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‘Thumbs Up’ for Travel to Kullorsuaq

Greenland Thaw: Measuring Change - Thu, 07/17/2014 - 16:46
The local coastline has been steeped in fog which prevents helicopters from flying the Upernavik to Kullorsuaq leg. (Photo M. Turrin)

The local coastline has been steeped in fog which prevents helicopters from flying the Upernavik to Kullorsuaq leg. (Photo M. Turrin)

For the last few days we have been laying the groundwork for getting to Kullorsuaq.  We have missed flights due to engine difficulties and have been grounded due to dense fog along the coastline. Today we are assured the helicopter will fly, taking us to our science destination.

While waiting at the airport for our helicopter, a small plane arrives from Upernavik filled with a local sports team decorated with medals hanging from ribbons around their necks. Tossing coins in celebration is part of the reception. (Photo M. Turrin)

While waiting at the airport for our helicopter, a small plane arrives from Upernavik filled with a local sports team decorated with medals hanging from ribbons around their necks. Tossing coins and a Greenlandic cheer set against the fjord is part of the celebration. (Photo M. Turrin)

Our flight is delayed a few hours due to low-lying fog. At the small airport a smiling woman approaches us asking our plans in one word “Kullorsuaq?”  We smile and nod and she grins broadly motioning that she and her daughter are going there too – it is their home she manages to convey.

Landing at the Kullorsuaq ‘helipad’. The helipad is surrounded by canisters of gasoline used to refuel for the return leg. The local transport of luggage and gear is a front loader that delivers the gear to your door. (Photo M. Turrin)

Landing at the Kullorsuaq ‘helipad’. The helipad is surrounded by canisters of gasoline used to refuel for the return leg. The local transport of luggage and gear is a front loader that delivers the gear to your door. (Photo M. Turrin)

Community turns out to wait for helicopter.  Child is holding a Greenlandic flag. (Photo M. Turrin)

Community turns out to wait for helicopter. Child is holding a Greenlandic flag. (Photo M. Turrin)

There are five on our helicopter, our friend from the airport and her young daughter and another woman who slides to the middle seat and willingly becomes our ‘navigator’, pointing on the map and motioning in gestures to us regularly. She mimes birds, seals, steep cliffs, and finally the thumb that marks our final destination – Kullorsuaq, or Big Thumb, named for the prominent thumb shaped rock that projects skyward in the middle of the small island. Some maps use the Danish name Djoevelens Tommelfinger (Devil’s Thumb) a name that Edvard had noted was in reference to the difficult currents that in stormy conditions can surround the island and threaten a boat.

 

 

 

 

 

 

Kullorsuaq Island, Greenland -  the Big Thumb. (Photo M. Turrin)

Kullorsuaq Island, Greenland – the Big Thumb. (Photo M. Turrin)

Now that we have arrived in Kullorsuaq we are in reach of the fjord we have come to measure. Communication is a challenge – a word or two meets with smiles and agreement but ‘hello’ and ‘bye’ seem to be the extent for most.  The village is small, overlooking a southern spur on the main fjord.  Our goal is to travel to the north where Alison glacier empties, so we climb to a high point to see if we can get a better idea of the ice extent.  From our vantage we can see open water, which is encouraging, but we don’t have a view of the full fjord where conditions may differ.

Overlooking the small village of Kullorsuaq. (Photo M. Turrin)

Overlooking the small village of Kullorsuaq. (Photo M. Turrin)

A check in later with the science team in Kangerlussuaq gives us the disappointing news that the satellite image shows that sometime between the 8th and 11th Alison fjord has filled with mélange (chunks of ice). The innermost data points will be unreachable unless conditions change so we will spend a few hours re-planning collection points so we are ready if current conditions persist. Tomorrow the teacher we have been in contact with in the local school is due to return and we can begin to build connections with the local community members, asking for their help in traveling into the fjord.

Looking down on the bay from atop the western end of Kullorsuaq. (Photo M. Turrin)

Looking down on the bay from atop the western end of Kullorsuaq. (Photo M. Turrin)

Project Information: Dave Porter and Margie Turrin are in northwest Greenland working with local community members to collect water column temperature profiles. The Leveraging Local Knowledge project will work with members of local Greenlandic communities to collect water measurements in the fjords. This will assist in determining if warming Atlantic Ocean water is circulating up through Baffin Bay where it enters the fjords to lap against the frozen glacier footholds, causing them to loosen their hold on the rock below. Alison Glacier (74.37N and 56.08W) is selected as the project focus. Emptying into Melville Bay to the east of Kullorsuaq Island and has been undergoing dramatic change over the last decade.

The project is funded by the Lamont Climate Center with support from the NASA Interdisciplinary Program and logistical support from NSF.

http://www.ldeo.columbia.edu/~dporter/Kullorsuaq/

Dead Giraffe?! Weirdest Things Found in NYC Waters - LiveScience

Featured News - Thu, 07/17/2014 - 14:25
From a robotic hand to a dead giraffe, lots of strange objects were found in and around New York's waters through geophysical surveys led by Lamont-Doherty scientists.

U.S. Raises Threat of Quake but Lowers Risk for Towers - New York Times

Featured News - Thu, 07/17/2014 - 11:00
"Where you should really be worried in New York City is the common brownstone and apartment building and buildings that are poorly maintained,” said Lamont-Doherty seismologist John Armbruster.

The Son of a Hunter

Greenland Thaw: Measuring Change - Mon, 07/14/2014 - 21:36
Dave (r) speaks with Edvard (l) about his life as a young Greenlandic growing up as the son of a hunter. (Photo M. Turrin)

Dave (r) speaks with Edvard (l) about his life as a young Greenlandic growing up as the son of a hunter. (Photo M. Turrin)

A visit to the Upernavik museum brought us to ‘Edvard’ a young Greenlandic and the local museum curator.  Embracing the opportunity to practice his English he enthusiastically spent time sharing the historic art and past of the community and his experiences as a young adult growing up in a Greenland that is shifting from one set of cultural norms to another.

Greenlandic mythology (photo M. Turrin)

Greenlandic mythology image (photo M. Turrin)

The first building of the museum is dedicated to traditional Greenlandic art.  An entire room is filled with the creatures of Greenlandic mythology dating back to well before the Danish arrived in the land. The focus of the art revolves around the challenge of the life of a hunter: Ingnerssuit the underground spirits who weep with the springtime cracking of the ice which ends the winter hunt season; Imap Ukua, mother of the sea who must right the evil deeds of all mankind by releasing the seals that have become bound, thus enabling the hunters’ success; Anguit the spirit and looks like a seal who guides the success of the hunt.

The second building is filled with skins, boats and the tools of the hunt.  Seals dominate the display but a walrus and narwal are also on exhibit.  The life of a hunter is hard, it is a test of strength, seal against man.  Edvard explains that one will lose and it is sometimes the hunter.  A choice must be made whether to release the catch or be pulled to their death.  It takes physical strength, understanding of the situation and conditions and the ability to judge when to continue and when to let go of the hunt. A hunter is a respected member of the community, there is much to know in being a good hunter.

Greenlandic (harp) seal skin with the horseshoe shape on its back. (Photo M. Turrin)

Greenlandic (harp) seal skin with the horseshoe shape on its back. (Photo M. Turrin)

Here Edvard begins to talk of his own father, born a hunter. For many years he supported his family hunting seal, polar bear and whale.  Both Menke & Narwal (monodon monoceros – meaning one horn one tooth) were part of his catches over the years. He loved the life of a hunter and Edvard, his son, was anxious to join in his trips, asking as a young son if he too could go.  His father was careful in sharing this hunting life with his son, seeing that change was coming and that the life of a hunter was no longer going to be a way for many of the people.  He did not want Edvard to join him in hunting for fear he would like it too much, for he know that Edvard was born with a hunter’s spirit just as he was himself.  He wanted his son to be free to have a different life.

Anguit, in Greenlandic mythology the spirit who looks like a seal and guides the success of the hunt. (Photo M. Turrin)

Anguit, in Greenlandic mythology the spirit who looks like a seal and guides the success of the hunt. (Photo M. Turrin)

By 2000 Edward’s father’s love for hunting could not continue to sustain their family.  The ice season had shortened, and the changes in the ice meant that he could hunt for only 5 or 6 months, not enough to support his family.  For musk ox there was a lottery designed to ensure that not too many were taken, while offering a protection for the animal it caused problems for the hunters who depended on their meat and skins. Hunters today must also be fishermen taking advantage of the open water where the ice once filled the bay. That is a hard life.

Ingnerssuit the underground spirits who weep with the springtime cracking of the ice which ends the winter hunt season (Photo M. Turrin)

Ingnerssuit the underground spirits who weep with the springtime cracking of the ice which ends the winter hunt season (Photo M. Turrin)

Edvard’s father now drives a truck in the town hunting only as a hobby, able to join a friend who continues to fish and hunt for a livelihood.  The knowledge of where the prey will be, the water depths and currents, all the pieces that are essential to a successful hunter are still valued, but the changed conditions means there is not the ability to support all who once hunted. The changes in the ice are having a direct impact on the Greenlandic people.  Perhaps we should turn to the Greenlandic mythological spirits and ask for their help.  Where are Anguit and Imap Ukua?  Are the Ingerssuit weeping so loudly the other gods can not hear?

Project Information: Dave Porter and Margie Turrin are in northwest Greenland working with local community members to collect water column temperature profiles. The Leveraging Local Knowledge project will work with members of local Greenlandic communities to collect water measurements in the fjords. This will assist in determining if warming Atlantic Ocean water is circulating up through Baffin Bay where it enters the fjords to lap against the frozen glacier footholds, causing them to loosen their hold on the rock below. Alison Glacier (74.37N and 56.08W) is selected as the project focus. Emptying into Melville Bay to the east of Kullorsuaq Island and has been undergoing dramatic change over the last decade.

The project is funded by the Lamont Climate Center with support from the NASA Interdisciplinary Program and logistical support from NSF.

http://www.ldeo.columbia.edu/~dporter/Kullorsuaq/

The Changing Upernavik Waterfront

Greenland Thaw: Measuring Change - Mon, 07/14/2014 - 07:01

Leveraging Local Knowledge to Measure Greenland Fjords: Understanding the Community 

GreenlandicLight2Sm

Project location. Currently we are located in Upernavik prior to moving on to Kullorsuaq.

Project location. Currently we are located in Upernavik prior to moving on to Kullorsuaq.

Project Background: Changing conditions in Greenland’s northwest glaciers over the last decade have led to a range of questions about water temperature and circulation patterns in the fjords where ocean water meets the glacial fronts.  We can use satellites to measure the loss of elevation, the acceleration of ice flow, or the retreat of ice from a glacier, but we can’t use satellite measurements to collect water column temperature profiles. Water column profiles would allow us to better determine how much melt is possible at the glacier connection to the ocean, and help us pinpoint why neighboring glaciers are behaving differently.

The Leveraging Local Knowledge project will work with members of local Greenlandic communities to collect water measurements in the fjords. This will assist in determining if warming Atlantic Ocean water is circulating up through Baffin Bay where it enters the fjords to lap against the frozen glacier footholds, causing them to loosen their hold on the rock below. Alison Glacier (74.37N and 56.08W) is selected as the project focus. Emptying into Melville Bay to the east of Kullorsuaq Island and has been undergoing dramatic change over the last decade.

Our Journey: Our research trip to the small village of Kullorsuaq is a journey that will start 200 kms to the south in the community of Upernavik, located 800 kms north of the Arctic Circle. Flying in on a small 37 seat Dash 7 airplane we overlook a coastline that is lined with glaciers flowing into a bay that is dotted with islands.  Most are uninhabited, but Upernavik is home to a population of 1500 permanent residents. An island community, the main employment is fishing with the waterfront sporting a range of both commercial and smaller independent fishing boats.

Fishing

Fishing is a major occupation in this waterfront community (Photo M. Turrin)

Upernavik town was established by the Danes in the late 1700s but trade and a religious mission in the early 1800s cemented it as a permanent settlement. The southern end of the island is dotted with a cross covered graveyard representing the religion the Danish settlers brought and the practice of the current community. Christmas, Three Kings Day and other religious holidays are all causes for the community to celebrate. This week the priest will visit Upernavik to celebrate three weddings (Friday and Saturday) and the Confirmation (Sunday).  With all such events scheduled for when the priest can preside the parties and celebrations will involve the whole community for days. Celebration and gatherings are a large part of this community’s practice.

Upernavik graveyard (Photo M. Turrin)

Upernavik graveyard (Photo M. Turrin)

The Setting: The icebergs being sloughed from the neighboring glaciers dominate the horizon, littering the waterfront with ice ranging from house-sized blocks to looming masses that appear as large as the neighboring islands. Looking around at the open water it is hard to imagine the origin of these large masses of ice.  The closest blocks of ice move during the course of the day, shifting back and forth from north to south and back again.  With the shifting and changing of the icebergs the sound of the settling and collapsing of ice is drilled into our consciousness – the sharp crack of the ice as if fractures and the larger canon-like rumble as sections break and fall into the water.

Large Iceberg on the waterfront (Photo M. Turrin)

Large Iceberg on the waterfront (Photo M. Turrin)

Our local host, a Dane who has lived in Upernavik for 40 years, has fully blended himself into the community where he and his family are well known and liked by both the Inuit and the Danish population. When he learns of our project he observes that in his time here ice cover has significantly changed. He recalls his early years here when the ice in May was so solid in the bay that visiting boats had to drop dynamite on the ice to open a pathway. He points to the open water and the line of haze that hangs on the horizon offering a cause, ‘global heating’.

The Community of Upernavik (Photo M. Turrin)

The Community of Upernavik (Photo M. Turrin)

Other changes have hit Upernavik.  We meet a Danish couple who had spent 4 years living in the community, now returning after 30 years to ‘close out their memories’.  They spoke with fondness of this lost time when they raised their small children as they worked as a teacher and a nurse.  With a team of 10 dogs ‘Lars’ had hunted Greenlandic seal and still had a sharp eye picking a bobbing seal head out on the horizon. They spoke of the people numbering 900 while the Greenlandic dogs had numbered 3000, many times more than the dogs are now. Dogsleds were an important part of that older Upernavik when individual hunting and fishing were the mainstay of the community. While hunting and fishing are still important today Lars notes that things have changed becoming less rugged for an individual. Whether the changes in ice cover have played a part in this is hard to determine.

Bear Skin

Polar Bearskin hangs off front porch in Upernavik (Photo M. Turrin)

In our few days here in Upernavik we learn that residents are happy to help, they have networks that reach from one island community to another.  Names and contacts are offered freely – “try this person for a place to stay”, “this teacher may be interested in helping you”.  It is this networking of local people that we will rely on for the project. Their overall interest in what is happening to their community will be an important part of its long term success.

Glaciers in Upernavik Waterfront (Photo M. Turrin)

Icebergs in Upernavik Waterfront (Photo M. Turrin)

 

Leveraging Local Knowledge to Measure Greenland Fjords:
Dave Porter and Margie Turrin are in northwest Greenland working with local community members to collect water column temperature profiles.  The project is funded by a Lamont Climate Center grant with support from the NASA Interdisciplinary Program and logistical support from NSF.

http://www.ldeo.columbia.edu/~dporter/Kullorsuaq/

 

 

The Changing Upernavik Waterfront

Arctic Thaw: Measuring Change - Mon, 07/14/2014 - 07:01

Leveraging Local Knowledge to Measure Greenland Fjords: Understanding the Community 

GreenlandicLight2Sm

Project location. Currently we are located in Upernavik prior to moving on to Kullorsuaq.

Project location. Currently we are located in Upernavik prior to moving on to Kullorsuaq.

Project Background: Changing conditions in Greenland’s northwest glaciers over the last decade have led to a range of questions about water temperature and circulation patterns in the fjords where ocean water meets the glacial fronts.  We can use satellites to measure the loss of elevation, the acceleration of ice flow, or the retreat of ice from a glacier, but we can’t use satellite measurements to collect water column temperature profiles. Water column profiles would allow us to better determine how much melt is possible at the glacier connection to the ocean, and help us pinpoint why neighboring glaciers are behaving differently.

The Leveraging Local Knowledge project will work with members of local Greenlandic communities to collect water measurements in the fjords. This will assist in determining if warming Atlantic Ocean water is circulating up through Baffin Bay where it enters the fjords to lap against the frozen glacier footholds, causing them to loosen their hold on the rock below. Alison Glacier (74.37N and 56.08W) is selected as the project focus. Emptying into Melville Bay to the east of Kullorsuaq Island and has been undergoing dramatic change over the last decade.

Our Journey: Our research trip to the small village of Kullorsuaq is a journey that will start 200 kms to the south in the community of Upernavik, located 800 kms north of the Arctic Circle. Flying in on a small 37 seat Dash 7 airplane we overlook a coastline that is lined with glaciers flowing into a bay that is dotted with islands.  Most are uninhabited, but Upernavik is home to a population of 1500 permanent residents. An island community, the main employment is fishing with the waterfront sporting a range of both commercial and smaller independent fishing boats.

Fishing

Fishing is a major occupation in this waterfront community (Photo M. Turrin)

Upernavik town was established by the Danes in the late 1700s but trade and a religious mission in the early 1800s cemented it as a permanent settlement. The southern end of the island is dotted with a cross covered graveyard representing the religion the Danish settlers brought and the practice of the current community. Christmas, Three Kings Day and other religious holidays are all causes for the community to celebrate. This week the priest will visit Upernavik to celebrate three weddings (Friday and Saturday) and the Confirmation (Sunday).  With all such events scheduled for when the priest can preside the parties and celebrations will involve the whole community for days. Celebration and gatherings are a large part of this community’s practice.

Upernavik graveyard (Photo M. Turrin)

Upernavik graveyard (Photo M. Turrin)

The Setting: The icebergs being sloughed from the neighboring glaciers dominate the horizon, littering the waterfront with ice ranging from house-sized blocks to looming masses that appear as large as the neighboring islands. Looking around at the open water it is hard to imagine the origin of these large masses of ice.  The closest blocks of ice move during the course of the day, shifting back and forth from north to south and back again.  With the shifting and changing of the icebergs the sound of the settling and collapsing of ice is drilled into our consciousness – the sharp crack of the ice as if fractures and the larger canon-like rumble as sections break and fall into the water.

Large Iceberg on the waterfront (Photo M. Turrin)

Large Iceberg on the waterfront (Photo M. Turrin)

Our local host, a Dane who has lived in Upernavik for 40 years, has fully blended himself into the community where he and his family are well known and liked by both the Inuit and the Danish population. When he learns of our project he observes that in his time here ice cover has significantly changed. He recalls his early years here when the ice in May was so solid in the bay that visiting boats had to drop dynamite on the ice to open a pathway. He points to the open water and the line of haze that hangs on the horizon offering a cause, ‘global heating’.

The Community of Upernavik (Photo M. Turrin)

The Community of Upernavik (Photo M. Turrin)

Other changes have hit Upernavik.  We meet a Danish couple who had spent 4 years living in the community, now returning after 30 years to ‘close out their memories’.  They spoke with fondness of this lost time when they raised their small children as they worked as a teacher and a nurse.  With a team of 10 dogs ‘Lars’ had hunted Greenlandic seal and still had a sharp eye picking a bobbing seal head out on the horizon. They spoke of the people numbering 900 while the Greenlandic dogs had numbered 3000, many times more than the dogs are now. Dogsleds were an important part of that older Upernavik when individual hunting and fishing were the mainstay of the community. While hunting and fishing are still important today Lars notes that things have changed becoming less rugged for an individual. Whether the changes in ice cover have played a part in this is hard to determine.

Bear Skin

Polar Bearskin hangs off front porch in Upernavik (Photo M. Turrin)

In our few days here in Upernavik we learn that residents are happy to help, they have networks that reach from one island community to another.  Names and contacts are offered freely – “try this person for a place to stay”, “this teacher may be interested in helping you”.  It is this networking of local people that we will rely on for the project. Their overall interest in what is happening to their community will be an important part of its long term success.

Glaciers in Upernavik Waterfront (Photo M. Turrin)

Icebergs in Upernavik Waterfront (Photo M. Turrin)

 

Leveraging Local Knowledge to Measure Greenland Fjords:
Dave Porter and Margie Turrin are in northwest Greenland working with local community members to collect water column temperature profiles.  The project is funded by a Lamont Climate Center grant with support from the NASA Interdisciplinary Program and logistical support from NSF.

http://www.ldeo.columbia.edu/~dporter/Kullorsuaq/

 

 

Unlocking the Cascadia Subduction Zone's Secrets - Earth magazine

Featured News - Fri, 07/11/2014 - 09:43
Coverage of research on the R/V Langseth led by Lamont-Doherty geophysicist Suzanne Carbotte.

Iron Fingerprints

Geopoetry - Fri, 07/11/2014 - 00:20
Jacques Descloitres, MODIS Rapid Response Team, NASA/GSFC (reposted from Nature.com)

Saharan dust in the wind. Photo: Jacques Descloitres, MODIS Rapid Response Team, NASA/GSFC (reposted from Nature.com)

 

Metals galore in deep Earth,

But at the sea surface, a dearth.

Iron is key

For greening the sea …

To planktic cells, gold has less worth.

 

Whence this precious resource?

Isotopes hint at the source.

Dust takes the lead,

While vents slowly bleed,

Could inputs affect climate’s course?

 

_________________________________

Further reading:

Ocean chemistry: Fingerprints of a trace nutrient, Resing and Barrett, Nature 2014

Quantification of dissolved iron sources to the North Atlantic Ocean, Conway and John, Nature 2014

This is one in a series of poems written by Katherine Allen, a researcher in geochemistry and paleoclimate at the Lamont-Doherty Earth Observatory.

Sustainability Science Requires the Freedom to Observe and Understand the Planet - Huffington Post

Featured News - Thu, 07/10/2014 - 11:00
Op-Ed coauthored by Lamont-Doherty director Sean Solomon and deputy director Arthur Lerner-Lam.

Glacier Marks on Mount Chirripó

Sculpting Tropical Peaks - Wed, 07/09/2014 - 15:39

By Max Cunningham
June 12, 2014
We continued to sample boulders in Valle de Las Morrenas, Valle Talari, where the hostel sits, and several places along Mount Chirripó’s ridgeline.

Max 7.1

Large boulders of granodiorite line the ridge of Mount Chirripó. These are likely produced by exfoliation, a process that occurs in response to stress release associated with the melting of glacier ice.

The view from the top of Mount Chirripó is spectacular.  Looking out along the ridge I could see huge boulders of granodiorite produced by exfoliation, or the response of rock at the surface to the removal of ice.

Max 7.2

Striations in the meta-sandstone at the summit of Mount Chirripó point down the axis of Valle de Los Lagos, (a mechanical pencil and sample bag are included in the picture for scale, the pencil points in the direction of striations). Striae are a telltale sign of glacial coverage.

The actual summit of Chirripó, however, is a very different kind of rock.  I believe the peak is composed of a sedimentary rock that was melted and then fused back together as the magma that formed the granodiorite rocks moved toward the surface.  This metamorphosed sandstone (meta-sandstone) is extremely hard, and resistant to weathering processes.

In the meta-sandstone near the summit of Mount Chirripó, I discovered glacial striations.  These striations occur at 12,513 feet (the summit is 12,529 feet), which is a good 1,000 feet above the moraines in the upper portion of Valle de Las Morrenas.

Back to Mount Chirripó

Sculpting Tropical Peaks - Tue, 07/08/2014 - 11:14

By Max Cunningham
June 11, 2014

 Volunteers  at the Cloudbridge Reserve stay in a series of houses built in the Costa Rican rainforest.   They work towards returning mountainsides near Mount Chirripó to natural conditions.

Volunteers at the Cloudbridge Reserve are returning the hills near Mount Chirripó to natural conditions.

Mike and I hiked down 7,000 feet from Mount Chirripó to the Cloudbridge
Reserve early on the morning of June 10th to refuel and replenish supplies.

At this point, the Cloudbridge Reserve deserves a special mention.  Tucked away in the forest above San Gerardo de Rivas, volunteers at the Cloudbridge Reserve work to transform old farmland into natural forest.  After the cold ruggedness of the Mount Chirripó summit, the volunteers at Cloudbridge provided an exceptionally welcoming and engaging environment.  Mike and I were extremely lucky to have such a supportive base camp.

I kept an eye out for interesting geomorphology as I walked along the trails of the Cloudbridge Reserve.  The rivers here are particularly beautiful.  The water is clear and blue, and channel beds are floored by bedrock and boulders (all granodioritic in composition, like many of the rocks atop Mount Chirripó).  I was struck by the power of the local rivers; the erosional features carved into this hard, granodioritic rock were impressive.

The raging Chirripó River cuts through granodiorite, about 1 mile away from the Cloudbridge Reserve.

The raging Chirripó River cuts through granodiorite, about 1 mile away from the Cloudbridge Reserve.

After two days of rest and catching up on all we’d missed while isolated on Costa Rica’s highest peak, Mike and I headed back up to Mount Chirripó to continue sampling and to learn more about the processes shaping this landscape.

During our second journey, we hoped to extend our sampling range by venturing farther into glacial valleys and higher onto peaks.  We targeted Valle de Las Morrenas, a valley that we knew well from our first sampling trip and that other researchers had discussed extensively.

Earlier, we sampled boulders from moraines adjacent to large lakes.  This time, we targeted a steep drop-off (what we called a “lip) that occurs in the valley directly below the lakes.  Looking at maps and satellite images, it appeared that the lower valley was actually a remnant cirque:

A 60-foot drop-off separates the upper and lower valleys in this picture.  The lip may represent the retreat of a large glacier that once filled lower Valle de Las Morrenas.

A 60-foot drop-off separates the upper and lower valleys in this picture. The lip may represent the retreat of a large glacier that once filled lower Valle de Las Morrenas.

Our discovery of a large lateral moraine in the lower valley corroborated our hypothesis that a glacier produced the pronounced lip in Valle de Las Morrenas.  The vegetative cover increased substantially as we moved lower in the valley, which made accessing the moraine a real challenge.  After pushing through thick, woody bushes, we finally found ourselves on the crest of the moraine.

From the image it’s hard to tell, but this is actually a pretty big moraine, Max 6.4about 50-60 feet in height.  Meandering rivers cut through cobbles along the moraine’s edge, analogous to what we saw in Sabana de los Leones, only here with water raging through the channel.

Max 6.5We quickly came to realize that the boulder selection on the crest of this lower moraine was a far cry from the beautiful, large, flat boulders we saw along moraines in the upper valley.  Here, boulders seemed to be more deeply weathered, and more sparsely scattered.

While the lack of good boulders for sampling induced a bit of hand wringing (made worse by storm clouds quickly moving up the valley), the effectiveness of weathering on these boulders may add to the story of glaciation at Mount Chirripó.  Deep weathering of boulders suggests that they have been sitting around, exposed to the atmosphere, for a long time.  How long?  Glaciologists have employed relative weathering techniques for centuries to estimate exposure age, but 10-Be dating will tell us for sure.

 

 

Hudson Highlands Earthquake Prompts Questions - (Rockland, N.Y.) Journal News

Featured News - Tue, 07/08/2014 - 10:09
Lamont's John Armbruster discusses the magnitude 2.5 quake that struck Garrison on July 5.

Did Halley’s Comet Convert the Irish to Christianity? - Smithsonian Channel

Featured News - Tue, 07/08/2014 - 09:57
Lamont's Dallas Abbott and the Lamont-Doherty Core Repository appear in a new documentary linking the passing of Halley's Comet 5,000 years ago to a change in Ireland's religious beliefs.

Small Earthquake Recorded in Hudson Valley - WAMC

Featured News - Mon, 07/07/2014 - 11:00
Features Lamont-Doherty seismologist Leonardo Seeber.

Earthquake Hits Hudson Highlands - (Rockland, N.Y.) Journal News

Featured News - Sat, 07/05/2014 - 11:00
The Lamont-Doherty seismic network records a magnitude 2.5 earthquake in the Hudson Highlands, in Garrison, New York.

Nuclear Power: Worst-Case Recalibration - Capital New York

Featured News - Wed, 07/02/2014 - 13:41
Lamont-Doherty seismologist Lynn Sykes highlights the risks that were unknown at Indian Point nuclear power plant at the time it was built.

Editorial: Towns Can Avoid Fracking Future - (Rockland, N.Y,) Journal News

Featured News - Tue, 07/01/2014 - 14:40
Cites research linking disposal of waste fracking fluid to earthquakes.

Lamont-Doherty Researchers Make Their Mark on the Map - Columbia Record

Featured News - Tue, 07/01/2014 - 11:00
Feature on map features named for Lamont scientists.

Global Warming Makes Drought Come on Earlier, Faster, and Harder - Guardian

Featured News - Mon, 06/30/2014 - 11:13
A new study coauthored by Lamont's Richard Seager tries to separate natural and human influences on drought.

Australopithecene Dental Calculus

Geopoetry - Fri, 06/27/2014 - 09:36
 AG Henry, Nature, 2012.

Phytoliths — mineral particles formed by plants — found in the teeth of one of our ancient ancestors. Photo: AG Henry, Nature, 2012.

Across a mixed landscape, Au. sediba plods
Sometimes on two feet, and sometimes on four,
Munching on fruits and leguminous pods,
Nuts and some seeds … C3 foods galore!
They did have a choice (so coprolites hint);
Lush grasses, fat grazers were also around,
But in these old ancestors (destined for flint?)
New clues, new stories have just now been found.
With lasers and microscopes, old dental plaque –
Tiny, stuck phytoliths show a rich diet!
Scratched-up enamel, it all brings us back
To lives of these creatures that have long been quiet.
What wonders are learned from plaque and from feces,
History bound in compounds beneath!
So, we should say to that wonderful species:
Thanks for not brushing your teeth!

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Further reading:

Palaeoanthropology: The ancestral dinner table, Nature, 2012

The diet of Australopithecus sediba, Amanda G. Henry et al., Nature, 2012

This is one in a series of poems written by Katherine Allen, a researcher in geochemistry and paleoclimate at the Lamont-Doherty Earth Observatory

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