The Accretionary Wedge # 41: Something's Slumping

It is time for me to participate in the Accretionary Wedge once again. This month's topic is: What is the most memorable/significant geologic event that you have experienced?

What we seek for AccretionaryWedge #41 is an account of a geologic event that you experienced firsthand. It could be an earthquake, a landslide, a flood, a volcanic eruption, etc. (but don’t feel compelled to stick to the biggies – weathering, anyone?) – some geologic process that you were able to directly observe and experience. - Ron Schott

This is a toughy. I have never seen a volcano erupt, been in an avalanche or really in any life threatening geologic events in my short career. Thus far in my life I have experienced one earthquake, in Ottawa, and a few other smaller events such as watching rivers erode banks, observing coral reefs and sedimentation processes in Bermuda, climbing a glacier in New Zealand. All of these things are cool, but I think the coolest of them all is the time I spent working in the massive retrogressive thaw slumps located in the Northwest Territories where I have done fieldwork. I think it is fair to say that these slumps are geologic events in progress. Indeed, standing in a  slump is to watch ice, rocks, trees and mud cascading from the headwall around you and if you close your eyes you can hear the cacophany of the slumping process all around you, mostly in the form of plopping and thuds.

The Charras slump. It is about 1-1.5km across.

These slumps are formed in permafrost regions and are due to melting of permafrost and a thickening of the active layer, which is the layer of soil that melts on an annual basis. This melting can result either in active layer detachments, which is when the melted surface layer slides off the permafrost below, exposing it to melting, or when the melting occurs on slopes that result in a landslide. These slumps can be extremely large and have a huge impact on the land and watersheds they form in as they dump millions of tons of sediment into nearby streams and lakes.


Basically a slump consists of the three main parts: the headwall, the body and the mudflow. The headwall is the front of the slump where is it retrograding backward into permafrost which then collapses into the hole as it melts. The body is the big hole in the landscape and the mudflow is the trail of sediment that has flowed downhill and either been carried away or is damming a stream. 

The mudflow. This one is about 2-3km long and has completely filled the stream valley.

My work in the slumps near Fort McPherson, NWT consists mainly of taking water samples in nearby creeks, samples of peat moss and samples of ice from the headwall for geochemical analysis of stable and radioisotopes. Our usual routine consists of camping in Fort McPherson and then driving out to near the slumps and then bushwhacking/hiking out over the land to reach them, which takes about 45 minutes. These slumps are an awe inspiring site and every time I go out to them I am truly overwhelmed at their size and the magnitude of destruction they have caused to the land around them. Honestly, walking into a slump is like waking onto another planet because one minute you are surrounded by green shrubs and peat moss and the next mud! Mud is everywhere, completely dominating the landscape and flowing everywhere. In fact, the inside of a thaw slump is like visiting the moon. 

Closeup of the mud with "craters" left by raindrops

The headwall. It is around 30m high. You have to be really careful when on top of the headwall since you can't tell from above if you are standing on an overhang or on solid ground!! Also, when in the slump you have to watch your footing since the mud can be pretty treacherous and suck you in. It is best to travel in groups.

Furthermore, in the summer the thaw slumps are ever changing. I alluded to the sound a slump makes as rock and ice cascade down into the slop below, but it is difficult to describe how rapidly the appearance and conditions can change. For example, a week of sunny weather will lead to lots of melting in the headwall and the collapse of a large amount of land and a rainstorm the following week will wash it all out onto the mudflow. Indeed, features that seem immense one week will be gone the next and don't even think about trying to spot the same features from year to year!! 

Week 1

Week 2. I kind of think this looks like a face. Particularly Sideshow Bob from the Simpsons. Also, notice that the bush on top in Photo 1 is now gone as are many of the trees.

Well, that is my most interesting experience of geology in action: hanging out in a thaw slump. I hope you enjoyed the read! If you have any questions feel free to ask them. Thanks for reading.


Matt

Look out for bears!!

Sampling the headwall.

The 12 Million Years of Christmas

Well it is the Christmas season so it is time to celebrate! Here is a slightly modified version of the 12 Days of Christmas that is more in keeping with the theme of this blog. I hope you enjoy it!

Santa!!

If you would like to find the tune to sing along here is a link: 

http://www.youtube.com/watch?v=NfeSSqWTSQs

On the first day of Christmas,
my true love sent to me
A T. Rex in a tar pond.

On the second day of Christmas,
my true love sent to me
Two oil wells,
And a T. Rex in a tar pond.

On the third day of Christmas,
my true love sent to me
Three trilobites,
Two oil wells,
And a T. Rex in a tar pond.

On the fourth day of Christmas,
my true love sent to me
Four climbing ripples,
Three trilobites,
Two oil wells,
And a T. Rex in a tar pond.

On the fifth day of Christmas,
my true love sent to me
Five flannel shirts,
Four climbing ripples,
Three trilobites,
Two oil wells,
And a T. Rex in a tar pond.

On the sixth day of Christmas,
my true love sent to me
Six geo's a drinking,
Five flannel shirts,
Four climbing ripples,
Three trilobites,
Two oil wells,
And a T. Rex in a tar pond.

On the seventh day of Christmas,
my true love sent to me
Seven miners a mining,
Six geo's a drinking,
Five flannel shirts,
Four climbing ripples,
Three trilobites,
Two oil wells,
And a T. Rex in a tar pond.

On the eighth day of Christmas,
my true love sent to me
Eight slumps a slumping,
Seven miners a mining,
Six geo's a drinking,
Five flannel shirts,
Four climbing ripples,
Three trilobites,
Two oil wells,
And a T. Rex in a tar pond.

On the ninth day of Christmas,
my true love sent to me
Nine earthquakes trembling,
Eight slumps a slumping,
Seven miners a mining,
Six geo's a drinking,
Five flannel shirts,
Four climbing ripples,
Three trilobites,
Two oil wells,
And a T. Rex in a tar pond.

On the tenth day of Christmas,
my true love sent to me
Ten plates a shifting,
Nine earthquakes trembling,
Eight slumps a slumping,
Seven miners a mining,
Six geo's a drinking,
Five flannel shirts,
Four climbing ripples,
Three trilobites,
Two oil wells,
And a T. Rex in a tar pond.

On the eleventh day of Christmas,
my true love sent to me
Eleven volcanoes erupting,
Ten plates a shifting,
Nine earthquakes trembling,
Eight slumps a slumping,
Seven miners a mining,
Six geo's a drinking,
Five flannel shirts,
Four climbing ripples,
Three trilobites,
Two oil wells,
And a T. Rex in a tar pond.

On the twelfth day of Christmas,
my true love sent to me
Twelve crystals forming,
Eleven volcanoes erupting,
Ten plates a shifting,
Nine earthquakes trembling,
Eight slumps a slumping,
Seven miners a mining,
Six geo's a drinking,
Five flannel shirts,
Four climbing ripples,
Three trilobites,
Two oil wells,
And a T. Rex in a tar pond! 

Hope you liked it.

Matt

GeoMedia: Indisputable evidence of water on Mars!!

The Mars rover Opportunity has found indisputable evidence that water existed on Mars in the form of a vein of the mineral gypsum in bedrock! The vein is about twice the width of a human thumb and half a metre long. This is first direct proof that water existed on Mars and had flowed through a fracture in the rock depositing the gypsum.

This false-color view of a mineral vein called "Homestake" comes from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity. Image Credit: NASA/JPL-Caltech/Cornell/ASU

Gypsum (CaSO4·2(H2O)) is a mineral that is commonly found on Earth often in exactly the same situation as it has been found on Mars. The formation of this vein was likely due to groundwater saturated in calcium and sulphate flowing through a fracture in the bedrock. The highly saturated groundwater then precipitated the gypsum, filling in the fracture and leaving behind a vein of gypsum. Precipitation from water is the only possible way that such a structure could have formed and is the way veins of minerals form on Earth. While this sort of feature is relatively common on Earth, this is the first time it has been seen on Mars. The source of the calcium in the water is believed to be from volcanic rocks that were leached by groundwater. The suphur is likely also from volcanic rocks or volcanic gases that were dissolved in the water as well.

This is not the first time gypsum has been found on Mars as previously gypsum sand dunes had been discovered. However, this is the first time that it has been found in-situ, or where it formed, as opposed to having been eroded and then transported by wind as was the case with the dunes. This means that liquid water actually flowed through this fracture!

For more details here is the link to the NASA article: 

http://www.jpl.nasa.gov/news/news.cfm?release=2011-377&cid=release_2011-377#2

Matt

What is this??

The point of this post is to get you to give me your input on what you think the picture below is. First though, a little backstory...

A few years ago I was on vacation in Australia with a friend. We were travelling around the country and trying to see as much of it as we could. We both felt that a visit to Australia was not complete without a visit to the outback. Luckily, my friend had made some contacts on a previous trip for a school exchange. Therefore, while we were in South Australia we took the bus north to meet up with a friend whose family lived in the outback on a large sheep station about an hour north of Port Augusta, South Australia.

The station was a beautiful place. Wide open spaces with a huge mix of landscapes such as desert, salt flats and the foothills of the Flinders Ranges literally in the backyard. On top of this it was once of the most varied geological environments I have ever visited. All in one small area were limestone beds containing beautiful stromatolites and ripples interbedded with microbial mats.

Stromatolites

Ripples and microbial mats

In addition to these awesome features the station was also home to giant kangaroo bones from the Pleistocene. 

The foot of a Pleistocene kangaroo

The ?femur? of a modern kangaroo being held next to that of a Pleistocene kangaroo.

Aside from the great geological attractions of the station were archaeological curiosities as well such as this aboriginal arrowhead that I found laying in the ground.

Aboriginal arrowhead

However, I digress. The real purpose of this post is to gather your opinion on what you think the upcoming picture is of. I have my own theory, which I will outline below the picture. I apologize for the poor quality. The shape in question was on the bottom of a cliff face which I had to climb up to and then lean out to take a photo of with full zoom. You are viewing this in plan view so imagine a flat surface above your head that contains the shape and you are looking up to see it.

?????????????????????????????????????????????

The rock containing the strange oval shape (~10cm) above is a sandstone and is the bottom of a bedding plane with apparent ripple marks. The red colour is due to iron oxide in the rock staining it red. Any ideas?

My theory, and I like to think that this could be the right one, is that this is a fossil of an extremely ancient organism called Spriggina. Spriggina lived in the Ediacaran, the most recently named of all geologic periods, which spans a time from 635 - 542 million years ago and was the period right before the Cambrian. 

Spriggina. Scale is in mm. (Wikipedia) 

In fact, the name Ediacaran comes from the tiny village of Ediacara, located only a few hundred kilometers north of where I was, in the heart of the Flinders Ranges. Most of the fossils found in the Ediacara area can be seen on the bottom of sandstone bedding planes that contain ripple marks, which is one reason why I think that my picture could be some sort of Ediacaran biota. At least the depositional environment is right as well as the general shape.

The problem with my Spriginna theory is that the fossil in my picture is very large compared to Spriginna fossils that have been found to date which are around 3cm. Who knows though? There are other types of Ediacaran fossils that could also fit the description of this one and maybe it is one of these? Perhaps it is just a strange weathering feature and not even a fossil?

So that is it? What do you think the mystery structure is?

For more information on the Ediacaran see this link: http://en.wikipedia.org/wiki/Ediacara_biota

Matt

Brinicles!

This is just quick post to call attention to something that I think is really cool.

The something that I think is cool is called a brinicle. So what is a brinicle (pronounced: brine-icle)? A brinicle it is a vertical column of ice that forms below sea ice. Sea ice is much fresher than the sea water that it forms from. This means that when sea ice forms it leaves a super-saline brine behind. The super-saline brine that is left out sinks through channels within the ice and back into the ocean below. However, this brine has been cooled by its journey through the ice to very low temperatures which are enough to freeze the water around it as it sinks. This forms a column of ice around the sinking plume of brine leading from the brine channels to the sea floor.

Check out this awesome video by the BBC which is part of the new David Attenborough special "Frozen Planet". I won't go on since you can watch the video and hear it from David Attenborough. Here is a link to the article where I originally saw the video and the video itself.

Enjoy,

Matt

BBC Article: http://www.bbc.co.uk/nature/15835017?ref=nf

The Facts about Fracking

One aspect of geology that has been making the news lately is the practice of hydraulic fracturing. Usually the news about fracking is not very flattering as it seems to shoulder the blame for any sort of groundwater contamination, earthquakes and plagues of locust that should strike. Most reports that concern fracking, properly called hydraulic fracturing, don't adequately explain what it is and why it could be causing all of these problems. However, that is about to end since you can just read the following handy post to learn what the frickin fack is up with fracking.

Why are we fracking?


The first question that we should ask, before discussing what fracking is, is why are are we using hydraulic fracturing and what are its benefits. It's an undeniable fact that the world is highly dependent on fossil fuels for energy, particularly natural gas and oil. However, our thirst for fossil fuels has led to the depletion of most of the easily accessible reserves around the world. This means that oil and gas companies, in their quest to meet demand, are developing new technologies and exploring new regions that were previously overlooked. One new source of natural gas is in shale. Most oil and natural gas is produced in shales due to their high organic content and subsequent heating during lithification (turn to rock). This heating produces oil and natural gas that slowly migrates from the shale into other rocks where it is trapped in what, until recently, were conventional reserves. Oil and gas recovery in the past focused on looking for places where oil and gas was trapped. However, the depletion of these reserves has forced us to look elsewhere, such as in the source rocks like shale, primarily for natural gas and coalbed methane. In theory this sounds great, similar to the old adage: why get an apple from the basket when you can get one from the tree, but in practice things are a little more difficult. The reason for this is that shale is made of very, very fine mineral grains. The natural gas that we would like to recover is trapped in the tiny pore spaces between these grains making it almost impossible to extract. In order to overcome this, the oil and gas industry has been forced to develop new technologies to enhance recovery. One of the most successful, but controversial, is fracking.

What is Hydraulic Fracturing (Fracking)??


The simplest answer to "what is fracking" is that it is a process in which fluids (more on that later) are injected into a borehole to increase pressure. This results in the rock at the bottom of the borehole fracturing. This allows us to recover resources that are hard to get more efficiently.

EPA Hydraulic Fracturing Study Plan, November 2011

A good analogy is to think of a common scenario you likely tried as a kid. Imagine you have a juice box and instead of sucking on the straw (which represents the borehole) you blow into it instead. Most often this increase in pressure results in juice spraying out to top of the straw. However, one day you blow particularly hard, so hard that the sides of your juice box spit open and you experience catastrophic juice spillage on your favourite pants (not that this actually happened to me or anything...) However, the point is that this increase in pressure inside your juice box resulted in the sides splitting. Fracking works on the exact same principle.

What gets injected?


Unfortunately, only the oil companies know the exact answer to this question. However, we do know that the mixture is mainly water with numerous chemical additives.


EPA Hydraulic Fracturing Study Plan, November 2011

 Obviously there is a laundry list of chemicals that may be incorporated. It is worth noting that it would certainly not be beneficial to ingest any of these substances or to find them in groundwater. Furthermore, this is by no means a full list. The above chart is merely and example of some the chemicals you might expect to find in a fracking fluid. The fracking fluid that is used for each well is tailored specifically for that rock formation being targeted in order to maximize recovery.

What are the environmental effects?


One of the most controversial issues with fracking is the potential for environmental harm that may result from the practice. Some of these include surficial spills of the fracking fluid at the well site, contaminating groundwater either through subsurface migration of the fluid, infiltration from a spill, leaking around a bad well casing, or even earthquakes from the injection of the fluids. Furthermore, fracking requires large amounts of water and also produces large amounts of waste water. The problem created by getting this much clean water and then disposing of the resulting waste water also has potential for large environmental impacts on water sources such as local groundwater reserves in terms of both depleting and contaminating them.

EPA Hydraulic Fracturing Study Plan, November 2011

As of now, the impact of fracking is still being studied and moratoriums on drilling and fracking exist in many states and provinces in the U.S. and Canada. To date there have been numerous studies on the environmental impact of fracking and it is essential that these studies be performed in order to truly gauge the impact fracking could have at a particular site.

That is all for now. I realize that I have not addressed some of the more complex issues surrounding fracking. My intention was not to omit any piece of information, but to provide a basic primer about what fracking is and the issues surrounding it. For more detailed information or information about a particular site I encourage you to do more research. Thanks for reading.

Matt

References:

US Environmental Protection Agency: http://water.epa.gov/type/groundwater/uic/class2/hydraulicfracturing/index.cfm

US Environmental Protection Agency Hydraulic Fracturing Study Plan
http://water.epa.gov/type/groundwater/uic/class2/hydraulicfracturing/upload/hf_study_plan_110211_final_508.pdf

Chesapeake Energy - Hydraulic Fracturing Facts
http://www.hydraulicfracturing.com/Process/Pages/information.aspx

Extreme Ice Survey Videos

In my daily procrastinations and surfing through geology news I came across some fantastic time-lapse videos made by Extreme Ice Survey of glaciers in Alaska, Greenland and Iceland. These excellent videos show a series of photos taken every hour during daylight hours. The photos are then put together to create a time lapse video that shows changes in the glacier over a period of a few years. The incredible changes that occur in such a short time are nothing short of awe-inspiring, and this is the best way to see them. These videos show glaciers, long thought of as a slow moving and stationary objects, as dynamic and rapidly changing environments, which is what they really are.

Extreme Ice Survey Logo

The makers of the videos are called "Extreme Ice Survey". Extreme Ice Survey is an organization dedicated to informing the public and scientists about the changes that occur in our environment. EIS was founded by acclaimed nature photojounalist James Balog in 2007 upon seeing the rapid changes in glaciers he was shooting for a National Geographic assignment.

The difficulties of filming in such landscapes are enormous both due to the remoteness of the location and the harsh conditions the crew and materials will experience. I can certainly attest to the challenge of hiking all of your gear into a remote location over the tundra to hang out in a muddy, wet place all day. However, in the case of the EIS crews the difficulties are twofold as they must equip their gear to weather the extreme conditions that it will have to face over the course of the year.

Thanks for reading and again, check out the Extreme Ice Surveys website for more videos, pictures and information.

Matt

Trip to Cantley Quarry

As a graduate student part of my responsibilities besides lab work, data management and beer drinking are acting as a teaching assistant for courses during the academic year. This year I am TA’ing an introductory geology course. Part of the course involves field trips (we would be a pretty crappy geo department if we didn’t take students to the field) to various locations in the Ottawa area. Our most recent trip was to Cantley Quarry in Cantley, Quebec to look at evidence of glacial erosion caused by the Laurentide Ice Sheet during the Pleistocene (see my earlier post on the Pleistocene). The effects of the glaciers are pretty amazing and evident on large scale at Cantley. Here are a few photos taken by Roshenek Sonei, my co-TA.

Huge glacial erosion feature. This is a rat-tail in marble. The gneiss xenolith is to the right of the photo and looks rusty.

 

Another view of the massive rat-tail

Smaller, more well defined rat-tails within a larger rat-tail.

Rat-tail on a vertical section. Note the grooves in front and to the sides of the raised area. Glacial movement was from right to left.

The rock that the glaciers have eroded at Cantley is marble that contains gneiss xenoliths. The gneiss xenoliths are much harder than the surrounding marble and therefore did not erode as easily. This fact is what created the spectacular shapes at Cantley. When the glacier was present at Cantley there was sediment rich water flowing underneath it at high pressure. This water acted like a pressure washer might on your deck. It cleaned everything off the rock and eroded the marble. However, the marble behind the gneiss xenoliths was somewhat protected from the flowing slurry of destruction beneath the glacier and was not eroded. This is why there are so many odd ridge shapes at Cantley. These features are known as rat-tails. A good analogy for the formation of a rat-tail is to look at the way water flows around a bridge pillar. When the water hits the pillar it is pushed back away from the pillar and then wraps around it leaving the area directly behind the pillar protected. The xenoliths acted the same way protecting the marble directly behind them but causing erosion at the edges of the protected area and directly in front of the xenolith.  The other hypothesis for the formation of rat-tails involved direct abrasion by the glacial ice itself, however this theory does not explain the odd direction of some the rat-tails at Cantley as the glacial ice would not have been able to change direction. This suggests the rat-tails were more likely formed by the slurry of destruction that occasionally changed direction due to changes in the pressure regime under the glacier which would be the result of the glacier’s movement or changing size.

One interested piece of information that can be gleaned from looking at rat-tails is the direction the glacier was moving in. This is evident since the xenolith protects the marble behind it. Therefore the glacier must have encountered the xenolith first meaning we can figure out which direction the glacier was moving. At Cantley the direction of glacial movement was roughly from north to south.

Another beautiful glacial feature found at Cantley are striations which are caused by rocks stuck to the bottom of the glacier that are dragged over the rock creating long scratches and grooves. These striations can be several metres in length and create a surface akin to ice after a hockey game. At Cantley the white marble makes it look exactly like that.

Glacial striations

Thanks for reading and if you have any questions or comments about glacial features or glaciers feel free to post them.

Matt

10,000 Views!!!

Hi!

Just a quick little note to celebrate a blog milestone. Today I reached 10,000 views!! Thanks to all of my regular and occasional readers. Stay tuned for lots more to come. I encourage you to comment or participate in this blog and I love hearing from you.

Thanks,

Matt

Interesting Search Terms that Found my Blog

This is an idea that I saw on another geoblog: Georneys, written by Evelyn Mervine. I thought it was quite brilliant. I am continually amazed by the random stuff that people type into their browsers that leads them to my little corner of the internet. Here are a few of the ones that I think are most memorable to date:


hipster geologist (19/07/2011) - haha. flat out hilarious


big fluffy sponge (2/08/2011) - it is kind of comforting to know that I have the big fluffy sponge of blogs


confuciusornis trace metal (3/08/2011) - that is one specific search!


reptile hipped dinosaur (07/08/2011) - just a great thing to see typed into google.


mesozoic poem (29/08/2011) - yeah!!! the trend is spreading!


giant sea turtle from the cretaceous (29/08/2011) - sounds like an old horror movie! daa dum.


radioactive meteorites (30/08/2011) - this would be a good name for a rock band. 
                                                          
philosophy of geology (30/08/2011) - it is good to see that other people think about this too. 


geologic atmospheric time scale (02/09/2011) - I am not too sure what this is. 


old bible pages (08/09/2011) - not something I usually deal with here at GeoSphere.


bill martindale (09/09/2011) - who is looking for bill...??


geologist stereotypes (9 times) - I am glad that others are concerned about this crucial issue.


geosphere and water crystals (14/09/2011) - water crystals...aka...ice.


distance from whitehorse to fort mcpherson (14/09/2011) - far!!!!!!!!!

Randy Marsh - geologist extraordinaire

Field Work 2011

I have just recently returned from a two week field trip to Fort McPherson NWT. So I think it is appropriate to share with you a few of the field highlights and where we were working this year. Therefore, this post will be less sciencey and more about cool travel photos.

Our travels started in Whitehorse, Yukon where we picked up some of our field gear, went grocery shopping and did other necessary running around to get ready for the long car trip north and sampling along the way.

The map above shows the route we took from Whitehorse to Fort McPherson, a total distance of 1,044km. The route we took (the only route) is up the Klondike Hwy to Dawson City. From Dawson we got on the Dempster Highway, which in my opinion is one of the most beautiful but challenging roads in the world. We drove to Eagle Plains, where we spent a very wet night before heading the rest of the way to Fort McPherson. 

The sign marking the beginning of the Dempster Hwy.

Driving the Dempster is a wild ride. As I said I believe it is one of the most beautiful roads in the world, however, it could also be considered one of the most treacherous. It is a long winding, gravel road with lots of changes in elevation. Furthermore, it is greatly affected by changes in weather. On our drive up the Dempster the Eagle Plains area had experienced about a week of rain making the road into a slippery, rutted mud-pit. I think our top speed on that section was about 20 km/hr and it was a nail-biter. The bar at the Eagle Plains hotel (which had no vacancy) was a very welcome sight that evening!!

The Millen Bar at the Eagle Plains Hotel

Once past Eagle Plains the weather cleared and we made good time the rest of the way to McPherson where the actual field work was about to start....

Our field work this year was a bit of a whirlwind. We had lots of work to do and not a lot of time in which to accomplish it. Our site was in a retrogressive thaw slump in the Peel Plateau on the west side of the Peel River. Our plan was to sample ice, soil, peat moss, permafrost and water. For my project I was most interested in the peat and the permafrost samples, but I also assisted with others work as well. To get a feel for the site we were working in here are a few photos of the slump. It is pretty impressive!!

The headwall of the slump is approximately 30m high and is composed mostly of ice interbedded with thin layers of clay (we are working on a hypothesis to explain this). The ice is around 10,000 years old and remains from the time of the last glaciation during the Pleistocene. There is a thin layer of till and peat above the ice, which as the slump grows falls into the basin and down the river valley nearby in the form of a large and destructive mudflow where it eventually empties into the Peel River.

Our work in the slumps investigates why they form and how they stop, the impact they have on the local watershed and the environment. We also do some opportunistic sampling for other projects. For example, I am looking at 129-Iodine in the frozen peat section overlying the ice and others are looking at the impact the slumps have on local fish populations in streams that are affected by the mudflow.

Drilling into frozen peat and till above the headwall of the slumps to collect core. (I am in the checked sweater).

In the future I'll do a post explaining some of more scientific and geological aspects of the slump. Thanks for reading and please feel free to post any questions or comments. Here are a few scenic photos I took on our way back down the Dempster.

On the Dempster driving through the Richardson Mountains close the Yukon/NWT border.

A view of the Ogilvie Mountains

The Tombstone Mountain Range. The top of Tombstone Mountain is obscured by fog.

The Accretionary Wedge #37: Crazy Coral

I have decided to join the ranks of other geology bloggers who participate in the monthly edition of the Accretionary Wedge. The Accretionary Wedge is a blog carnival, a term I was not familiar when I first read it. A blog carnival is simply a monthly collection of posts that are all related to a particular topic and collected in a central location. Since Accretionary Wedge is the geology themed blog carnival it fits beautifully into the mission of this blog.

The topic of the month for August is "Sexy Geology". So what aspect of geology makes my palms sweaty and my heart race? Well, when I was doing my undergraduate I was lucky enough to participate in a sedimentology field trip to Bermuda, where we spent a week snorkelling, swimming and drinking. It was great! One thing that struck me as soon as I got in the water was the diversity and beauty of the coral reefs we were snorkelling on. In short, I thought they were pretty sexy.

Millepora alcicornis (Fire Coral) colonizing a Gorgonian. (Photo: Bill Martindale)

Why do I think coral are so sexy? Well, I could tell you tales about their gently reaching arms and ethereal beauty, but that just wouldn't describe it, although those are fair points for why I like looking at coral.

No, the real reason is more geologically oriented. Corals are some of the most diverse and interesting organisms that inhabit Earth. They have existed for a very long period of time in one form or another and their reef building abilities have been crucial to the evolution of marine life. The rest of this post will examine some of the most interesting features of coral.

Sexy Bermudan coral (Photos: Bill Martindale)

Coral Evolution and Characteristics

Coral as we know it today first evolved in the middle Triassic. However prior to the appearance of today's scleractinian corals there were other reef building organisms that evolved and went extinct throughout geologic time. The earliest reef builders were the stromatolites, which were primitive mounds of photosynthetic cyanobacteria. They were the first large reef builders and were just large colonies of single celled bacteria and sediment. They are mostly found in the fossil record but they do still exist today in one location: Shark Bay, Australia. The early Paleozoic reef builders were mostly dominated by stromatoporoid sponges, which were very similar to modern coral in many respects such as size and shape. Other corals unrelated to those of today also existed during the paleozoic. The late Paleozoic saw the extinction of the stromatoporoids at the end of the Devonian and the rise of reefs made mostly of algae and other encrusting organisms. However, the Mesozoic was a time of massive reef development sparked by the evolution of the scleractinian corals the same order as coral today. There was also a time in the Cretaceous when reefs were built by giant clams called rudists.

Geologic timescale showing episodes of major reef development and the major type of reef building organism (accessscience.com)

Modern corals belong to the phylum Cnidaria, which notably includes jellyfish. Their order is called Scleractinia and is defined by their ability to build skeletal structures of calcium carbonate. Coral are basically composed of two parts: the calcium carbonate skeleton and the living coral polyps, which are similar in appearance and function to the tentacles of a sea anemone or a jellyfish. One of the most unique features of modern coral is their symbiotic relationship with the single celled algae called zooxanthellae. The zooxanthellae live within the tissue of the coral and photosynthesize feeding the coral and helping to produce more calcite. This relationship allows coral to thrive in ocean environments that have very low nutrients, which often prevent other ecosystems from succeeding.

 A cutaway view of a modern scleractinian, zooxanthellate reef coral. Figure shows the massive and complicated underlying skeleton (white), all of which was secreted by the soft polyps and tissue of the living surface (colored). In the cutaway view of one polyp, are seen the tentacles, mouth and enteron, where captured prey are digested. Box in upper left (enlarged), shows a view of a tentacle and the encysted zooxanthellae (round bodies) which reside in great abundance in the endodermal tissues. From Veron (2000).

Coral is a somewhat picky organism with respect to the environment it can thrive in. I suppose part of the sex appeal of coral is the way it plays hard-to-get in most of the ocean. A former professor of mine, Noel James, called this the Goldilocks Principle (I am not sure if he coined this term, but it is still great). The Goldilocks Principle, like it namesake, states that in order for coral to thrive everything must be just right. This means that the temperature, salinity, turbidity, light conditions, wave energy and nutrient levels must all be within a specific range in order for coral to grow. If these conditions change suddenly the coral will die. Talk about needy!!

The Goldilocks Principle

The Importance of Coral

Coral is undoubtedly one of the most important organisms on Earth for a host of reasons. This biggest reason why coral is important to the ocean is the incredible ecosystems that grow and thrive around reefs. Without the coral these diverse, and beautiful reef environments would not exist as the coral provides shelter and a source of food in places where the lack of nutrients would generally inhibit such abundant ecosystems.

Fossilized coral in the sedimentary record is also useful to geologists. When I find coral in the fossil record there are many things it can tell me. The coolest is what the paleoenvironment was. When we look at rocks today it can be very difficult to ascertain what the climate and ocean conditions were like millions of years ago when the rock formed. However, by using the fossils in that sedimentary rock, particularly coral, it is possible to look back in time and see what the environmental conditions were like when the sediment forming that rock was deposited. As I mentioned above coral only grows in a very specific range of ocean conditions. Therefore, if I find coral in a sedimentary rock I know exactly what the ocean conditions were like millions of years ago. Another really useful feature of coral is its shape. All ancient and modern corals have very specific shapes that are dictated by the depth of water they grow in and the wave energy around them. For example, coral that is in shallow water, but has lots of waves will be very robust both now and in the past. However, coral that grows in much deeper water, where there is less light, but no waves, will have large. delicate plate like surfaces to capture as much sunlight as possible. Therefore, when I see coral of a certain shape and growth morphology in the fossil record I can look back in time to discover how deep underwater it was growing and what the wave energy was like.

Zonation of a near shore reef

Current Reef Health


It is no secret that the coral reefs of the world today are threatened and many formerly vibrant reef ecosystems are now bleached skeletons of their former selves. One of the greatest threats to coral are changing ocean conditions. For example, the El Nino event of 1998 led to change in ocean temperature that caused widespread coral bleaching (Souter, 2000) Furthermore, increasing coastal populations are affecting coral by increasing the nutrient load and turbidity near reefs resulting in their death.

Brain coral (Diploria) that is partially bleached

This post turned into more a factual exploration of why I think coral are amazing. All I can say is they rev my engine for a host of reasons. I am off to the Yukon/NWT tomorrow bright and early so stay tuned for a field update with lots of photos of the Arctic in autumn...yeah, it is autumn there.

References:

David W. Souter, Olof Linden, The health and future of coral reef systems, Ocean & Coastal
Management, Volume 43, Issues 8-9, 2000, Pages 657-688, ISSN 0964-5691, DOI:
10.1016/S0964-5691(00)00053-3. 
(http://www.sciencedirect.com/science/article/pii/S0964569100000533) 

Rachel Wood, The Ecological Evolution of Reefs Annual
Review of Ecology and Systematics 
Vol. 29, (1998), pp. 179-206 

Veron, J. E. N., Odorico, D. M., Chen, C. A., & Miller, D. J. (1996). Reassessing
evolutionary relationships of scleractinian corals. Coral Reefs, 15(1), 1-9.

"What we have here is...failure to communicate"

Cool Hand Luke

The issue of nuclear waste disposal is on the mind of every Canadian. The disposal of our nuclear waste poses a difficult and challenging problem and is one that requires huge amounts of study and consultation to address properly. It also seems to raise fear and anger like few other issues in the public eye but the problem remains that we must dispose of our waste safely and for a long time. However, there is a larger problem causing much of the dysfunction that exists in the debate of the storage of nuclear waste.

The problem to which I refer is the gulf that exists between the scientific community and the public. As a scientist who has a large amount of experience observing the public response to nuclear waste (I grew up near Port Hope, Ontario) I feel that I am able to understand both view points and hopefully comment constructively on the division that exists between them.  I will also suggest a few ways in which both sides could unify, as the ultimate goals of both groups are the same: to store nuclear waste safely and responsibly.

In order to address this lack of communication it is important to ask why it exists in the first place, and what factors are perpetuating it despite the best efforts of many scientists and members of the public. The first part of the problem is the overall lack of geoscience education that people are exposed to during their education. In Ontario the last time many people learn about the earth sciences is in Grade 4. Grade 4!! The basic principles of geology are not covered at all later in elementary school or in general high school science classes and many high schools do not offer an earth science course to those interested in pursuing science later in life. Furthermore, most universities do not require those entering science programs to take a geology course. That means that when a geoscientist is attempting to communicate with the public about complex issues, such as waste storage over a one million year time frame, they might as well be talking to a 9 year old; as that is the level understanding the majority of the public and decision makers have. This lack of even the most basic understanding of geologic concepts makes it utterly impossible for geoscientists to communicate effectively. Unfortunately, this lack of communication leads to mistrust, and a communication void, which is eventually filled by the media, who I believe are the primary factor in perpetuating the problem as opposed to solving it.

I realize that the goal of any media story is to inform and educate the public about current events. However, the nature of the media causes it to be driven by sensationalism as opposed to an objective presentation of the facts. The upshot of this is that stories about nuclear waste storage and geology are written not to present information, fact and context, but to cause fear and emotional responses and in doing so, sell the news. This leads to a vicious cycle of fear and sensationalism that not only perpetuates the lack of communication between the science community and the public but also breeds mistrust leading to an ever-widening gulf between the two parties.

I have defined the problem, but how do we overcome the cycle of fear and bad journalism that prevents cooperation and understanding? I have a few suggestions:

1.      As I mentioned above, I believe that the underlying cause of the problem is a basic lack of public education. A long term solution is to introduce a geosciences component into the high school curriculum that focuses on the basic principles of environmental geology that people will encounter in later life such as: hydrogeology or mine waste management. Courses in upper years of high school would also be beneficial, as would a mandatory geology course for science majors entering university. My personal experience is that having an understanding of the geosciences helps me to enjoy and appreciate the complexity of the natural world, thus I do not see this as a horrible imposition upon the education system.  

2.      I believe that the media is one of the major factors in contributing to the poor communication between the scientific community and the public. In fact, by sensationalizing stories, they do their readership a disservice by presenting poorly researched opinion as fact. Most science stories now are not written by science journalists and thus often misrepresent the facts. I feel that an overhaul of science journalism is needed. The media could be a tool for productive communication between scientists and the public, but the focus needs to change to a more objective presentation as opposed to human interest.

3.      Finally, scientists need to improve their skills and outreach in dealing with the public and media. As a scientist it is very easy to become wrapped up in one specific problem and fail to communicate the big picture or long term ramifications of my work. However, when trying to communicate with a lay audience I and others need to remember that we have a responsibility to educate and promote understanding. Opportunities to do this include public lectures and conferences and events. For example, an organization called “Bacon and Eggheads” allows members of parliament to listen to a scientist explain recent advances in science and engineering. More organizations such as this would help to bridge the gap between the public, policy makers, the media and the scientific community.

Well that is all for now. Obviously all of the above is my opinion on these matters, and I encourage readers to add their own opinions in the comments section. How can communication between scientist and the public be improved?