Photo: New York Times

This is a continuation of the Everglades fire and the good and bad repercussions. Apparently some tragedies are not entirely tragic. They are still uncertain as to the fate of the Cape Sable Seaside Sparrows.

By DAMIEN CAVE

Published: May 23, 2008

The New York Times

REDLAND, Fla. — Rick Anderson, the fire management officer for Everglades National Park, stood in the burnt grass where the largest fire in 19 years began here last week and assessed the costs and benefits.

The fire, which was 70 percent under control on Thursday, has scorched about 40,000 acres, sent smoke over Miami and forced schools to close temporarily. And yet, it has also poured nutrients into the soil, killed nonnative plants and made it harder for hawks to prey on the endangered Cape Sable seaside sparrow.

Park officials said someone sparked the fire accidentally or by arson, but is the impact good or bad?

“Like so much here, it’s not just one thing,” said Mr. Anderson, who starts planned fires in addition to fighting those that are unwanted. He added, “Fire is our grizzly bear or our wolf: it has to be here.” Then he pointed toward a house in the distance. “But it can’t be over there.”

The Everglades has long faced the challenge of balancing humankind versus nature, and the latest fire is no exception. From its start in a beer-bottle strewn area on the park’s eastern edge, near both homes and the seaside sparrow’s habitat, the blaze has exemplified the struggle to revive a fragile ecosystem that abuts one of the nation’s most developed areas.

Many environmentalists here have described the fire as an indictment of the federal Everglades restoration plan, which after eight years has failed to seize enough water from nearby communities to rehydrate the so-called river of grass.

“This is exactly the area of the park where we should be having more water this time of year,” said Alan Farago, executive director of the Everglades Defense Council. “The park’s on fire, Florida Bay is a disaster, and we’re still fighting over getting enough water of the right quality.”

Mr. Anderson warned that more water alone would not have kept the Everglades from burning. With its wispy vegetation, dry season and high winds, “this place is built to burn,” he said. Even in an idealized Everglades, “there would still be fires,” he said.

But several scientists at the park said the perpetual lack of water had made the fire’s impact more severe. Indeed, the blaze burned 100 acres in just its first few hours, before sunrise on the morning of May 14. And from there it took off, racing along at speeds of up to 8 miles an hour, faster than most people can run.

Park officials initially figured the fire could be managed without affecting nearby neighborhoods because the winds were blowing west, into the park’s roughly one million acres. Mr. Anderson even considered allowing some extra acres to burn, as he often does with fires caused by lightning.

“The Everglades dies without fire,” he said, noting that the ash offers some of the only nutrients available. So his first thought was how to make the blaze serve the ecosystem. His second thought was how to keep the fire from the seaside sparrows’ nests.

Then on the afternoon of May 15, the winds shifted north and east, toward a prison on the park’s edge and the outer rings of South Miami-Dade County. Suddenly, the emphasis became people and property.

Miami-Dade firefighters began going door to door to make sure families knew the fire might be coming. Several hundred prisoners were evacuated, and a handful of schools closed temporarily or canceled outside recess because of smoke.

More than 200 firefighters worked up to 16-hour days to fight the blaze. At one point, park officials said they persuaded the South Florida Water Management District and the Army Corps of Engineers to push more water into the park. But it was not enough.

“Even with all the water they let in, it didn’t do much because the water levels were so low,” said David E. Hallac, chief of the biological resources branch. He pointed to a canal nearby that showed dry, crusty earth three feet down.

So eventually, officials turned to fire retardants, dropped near the park’s northeastern corner. It was a break with policy that park officials are hoping did only minimal damage because they were heavily diluted.

And a planned fire from a year ago also seems to have played a role in keeping the latest blaze from spreading to more residential areas. By denying the blaze fresh fuel, it helped firefighters keep the fire on one side of a road near the park’s boundary.

Inside that area on Thursday, scientists in yellow fireproof shirts carried clipboards and cameras to the clusters of trees where the park’s biodiversity is concentrated. Mr. Hallac and his team emerged with evidence of both life and death. The trees had been burned to a dry rust or dark black. Mr. Hallac said he saw a scorched turtle that might have survived had there been a puddle of water for it to hide in.

But a lizard also slid past him and green sprouts of grass could be seen in areas that had been on fire only a few days ago.

As helicopters with firefighters or water passed overhead, the scientists said they were still trying to figure out the mix of positive and negative consequences.

It was unclear how the seaside sparrow fared, and no one could say for sure whether the invasive plants that had been killed by the fire would return. Everglades National Park had once again been altered by man and was in the process of moving on.

“This thing is alive,” Mr. Anderson said of the park. “It’s always changing, and any change from outside kicks it another direction. This environment is dynamic as hell.”

Point Reyes has been termed the second foggiest place on the North American continent. There were numerous shipwrecks with not only loss of cargo, but of lives also. The building of a lighthouse was extremely important and was finished in 1870.

Lighthouses provide mariners some safety by warning them of rocky shores and reefs. They also help mariners navigate by indicating their location as ships travel along the coast. Mariners recognize lighthouses by their unique flash pattern. On days when it is too foggy to see the lighthouse, a fog signal is essential. Fog signals sound an identifying pattern to signal the location to the passing ships. Unfortunately, the combination of lighthouses and fog signals does not eliminate the tragedy of shipwrecks.

Because of this ongoing problem, a lifesaving station was established on the Great Beach north of the lighthouse in 1890. Men walked the beaches in four-hour shifts, watching for shipwrecks and the people who would need rescue from frigid waters and powerful currents. A new lifesaving station was opened in 1927 on Drakes Bay near Chimney Rock and was active until 1968. Today, it is a National Historic Landmark and can be viewed from the Chimney Rock Trail.

The lens in the Point Reyes Lighthouse is a "first order" Fresnel (fray-nel) lens, the largest size of Fresnel lens. Augustin Jean Fresnel of France revolutionized optics theories with his new lens design in 1823.

Before Fresnel developed this lens, lighthouses used mirrors to reflect light out to sea. The most effective lighthouses could only be seen eight to twelve miles away. After his invention, the brightest lighthouses could be seen all the way to the horizon, about twenty-four miles.

The Fresnel lens intensifies the light by bending (or refracting) and magnifying the source light through crystal prisms into concentrated beams. The Point Reyes lens is divided into twenty-four vertical panels, which direct the light into twenty-four individual beams. A counterweight and gears similar to those in a grandfather clock rotate the 6000-pound lens at a constant speed, one revolution every two minutes. This rotation makes the beams sweep over the ocean surface like the spokes of a wagon wheel, and creates the Point Reyes signature pattern of one flash every five seconds.

Keeping the lighthouse in working condition was a twenty-four hour job. The light was lit only between sunset and sunrise, but there was work to do all day long. The head keeper and three assistants shared the load in four six-hour shifts.

Every evening, a half-hour before sunset, a keeper walked down the wooden stairs to light the oil lamp, the lighthouse's source of illumination. Once the lamp was lit, the keeper wound the clockwork mechanism, lifting a 170 pound weight, which was attached to the clockwork mechanism by a hemp rope, nine feet off the floor. The earth's gravity would then pull the weight, through a small trap door, to the ground level 17 feet below. The clockwork mechanism was built to provide resistance so that it would take two hours and twenty minutes for the weight to descend the 17 feet. And as the weight descended and the clockwork mechanism's gears spun, the Fresnel lens would turn so that the light appeared to flash every five seconds. In addition to winding the clockwork mechanism every two-hours and twenty minutes throughout the night, the keeper had to keep the lamp wicks trimmed so that the light would burn steadily and efficiently, thus the nickname "wickie."

Daytime duties for the keepers included cleaning the lens, polishing the brass, stoking the steam-powered fog signal and making necessary repairs. At the end of each shift, the keeper trudged back up the wooden staircase. Sometimes the winds were so strong that he had to crawl on his hands and knees to keep from being knocked down. The highest wind speed recorded at Point Reyes was 133 M.P.H., and 60 M.P.H. winds are common.

The hard work, wind, fog and isolation at Point Reyes made this an undesirable post. Even so, one keeper stayed for about twenty-four years, a testament to his devotion and love of Point Reyes!

The lighthouse was replaced after 105 years of service. Today everything is automated as this is more cost effective. The lighthouse still stands in its original spot and can be toured while visiting Point Reyes National Seashore.

What is a sneaker wave and why are they potentially dangerous? A sneaker wave is an unexpectedly large wave, higher, stronger and reaching farther up the beach to levels far beyond where the normal waves reach. Beach goers, particularly children, can quickly be caught in the rip current and pulled out to deep water. If the person can not escape the current, they may drown. This has occurred numerous times at Point Reyes National Seashore beaches. Sneaker waves also have the ability to toss around large driftwood logs that may fall on a person, injuring or even killing them.

Even though the ocean may appear calm, there is still the potential for sneaker waves. Larger waves, moving fast, pick up smaller waves and carry them toward the beach. Some people erroneously think that sneaker waves can be predicted, i.e., every fourth or fifth wave, but in truth they are unpredictable. They can occur at any time, day or night, during incoming and outgoing tides, during storms and during sunny calm weather.

How to avoid sneaker waves:

Never turn your back on the surf. Stay at least thirty yards away from the water on beaches facing the open ocean, particularly the Great Beach (North and South beaches), McClures Beach and Kehoe Beach in Point Reyes. Watch out for sneaker waves.

Sneaker waves are often preceded by a sudden lowering of the water level. Supervise children at all times. Avoid slippery rocks. Rock outcrops can be slippery from mist, rain, or spray. Large waves can knock people off rock outcrops and severely injure them or knock them unconscious. Stay away from rocky areas, particularly during storms, high tide, or tidal changes.

Avoid logs and debris. Sneaker waves are strong enough to take the biggest log and toss it on you. Stay away from logs in surf or wet sand. Do not sit or stand on logs. Keep children away from logs and large debris.

Playing at the beach can be great fun, but it always pays to be cautious and be informed of potential dangers in the area you are visiting. Most Visitor Centers of national parks will have information about possible dangers in their area. Resorts should also be able to let you know about areas of caution.

In Yukon-Charley Rivers National Preserve there are several cabins available to the wandering backpacker where he or she can stay for the night free of charge, some of which were built by the brave souls that dared to make their leaving in rugged Alaska. One of these structures was built by a unique individual. It is uncertain whether all of his buildings are gone or if the NPS had rebuilt some of these. As of the date of this posting, I was unable to reach the park to ask for this information. Continue reading to learn more about James Taylor and no, it’s not the singer. more...

To learn more about the possibility of a volcanic eruption, we are going to look at Lassen Volcano National Park as our example. Before Mt. St. Helens erupted, Lassen was the last volcano to erupt in the Cascade Mountain range. more...

Mining techniques are generally divided into two categories: placer mining and lode mining. more...

Here are some interesting questions and answers about Devils Tower National Monument. This is a great place to get in some excellent rock climbing. To learn more about this unique place, check out Adventure-Crew.com at this link: Devils Tower

Is it part of an old volcano?- One scientific hypothesis states that Devils Tower is the neck of a small volcano.  Another theory says that it is part of a laccolith.  A third theory is that Devils Tower is a plutonic plug - an igneous intrusion that failed to reach the surface.

Is it hollow?- No!  You could compare it to a bunch of pencils held together by gravity.

What kind of rock is it? - Phonolite porphyry, it is similar in composition to granite but lacks quartz.  Phonolite refers to the ringing of the rock when a small slab is struck, and its ability to reflect sound.  Porphyry refers to its texture, large crystals of feldspar embedded in a mass of smaller crystals.

How often do the columns fall?- There have been no major falls since we have a history of it (200 years).

The peak visitation times are May through September.

With 80 Americans killed each year by lightning strikes, it pays to be informed of good safety tips. Keep reading to be prepared the next time you find yourself in an electrical storm or it finds you!  Corie Marks, Staff Writer

Lightning strikes the earth as often as 2,000 times an hour in the United States. Every year an average of 80 Americans are killed by lightning. Most deaths occur in the late summer, a time when thunderclouds boil over the horizon and when many people vacation out-of-doors.

On a hot summer day, heat rises from the ground and travels upward into the clear sky. As the air rises, it cools. Moisture in the air condenses, forming the ice crystals and water droplets that give shape to towering cumulonimbus clouds. These condensation particles cool and fall through the rising warmer air; they then warm and rise again as other particles fall, creating turbulent currents with speeds of up to 100 miles per hour. As the particles rush through the air, they lose or gain electrons, becoming positively or negatively charged. For reasons not clearly understood, the positively charged particles gather at the top of the cloud, while the negatively charged particles gather at the bottom.

As the cloud moves over the earth, its negatively charged underside induces a positive charge in the ground. It is this charge you experience when your hair stands on end; you may also hear humming or sizzling, or experience a tingling sensation. Tall objects may glow with a blue light known as St. Elmo’s Fire. These are all signs that a lightning strike is immanent.

A lightning bolt heats the air within its channel to temperatures in excess of 50,000 degrees F. The air explodes, creating a supersonic shock wave. As the wave slows to the speed of sound, you hear thunder. Because sound travels at a rate of roughly 1,000 feet per second, you can determine your distance from the strike by counting the seconds between the lightning flash and when you hear thunder. Dividing by 5 gives the distance in miles. Although this may help you determine your margin of safety, it can be difficult to be sure that the thunder you hear originates from the lightning you saw. Remember too that while the sky may be blue directly above you, lightning can strike several miles from its source cloud. Whenever you hear thunder, you are close enough to be hit by lightning. Lightning danger persists as long as 30 minutes after you hear the last thunderclap.

When lightning strikes a tree, the sap flashes into steam and the tree explodes. When lightning strikes a human being, the effects are less dramatic, but still potentially fatal. Victims of lightning strikes are almost always knocked unconscious; intense muscle contractions often throw them to the ground, causing broken bones or other injuries. Burns may be internal or external, light or severe. Most lightning deaths occur because the lightning interrupts the electrical impulse that regulates the heartbeat. The result is cardiac arrest.

Lightning has been known to strike the same place, and even the same person, more than once. Your best option is to avoid the first strike.

Outdoors

Avoid exposed areas like mountaintops and scenic overlooks where you are the tallest object.

Get out of and away from open water.

Put down umbrellas, golf clubs, and other objects that may act as lightning rods.

If at all possible, take shelter in an enclosed building or in an all-metal vehicle with the windows rolled up. Avoid contact with metal components of the vehicle. Convertibles, small sheds in open areas, and open-sided picnic shelters will not protect you from lightning.

If you cannot reach a car or building, stay away from metal conductors such as fence lines, metal pipes, and rails which may carry lightning from a distance.

Do not stand beneath natural lightning rods such as tall trees. In a forest, seek shelter in groves of shorter trees or in low-lying areas.

Move to a low place, such as a valley, but be alert for the possibility of flooding.

Caves and crevices may not be safe shelters—moisture in their walls and floors can conduct electricity.

If no shelter is available, do not lie flat on the ground.  Crouch with your feet together and your hands over your ears to minimize hearing damage from thunderclaps. Stay at least 15 feet away from other people so that lightning does not jump between you.

Indoors

During electrical storms, avoid contact with electrical wiring, plumbing, or telephone lines, which may act as conduits for lightning striking the house. This is not a good time to take a bath or a shower.

Victims of lightning strikes do not carry an electric charge and should be assisted immediately. If the victim is not breathing, provide mouth-to-mouth resuscitation; if their heart has stopped beating, administer CPR. For other victims, check for and treat burns, and monitor for shock. All victims of lightning strike require advanced medical attention.

Sources:NPS

If you’ve read enough of our park pages, you will notice that Giardia warnings are fairly frequent in the national parks. So what in the world is it?

Giardia is a parasite found in contaminated water. It actually has two forms: a dormant cyst and a trophozite, the disease-forming one. Since the cysts are hardy little buggers, they can survive even very cold water. When someone ingests the cyst, it changes into a trophozite, attaching itself on the intestinal wall and living off the “fat-of-the-land”. Now some of these are carried out with feces, but they often end up contaminating other water sources, thus spreading the organism. The treatment is antibiotics.

The symptoms can take from 7-10 days to show up and usually by that time, the victim is already back home. The victim usually has flu like symptoms which make them forget that they were out in the wilderness and could have possibly ingested contaminated water. Also, not everyone gets sick from the cysts, confusing the diagnosis even further. You can usually expect explosive diarrhea, bloating and cramps, horrible gas, severe vomiting, weight loss, and loss of appetite. If not treated, you could end up with long-term gastrointestinal problems.

The best bet is prevention. Treat all water sources by boiling for at least one minute, using water purification systems or chemical treatments. Follow all rules about distance from water sources for camping and stock use. When possible, bring your own water.

What is archaeology? What does it have to do with the national parks? Archaeology is a science dedicated to improving our understanding of our collective human past through study of physical remains left behind. Artifacts are perhaps the best known unit of study. These include all portable objects (from stone tools to forks) that have been made, modified or used by human beings. Features are objects, such as cooking hearths, rock walls, or storage pits, that cannot be removed without destroying their basic integrity. Clustered concentrations of artifacts and features on the landscape typically are defined as archaeological sites. The patterned configuration of sites with their associated features and artifacts provides a valuable archaeological record of long-term human use of a place –a record no less important at Mount Rainier than at parks, such as Mesa Verde in Colorado or Chaco Canyon in New Mexico, better known for their spectacular archaeological remains.

Although artifacts and features may be studied and appreciated in isolation from one another, it is their context --their spatial and temporal relationship to one another, to geological features in the ground, and to other sites across the landscape-- that provides the most meaningful information about the past and gives the objects and sites their greatest scientific value. Archaeological remains at Mount Rainier or other parks represent a uniquely important record of long-term human activity in the park. So long as it remains intact, that record provides a means to develop a better understanding of ancient peoples’ ways of life, how the mountain or area fit into broader regional subsistence and settlement patterns, and how those patterns changed through time.

Charred bone and plant remains found in archeological sites, for example, provide information about animals and plants hunted and gathered long before they were documented in historical records. These remains can indicate the age of the site, and the seasons in which people visited that location. In addition, they can answer questions about past habitat conditions and animal species inhabiting park landscapes.

The manufacture of stone tools and the debris can tell us about the technology of native peoples and how they organized their hunting and gathering activities. Site distribution patterns inform us as to how they allocated use of space. Even more recent archaeological remains such as old cans, bottles, machinery and other abandoned objects can tell us about aspects of the lives of local people which were never written down in historical documents.

Preservation of both artifacts and their context is critical because the archeological record is a finite, fragile and non-renewable resource. Archaeologists are ever mindful of the fact that collection of objects through excavation or surface collection is a destructive activity. Once you remove an object from its original context, you can't recreate its relationship to other objects and it loses most of its scientific value.

The archeological record is somewhat like having only a single copy of a history book covering large expanses of time. Damaging or removing parts of an archeological site is like tearing a page out of that book and destroying it. Once destroyed, all the information on that page is lost and a significant part of the human story of the park lands is gone forever.

Because archeological resources are so fragile and unique, a number of federal laws have been passed to protect them.

• The Archeological Resources Protection Act (ARPA) makes it a crime to disturb or remove archeological resources from federal lands without a permit.

• The Native American Graves Protection and Repatriation Act (NAGPRA) does the same for the graves and human remains of Native Americans.

• The National Historic Preservation Act (NHPA) requires all federal land-managing agencies to consider the effects of their development and maintenance activities on historic properties, which include archeological sites, so that they do not inadvertently disturb or destroy the archeological sites under their care. The act also requires federal agencies to inventory, evaluate, and manage historic properties under their jurisdiction, and to nominate eligible properties to the National Register of Historic Places.

Remember this when you visit the parks and never remove or disturb artifacts that you may come across. If you think it may be something that has not yet been uncovered, tell the park officials. You may just have helped discover a new archeological site!

Avalanches are real dangers in snowy mountainous areas. Familiarize yourself with what the danger levels mean in area forecasts. Learn the terrain and weather factors that influence avalanche danger. Put that knowledge to good use when selecting the route you will travel, or even if you will travel. Knowledge can help you avoid being caught by a snow avalanche and will help you survive if you are caught. What does the danger level indicate about snow conditions?  What should skiers, snowboarders, and others know before leaving?

LOW: The snow is generally stable with isolated areas of instability. Natural avalanches are very unlikely. Human triggered avalanches are unlikely. Travel is generally safe. Normal caution is advised.

MODERATE: Unstable snow slabs are possible on steep terrain. Natural avalanches are unlikely. Human triggered avalanches are possible. Use caution in steeper terrain on certain slope aspects.

CONSIDERABLE: Unstable snow slabs are probable on steep terrain. Natural avalanches are possible. Human triggered avalanches are probable. Be increasingly cautious in steeper terrain.

HIGH: Unstable snow slabs are likely on a variety of aspects and slope angles. Natural and human triggered avalanches are likely. Travel is not recommended. Safest travel will be on windward ridges and low angle slopes without steeper terrain above.

EXTREME: Extremely unstable snow slabs certain on most aspects and slope angles. Large destructive avalanches possible. Widespread natural or human triggered avalanches are certain. Travel in avalanche terrain should be avoided and travel confined to low angle terrain well away from avalanche path run-outs.

The safest routes are on ridge tops and slightly on the windward side of ridge lines, away from cornices. If you can’t travel on ridges, the next safest routes are out in the valleys, far from the bottom of slopes. About 80% of all snow avalanches occur during, and shortly after, storms. Snow falling at the rate of 1" per hour, or more, rapidly increases avalanche danger. Storms starting with low temperatures and dry snow, followed by rising temperatures and wetter snow, are more likely to cause avalanches. Rainstorms or spring weather with warm winds and cloudy nights can warm the snow cover resulting in wet snow avalanches. Wet snow avalanches are more likely on south slopes and under exposed rock.

The terrain can affect conditions of avalanches. Large rocks, trees and heavy shrubs help anchor snow. Dangerous slab avalanches are more likely to occur on convex slopes. Leeward slopes are dangerous because windblown snows add depth and create unconsolidated slabs. South facing slopes are most dangerous during springtime. Snow avalanches are most common on slopes of 30 to 45 degrees.

Treat avalanche danger with utmost caution. Taking a route around an avalanche track is advisable under any circumstance, but becomes essential during the more hazardous conditions. Consider the value of having everyone in your group wear an avalanche transceiver (an electronic device whose beeps help locate buried victims) and be familiar with its use. A readily available shovel and avalanche probe can also allow you, as a survivor, to rescue a victim.

If you are caught in an avalanche remember these tips. Discard all equipment. Make swimming motions. Try to stay on top of the snow and work your way to the side of the avalanche. Before coming to a stop, get your hands in front of your face and try to make an air space in the snow. Try to remain calm.

If you are the survivor: Mark the place where you last saw the victim. Search directly down slope below the last seen point. If the victim is not on the surface, scuff or probe the snow with a ski pole or stick. Keep searching! Do not leave to go for help unless help is only a few minutes away. Only 50% of victims survive after one hour of burial.

To be the best prepared you can be for heading into avalanche territory, take a course in avalanche survival and preparedness before you arrive. The more knowledge you have, the better your chances of survival are in the event of encountering an avalanche on your climbing or backpacking trip.

The theory of plate tectonics helps explain the distribution and occurrence of volcanoes and earthquakes around the world. The surface of the earth consists of eight major "plates" and about a dozen smaller ones. Each plate is about 50 miles thick and consists of a relatively shallow upper layer that deforms by either brittle breaking or elastic bending. A second deeper layer of the plate yields plastically, while an even lower layer is like a viscous fluid. It is on the lower viscous layer that the entire plate slides.

Similar to a piece of paper floating on water, the plate can move about on the surface without distorting. The earth's plates tend to be internally rigid and interact mostly at their edges. Most earthquake activity is a result of a difference in motion between the adjacent plate boundaries. The plates move relative to each other at rates that range from 1/2 inch up to about 5 inches per year. Although these rates are slow by human standards, they are extremely rapid by geologic standards. For example, a motion of 2 inches per year adds up to 30 miles in one million years. And some plates have been in continuous motion for 100 million years.

Deep within the oceans are a series of nearly continuous submarine mountain ranges. These great submarine ridges are marked by earthquakes and submarine volcanism. It is along the mid-ocean ridges that sea floor spreading occurs. Hot material from deep within the mantle rises up continually, adding new material to the earth's crust. The size of the earth is not expanding, so this new material must be consumed someplace else.

At trenches where plates collide, one plate is forced beneath the other in what is called a "subduction zone". As the subducted plate is forced to descend, it slips and slides, generating earthquakes. Tilting downward, the plate will plunge into the mantle to depths of 450 miles before the crustal material becomes molten. Being less dense than the mantle, the molten crustal material rises toward the earth's surface where much of it erupts as lava and builds up volcanic peaks. Typically, a belt of volcanoes lies above the inclined earthquake zone.

The Aleutian Island subduction zone lies about 30 miles beneath the surface of the Kenai Peninsula, but abruptly dives to depths greater than 65 miles beneath the western edge of Cook Inlet, and to a depth greater than 100 miles beneath Redoubt and Iliamna volcanoes at the eastern end of the Lake Clark National Park and Preserve. Here, the Pacific Ocean plate is being pushed beneath the North American Plate. The subduction along the Aleutian trench has been going on for the last three million years at a rate of 2.6 inches per year, and earthquakes and volcanoes are prevalent. Thirteen earthquakes of magnitude 5-6 on the Richter scale have occurred in the area since 1972, mostly at depths of 55-110 miles beneath Chinitna Bay and Tuxedni Bay. Strong earthquakes and volcanic eruptions can be expected to continue in the eastern part of the park as the Pacific plate continues to dive beneath the North American plate.

Within the Lake Clark region itself there are four active (and three of the tallest) volcanoes. Mount Spurr, at 11,070 feet, lies just north of the park. Mount Redoubt, at 10,197 feet, and Mount Iliamna, at 10,016 feet, are both located in the park. To the south of the park lies Saint Augustine Island.

Mount Spurr erupted on July 9, 1953. That spectacular explosion sent a cloud of ash up 70,000 feet in just 40 minutes, according to U.S. Air Force pilots who were flying in the area when the eruption occurred. Ash dropped on Anchorage, only 80 miles east, with a total accumulation of 1/8 to 1/4 inch. The most recent eruptions took place on June 17, August 18, and September 16-17, 1992, with ash plumes reaching up to 30,000 feet, darkening the skies, and dusting Anchorage with ash once again.

The other volcanoes have also been active. Gases are frequently seen venting near the summit of Mount Iliamna, but there are no documented reports of recent eruptions, according to the USGS. Redoubt Volcano, just north of Iliamna, awakened December 14, 1989, dumping varying amounts of ash primarily north and west of the volcano and lightly dusting Anchorage and Kenai. Periodic eruptions continued throughout the week before Christmas, disrupting holiday air traffic. Eruptions continued until April 21, 1990. Until 1989, Redoubt had not erupted since 1966.

Like precarious stepping stones, the Aleutian Islands span the seas between the New and Old worlds - reaching westward from the Alaska Peninsula to within 500 miles of the Asian peninsula of Kamchatka. Situated between the Bering Sea and the Pacific Ocean, along the seam of the Pacific and American geologic plates, this 1,100 mile long archipelago has been, and continues to be, the focus of climatic and tectonic events. The Aleutian Chain's foundation of shifting geologic plates results in active volcanism and earthquakes - the birth processes of the islands themselves. The Aleutians betray their violent origins in their rugged landscape: mountainous terrain, precipitous coastlines, and black sand beaches. It is thought that at least twenty-six of the Chain's fifty-seven volcanoes have erupted within the past two centuries.

The 15 active volcanoes that line the Shelikof Strait make Katmai National Park and Preserve one of the world's most active volcanic centers today.  These Aleutian Range volcanoes are pipelines into the fiery cauldron that underlies Alaska's southern coast and extends down both Pacific Ocean shores--the so called Pacific Ring of Fire.  This Ring of Fire boasts more than four times more volcanic eruptions above sea level than any other region in historic times.

Nearly 10 percent of these more than 400 eruptions have occurred in Alaska; less than two percent in the rest of North America. The Ring of Fire marks edges where crustal plates bump against each other.  Superimposing a map of earthquake activity over a map of active volcanoes creates a massed record of violent earth changes ringing the Pacific Ocean from southern South America around through the Indonesian archipelago.

The Aniakchak Caldera is the result of a series of eruptions, the latest in 1931 that took place in Aniakchak National Monument and Preserve. Nearly six miles in diameter and covering some ten square miles, it is one of the finest examples of dry caldera in the world. Aniakchak’s' outer slopes are characterized as having sparse vegetation, barren ash flows, precipitous cliffs, and tilted rock strata. The interior of the caldera contains examples of almost every kind of volcanic feature: lava flows, areas of unusually high ground temperature, cinder cones, a lava plug, warm springs, explosion pits, and layers of volcanic and sedimentary rocks exposed by volcanic action. Vent Mountain, one of the cinder cones, is unusually high at 2,200 feet above the caldera floor. Cinder cones rarely exceed 1,000 feet in height. In the top of the Vent there is a crater about 2,000 feet in diameter. Other cinder cones in the caldera are over 200 feet high. The 1931 volcanic eruption, which probably took place in the southwestern section near Half Cone, added to the ash blanket in the vicinity of the volcano. Since 1931, the volcano has not been known to be active, though a U.S. Geological Survey researcher found areas of high-ground temperatures in the western portion of the caldera. This, plus the warm springs that are feeding Surprise Lake, indicate potential for future volcanic activity.

The event which heralded the doom of Mt. Mazama almost 7,000 years ago, and the beginning of Crater Lake, was the opening of a vent somewhere on the north side of the mountain. A column of ash and pumice was sent up by the volcano, creating a blanket of debris 20 feet thick in places. As the pressure of the underground magma grew, a series of other vents around the mountain opened up. Enormous quantities of pyroclastic, or molten rock composed of pumice, material were released. These lava flows traveled up to 25 miles beyond the base of the volcano. As the volcano emptied itself of molten rock, an empty chamber was left underground. The mass of the mountain collapsed in on this void within a matter of days after the eruption. What was left, a 4,000 foot deep caldera and a myriad of other geologic formations, have awed and inspired people for generations. Following the collapse of Mount Mazama, lava poured into the caldera even as the lake began to rise. Today, a small volcanic island, Wizard Island, appears on the west side of the lake. This cinder cone rises 760 feet (233 meters) above the lake and is surrounded by black volcanic lava blocks. A small crater, 300 feet (90 meters) across and 90 feet (27 meters) deep, rests on the summit. The crater is filled by snow during the winter months, but remains dry during the summer.

Mount St. Helens erupted at 8:32 Sunday morning, May 18, 1980. Shaken by an earthquake measuring 5.1 on the Richter scale, the north face of this tall symmetrical mountain collapsed in a massive rock debris avalanche. Nearly 150 square miles of forest was blown over or left dead and standing. At the same time a mushroom-shaped column of ash rose thousands of feet skyward and drifted downwind, turning day into night as dark, gray ash fell over eastern Washington and beyond-to Portland, OR 45 miles away, and 16 hours later, to central Colorado. The hot gas and magma melted the snow and ice that covered the volcano. The resulting floodwater mixed with the rock and debris to create concrete-like mudflows that scoured river valleys surrounding the mountain resulting in the largest landslide in recorded history. The eruption lasted 9 hours, but Mount St. Helens and the surrounding landscape were dramatically changed within moments.

The most isolated major island group on earth, the Hawaiian archipelago is 2400 miles (3862 km) from the nearest continent and has never had connection to any other land mass. They were formed as the Pacific Plate moved across a volcanic “hot spot” within the earth’s mantle. Hawaii Volcanoes National Park encompasses diverse environments that range from sea level to the summit of the earth's most massive volcano, Mauna Loa at 13,677 feet. Kilauea, the world's most active volcano, offers scientists insights on the birth of the Hawaiian Islands and visitors views of dramatic volcanic landscapes. Haleakala National Park is renowned for its inspiring volcanic landscapes. These amazing landscapes result from the constant clash of the constructive force of volcanism and the destructive forces of erosion. Haleakala is a shield volcano that has been above the ocean surface for about 1.5 million years. Haleakala is considered an active volcano and is monitored remotely through equipment which sends information to the Hawaii Volcanoes Observatory on the Island of Hawaii.