Sediment Flux and Luggage Carousels
Research that I have been doing recently involves the study of sediment flux. That is, what is the history, the temporal distribution, of the erosion, transport, and deposition of sediment. From the erosion of a particle in the uplands, into a river system, perhaps spending some time in a coastal system, and then into a deep marine basin. I’ve been looking at a temporal scale of hundreds to thousands of years, but one could examine this at a scale of millions of years. Of course, the farther back into Earth history, the lower the resolution. Moreover, the farther back in Earth history, the more fragmented is the contextual information about the system. Investigating sediment flux requires a lot of context
The ultimate question is, of course: what are the controls on sediment flux? Can we deconvolve interacting factors including, but not limited to:
- climate (e.g., increased precipitation leading to increased runoff/streamflow)
- sea-level stands (e.g., lowstands of sea level during glacial maxima)
- tectonic movements (e.g., increased uplift rate of sediment source area leading to increased erosion rate)
- intrinsic behavior of the sedimentary system (e.g., meandering of a river, migration of dunes and other bedforms, distributive patterns, etc.)
This is what I spend my time pondering. Earlier today I was standing at the luggage carousel in the airport. Everybody stands there staring at the mouth of the conveyor from where their bag (hopefully) appears. We stand there and wonder what controls the order, why the delivery of bags come in clusters, and other nonsense….essentially, we are wondering what is controlling the flux of luggage. Well, maybe only I wonder this…..anyway, all we have to do to figure this out is simply observe what is happening on the other side of the luggage delivery system.
I don’t really care about luggage delivery systems…I just want my bag. But I do care about sedimentary systems. It’s definitely more complex than the carousel too. In the coming weeks I am going to post more about this area of my research. Check out a post from February in the meantime.
Image at top of Santa Ynez Creek, California; from Jon Warrick’s work
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A few photos from vacation
I’m sittin’ in Denver International Airport on my way back to California. We spent a week in the north woods of Minnesota, in the Boundary Waters Canoe Area. I had never been….it was fantastic. Yes, there were some mosquitos but they weren’t as bad as I had imagined. Besides, we were in a nice cabin and not camping…so that was a bonus. We spent the week paddling around the lake, exploring small bays, watching the wildlife, and relaxing. Very nice…I needed it.
I need to catch up on some of latest and greatest in the geoblogosphere….in the meantime, check out some of these photos from the Boundary Waters.
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Who said you could go on vacation…
…is what the grad-student-guilt angel is whispering in my ear on one shoulder. On the other shoulder is the holy-crap-you-deserve-a-break devil saying…..well, saying what he always says.
I’m gonna actually listen to the devil for once. I will be away from the internets (and phones even!) until July 2nd. In the meantime, check out some of the blogtastic goodies out there:
- Where on (Google)Earth? 2.0: Ron and the Lab Lemming are taking my WoGE series to new levels. Posts are now coming from and being solved by more people. It is getting a little more geological instead of pure trivia (which is great). And we have plans to make it even better as time goes on. Check out my geoblogosphere ticker on the sidebar for the latest….or check out their blogs directly (links above) for the latest. Click here to see all the old WoGE 1.0 posts.
- I’ve been checking out some new blogs of late as well (new blogs to me, that is).
- I’m not sure what The Anterior Commissure is, but it has something to do with neuroscience. This blog has some great writing about an area of science I have little knowledge about. The author, Kate, explains things with the right combination of technical details (to help further my knowledge) and the important why-should-we-care rationale.
- At first this blog led to decreased productivity because I spent time reading it. But now, the topics on Academic Productivity are helping me think about how to manage the information that I collect and compile.
- Letter Never Sent is a potpourri of interesting writing and ideas. I especially like the post about simplifying your life.
- Tamino has teamed up with Maribo and Eli Rabbett for a new series of climate science posts. These are not new blogs individually, but the collaboration, or ‘mob blogging’ as they call it, is a new approach. The posts at Open Mind continue to impress me with the caliber of analysis and explanation of a complex system like climate. Check out one of the first posts of this series over at Rabbett Run dealing with the fundamentals of the carbon cycle.
- I’ve also been enjoying the TED talks. Every year in Monterey, CA a gathering of very sharp people (scientists, technologists, economists, social activists, artists, etc.) present talks about their ideas. Now you can view or download these talks at the TED website. They have everything from talking about reverse engineering the brain to the promise and perils of nanotechnology to beat poetry. It is a very slick site in terms of choosing from the database of talks based on topic tags. And they’ve made it very easy to download right to your video iPod, if you happen to have one. Great stuff…check it out.
See you in a couple weeks!
image above from here
That wonderful time of year…
Some people hate it, some love it. Usually the ones that don’t care for it move away at some point. It’s summer time in San Francisco and that means …. fog.
I love it. It’s a natural air conditioner. When I spend most of the day in other parts of the Bay that don’t get the fog it can be well into the 90s F. And then I’ll travel 20 or 30 miles into SF and it’ll be in the 60s. In addition to the cooling aspect, I think it is beautiful to watch and seems to add drama to what would normally be a typical boring day in modern life. Plus, I have to admit, I do get a kick out of tourists who come to San Francisco in the summer expecting it to be like southern California. They are in shorts and short-sleeved shirts standing on top of Twin Peaks while its 55 degrees F and rather blustery. Tough break…shoulda brought a jacket.
Why fog in the summer?
The graphic above is from a San Francisco Chronicle article a couple years ago (click on image to see the full story). Depending on how thick this marine layer gets, the fog will blanket more of the Bay Area. Since San Francisco is at the outlet to the ocean (Golden Gate), even a weak/thin marine layer will create some fog. On other occasions, the marine layer is thick and robust and can overtop the Santa Cruz Mountains to the south. And other times, the inland valley will be so dang hot, that it just sucks that fog right up the Sacramento delta and river.
Once in a while you’ll get this very low, ground-hugging type of fog that has a very sharp upper boundary. It’s usually when its rather windy too so it’s moving along pretty fast. I’m writing this post because that’s how it is this afternoon. I wish I had a nice video camera….it is quite spectacular. We live on the lee side of a major set of hills, so the fog is cascading over the side like a waterfall of fog…a fogfall I guess.
I guess I don’t need a video camera….amazingly I found one on YouTube that shows this type of fog at the same general location.
photo above from here
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Metablogging
Why do bloggers eventually end up blogging about blogging at some point?
- profound realizations through examination and reflection of self
- running out of ideas
- too lazy to think of ideas
- something to do during bouts of writer’s block while trying to write about about the controls on Holocene turbidite accumulation offshore of southern California
Regardless, metablogging can be an interesting exercise (am I meta-metablogging right now?).
Someone asked me the other day why I spend time with a blog. Good question. When I first started it (fall 2006), it was more of the public journal/diary type with some personal commentary. That was okay, but there’s plenty of commentary out there…and some of it very well-written and engaging. I’m not one to share every thought in my head to the public at large so the diary type of blog wasn’t really my thing either. As the geoblogosphere community grows, I find it more satisfying to post about earth science-related topics most of the time (although the beauty of the blog is to be able to throw in some random stuff from time to time….we all should take advantage of this wonderful self-publishing freedom). Besides, thinking and writing about geology is what I spend nearly all my time doing anyway.
Nowadays, I view this blog as the online equivalent of that person who, in the pre-internet days, would cut out and tack up various clippings from magazines or newspapers on their office door. I enjoy telling people about stuff I think is interesting but I really don’t like bothering people. In that sense, the blog is perfect. Readers can check it out if they like…or they can move on. The majority of my posts are brief, contain a link or two, and include some imagery (photos or video) about a specific topic or current event.
I would love to create posts about the specific research i’m doing in a lot more detail. But, being relatively early in my research career, I don’t have this stuff out in the literature yet. I’m focused on getting my work submitted and published in peer-reviewed journals first. When (not if) the papers start coming out, I will very much enjoy writing posts about my own research (i’ve got some stuff in the pipeline that will be featured on here soon). Others may disagree, but I think it’s prudent to wait to put your science on a blog until it reaches a “cite-able” status. At least for work that one would want published. I think scientific blogs have the potential to be an appropriate venue for presenting original results someday too, especially review papers and others studies that look at previously published data with a new perspective or in light of other findings.
The media’s anthropomorphization of Pluto
A quick survey of mainstream media reporting on Pluto this weekend reveals their continued (and incredibly annoying) obsession with turning Pluto into an conscious being with feelings.
Here a few examples. Note red circles (mine).
The San Francisco Chronicle mentions Pluto’s pride. CNN claims the planetary body is suffering from indignity. I guess at least BBC said that Pluto’s status suffered a blow, instead of the dwarf planet itself suffering.
What the hell is the problem? Big deal…we’ve reclassified Pluto. It’s a damn label to help science better communicate. This is how it works. The general public (and apparently science reporters too) can’t seem to grasp the concept of classification. This is a human-made abstraction to help us better understand natural phenomenon. There is no true organization…at least not in this simplified outline form. Classifications are supposed to be refined, changed, tweaked, tanked, overhauled, etc. over time. This is part of doing science!
Maybe you’re saying – ‘relax, they’re just having fun’. I understand that…yeah, sure it’s cute. But if this style of reporting misrepresents how science is done, then I don’t find it so cute.
Besides, if people are really worried about the feelings of a planet (dwarf or otherwise), maybe they should ask Earth.
UPDATE: Add SEED magazine to the list too. Apparently Pluto “…got kicked out of the brotherhood of planets and demoted…”. Sucks to be you Pluto! Oh wait, Pluto is an inanimate body of rock and ice.
Time lapse video of migrating ripples
The previous post showed the sedimentary structure climbing ripple cross-lamination as it appears in a preserved deposit. This post links you to a fantastic video showing plan-view ripple migration in time lapse.
Unfortunately, I couldn’t get this movie embedded so when you click on the screenshot at right it will take you to the USGS website where its hosted.
The movie shows a 40×60 cm area looking down on an active ripple field in a flume experiment. It is created from photographs taken once every 40 seconds for six hours. The bedforms migrate from top to bottom.
Note that these are not the highly aggradational ripple bedforms shown in the last post, but your run-of-the-mill migrating ripples.
What’s interesting when watching the time lapse is how uneven the pace of the migration is. There seems to be spurts of faster-migrating ripple crests, usually in a relatively narrow strip, every so often. I don’t know if the flow speed in the flume was kept constant…it doesn’t say either way…but, I’m presuming it was.
Check out the index page for more movies and illustrations of bedforms in action.
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Friday Field Foto #21: Climbing ripples
Today we are gonna look at some ripple cross-laminated sandstone. More specifically these are called ‘climbing ripples’, or sometimes you may see this sedimentary structure referred to as ‘ripple drift’. These show up particularly nice in this photo because of the light-dark contrast of the sandy vs. muddy laminae.
Climbing ripples record both migration (lateral) and aggradation (vertical) of the bedform. In this example note the very prominent ripple set in the middle section of the photo nicely showing the ‘climb’ from left to right. Different angles of climb represent different ratios of migration and aggradation. Climbing ripples are commonly interbedded with or grade upwards into wavy laminae.
This image at left is a classification of types of climbing ripple-laminated structures based on the angle of climb (click on image for larger view; click here for source of image).
Climbing ripples are most commonly seen in river and turbidity current deposits, typically in sub-environments of high rates of deposition from decelerating flows.
On a side note, Dr. Lemming has pointed out a new geology-related blog out there. It’s called All of My Faults Are Stress Related and looks to be a nice addition to the geoblogosphere. I have a few more new links over there on the sidebar that i’ll post about soon.
I also have an updated album of Patagonia photos you can check out here. The above image is from that collection.
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some funky jazz
I haven’t had a music post in a while….here is a video of Medeski, Martin, & Wood playing “The Lover” in 2005. They are a jazz trio from NYC and one of my all-time favorites. Billy Martin is the man on the drums…and makes some interesting art too.
Check ’em out if they come to your town.
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Where on (Google)Earth #14?
This one might not take too long.
Good luck!
Clastic Detritus 