By Don Elzer
Some surprising events continue
to occur in the British Columbia interior that places us on center stage as we see our planet transforming as a result of environmental changes.
By the time the mountain pine beetle infestation is over, scientists estimate the beetle will have been responsible for the release of 990 million tonnes of carbon dioxide, or 270 million tonnes of carbon. The figures include the amount of carbon the dead trees are no longer taking up as well as the carbon released as they decay.
The tiny insect has transformed British Columbia's vast pine forests into a major source of greenhouse gases, federal scientists say.
By the time the unprecedented infestation ends, the rice-sized beetles will have killed so many trees an extra billion tonnes of carbon dioxide will be wafting through the atmosphere, researchers from the Canadian Forest Service reported recently in the journal Nature.
According to one of the authors of the report, Werner Kurz that is five times the annual emissions from all the cars, trucks, trains and planes in Canada, and will impact the planet far beyond the B.C.’s border.
Forests, along with oceans and grasslands, are critical sinks that soak up carbon dioxide from the atmosphere. Carbon dioxide is one of major heat-trapping gas linked to climate change.
"This piece of real estate is no longer contributing to the uptake," Mr. Kurz says of B.C.'s central interior forests. "To the contrary, it is currently a net source." This is because dead trees release carbon as they rot and burn.
Mr. Kurz and his colleagues at the Pacific Forestry Centre say B.C.'s beetle infestation is of "unprecedented scale and severity" and an order of magnitude larger and more severe than any other outbreak on record.
The study in Nature focuses on the B.C. outbreak that took hold in 1990s and includes several factors converged to set what Kurz describes as a "buffet" for the ravenous beetles.
Large fires had swept across the western provinces and states in the late 1800s and early 1900s, making way for vast pine forests, however a century of fire suppression allowed the forest to reach a greater age, over a greater area. As temperatures in the 1990s began to climb, putting an end to the severe winter cold snaps that used to keep the pine beetle in check.
"Now you have a beetle that is able to go farther north and to higher elevation," said Kurz. After the beetle bores under the bark and into the wood below, the trees' green needles turn red and eventually drop off, creating a serious fire hazard.
The outbreak has been a disaster for B.C. It is estimated more than 435 million cubic metres of timber has been lost. Many communities, fishing lodges and parks are now in the midst of dead forests that can stretch hundreds of kilometres.
Today, with huge dead forests and a warming climate, more than ever, we are under the threat of further emissions as a result of potentially many forest fires.
B.C.'s forests and wildlands cover over 94 million hectares (nearly a million square kilometres) and are the most diverse in Canada. Confronted by an average of 2,000 wildfires each year, highly trained fire crews are successful in containing 92 percent of all wildfires in B.C. within the first 24-hours of discovery.
We can only hope that such a success rate can be sustained.
While there is much that we do understand about our own negligence in starting fires, there’s also much that we don’t understand about how our environment and climate is changing, and how those changes might impact the threat and behavior of wildfires.
Now in the middle of a dead forest the size of New Brunswick there is a little known and strange event that is surfacing that is quite surprising and still remains a mystery.
On Wednesday October 10, 2007, the first of a swarm of small earthquakes was recorded by seismic monitoring equipment in place in the upper Baezaeko River region, about 100 km west of Quesnel. Eight microearthquakes of magnitude 2-3 occurred on October 10 and 11, and more than 100 tremors of less than magnitude 2 had occurred between October 10 and October 18.
This steady rumble is believed to be volcanic activity.
Volcanologist Catherine Hickson told the Prince George Citizen that they're an indication of magma, or liquid rock, pooling in a weak spot about 25 km. below the earth's surface but may not lead to an actual eruption.
When an eruption is looming, she said the intensity of the readings becomes much larger, about 4.0 on the Richter scale.
If one does occur, it's expected to be like the kind seen in Hawaii, namely lava flows with fire fountains that affect a relatively small area of a few square kilometres, although it could spark a forest fire in the tinder-dry region.
Such a minor volcanic event would be an amazing occurrence, however under the present circumstances the possible impacts would have been unimaginable a mere decade ago.
The activity has been detected about 20 km west of the Nazko Cone, a small, cinder-style volcano that last erupted 7,200 years ago. Located about 75 km. west of Quesnel, the Nazko Cone is the easternmost volcano on the Anahim volcanic belt, which stretches about 600 km. west to just north of Vancouver Island.
The small tree-covered cone rises 120 m above the Chilcotin-Nechako Plateau and rests on glacial till. It was formed in three episodes of activity, the first of which took place during the Pleistocene interglacial stage about 340,000 years ago. The second stage erupted beneath the Cordilleran Ice Sheet during the Pleistocene. Its last eruption produced two small lava flows that traveled 1 km to the west, along with a blanket of volcanic ash that extends several km to the north and east of the cone.
The volcano has been dormant for about 7000 years, but now present seismic activity is believed to be the upwelling of magma because the area is not close to any faults or tectonic plate boundaries. This is the first indication of potential volcanic activity in Canada since around 1830 to 1850 when activity occurred in northwestern British Columbia.
It’s important to realize that based on the number and size of the seismic events, there is no evidence at this time to suggest that a volcanic eruption is likely. It is possible that magma intruding at depth may stall without immediately rising towards the earth’s surface, and swarms of small magmatic earthquakes may occur at volcanoes without being followed by eruptive activity.
But if magma were to ascend towards the surface in the Nazko region, it is anticipated that the size and number of earthquakes would increase significantly, providing a warning in the very unlikely event of an eruption. If an eruption were to occur, scientists believe that it would be a small cinder cone building event, similar to the Nazko eruption that took place about 7000 years ago.
Scientists at the Geological Survey of Canada surmise that this last eruption at Nazko cone may have started forest fires because charcoal is found within the tephra layer.
It’s believed an ash cloud that may occur would be minor, however there is yet to be any scientific examination of risks and impacts that may occur if the volcanic activity sets fires that grow as a result of a tinder dry and dead pine forest.
It’s probably considered a slim chance of happening, but still, we do have Mount St. Helen’s in our recent history, and this year, we will more than likely surpass the 40 earthquakes reported in Canada during 2007, and most of the quakes occurring this year are within the BC interior and north coast.
We are learning everyday that we know so little about what causes our Earth to change, and how both humans and natural occurrences contribute to those changes.
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Don Elzer writes and comments about travel, current affairs and the natural world. He is the Director of the Wildcraft Forest Ecomuseum and Bearfoot Canada and is the editor of The Monster Guide which can be found at www.themonsterguide.com
He can also be reached by email at: treks@uniserve.com
