Posts Tagged "patagonia"

Glaciers Influence Marine Invertebrates in Chile

Posted by on Feb 25, 2015 in All Posts, Featured Posts, Science, Uncategorized | 0 comments

Glaciers Influence Marine Invertebrates in Chile

Spread the News:ShareZooplankton are tiny creatures that drift in water bodies. A recent study by Meerhoff et al. in Progress in Oceanography describes linkages which connect them with glaciers. The researchers observed meroplankton—organisms which have planktonic features in their larval stages, but live sessile in the bottom as adults. They worked in the fjords of the Baker River, which is located between the Northern and Southern Patagonian ice fields in Chile. Physical and chemical conditions vary widely in these fjords, due to tides and to seasonal fluctuations in glacier meltwater and other contributions to river flow. These varying conditions, in turn, influence the dynamics of zooplankton communities, including productivity patterns, biomass, and community structure (the distribution and interactions of different species). Zooplankton community dynamics in fjords are influenced by the strong vertical and horizontal gradients in hydrographic structure, such as freshwater discharge and tides. Studies have shown that temporal and spatial distributions of zooplankton are controlled by environmental conditions. Temperatures influence temporal scale by influencing metabolic rates and swimming behaviors of zooplankton. The salinity of water constrains the spatial distribution of estuarine zooplankton because each species can tolerate only certain levels of salinity. These two environmental factors also influence food availability and predation stress, which also affects the community structure of zooplankton. The input of freshwater from glacial meltwater can change salinity, generate internal tides and reshape the circulation pattern in estuarine systems. Moreover, the turbidity of the water is influenced by glacial input. Even though the glaciers are virtually pristine, the meltwater is able to carry sediments along its way, known as rock flour. These finely ground particles, formed by the interaction of glaciers with their beds, are so small that they remain in suspension, making the water less transparent. This increase in turbidity limits light penetration and thus restricts primary production through photosynthesis by phytoplankton—the minute plants which float in the water column. Using vertical tows, Meerhoff and her associates collected samples in three sites close to the river mouth, during the Baker river minimum outflow season (October 2012) and during the maximum outflow season (February 2013). They observed strong hydrographic gradients, both horizontal and vertical, in early spring (October) and late summer (February). They have also found that these two seasons are significantly distinct in water-column conditions. Such variations are largely caused by freshwater discharges from nearby glaciers. This study found a number of kinds of meroplankton in these fjords; the dominant organisms are larval forms of barnacles, squat lobsters, crabs, snails and bivalves. The study also indicated that zooplankton community shows seasonal variations. Specifically, barnacle larvae are favored in spring, when river outflow is at its minimum, while its food sources, phytoplankton, are more abundant. In contrast, bivalve larvae are dominant in summer due to higher surface water temperature. At this time, river outflow is at its maximum and phytoplankton availability is much lower than in spring, reflecting the greater turbidity of the water that carries glacier rock flour. Studies are needed to demonstrate whether bivalve larvae in this estuary feed on bacteria when phytoplankton are unavailable, as they do in other regions. This study shows how freshwater input, along with other factors, affects zooplankton composition and distribution. It is remarkable to think of the numerous marine invertebrate larvae whose populations respond to glaciers located well inland of their estuarine home. Look here for other stories about invertebrate life near and on glaciers. Spread the...

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Photo Friday: The Frozen Diamonds in Patagonia

Posted by on Oct 10, 2014 in All Posts, Art/Culture, Featured Posts, Images, News | 1 comment

Photo Friday: The Frozen Diamonds in Patagonia

Spread the News:ShareA Glaciers Photo Contest was held last summer by ViewBug and Resource Magazine. It is difficult to capture galciers due to the size, location, and reflection of light. However, the winner of this contest, Paul Cashman, mastered the task with “The Coldest Shots of Patagonia“. In order to well capture these cold giants, he traveled to Torres Del Paine and Mount Fitzroy in Chile and Argentina where most of the pictures were taken. Check out the wining photo of Paul Cashman and more photos for this project, or visit his website. Photo Friday highlights photo essays and collections from areas with glaciers. If you have photos you’d like to share, let us know in the comments, by Twitter @glacierhub or email us at glacierhub@gmail.com. Perito Moreno Glacier The Coldest Shots of Patagonia (source: © Paul Cashman) Perito Moreno Glacier Glaciers Photo Contest Winning Photo (source: © Paul Cashman) Perito Moreno Glacier The Coldest Shots of Patagonia (source: © Paul Cashman) Perito Moreno Glacier The Coldest Shots of Patagonia (source: © Paul Cashman) Perito Moreno Glacier The Coldest Shots of Patagonia (source: © Paul Cashman) Perito Moreno Glacier The Coldest Shots of Patagonia (source: © Paul Cashman) Perito Moreno Glacier The Coldest Shots of Patagonia (source: © Paul Cashman) Perito Moreno Glacier The Coldest Shots of Patagonia (source: © Paul Cashman) Spread the...

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Photo Friday: Glaciers for all seasons in Patagonia

Posted by on Aug 29, 2014 in All Posts, Communities, Featured Posts, Images, Tourism | 0 comments

Photo Friday: Glaciers for all seasons in Patagonia

Spread the News:SharePatagonia’s stunning scenery was the reason this area of southern Argentina became the namesake of the popular brand of outdoor clothing. Photographer Alex Proimos photographed its glacier ice caves, mountain lakes and the impressive Fitz Roy mountain in 2011. See more pictures from his trip in his Flickr gallery. Photo Friday highlights photo essays and collections from areas with glaciers. If you have photos you’d like to share, let us know in the comments, by Twitter @glacierhub or email us at glacierhub@gmail.com. _MG_2434 El Chaltén, a well-known spot for trekking and hiking, is a small village of 1,000 people located 216 km (134 miles) from El Calafate. Its tourist infrastructure is very limited and intended for hikers. Most of the expeditions to the Fitz Roy and Torre mountains depart from here.(Alex E. Promios/Flickr) _MG_2822 The Glacier and Cerro Torre. (Alex E. Promios/Flickr) IMG_2640 Fitz Roy and the Lagunas. (Alex E. Promios/Flickr) _MG_2124 Perito Moreno Tour Boat (Alex E. Promios/Flickr) IMG_2116 Perito Moreno Glacier Ice Cave (Alex E. Promios/Flickr) _MG_2075 Glazing at the Ice. (Alex E. Promios/Flickr) IMG_1998 A trip to this imposing glacier gives you a chance to walk on the ice wearing cleats and to see and hear a truly astounding spectacle: blocks of ice rupturing and floating away as icebergs. (Alex E. Promios/Flickr) Spread the...

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