Geology Reconnaissance through UT- ID- WY Part 1: Craters of the Moon NM

My colleague and I recently got the "go ahead" to develop a geology field course this summer, something we've been doing to a lesser extent for several years as geology club advisors. We teach at a community college without a dedicated geology or geosciences program, but were interested to see if we could generate enough interest to run such a course as a fulfillment of a natural science course as part of another program, or simply to find some interested parties who might be interested in seeing and learning about some awesome geology. One of the challenges, I find, of teaching students who are not declared majors is that you are constantly trying to amaze your audience to convince them that studying rocks is cool. This is just the latest of my own personal songs and dances. :)

So in late July, we flew to Salt Lake City (a blog could be written about that leg of the trip entirely), spent a night in downtown Salt Lake, and departed the next morning for Craters of the Moon National Monument (COTM) in Idaho. As a New Yorker, my visions of Idaho mostly concerned potatoes, and that is certainly a segment of the state, but it is much cooler than I ever thought. There is just SOO much lava in Idaho, mostly associated with the Snake River flood basalts. En route to COTM, the road passes through the Idaho Nuclear Laboratory, or something to that effect, which is both funny and bizarre because of the nothing that surrounds you in all directions. Although I have been out west several times, I am always impressed with how much nothing there still is, in our age of over-population.



COTM was created by a series of basaltic lava flows about 2000 years ago. The volcanism was the result of extension in the North American Basin and Range province. Thinning crust resulted in melting and extrusion of multiple basaltic lava flows. Though Jessica, my colleague, and I, had been to COTM previously, one tends to look at things differently when preparing field assignments. The textural differences between some of the volcanic rocks at this location are striking. There are beautiful examples of pahoehoe and aa lava flows, in addition to the strikingly irridescent Blue Dragon flow, with higher concentrations of magnetite. Additionally, there are several spatter and cinder cones in the park, some visibly aligned along rift zones, as well as lava "caves," which formed from collapsed lava tubes. There are also some pretty great dead trees in the area. Jessica kept remarking how "tortured" the trees looked, and I had to agree. There are also some small flora growing in cracks in the lava... some organisms have easier lives than others, I guess.



We spent a few hours in Craters... a word of advice. EVERYTHING is black in COTM, lava and pavement, and there is very little shade. Temperatures are scorchingly hot in the summer. If this is a field stop of yours, plan it for the morning. En route to and from Craters is the teeny town of Arco, ID, which claims to be the first town powered exclusively from nuclear power. In the bedrock that overlooks Arco are a series of numbers spray painted on the rock. Starting back in the 1930s (I think), each graduating class would climb the rocks and add their graduation year to the others. For a good time, check out the Grand Motel and Mall... I nearly stayed there on a previous trip to COTM, where lodging is sketchy at best. We decided to find alternate plans when we saw all the signs in the front window: "For Sale," "For Lease," "Missing Children," etc., followed by boarded up windows and a couch randomly situated in the parking lot. Ahh, Arco. We stayed in the D&K Motel down the road (next to the Atomic Pickle Restaurant, no less) in that excurson, which was quite an improvement. However, for our July 2010 trip, we drove on to Jackson Hole, WY, to continue our trip in the Tetons the next day.

Paddling the ancestral Genesee

Today could have gone really well, or really poorly, and I'm happy to say that it was the former. My husband and I decided to take our twin daughters (3.5 yo) out to do one of our favorite outdoor activities, kayaking. We used to kayak fairly regularly before the kids arrived, but haven't made time to since then.

So we next realized that two tandem kayaks might not be the idea either, since someone is always arguing about who sits where, etc., so opted instead to rent a canoe. We headed to Bay Creek Paddling Center in Rochester, where we had previously rented kayaks. Bay Creek has very friendly staff and reasonable prices; I highly recommend them if you're looking for a fun way to spend a nice morning or afternoon. They seemed unimpressed with our pint-sized riders, which gave me some confidence that our endeavor wasn't necessarily doomed. The kids got a kick out of wearing life vests and seemed to enjoy the scenery, wildlife, and overall experience for over an hour, which is an eternity in toddler-years.

We started by paddling up Irondequoit Creek, which flows north and empties into Lake Ontario in Irondequoit Bay. While the water level was fairly high (neither of us remembered being so close to the Empire Blvd underpass on previous excursions), the flow was gentle, and we paddled for a bit though the meandering creek amid the cattails. While we never did find the otter my daughter was seeking, we did encounter a few families of ducks, a turtle sunning itself on a downed tree, a blue heron, and a few giant white swans.

Irondequoit Creek is a large, buried glacial valley just west of Rochester, NY. The Genesee River, the only river to completely cut through NYS, empties into Lake Ontario just to the east in Charlotte. However, the current channel for the Genesee River was created during the waning Late Wisconsin glaciation, when a moraine, or large pile of unsorted glacial sediment, was deposited in Portageville, NY, blocking the river and created a proglacial lake. It is during this time that the Genesee River cut a new path through Letchworth State Park, creating a series of three cataracts. Further deposition of glacial sediment near Avon, NY resulted in a diversion of the Genesee River yet again, this time from its ancient path through Irondequoit Creek and through the city of Rochester, again creating a series of three waterfalls as the river eroded through Silurian and Ordovician sedimentary layers.

The valley walls of the ancestral Genesee are easily visible paddling up the creek, as are large, poorly consolidated deposits of glacial channel sands. When we ventured into the bay a bit, a nice exposure of thinly bedded sand deposits are visible and relatively accessible by canoe or kayak on the east side of the bay.

All in all, a nice way to spend a day outdoors, see some cool geology, and wear out the children.

Haiti of the Future?

Today, the NY Times about shoddy or older construction methods used in cities around the world. Where will the next Haitian disaster occur? Find out here!

Slippin' and Slidin' in Cali

Chances are that you have either read about the recent mudslides in California or you have heard about them in previous instances. Portions of California are unfortunately located in a perfect storm of environmental conditions for mudslide development.

So what are the basic ingredients of a good mudslide, besides Kahlua? Mud, most obviously, which forms when very fine sediment called clay is surrounded by water molecules. Clay particles are often electrically charged, so one clay particle is usually electrically attracted to another, and so on, creating a viscous, sticky mass of sediment. When water molecules fill the voids surrounding clay particles, the resulting mud becomes saturated, begins to lose cohesion and slides downslope. This is especially true if the area has been denuded of vegetation, either intentionally or as a result of fire. The root systems of plants act as powerful anchors to soil and sediment, but when these systems are impaired, mass wasting events (when materials slide downslope) and erosion occur with greater frequency. Similarly, if an area is prone to earthquakes, sediment can vibrate at such a frequency that again, sediment particles are no longer touching, and can behave like a fluid, a process called liquifaction. Finally, rock and sediment are more likely to slide downhill in rugged, steep terrain.

Given these variables: steep terrain, water, fire, earthquakes, it is easy to see why much of California is prone to this sort of geologic hazard. Much of California enjoys warm, dry summers, often creating conditions suitable for wildfire. You can probably think back to previous summers, reading about tens or hundreds of homes destroyed by wildfires in California, which has been experiencing drought conditions for nearly a decade. Winter months are often wet for portions of California, and those same canyons that experienced fire in the summer are likely to experience mudslides in the winter. California is a seismically active, rugged region, which only increases the likelihood of mudslide.

While only 100 people in California have died as a result of mudslide in the past 25 years, that is largely due to evacuation, sound scientific advice, and in some cases, engineering efforts. In Colombia, the eruption of the Nevada del Ruiz volcano melted its snowcap, creating a volcanic mudslide that killed 23000 people in a single day in 1985.

The California Geological Survey advises that people in mudslide-prone regions to not sleep in bedrooms on lower levels during rainy periods, especially those living near rivers and canyons, where mudslides are generally confined. They recommend avoiding building on steep slopes or adjacent to rivers, which is true in all areas of the world. In existing structures, installation of a rain gauge is recommended to be more aware of possible soil conditions, as mudslides are more likely to happen after 3-4" of rain have saturated soils. In some rare instances, retaining walls, as seen in the figure above, can be built around the property, deflecting mudslides to adjacent areas.

As people continue to develop in unsustainable or unsuitable terrains, expect to hear about these events with increased frequency!

A whole lotta shakin'... will continue.

The recent tragedy in Haiti exemplifies a growing problem in our world... a large population of people living in geologically active areas already straddled with staggering poverty.

By now, most of us have seen at least one video clip on the news depicting the geologic setting of Haiti, clinging to the edge of the Caribbean Plate, which is sliding east while the North American Plate slides west, known as a transform plate boundary. Each time there is motion along this plate boundary, potential energy stored in rock layers is released, producing an earthquake, in this case, approximately 6 mi below Haiti. Since the mag 7 earthquake rocked Port-au-Prince on 1/12/10, several aftershocks have shaken the small nation, the most recent of which occurred this morning, a magnitude 4.4 on the Richter scale. It is important to recognize that the Richter Scale is logrithamic, so a magnitude 7.0 earthquake is actually over 6000 times more energy than a mag 4.4. The USGS anticipates many aftershocks of this size over the coming months.

But Haiti exemplifies a global problem that is likely to get worse in the coming years. Many of the world's poorest countries around the globe are located along active plate boundaries and are ill-equipped to utilize more "earthquake safe" (and expensive) technology that allows much of California to successfully weather many an tremblor.

The UN named the Solomon Islands, located north of Australia and east of Papua New Guinea, one of the least developed countries in the world. The average annual per capita income is approximately $2900 USD. It was struck by a magnitude 8.1 earthquake in 2007, which in turn generated a tsunami estimated to be as much as 33' high, killing ~50 people and destroying nearly 1000 homes. Granted, the Solomon Islands have a relatively small population (about 500K) when compared to Haiti (>3M), but the threat is real for many developing nations.

The USGS has created a pretty cool program called PAGER (Prompt assessment of global earthquakes for response, found at http://earthquake.usgs.gov) which estimates the number of people and names of cities at risk after an earthquake has occurred. PAGER describes the Solomon Islands as a location where "the population lives in structures prone to earthquake shaking, though some resistant structures exist." An earthquake that struck this region 1/19/10 (mag 5.5) shook two small cities with a total population of ~60 k people.

So while the priority of international efforts must now be one of basic humanitarian aid to the Haitian people, perhaps in the future, instead of rebuilding grand palaces and tourist resorts, aid could be directed toward building homes able to resist some of the tremblors that will continue on into the foreseeable future.