Cascadia Subduction Zone: Unprepared and Liquefaction

Call me paranoid, but when I see a 7.8 earthquake in Indonesia, and the news recalls the 8.9 magnitude earthquake that triggered the deadliest tsunami in history in 2004 killing more than 200,000 people, I’m reminded that we live in the shake zone of earthquakes and tsunamis, the Cascadia Subduction Zone. It doesn’t help when The New Yorker Magazine tells us that the “Really Big One” is coming and we’ll be able to surf to Idaho soon.

Last year, OPB-TV won awards for their “Unprepared” television series and documentary on the historical “big one” coming to the Pacific Northwest. It led to discussions around the state of Oregon involving geologists, seismologists, and area experts, all asking if we are prepared and what are we going to do or not do about it. They talked about the state of our bridges, schools, and the impact of liquefaction on our ports, home to fuel tanks, some almost 100 years old, that could rupture, dump into our precious waterways, and burn for ages. It was a wake-up call for all of us.

As a rock lover, I started questioning the ground under my feet. According to FEMA’s Earthquake Risk and Cascadia Region Earthquake Workgroup (CREW) and their educational Cascadia Subduction Zone Earthquakes 9.0 Magnitude Scenario (PDF), while I’m personally outside of the tsunami zone, besides being cut off from the rest of the world, the thing to fear most is: Liquefaction.

Tilted Victorian Home in San Francisco due to liquefaction - Photograph by G.K. Gilbert of the U.S. Geological Survey

Liquefaction is the process in which soil, often thought to be firm and solid, is “reduced” by earthquake shaking. While most commonly associated with saturated soils, liquefaction occurs in dry soils where there is space between the particles. Take a jar and fill it full of flour or grains. Tap it against the counter and you will see the level drop. Depending upon the space and shape of the grains, it might drop a little or a lot. That’s liquefaction in action. Continue reading “Cascadia Subduction Zone: Unprepared and Liquefaction”

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Scientists Release List of the Rarest Earth Minerals

BBC News Science and Environment column reported that scientists have catalogued the largest list ever of rare minerals. The list, published in American Mineralogist, was authored by Dr Robert Hazen, from the Carnegie Institution in Washington DC, and Prof Jesse Ausubel of The Rockefeller University, in New York, and includes more than 5,000 mineral species.

“Scientists have so far tracked down 5,000 mineral species and it turns out that fewer than a 100 constitute almost all of Earth’s crust. The rest of them are rare, but the rarest of the rare – that’s about 2,500 minerals – are only found at five places on Earth or fewer,” Dr Hazen told BBC News.

“And you ask: why study them; they seem so insignificant? But they are the key to the diversity of the Earth’s near-surface environments.

“It’s the rare minerals that tell us so much about how Earth differs from the Moon, from Mars, from Mercury, where the same common minerals exist, but it’s the rare minerals that make Earth special.”

The list includes rare examples including cobaltominite, abelsonite, fingerite, edoylerite, and the extremely rare “vampire-like minerals” that fall apart immediate when wet or the sun shines on them: edoylerite, metasideronatrite, and sideronatrite.

For more information:

Washington State Rocks and Minerals Exhibit at WWU in Bellingham

If you are heading north into Washington State, way far north towards the Canadian border, take time to drop by Western Washington University in Bellingham for their free and open to the public exhibit of the minerals, fossils of Washington state, reports the Bellingham Herald. The exhibit is on the ground floor and part of the first and second floors of the Environmental Studies Building.

It’s like a mini-museum, with displays that include mineral crystals, mammoth teeth and fossilized plant leaves, along with interpretive exhibits that highlight coal mining in Whatcom County and show some of the tools and equipment that scientists use to study the Earth. There’s even a seismograph and seismometer.

…Possibly the most fascinating display is a four-foot slab of sedimentary rock containing the three-toed footprint of a diatryma, a giant flightless bird from the Eocene Period, some 34 million to 56 million years ago. It was discovered in sedimentary rock that shook loose in a landslide several years ago near Racehorse Creek in the Mount Baker foothills. The slab was airlifted by helicopter to WWU.

As our members know well, Washington (as well as Oregon) is one of the most geologically dynamic areas in the world. This exhibit is designed to showcase what they are calling “Northwest Origins” going back more than 1 billion years old.

If you head up there, please let us know and consider writing a report about the exhibit for the website and newsletter.

The Strongest Mineral on Earth Found Along the Sea

Geothite by Wiki Commons.

For those working in the lapidary arts, we’ve been dazzled by the strength of the minerals and gems we find. The Washington Post announces there is something in nature stronger than diamonds and steel, and unbreakable by bullets.

Currently, the strongest natural material known is the silk of a spider. With this new research, your next tidal pool adventure along the Pacific Northwest coastline might come with a new perspective, and a new respect.

In a study set to come out this month in the Journal of the Royal Society Interface, British researchers announced that the teeth of shelled, aquatic creatures called limpets are the strongest biological material on Earth, overtaking the previous record-holder, spider silk.

The teeth, which are so small they must be examined with a microscope, are composed of very thin, tightly-packed fibers containing a hard mineral called goethite. Limpets use them to scrape food off of rocks, but lead author Asa Barber said humans can adapt the technology to build better planes, boats and dental fillings.

Testing found the mineral material in the snail-like creatures commonly found along tidal pool areas to be nearly flawless in their very thin filaments, reinforcing the structural components, and have a strength of 5 gigapascals, five times that of most spider silks.

The teeth also bested several man-made materials, including Kevlar, a synthetic fiber used to make bulletproof vests and puncture-proof tires. The amount of weight it can withstand, Barber told the BBC, can be compared to a strand of spaghetti used to hold up more than 3,300 pounds, the weight of an adult female hippopotamus.

For information on geothite, see:

Our 56th Annual Rock and Mineral Show

Tualatin Valley Rock and Gem Show vendors row.The Tualatin Valley Rock and Gem Club 56th Annual Rock and Mineral Show will be at the Washington County Fair Complex in Hillsboro, Oregon, Friday and Saturday, March 7-8, 2014.

Admission is $1 per person, children younger than 12 free when accompanied by an adult.

Hourly door prized, raffles, demonstrations, and kid’s activities will be all day and a silent auction will offer some exciting opportunities to win some previous rocks and minerals.

“There are many vendors and exhibitors at the show this year, and we are delighted to have so many who’ve been with us for a decade or more as we continue this tradition in Hillsboro,” says Club President Mitch Metcalf. “I’m so proud that we’ve been able to continue the tradition and that we have some of the best volunteers to help run the show, bringing their geology expertise and passion to the public.”

The annual rock and mineral show benefits the Tualatin Valley Rock and Gem Club educational activities and projects, and also go to the Rice Northwest Museum in Hillsboro, a world-class rock and mineral museum and partner and affiliate with the club.

Updates

OregonLive announced the show on March 7 in their weekend activities section.

Impressions of My First Regular Club Meeting by Susan Schmidlin

By Susan Schmidlin

I had the opportunity to attend the Tualatin Valley Rock and Gem Club on the second Thursday of the Month and I was able to see how the club holds its general (more formal) meetings.

Some of the regular members set up a table with strong lights for a display area. Several members brought special pieces to be highlighted during the meeting. The petrified wood pieces were spectacular. One was thinly sliced and showed beautiful transparent red throughout the ringed body while having an outer shell of green coloring covering the edges.

Rhodocrosite from Romania was the feature of the special display. It was an underground stalactite when discovered, hanging down into a cavern. Imagine walking through and seeing four foot formations suspended from the ceiling that are a spectacular pink color! The specimen that was displayed during the meeting was a slice of the stalactite that was as big around as a whole pie and was standing upright on a base. The pink stood out with white florettes gracing the surface, it was thin enough for the lights to shine through and show the intricate designs front and back.

Continue reading “Impressions of My First Regular Club Meeting by Susan Schmidlin”

My first TVRGC ‘rock swap’ meeting.

I went to my first “Rock-Swap” and had such a wonderful time that I wanted to share the experience.

Imagine a group of kids, giddy with anticipation at a chance to show their treasures at show and tell.  Now picture that the kids are all ages with a family-friendly camaraderie, and that the treasures are diverse works of art. Some of them are very basic and rough while others are finely crafted and displayed as such.

That is how it is at the Senior Center in Forest Grove on the 4th Thursday of each month at 7:30 pm, when the Tualatin Valley Rock and Gem Club holds a meeting and rock-swap.  It was great fun to see all the amazing treasures at the meeting that I attended. Continue reading “My first TVRGC ‘rock swap’ meeting.”

TVRGC Annual Picnic: A Non-Member View

by Susan Schmidlin

I want to share a great find that I recently stumbled upon. I received an invitation to learn more about a local club.  I thought to myself, I’m really busy this time of year and I don’t think I have much time to spare. Then I was told that the club was having their annual picnic at the Rice Museum in Hillsboro. Well, I had been there before, and loved it. I could certainly find enough time to investigate this club. A picnic, a beautiful setting and the opportunity to learn something new…how could I refuse? A visit to the Rice Museum alone would make it worth my time so I said yes, I would come.

I have always enjoyed seeing all the displays at the museum, but it has been a couple of years since I have had the opportunity to see the beautiful home that has been turned into a showplace for rocks and minerals from around the world. The Museum has outgrown the huge house and filled a second building as part of the complex. A nature path leading into the woods filled with 100 ft. fir trees adds to the charm of the property and many weddings are held in the picturesque setting. Continue reading “TVRGC Annual Picnic: A Non-Member View”