B.C. rocked by blasts in the past

Volcanic potential: Province has experienced at least 60 significant eruptions over 10,000 years

On a mild summer evening 241 years ago, the ailing and exhausted crew of a small Spanish schooner dropped anchor in a tranquil bay near what’s now the border of northern B.C. and Alaska.

Huge seas had pounded the tiny Sonora, barely the size of a small racing yacht. One giant wave rolled the vessel, injuring sailors on deck and aloft. So many were hurt and ill that under sail the captain had to man the bilge pump himself.

This was an “off-the-books” expedition of discovery undertaken by a couple of insubordinate lieutenants. They had conspired to defy their commander. When he turned back to Mexico, they sailed north into uncharted waters.

Among the fascinating accounts from that 1775 journey is a diary reference to that night at anchor in mid-August, their sailor’s rest interrupted by a blast of heat and light from the mainland. The ship’s chaplain, Padre Miguel de la Campa, said the heat was so intense the crew “suffered” from it and the horizon was illuminated by “Great flames which issued from four or five mouths of a volcano and at night time lit up the whole district, rendering everything visible.”

Skeptics say they saw forest fires.

It seems unlikely seasoned observers would fail to know the difference. And wind blows toward forest fires, not away from them as it does from volcanic blasts. Furthermore, this observation coincides, more or less, with the known eruption of the Tseax Cone in the Nass Valley.

The poisonous gases, ash, lava flows and flooding from Tseax killed about 2,000 people in several Nisga’a villages. Which suggests the chaplain’s note corroborates Nisga’a oral histories that establish the worst verifiable natural human disaster in Canadian history was a volcanic eruption.

Lava beds from that eruption are now a tourist attraction — a tribal park bisected by the Nisga’a Highway between Terrace and New Aiyansh.

So what’s that account — first read haltingly in Spanish years ago and which sprang to mind with Sunday’s abrupt volcanic eruption of Mount Pavlof in Alaska’s Aleutian Islands — got to do with life in 21st-century Metro?

Well, human lives are brief. The geological time frame is long.

What’s relatively recent in one frame of reference seems unimaginably distant, even forgettable, in another. Yet, like it or not, we live in a shuddering, unstable place that is prone to volcanic eruptions, some of them doozies.

There have been at least 60 significant eruptions — more probably hundreds — within B.C. since humans began settling here about 10,000 years ago. Eighteen occurred in the arc of mountains that extends from Lillooet to Mount Baker, which shimmers over Vancouver like an iconic postcard image of the region’s beauty.

So perhaps it’s worth occasionally contemplating what brackets the Fraser Valley, where more than half the province’s population now lives.

Mount Meager, near Pemberton, last erupted around the time Alexander the Great was conquering Persia. It blew up like Mount St. Helens did May 18, 1980.

Torrents of molten rock and superheated gas went racing down surrounding valleys at speeds of up to 700 km/h. Thick layers of ash blanketed southern Alberta, 530 kilometres to the east.

The snow-clad volcanic cone of Mount Cayley towers over the Squamish and Cheakamus River about 93 kilometres north of downtown Vancouver. Lava from its sister cone of Mount Garibaldi near Whistler flowed to the outskirts of what’s now

Mount Meager, near P em ber ton, last erupted around the time Alexander the Great was conquering Persia. ...Torrents of molten rock and super heated gas went racing down surrounding valleys at speeds of up to 700km/h.

Squamish. Mount Baker, of course, is most obvious. It’s been active half a dozen times since Europeans arrived on the south coast. People in Victoria watched fiery eruptions in the mid-1800s. It began venting gas and steam again in the mid-1970s and still does.

The biggest concern for Mount Baker would be sudden thermal activity that released either fast-moving debris torrents like rivers of wet cement that could roar down valleys into the upper Fraser Valley or north of Bellingham or, worse, an explosive eruption like that of Mount St. Helens, which released pyroclastic flows of molten rock and superheated gas.

And Mount St. Helens was a pipsqueak. When Mount Mazama, part of the same volcanic complex, exploded in Oregon about 7,000 years ago, it vertically ejected 40 cubic kilometres of rock.

All worth a moment of contemplation when we hear of another volcanic episode somewhere in the unstable, fractured ring of fire and earthquake we call home, our brief lives lived in brief tranquillity — we hope — framed somewhere between catastrophe and cataclysm.