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Another braided river meets a gorge: Lamar River, Yellowstone NP

Like the Snake River I posted last week, today I’ve got another example of a river happily braiding through a wide valley (this time probably glacial, not structural) only to meet an obstacle in the form of topography. I’m looking at the Lamar River on the northeast entrance road to Yellowstone National Park. We’re north of the volcanic plateau here and just west of the Absaroka Range, so I think the geology is typical Cordilleran stuff.

One of the things that fascinates me about this example is how short (and steep) the gorge section is (< 3 km, ~100 m elevation drop). Is it a relict of the glacial influence on valley formation? Or is there something structural going on (the Yellowstone geologic map indicates a fault in about the right area)? Food for thought and an excuse to do some field reconnaissance someday maybe. Or you can go there now in Flash Earth.

Images below are a mixture of Google Earth, Flash Earth, and ground photos from my personal collection.

Lamar Valley above the gorge section (photo by Anne Jefferson)

Lamar River upstream of the gorge (photo by Anne Jefferson)

Lamar River gorge (photo by Anne Jefferson)

Lamar River showing gorge section (Flash Earth)

Lamar River upstream of the gorge (Google Earth image)

Lamar River gorge from Google Earth

When it rains a lot and the mountains fall down

Cross-posted at Highly Allochthonous

2006 debris flow deposit in the Eliot Glacier drainage, north flank of Mount Hood (Photo by Anne Jefferson)

The geo-image bonanza of this month’s Accretionary Wedge gives me a good reason to make good on a promise I made a few months ago. I promised to write about what can happen on the flanks of Pacific Northwest volcanoes when a warm, heavy rainfall hits glacial ice at the end of a long melt season. The image above shows the result…warm heavy rainfall + glaciers + steep mountain flanks + exposed unconsolidated sediments are a recipe for debris flows in the Cascades. Let me tell you the story of this one.

It was the first week of November 2006, and a “pineapple express” (warm, wet air from the tropic Pacific) had moved into the Pacific Northwest. This warm front increased temperatures and brought rain to the Cascades…a lot of rain. In the vicinity of Mt. Hood, there was more than 34 cm in 6 days, and that’s at elevations where we have rain gages. Higher on the mountain, there may even have been more rain…and because it was warm, it was *all* rain. Normally, at this time of year, the high mountain areas would only get snow.

While it was raining, my collaborators and I were sitting in our cozy, dry offices in Corvallis, planning a really cool project to look at the impact of climate change on glacial meltwater contributions to the agriculturally-important Hood River valley. Outside, nature was opting to make our on-next field season a bit more tricky. We planned to install stream gages at the toe of the Eliot and Coe glaciers on the north flank of Mt. Hood, as well as farther downstream where water is diverted for irrigation. But instead of nice, neat, stable stream channels, when we went out to scout field sites the following spring, we were greeted by scenes like the one above.

Because sometime on 6 or 7 November, the mountain flank below Eliot Glacier gave way…triggering a massive debris flow that roared down Eliot Creek, bulking up with sediment along the way and completely obliterating any signs of the pre-existing stream channel. By the time the flow reached the area where the irrigation diversion occur, it had traveled 7 km in length and 1000 m in elevation, and it had finally reached the point where the valley opens up and the slope decreases. So the sediment began to drop out. And debris flows can carry some big stuff (like the picture below) and like the bridge that was washed out, carried downstream 100 m and turned sideways.

2006 Eliot Glacier debris flow deposit (photo by Anne Jefferson)

2006 Eliot Glacier debris flow deposit (photo by Anne Jefferson)

In this area, the deposit is at least 300 m wide and at least a few meters deep.

Eliot Creek, April 2007 (photo by Anne Jefferson)

Eliot Creek, April 2007 (photo by Anne Jefferson)

With all the big debris settling out, farther downstream the river was content to just flood…

Youtube video from dankleinsmith of the Hood River flooding at the Farmers Irrigation Headgates

and flood…

West Fork Hood River flood, November 2006 from

West Fork Hood River flood, November 2006 from For the same view during normal flows, take a look at my picture from April 2007:

and create a new delta where Hood River enters the Columbia.

Hood River delta created in November 2006 (photo found at

Hood River delta created in November 2006 (photo found at

And it wasn’t just Mt. Hood’s Eliot Glacier drainage that took a beating in this event. Of the 11 drainages on Mt. Hood, seven experienced debris flows, including a rather spectacular one at White River that closed the main access to a popular ski resort. And every major volcano from Mt. Jefferson to Mt. Rainier experienced debris flows, with repercussions ranging from downstream turbidity affecting the water supply for the city of Salem to the destruction of popular trails, roads, and campgrounds in Mt. Rainier National Park (pdf, but very cool photos).

In the end, our project on climate change and glacial meltwater was funded, we managed to collect some neat data in the Eliot and Coe watersheds in the summer of 2007, and the resulting paper is wending its way through review. The November 2006 debris flows triggered at least two MS thesis projects and some serious public attention to debris flow hazards in the Pacific Northwest. They also gave me some really cool pictures.

Exciting times in the Watershed lab

The last few months have been busy, busy, busy for the members of this research group, and now, with the semester over, our hard work is starting to pay off.

Brock Freyer has accepted a job with Three Parameters Plus, an environmental consulting firm based out of Anchorage, Alaska. He’ll be back in Charlotte in the fall to defend his MS thesis.

Ralph McGee and Cameron Moore successfully defended their MS thesis proposals and are getting started on a busy summer of data collection at their field site in Gaston County.

I got a nice little write-up in the College of Liberal Arts and Sciences newsletter about the wonderful opportunities enabled my ADVANCE Bonnie Cone grant.

More tributes to Reds Wolman from all those who miss him

About two months ago, I noted with great sadness the passing of a legendary figure in fluvial geomorphology, M. Gordon “Reds” Wolman, long-time professor at The Johns Hopkins University and inspiration to hundreds, if not thousands, of geomorphologists, hydrologists, and environmental scientists around the world.

In the past two months, Wolman’s students and colleagues have done an outstanding job of paying tribute to our hero. On April 11th, generations of Wolman’s students gathered on the Hopkins campus for a memorial service, which included a eulogy from a childhood friend and reflections from Hopkins geomorphology colleague Peter Wilcock. The day before the memorial, many of the attendees conducted their own Reds’ style field trip to some of his favorite locations in Baltimore County and waved their arms and debated some of the same questions Reds had spent decades pondering. (Sadly, I could not attend the celebration, because I was leading my hydrogeology class on a field trip to Congaree National Park, but somehow I feel like Reds would understand.)

Among the lasting tributes to Wolman are a couple of JHU web pages, two wonderful videos (below), and perhaps my favorite memorial ever:

A permanent memorial tribute will be installed outside the classrooms in Ames Hall where Reds Wolman taught for more than a half century. Stones provided by students, colleagues and friends from around the world will be constructed into a path in a shape that mirrors a meandering river.

For those of you still wondering what all the fuss was about (and still reading this post), please take a few more minutes and listen to the preface of one of Wolman’s seminal works and some reflections from Wolman’s colleagues and students (including, if you listen carefully, me) and from Wolman himself.



Reds is deeply missed by all who knew him, but these wonderful tributes give us a small way to hang on to the man who influenced, encouraged, and inspired us.

Deltas into Rivers: Chippewa River into the Mississippi River, Wisconsin

The Chippewa River drains the glaciated terrains of north-central Wisconsin including major outwash plains from the margins of the Laurentide Ice Sheet.  The sand carried by the Chippewa is a major sediment source for the Upper Mississippi River for tens of miles downstream.  The Chippewa forms a beautiful delta into the Mississppi River, as seen below, creating the only natural lake on the Mississippi, in the form of Lake Pepin (birthplace of water-skiing, by the way).  I like this delta because we don’t often think of riverine deltas forming in the rivers, and their propogating upstream and downstream effects. Plus, it makes a pretty contrast to the dissected blufflands of the Driftless area.

Flash earth link: If you zoom in on Flash Earth you can get some nice imagery of the sand bars and fluvial islands of the Chippewa as you move upstream, plus some nice long anastomosing reaches.

Posted via email from Pathological Geomorphology

A selected few Eyjafjallajokull links

The eruption of Eyjafjallajokull (which means Island Mountain Glacier in Icelandic) started out in March as a relatively quiet and tourist-friendly Hawaiian style eruption. That petered out and then a few days later, the magma reemerged subglacially, producing the spectacular ash-producing phreato-magmatic eruption that has transfixed the world and stranded all would-be European air passengers. The Boston Globe’s Big Picture coverage has been as-usual spectacular. Check out these two photo sets (15 April, 19 April). NASA’s Earth Observatory has also been producing some nice images of the ash plume. Follow them here.

And few days into the eruption, the magmatic heat produced enough glacier melt not just to fuel the ash production but also to generate an outburst flood, as captured on video below:

The video above includes a rather spectacular train of standing waves, which led to some debate amongst some friends and I over whether they represented sub- or super-critical flow. Fortunately, I have access to an expert on the subject, Gordon Grant, who weighed in thusly:

The standing waves represent what is best referred to as “trans-critical flow”, that is flow that oscillates around Froude No. = 1. We have real-time (though very small scale compared to what you’re seeing in the video) measurements from Grant (1997; available on the WPG website). Basically flow on the downstream portion of the wave is accelerating (Fr >1), while flow on the upstream portion is decelerating. The flow then oscillates between Fr > 1 and Fr < 1, maintaining overall flow at close to Fr ~ 1. Cross-sectionally averaged Froude Number tends to be slightly less, due to drag at the boundary. See paper for details.

The paper to which he refers is Grant, G.E. 1997. Critical flow constrains flow hydraulics in mobile-bed streams: a new hypothesis. Water Resources Research. 33: 349-358. PDF available here:

For the best scientific coverage of the on-going Icelandic eruption, you absolutely can’t miss Erik Klemetti’s Eruptions blog. Erik is a volcanologist and has been doing an astounding job of keeping up with this (and all other volcanic activity). He also benefits from an active, engaged, and informed community of commenters to keep the rest of us up-to-the-minute on volcanic activity around the world.

The pathologically curvy Rio Grande Delta

I spent a summer in college staring at maps and aerial photographs of the Rio Grande delta in Texas and Mexico. Maybe now I can get some use out of it.  I was working with J.D.  Stanley at the Smithsonian’s NMNH and he pointed me to the apparently high sinuosity of deltaic channels on the Texas side of the Rio Grande delta.

According to my notes, the modern Rio Grande has a sinuosity of 2.075 in its delta, while Holocene channels have a sinuosity of 1.83, younger Pleistocene channels have a sinuosity of 1.81 and remnants of older Pleistocene channels have about 1.32. So our data suggests that the channels of the Rio Grande delta have gotten curvier over time. I also did a literature review of channel sinuosity in other deltas and found that the Rio Grande was indeed anomalously sinuous compared to many of the world’s major deltas.  In my review, only the Niger and Klangat Langat deltas were curvier. Unfortunately, we never came up with a good mechanism to explain why the Rio Grande was so curvaceous.

Indeed, if you look at the flash earth images (  below, you can see what caught our eye. One of the images is the majority of the delta (look for the anthropogenically straightened main outlet channel), one zooms in on the modern river mouth and area just to the north, one shows a portion of the southern, Mexico portion of the delta, and one shows the northern portion of the delta, which if I recall correctly has some of the oldest exposed deltaic deposits along with some eolian features (which can been seen in the image).

Posted via email from Pathological Geomorphology

Bombetoka Bay, Madagascar

Hunting for a Where on Google Earth location a while ago I ran across this wonderful tidally-influenced delta on the northwest coast of Madagascar. It is the mouth of the Betsiboka River and just north of the river mouth is the second largest port in Madagascar.

What struck me about the delta was not just the nice tug-of-war between riverine and tidal processes in shaping the islands, but the dramatic red color of the water in the Google Earth image (and others as well). This red color is symptomatic of the massive erosion resulting from rampant deforestation of the island.

The four photos are from Flash Earth, Google Earth, and the Gateway to Astronaut Photography, NASA Earth Observatory (ASTER satellite)

Flash earth permanent link:

Astronaut Photograph:

Earth Observatory ASTER image:

Posted via email from Pathological Geomorphology

Selected Resources for World Water Day

World Water Day 2010
More than one billion people (1 in 6) do not have access to adequate clean fresh water – which is defined as just 20 to 50 liters per day. (In contrast, the average American can use in excess of 400 liters per day indoors.) More than 2.5 billion people do not have access to basic sanitation facilities. Without sanitation, human and animal wastes reach drinking water supplies and illness proliferate. Diarrhea, caused by water-born pathogens, is the leading cause of illness and death in the world. And most of its victims are children under 5 years old.

Today is World Water Day, an annual recognition of the importance of freshwater and an opportunity for focusing attention on advocating for its sustainable management. World Water Day is organized by the UN Environmental Program. Each year has a particular theme, and in 2010 the theme is “Clean Water for a Healthy World.”


The all-around excellent Pulitzer Gateway “Downstream”is focused on water conflict and cooperation, water and economics, water and health, and water and climate. Of particular relevance for this World Water Day is the section on water and health, where I found the video and written account of women in Kakuma daily digging a dry riverbed for water because they couldn’t afford the 5 cents per jerry can fee for the clean, pumped water supplied by aid organizations and the local government.

(One thing you might notice if you watch some of these videos is that it is women and girls who are disproportionately affected by lack of access to clean water. Women are the ones who have to walk miles to fill jugs with water and girls drop out of school in order to do so. Improving access to water would give these women and girls additional opportunities to contribute to their own and their families’ economic well-being.)

In 2000, the UN set out its Millenium Development Goals, one of which is “By 2015, reduce by half the proportion of people without sustainable access to safe drinking water.” With five years to go, we haven’t gotten very far towards that goal. There are many organizations working to install wells and establish clean water supplies. There are also organizations working to develop and distribute affordable water purification technologies, some even using entrepreneurial solutions. Just as importantly, there are groups working to improve sanitation conditions. We need to break the taboo on sanitation and recognize it to be a necessary ingredient to preserving clean water resources. Unfortunately, all of these well-meaning organizations face significant limitations because of cost, political instability, hydrogeology, and climate.

No matter how much scientific geek-love I may have for streams and groundwater, mostly I take water for granted. Yet in other parts of the world, access to clean water is literally a matter of life or death. I’m glad for this year’s reminder of how fortunate I am, how far the world needs to go to meet basic human needs, and how many of the solutions are within our grasp, if concerted, adequately-funded efforts were made. Simply put, global health depends on access to adequate clean water and sanitation. It’s time to move water higher on our collective to-do list.

Chris Rowan speaking today in the department

I’m delighted to be hosting Dr. Chris Rowan of the University of Edinburgh. Chris’s specialty is paleomagnetic applied to both neotectonic and paleoclimatic problems, and he’s worked in some fabulously exotic locations. Chris is also the lead blogger at Highly Allochthonous, where I occasionally contribute posts as well.

Dr. Rowan will be giving a 2 pm seminar in McEniry 401 with the title: “In search of good palaeomagnetic data: a romp through New Zealand, South Africa and Oman” This talk is aimed firmly at the non-expert.

Dr. Rowan and I will also be convening an informal discussion called “Beyond LOLcats: Earth Science in the Internet Age” at 11 am in McEniry 401. We’ll be discussing how tools like RSS feeds, Google Wave/Docs and Twitter can enhance facilitate collaboration and enhance research productivity.

If you can, please join us for one or both of these interesting seminars.