ketchikan sits in the Gravina Belt, composed of mid Jurassic to early Cenozoic volcanic rocks, sandwiched between the Alexander Terrane, to the west, and the Stikine Terrane, to the east.  The Alexander Terrane is especially interesting; its Silurian and Devonian strata and their cargo of fossils indicate that it was torn away from Siberia as the Northern Pacific opened.  The Stikine Terrane, on the other hand, formed as a volcanic island arc from the late Paleozoic Era into the early Mesozoic.

Today, Ketchikan, sitting on the Inside Passage, is a cruise ship port during the summer months.  Having limited time for our journey, we will be flying from Denver (with a plane change in Seattle).  More on our adventure in upcoming posts.

Cackling Geese

On my walk along the South Platte this morning, I encountered a large flock of cackling geese, resting on the river.  Prior to 2004, these "small Canada geese" were considered to be subspecies of their larger cousins.  They are now classified as a separate species though they, themselves, are represented by several subspecies.

After nesting on the Arctic tundra of Northwest Canada and Alaska, cackling geese winter in the Pacific Coast States or in the south-central U.S.; their numbers seem to be increasing along the Colorado Front Range, both during migrations and throughout the winter.  When mingling with Canada geese, cackling geese are relatively easy to identify due to their smaller size, stubby bill, shorter neck and, in some subspecies, a white collar at the base of their neck.  They also have a higher-pitched call than Canada geese and, in my experience, tend to be calmer and quieter when resting on lakes or rivers.

Cackling geese are perhaps easiest to identify when flying at a distance.  While their coloration matches that of Canadas, their small size makes them look more like ducks than geese.  Should the flock approach your location, their higher-pitched calls confirm the identification.

American Tree Sparrows

On this mild, breezy afternoon, my wife and I took a walk around Perry Phillips Lake, south of Columbia, Missouri.  Two pair of red-tailed hawks cavorted in the wind but the lake remained frozen and no waterfowl were observed.  However, we did come across a flock of American tree sparrows, foraging in thickets along the south shore.

Residents of Alaska and Northern Canada where they breed in the Arctic Zone, these attractive sparrows are best identified by their rusty cap, white wing bars and light gray underparts with a central breast spot.  Gregarious during the winter months, they visit northern and central latitudes of the Lower 48, favoring open country with wooded streams or wetlands; while they visit backyard feeders on occasion, these sparrows are far more common in rural areas.  And though their name suggests otherwise, they spend most of their time on the ground or in low shrubs and saplings.

By late winter, the males begin to sing, longing to return to their northern homeland before warm, humid air invades the Heartland.  There they will pair up with a female and construct a nest in willow thickets or directly on the tundra.  Feasting on both insects and seeds during the breeding season, they consume grass and wildflower seeds during the winter months.

The Taiga Shrike

This morning, while wandering through South Platte Park, I encountered a northern shrike, hunting from a barren tree in a lakeside meadow.  A native of the taiga across Alaska and Northern Canada, this species spreads south to the northern and western U.S. during the winter months when its smaller cousin (the loggerhead shrike) has moved on to warmer, more southern climes.

Generally solitary in winter, northern shrikes hunt from an exposed perch in a tree or tall shrub, dropping to snare songbirds or small mammals with its hooked beak and talons.  Its habit of storing excess prey by impaling it on thorns or barbed wire has earned it (and other shrikes) the nickname of "butcher birds."

By mid spring, northern shrikes return to their breeding grounds, favoring the open woodlands where boreal forest meets the Arctic tundra.  There they nest in stunted conifers, adding large insects to their diet and that of their growing youngsters; in a landscape of ephemeral pools and perpetual summer daylight, that prey is especially abundant.

Eulachon

Eulachon are small marine fish (8-9 inches in length) that feed on plankton in the eastern Pacific, from Alaska to northern California.  In late winter, they move into estuaries and coastal rivers to spawn; most adults die after this process.  Fertilized eggs, which sink to the gravel beds, hatch in a month and the fry head to sea; there they will live in offshore waters for 3-5 years before returning to spawn.

Heavily laden with fat, the spawning eulachon are known as candlefish (since dried specimens can be lit like candles) and were called "salvation fish" by Native Americans of the Pacific Northwest since their calorie-rich bodies provided vital nutrition during the leans months of late winter and early spring.  Of course, Steller's sea lions, dolphins and sea birds also welcome their spawning runs.

Unfortunately, eulachon have all but disappeared from the coastal rivers of northern California, Oregon and Washington and their numbers have decreased significantly farther north.  Global warming, overfishing, water pollution and altered river sediments (due to hydroelectric dams) are all thought to be playing a role in the population decline of this smelt.

The Laurentian Divide

The Continental Divide of North America stretches from Alaska to Mexico, generally following the Brooks Range and Rocky Mountain corridor; this divide is commonly known to separate the streams flowing toward the Pacific Ocean from those draining toward the Atlantic Ocean and Gulf of Mexico.  Actually, the northern section of the Continental Divide, from Alaska through the Yukon Territory of Canada, separates streams flowing toward the Pacific from those flowing into the Arctic Ocean.  As far south as the U.S.-Canada border, it divides streams heading for the Pacific from those flowing toward Hudson Bay.

Geographers and hydrologists thus recognize the Laurentian Divide (also known as the Northern Divide), which stretches west to east between the Continental Divide and the Labrador Sea, dividing streams that flow northward to the Arctic or to Hudson Bay from those that flow southward toward the Gulf of Mexico or eastward to the Atlantic Ocean.  From Triple Divide Peak in Glacier National Park, this divide straddles the U.S.-Canada border through Montana, separating the watersheds of the Saskatchewan and Missouri Rivers.  Farther east, it angles southeastward through North Dakota and then northeastward through Minnesota, dividing the watershed of the Red River (which flows northward to Lake Winnipeg and thence northeast to Hudson Bay via the Nelson River) from those of the Missouri, Minnesota and Mississippi Rivers.  Running north of the Great Lakes, the Laurentian Divide follows the northern edge of the St. Lawrence watershed, eventually running atop the crest of the Laurentian Mountains as they curve through Quebec and Labrador.

The Laurentian Divide ends at the mouth of the Hudson Strait on the Labrador Sea.  While some argue that Hudson Bay and its Strait are hydrologically part of the Atlantic Basin (which they are), the ecology of the Hudson Bay region is closer to that of the Arctic than to Temperate latitudes to the south.  For purists, the Arctic Divide runs north of the Saskatchewan watershed and north of Hudson Bay, demarcating the southern edge of various watersheds (including that of the MacKenzie River) that empty into the Arctic Ocean.

Boreal Owls

Boreal owls are small raptors that inhabit mixed conifer-aspen forests across Alaska, Canada and northern Eurasia; their range also extends southward through northern Minnesota, the Cascades and the Rocky Mountains.  Though widespread and fairly common, boreal owls are rarely encountered, primarily due to their small size and strict nocturnal lifestyle.

When observed, they are generally perched in a conifer, where they spend the daylight hours; identification is made by their small size (females are larger than males), tuftless head, yellow eyes, speckled crown, white facial disc and brown and white plumage.  Feeding primarily on mice and songbirds, boreal owls may fall victim to larger owls, fishers or pine martens.  Tree cavities are used for nesting and the clutch size varies widely, averaging 5-6 young; the female incubates the eggs while the male guards the site and brings food.

Though widespread in the subalpine forests of Colorado, boreal owls are (in my experience) most commonly observed and reported near Cameron Pass, west of Fort Collins.  Of course, this may reflect the large population of birders along the Front Range urban corridor and the accessibility of that relatively low pass (10,300 feet).

White-Crowned Sparrows

Summer residents of Alaska, northern Canada and the alpine tundra of North America's western mountains, white-crowned sparrows winter across most of the Lower 48 (the Northern Plains, New England and South Florida excluded).  There they are usually found in sizable flocks, feasting on a variety of seeds in abandoned farm fields or in shrub lines along pastures; they might also visit feeders, especially in rural towns or semi-rural suburbs.

In Colorado, white-crowned sparrows are among the more common alpine summer residents and are best found near the stunted spruce and bristlecone pines at timberline.  While they migrate through the Front Range urban corridor in spring and fall, they are especially abundant in May as they return from the Southern Plains.  Here in central Missouri, white crowns are locally common winter residents on the farmlands that surround Columbia and, in my experience, are most often observed at suburban feeders in March or early April.

On their northern or alpine breeding grounds, these slender but hardy sparrows place their nest in low shrubs or directly on the ground; 3-5 young are raised and the family feasts on both insects and seeds throughout the summer months.  The male parent is highly territorial during this period and his distinctive song is delivered day and night.  By early autumn, the family members disperse; juvenile white-crowns retain their buff-colored head stripes until the following spring and are thus easily identified in winter flocks.

Mount Pavlov Eruption

Mount Pavlov, 8560 feet, is a stratovolcano on the Alaskan Peninsula, some 600 miles southwest of Anchorage.  It formed within the last 10,000 years, on the northeast edge of the Emmons Lake Caldera (the remnants of an ancient volcanic explosion); like all of the Aleutian Volcanoes, it is the product of subduction, as the Pacific Plate dips beneath the North American Plate, causing its edge to melt and fuel volcanism.

The most active volcano in Alaska, Mount Pavlov has experienced numerous eruptions, most of which have been relatively benign due to both the volcano's structure and its remote location.  The current eruption began earlier this week with little fanfare; however, over the past 24 hours, Mt. Pavlov's ash plume has intensified, rising 30,000 feet above sea level and threatening air traffic in the region.

Such is the nature of "natural disasters" across the globe.  While the physical evolution of Planet Earth continues, just as it has for 4.6 billion years, we humans ignore (if not dismiss) that evidence until it directly threatens our personal welfare.  As a consequence, we construct cities within subduction zones and along major fault lines, convinced that we are the endpoint of God's master plan, not just another species, subject to the natural forces that mold this planet.

Blame it on the Jet

Throughout most of this winter, the jet stream has produced havoc across a large portion of the Northern Hemisphere.  While it generally assumes a horizontal flow across central latitudes during the winter months, ushering in a series of storm systems and milder interludes, it took a different track this year and, until recently, seemed unwilling to budge.  Its stagnant undulation produced dramatically different but equally unwelcome weather in adjacent regions.

Streaming northeastward into southern Alaska, the jet brought mild air and copious rain, significantly reducing the winter snowpack; at the same time, this northward shift deprived California of its usual Pacific storms, greatly exacerbating the State's ongoing drought.  Dipping through the central and eastern U.S., the jet allowed Arctic air, displaced by the warm Pacific inflow, to plunge southward, bringing frigid weather to the Heartland and freezing precipitation to the Coastal Plain.  After directing a series of storms across the Northeast, the jet stream took aim on Europe, lashing the west coast of England with high waves and flooding rains.  Even Sochi, Russia, the site of the Winter Olympics, has been a victim of the fickle jet; unusually warm air has hampered efforts to maintain ideal snow and ice conditions.

Fortunately, this pattern has begun to break down.  The Pacific inflow has shifted southward, dropping heavy snows on the Cascades and Sierra Nevada, and a more typical, west to east jet stream should put an end to Arctic outbreaks (at least for now).  Hopefully, its menacing effects in Europe will abate as well.

Black Scoters off Longboat Key

For the second consecutive winter, I have observed a flock of black scoters off Greer Beach, on the northwest coast of Longboat Key, Florida.  These ducks breed along inland lakes of Alaska, northwest Canada and the northern Canadian Maritimes; there they nest in clumps of tundra grass, raising 6 to 10 young.

Migrations occur primarily along the Pacific and Atlantic Coasts of North America though a fair number are encountered on the Great Lakes and on large reservoirs of the central U.S.  Most winter in coastal marine waters, from the Aleutians to the California Baja and from Newfoundland to the Carolinas; while some also winter along the northern Gulf Coast, I have not seen other reports of their presence off the beaches of South Florida.

Yesterday's flock numbered twelve scoters, including two adult males, easily recognized by the orange knobs on their upper bill.  The birds remained in a tight flock while feeding and flying; indeed, even their dives occurred in unison.  Black scoters feed primarily on small fish, aquatic invertebrates and, to a lesser degree, on aquatic grasses.  Hopefully, these fascinating birds will become regular winter residents along Longboat Key.

The Kuskokwim River

Second only to the Yukon among Alaska's Rivers, the Kuskokwim (which means slow-flowing) drains the remote southwest region of the State's mainland, far from the tourist sites and most populated areas.  Its North Fork rises along the northwest flank of the Alaska Range before angling southwestward to flow between that range and the Kuskokwim Mountains, to its north; the latter range angles northeast to southwest and has summits that are generally below 4000 feet.

After merging with its East and South Forks and several other tributaries, the Kuskokwim angles northwest to slice through the Kuskokwim Mountains, and then meanders across Alaska's vast Coastal Plain, coming within 50 miles of the Yukon River, to its north.  Resuming its southwestward journey, the Kuskokwim passes Bethel, the largest town along its course, and eventually empties into the Bering Sea within the Yukon Delta National Wildlife Refuge.

The primary channel of the Kuskokwim is 724 miles long while the North Fork, its longest tributary, is 250 miles long; together, they represent the longest free-flowing river in the United States.  While secondary and tertiary tributaries rise in high terrain, the entire course of the Kuskokwim and its North Fork runs below an elevation of 1600 feet.  Renowned for its fishing, this wide, braided river, like the Yukon, connects the varied ecosystems of Alaska, home to a fabulous diversity of wildlife.

Alaska's Collage of Terranes

As the Mesozoic Era dawned, 225 million years ago, only northern and northeastern Alaska were part of North America.  Since that time, numerous terranes and sub-terranes, have accreted to that primitive coast, producing the vast and varied landscape of present-day Alaska.

Many of these terranes, carried in on oceanic plates, were once part of other continents or sub-continents, having rifted away as new seaways opened.  Others formed as volcanic island arcs above subduction zones, either along the expanding coast of Alaska or elsewhere.  Still other terranes were composed of oceanic crust, trapped and lifted between colliding continental segments or scraped from the upper surface of a subducting oceanic plate.  Those terranes arriving from other regions of the globe were composed of rock much older than the sedimentary or volcanic rocks that formed along their margins at the time of accretion and possess fossils that provide clues to their site of origin. For example, the Alexander Terrane of southeastern Alaska contains Silurian rocks that harbor marine fossils also found in the northern Ural Mountains of Siberia, suggesting that the two land areas once bordered the same sea.

As the various terranes assembled, from the Triassic Period to the present day, the collisions lifted mountain ranges; on either side of these mountain corridors, downwarping of the crust produced basins that, over time, filled with erosional debris from the adjacent highlands.  In other areas, volcanism along subduction zones (which shifted southward with each new terrane accretion), produced volcanic ranges, basalt flows, igneous plutons, ash sediments and lava dikes that, today, are interspersed with the strata of the terranes.  Fault lines remain active between many of the terranes (triggering intermittent earthquakes) and volcanism continues to mold the coastline, especially along the Aleutian Chain.  Needless to say, the geology of Alaska is highly complex, a jumbled collage of strata that range in age from ancient Precambrian rock to Pleistocene gravels, that originated anywhere from the tropics to polar latitudes and that have since been lifted, folded, incised, buried and eroded by tectonic forces, streams and glaciers.

The Porcupine Caribou

Named for the Yukon River tributary that drains most of their range, the Porcupine Caribou Herd inhabits northeastern Alaska and the northern Yukon Territory of Canada. According to the last official count, in the summer of 2010, the herd is now composed of about 169,000 individuals, making this one of the most spectacular concentrations of migrant mammals on our planet.

After wintering in mountainous regions south and east of the Brooks Range, the Porcupine Caribou begin their spring migration in March, led by cows and yearlings (bulls and juveniles follow a few weeks later). Using three primary routes across the Brooks Range of Alaska and British Mountains of the northern Yukon, pregnant cows reach the North Slope by late May and calving begins, synchronized to reduce the impact of predation by wolves, grizzlies and golden eagles; the formation of nursery groups and the rapid development of calves (able to run within 24 hours) also serve to diminish loss of the newborns. As the bulls and juveniles arrive, the caribou assemble in huge herds, feeding on the nutritious tundra and moving about to escape hordes of mosquitoes.

By late July, the Porcupine herd begins to leave the vast tundra plain and heads to the northern foothills of the Brooks Range where they now endure biting flies (warble and nose-bot flies) that deposit larvae in their hide and nostrils, respectively. The fall migration ensues by late August and the 2-week rut occurs in October, as frenzied bulls forego eating to gather and impregnate their harem. While some of the herd remains within the Brooks and British Mountains, most head for the Richardson and Ogilvie Mountains of the Yukon Terrority, in the upper reaches of the Porcupine River. Their neighbors, the Central Arctic Caribou herd, numbering about 20,000 individuals, have a much shorter migration, wintering in the Brooks Range and summering on the Coastal Plain. Both herds are threatened by global warming and by human development across their territories, especially the ongoing political pressure to drill on the Arctic NWR.

Great Gray Owls

One of the least conspicuous birds in North America, the great gray owl inhabits the boreal forests of Alaska and Canada and the mountain forests of the Cascades, Northern Sierra Nevada and Northern Rockies; during the winter months, they may also be encountered in Minnesota and northern New England. Preferring dense, coniferous woodlands, they hunt primarily at night but become increasingly crepuscular or diurnal during the colder months of the year; it is then that they are most often observed, perched on a limb that overlooks a forest clearing. While this owl is seldom seen, its deep, resonant hoots often echo through remote northern forests.

Though great grays are our largest owls by length and wingspan (the latter may be up to 5 feet), they are not as heavy as great horned owls; their large head and prominant, ringed facial disc accentuate their size and make their yellow eyes appear to be small and closely spaced. Despite their size, great grays are not overly aggressive and feed primarily on small rodents (mice, voles, hares), grouse and songbirds.

Adult great gray owls have little to fear from natural predators (lynx are among their few adversaries) but their young (born in mid-late spring) may fall victim to goshawks, fishers, wolverines, lynx or bears. Indeed, the adults are more endangered by the activity of man, who drains the bogs and logs the forests that provide refuge to this ghost of the Great Northwoods.