March 2010

Monthly Archive

Driving through spring

Posted by on 21 Mar 2010 | Tagged as: trip preparation

On the road

Here in California we find green grass, chirping birds, blooming flowers, and a lot of cars. I’ve enjoyed teaching Katmai what flowers and birds are, but the traffic can be a little overwhelming. I grew up in Seattle, but it’s easy to become “unadjusted” after awhile (and I never owned a car there). Coming from Seldovia, I sometimes forget just how many people live in the rest of the country. I hope they all come to our talks.

On the plane

We had a few events in Washington (including a great one at the Olympia Library!), but the main point of this tour is to hit spots we didn’t visit last time, so we’re here in the Bay Area now, staying with some good friends in Davis, and gearing up for four presentations over the next four days. It’s been a long time since I did a big road trip. I’ve never really been a big fan of car trips – sure you can see some stuff out the window, but it’s kind of mind-numbing as well. But my nightmares about bringing Katmai along are so far not coming true – it takes a constant effort, but he’s been fairly easy to entertain.

It’s challenging enough organizing the logistics of a tour like this from home, even more so to line up straggling details on the road. But after nearly every option fell through, we finally did figure out an event in Bozeman! on April 5. Of course now Hig is going and worrying that we’ll have too many folks show up, which I think would be a fine problem to have.

Giving the talk in Olympia – photo by Richard Hoagland

Visiting spring and family

Katmai drives too

A Long Trek Home drives the western US

Posted by on 15 Mar 2010 | Tagged as: book, events

Leaving the land of blowing snow, we have entered the realm of flowers, leaves, and visible ground. It’s spring in Seattle, and we’re here kicking off another book tour! We had an event on Bainbridge Island yesterday, and we’ll soon be picking up a rental car and heading South – next stop Olympia, WA

View A Long Trek Home – Spring 2010 book tour in a larger map

Ironically enough, for a book in which we spent an entire year without taking any form of motorized transport, we’ll be doing this tour in a great big driving loop around the western US (walking seemed a little slow for our purposes this time). We’ll be hitting cities in Washington, northern California, Utah, Colorado, and Montana (see map above). Do you live in one of these places? Do you know someone who lives in one of these places? I assure you that we have an awesome slideshow, and any help getting the word out is greatly appreciated!

You can click on the pips on the map, or see the schedule on the Book page – where you can get specific dates and times, and download posters to stick up in your town. (And if you’re not in one of these places, you can order signed books there as well, or get unsigned ones from Amazon). You can also get event details on A Long Trek Home’s Facebook Page.

I’m already nervous about whether it was a crazy idea to take a 13 month old on a month-long road trip. Please help spread the word and help us make this worth it!

Here’s a teaser in the form of a brief excerpt from the beginning of winter, in one of the journey’s more difficult sections. It seems more appropriate to Seldovia’s blowing snow than Seattle’s calm sun, but here you go…

“Wind wears on you. At times, it felt as though the world would never stop
howling—its shrieks penetrating every last corner of my thoughts. By the
third storm in a week, all I wanted was to turn off my ears—to curl up and
hide. Rain blew, sheeting across the pools of ice that lay in the low spots
between each dune. Even when we were standing still, the wind blew us
forward. We slid and spun, unable to stop without falling down or waiting
to hit a spot of sand.

We called it Desolate Bar. Wind howled, rain spattered, and nothing
but a small patch of dunes rose above the flat sand and the water of the
Copper River Delta. Five miles away, we could see a dim outline of trees
on a distant shore. In between, there were only channels, tide flats, and
ocean—flat and grey to the edge of the earth. Aside from the beach grass,
we were the only living species on our island of sand and ice—miniscule
specks in an enormous landscape. It felt as though we were standing in the
middle of the ocean. The storm raged around us, churning the delta into
a frothing chop we couldn’t hope to paddle. We couldn’t go anywhere. It
was a forsaken world.”

And here’s the blurb from the back of the book, A Long Trek Home: 4,000 Miles by Boot, Raft, and Ski:

From the Puget Sound to the Bering Sea

Four thousand miles along the edge of the Pacific

A world reduced to just two small packs and the next 100 yards…

In June 2007, Erin McKittrick and her husband, Hig, left Seattle for the Aleutian Islands, traveling solely by human power through some of the most rugged terrain in the world. This book tells the story of their unprecedented trek along the northwest coast and their encounters with pelting rains, ferocious winds, blizzards, and bears, as well as with the tiny communities that dot this wild region.

An epic wilderness adventure, their journey is also one of learning and discovery. Erin and Hig set out with a desire to better understand the interplay between human communities, ecosystems, and natural resources along their route. They pass through clear cuts, mining areas, and streams with declining wilds salmon populations. By taking each mile step by step, they intimately explore the coastal regions of Washington, British Columbia, and Alaska. By hiking, cross-country skiing, and packrafting, they see the wilderness in its larger context and gain a unique, on-the-ground perspective.

Whether discussing politics with off-the-grid back-to-the-landers, spooking a grizzly from the underbursh, repairing gear with dental floss, or catching a still-warm pizza falling from the sky, Erin and Hig experience a rich and varied coast, a world facing destructive change, but with hope for a sustainable future.

Seldovia Blizzard

Posted by on 12 Mar 2010 | Tagged as: home, southcentral alaska

Where once was a van…

A couple weeks ago, rain brought a slushy thaw to the land. It froze again quickly, but the snow cover was starting to look thin. Almost as if spring might be near. Almost.

First, there was snow. A foot of it, wet and perfect for snow forts. It made me wish Katmai was old enough to play in it.

Then there was powder snow, almost a foot again on top. We went winter camping with some friends from town. We slogged through deep drifts into blowing snow, as Katmai screeched his dismay at the wind from within his many layers. I wondered what we were getting ourselves into. But the rest of the weekend was calm – sunny even.

Hiking up Barabara valley

Dog in the snow

Bumming electricity in the storm

Snowy paradise

And then there was snow. Sleeping in the yurt again, I listened through the night as great piles of snow slid off the roof and thudded onto the ground below. In the morning, it was a blizzard.

Sideways snow battered the yurt, plastered the door, erased snowshoe tracks in a handful of minutes. The stronger gusts sent a ripple all the way around our fabric walls. We kept the woodstove roaring against the near zero temperatures and howling winds. Before long, the power went out, kindly preventing us from doing much work.

It kept snowing. Dede’s van was entirely buried at the foot of the driveway. Beneath six foot snow drifts, the trail was nowhere to be seen. The wind found its way into the yurt, sucking the heat away as soon as the fire died in the night. In the morning, long ice crystals criss-crossed our water bucket, and slush thickened berry jam.

Katmai’s dislike of blowing snow on his face pinned us indoors, aside from brief excursions to shovel a path to the outhouse or well, split wood, or film the storm. But after the first day without power, Hig bundled Katmai under his coat and we ventured to the neighbors’ for a brief interlude on our laptops.

The storm has receded. The power has returned. The van has been excavated. But still, it is snowing.

I wrote that last paragraph as I headed to bed last night, convinced the blizzard was done. But the nighttime sounds of rattling walls and the screech of sliding snow said otherwise. According to the National Weather Service, today was mostly cloudy with light winds. According my window, this morning, it was blowing and snowing. Dede’s van was buried all over again.

Apparently, we have been sitting in the bullseye of snow. While our blizzard continued, just across the bay Homer has bright blue skies. The whole town of Seldovia is getting antsy. Spring break starts tomorrow, and everyone is worried about being able to leave town. We haven’t had mail in a week, and hardly anyone has gotten across (though luckily the power crews made it yesterday). We’re leaving tomorrow too, if we can, headed out on book tour to lands where I hear there is bare ground. Even flowers!

It cleared up this afternoon, and with the blowing snow no longer pinning us indoors, I wandered around the newly drifted landscape of our front yard. Snapping pictures, thinking how the whole world looks perfect for snowshoe explorations… I’m going to miss the snow!

Snow in the spruce

Avalanching under the yurt

Pulling in wood

Outhouse drifts

Calm evening

Big Earthquakes

Posted by on 03 Mar 2010 | Tagged as: events, geology, maps, video

I got my PhD studying tsunamis and working with other scientists who study tsunamis. One thing that almost every scientist studying tsunamis has in common is that they’ve never actually seen one.

For several of my former colleagues, this changed when the tsunami from Chile spread throughout the Pacific. Andy recorded 7 distinct waves using a ruler he’d just purchased at Home Depot in Santa Cruz harbor. Jody (my former advisor) and Tanya watched ice shift in tsunami waves in the frozen harbor of Petropavlovsk, Kamchatka (Russia). Jody has been studying tsunamis since the 80s. In an email she told us all, “I am SURE I eyewitnessed a tsunami, for the first time in my life!”

Tanya watching the tsunami in frozen Avacha Bay.

Tsunami scientist Tanya Pinegina watches gentle tsunami waves in the ice in Avacha Bay, Petropavlovsk, Russia.

Photo by Jody Bourgeois

All I can say is that I may have seen a tsunami, albeit a really small one. On a beach here in Seldovia I watched the dropping tide. Did it drop a little faster during the last 5 minutes? Has it slowed now? The tide gauge in town definitely saw something… a wave several inches tall with a period of 10 minutes or so (link here, many gauges on this page, including a more easily seen example of a tsunami recorded by a tide gauge in King Cove a few hundred miles southwest of Seldovia).

I also set up my camera. I took a timelapse video, accelerating reality by 300x. I’ve watched this video many times now, and I think I can see slight variations in how fast the tide drops down the beach near the center of the image. Then again, maybe not… you can judge for yourself. (The boat in the distance probably isn’t being moved by the tsunami, as the period of its motion is only 1-2 minutes, as opposed to about 10 minutes.)

Chile tsunami timelapse in Seldovia, Alaska from Bretwood Higman on Vimeo.

The Santa Cruz harbor had a much more obvious tsunami, and there’s a small amount of video of the devastating tsunami in Chile.

What are the chances? Global occurrence of large earthquakes

The earthquake in Chile was a really big one. It’s amongst the largest ever measured, with the energy of a billion tons of TNT, enough to change the rotation of the earth. Decades pass without a single earthquake this large anywhere on the planet.

Does it seem like there are a lot of big earthquakes lately? Two recent deadly events, one in Haiti and one in Chile, have gotten a number people wondering if that is more than a coincidence.

In the case of Haiti and Chile, it almost certainly is just a coincidence. The earthquake in Haiti was a giant in terms of human tragedy, but as far as seismic energy, it was quite small in comparison to many earthquakes that have happened around the world lately. The USGS catalog records 16 earthquakes as large, or larger than the one in Haiti in the last year. The Haiti earthquake was large enough to increase the danger of other earthquakes on the same fault, but not large enough to influence tectonics a quarter of the way around the world in Chile.

However, the largest earthquakes – those over magnitude 8 – do seem to cluster in time. The three largest earthquakes in the 20th century, all magnitude 9 or more, occurred in 1952, 1960, and 1964. (Some catalogs list the 1957 Andreanof Islands earthquake as a 9.1, making four over 9 in that time range, but the USGS rates this one an 8.6.) After 1965, there were only two magnitude 8.3 earthquakes, and none higher until after the turn of the millennium. The statisticians have taken a look (Bufe and Perkins, 2005), and they don’t think that’s random. I plotted the data below, and you can judge for yourself.

Graph of the largest earthquakes in the instrumental record.

We’ve been measuring earthquakes since 1900, and the recurrence of the largest ones doesn’t seem random. There’s a clump of large earthquakes in the ’50s and ’60s, and then a lull through the turn of the Millenia. Things have been more active again in the past decade.

Click the graphic for a larger version, as well as data and vector graphic file.

And the past decade has been a big one for earthquakes. There have been five earthquakes above 8.3, including the 2004 magnitude 9.1 earthquake in the northeastern Indian Ocean. Each increase of 0.2 in magnitude corresponds to a doubling in energy released, so the 2004 magnitude 9.1 released as much energy as 16 magnitude 8.3 earthquakes.

What does this mean? We only have a short instrumental record (since 1900) and there’s a lot of variability, so it’s impossible to know whether we have another magnitude 9 just around the corner. But it seems likely that the period of tectonic quiescence starting in 1965 and ending with the gradual increase in seismicity in the late 90s is gone. It’s no time to dally on the science, both old-fashioned paleoseismic studies, and maybe some new methods that can help warn of impending earthquakes. And it’s no time to skimp on education and good infrastructure that can save lives during an earthquake. Likely the biggest difference that led to far fewer people killed in Chile than in Haiti was better building standards.

Why do the biggest earthquakes come in clusters?

At this point we don’t really know.

For an earthquake on a fault to happen, there have to be two things in place: The fault has to be under stress so it can provide energy for an earthquake, and some point has to fail, triggering the fault to move and that energy to be released. Stress increases over time and eventual failure is inevitable, but exactly when it happens is dependent on that trigger, which can be very subtle. The point where failure begins is the hypocenter (directly beneath the epicenter on the surface of the earth) and the entire portion of the fault that moves is the rupture area.

One way to think of it is to imagine the fault as a large building. Perhaps it is an apartment building in Istanbul, and as new floors are illegally added the stress on the structure increases. This unstable structure has a lot of energy in it, all in the form of cement and other materials suspended high in the air by weak architecture. But when it finally collapses, that collapse starts somewhere. Perhaps a pillar designed for two stories and holding five collapses because someone uses it to tie up their dog. Now the nearby pillars and walls must suddenly bear more of the weight, and they collapse as well. The failure spreads from the original “epicenter” pillar, and consumes the entire building, analogous to the earthquake’s rupture area.

So was it the dog that caused the building to collapse, or the extra stories? I’d say the cause was the additional stress, while the trigger was the dog. Earthquakes are the same way… caused by gradually building stress, but triggered when some point gives way.

Bufe and Perkins, 2005, discuss how an earthquake in one area of the world might lead to another far away and years later. Their first possible explanation focuses on triggering, while the others suggest that stress might increase on distantly separated faults at the same time:

  • Perhaps the vibrations from a distant earthquake increase the pressure of water trapped in pores in rock, and that pressure leads to a gradual weakening of the rock, initiating an earthquake.
  • Maybe a slow pressure wave moves through the lower crust after a large earthquake, and this wave causes stress to increase on other faults that then fail.
  • Perhaps large “silent” earthquakes, rarely detected because the deformation they cause is so slow, drive the system by running along plate boundaries and triggering their more violent kin.
  • It could be that the changes in where and how much ice is in glaciers changes the stress on faults and leads to times of quiescence or greater activity.
  • Or my favorite: Maybe the largest earthquakes change the stress on tectonic plates. As this stress moves around the planet it triggers more large quakes, until the crust has settled into a lower state of stress.