The Earth Story

Glacial Grooves 20,000 years ago, these Ordovician-aged limestones had nearly 2 kilometers of ice sitting on top of them. That ice picked up chunks of rock as it flowed over the landscape, and ground over the limestones. These incredible marks cover the ground on Kelleys Island, today surrounded by Lake Erie and in the state of Ohio. They were exposed at the surface when the ice sheets melted, and the rocks have lightly weathered while exposed to the elements since then. There is a faint pattern moving at an angle to the main grooves, maybe either an earlier ice motion direction or the remnants of streamflow beneath the glacier.

Most of us aren't going to be able to fly anywhere any time soon, but here's a view of what flights used to look like out the front window of a plane. This nighttime voyage on an Air France flight starts off in Chicago and flies over the Great Lakes and eventually Montreal Canada before heading out on the rest of its trip.

Glacial Grooves State Memorial

About 18,000 years ago, a 1.5-kilometer thick glacier scraped along Lake Erie, leaving behind large glacial grooves in the limestone of Kelleys Island; located about 6.5 kilometers off of Ohio’s northern shore. The grooves were initially found, and largely destroyed, by quarry miners in the 1830s; the surviving portion is 122-meters long, 11-meters wide, and 4.5-meters deep. The grooves themselves are long striations caused by subglacial meltwater and embedded rocks in the base of the glacier cutting through the surface of the limestone due to the immense weight of the thick ice pressing down on them. The striations go in the same general direction, allowing scientists to determine which way the glacier was flowing.

The grooves contain marine fossils from the Devonian Sea which dominated the area 350 million years ago. Organisms that died mixed with sediment to become part of the limestone, and some of their remains, such as shells and coral fragments, were cemented into the rock.

The Ohio Historical Society carefully removed the topsoil and sediments from the grooves in 1972, making them one of the largest exposed striations in the world. The area is now protected as Glacial Grooves State Memorial.

Photo Credit: Benny Mazur http://www.flickr.com/photos/benimoto/2548604147

Read More: http://www.stateparks.com/glacial_grooves_state_memorial_in_ohio.html http://geosurvey.ohiodnr.gov/portals/geosurvey/PDFs/Education/el07.pdf http://ohioseagrant.osu.edu/_documents/publications/GS/GS-017%20Kelleys%20Island%20glacial%20grooves.pdf

Fall from above NASA’s Terra satellite captured this picture earlier this week showing the peak of fall colors in upstate New York near the right of this frame. Areas to the south near the bend in the Appalachians of Pennsylvania are starting to turn but aren’t quite there yet and areas heading north up into Canada are at and then slightly past peak fall colors in this frame. -JBB Image credit: https://go.nasa.gov/2lllwmH

Niagara Falls, dry

In 1969, the U.S. Army Corps of Engineers, in coordination with U.S. and Canadian power companies, built a temporary dam to divert part of the Niagara River, which flows between Lake Erie and Lake Ontario.

The water that goes over the American side of Niagara Falls was diverted, part being sent over the neighboring Horseshoe Falls and part being sent through flow paths created for power plants.

The diversion allowed engineers to examine the condition of the riverbed and determine ways to slow down erosion and partially stabilize the position of the falls. Some construction equipment can be seen in this photo doing that work.

A trickle of water continues flowing over the falls, but most of the water has been removed. The scarp over which the falls flow can be clearly seen, as can a large pile of rock debris at the base made up of broken fragments of the Lockport formation; the dolostone which makes up the escarpment.

-JBB

Image credit: William (Bill) Bryan, shared under Flickr license http://www.flickr.com/photos/wbryan/5275141596/in/set-72157594160751442

Info: http://photoblog.nbcnews.com/_news/2010/12/16/5661928-niagara-falls-without-water-as-seen-in-1969

Lake Effect: Restoration Efforts in the Great Lakes

In any map of North America, the Great Lakes draw the eye to their irregular shape, stamped on the continent like an aquatic Rorschach test. Formed after the last glacial period, the five lakes straddle the border between the US and Canada and contain centuries of history in their shipwreck-studded depths. Erie, Ontario, Huron and Michigan, and the largest of them all, Superior, together make up the largest system of fresh surface water in the world, providing drinking water for 40 million people around their shores and generating billions of dollars in revenue from tourism and recreational or commercial boating and fishing.

The Great Lakes play a crucial ecological role, providing critical breeding, feeding, and resting areas for a wide range of native species as well as migration corridors for migratory birds. For many years, though, the lakes have been subject to ecological degradation: polluted by industrial and agricultural activities, invaded by non-native species, and hit by toxic algal blooms. In 2014, for example, 500,000 residents in the city of Toledo, Ohio went without water for three days because of an algal bloom in Lake Erie. We’ve covered the effects of algal blooms before (http://bit.ly/2opK8eo); they happen when runoff of phosphorus-heavy fertilizer from farmlands and feedlots provides a surge in available nutrients for algae in waterways, leading to an explosion of growth.

In 2010, a federal effort called the Great Lakes Restoration Initiative was launched to help strengthen and protect the Great Lakes ecosystem. Previously, target areas of significant degradation had been designated as “Areas of Concern;” the initiative aims to delist all of the US AOCs by funding more than 3,000 projects to rehabilitate the lake environments. To deal with the pollution that causes algal blooms, watershed management programs have partnered with farmers to reduce excess fertilizer runoff, while green infrastructure projects and wetlands restoration in shoreline cities like Chicago, Detroit and Milwaukee reduce urban runoff. In the Toledo area, best practices have been established for farmers, and parks and roadways have been retrofitted with rain gardens and bioswales (landscape elements designed to trap contaminants) to capture and filter runoff into Maumee Bay, the site of the 2014 algal bloom.

Other projects aim to keep the water in the lakes safe for drinking and recreation, control the spread of harmful invasive species, restore natural habitats, and promote the health of endangered and threatened native species like the Canada lynx, piping plover, and the Lake Erie water snake, which is one of only 23 species to be removed from the Endangered Species List due to recovery. In 2016, the five-year program was renewed through 2021 by Congress, which appropriated $300 million per year of funding for the initiative. However, budget proposals for the coming year reduce funding 97%, despite broad bipartisan and local support for the program.

Live in the Great Lakes watershed and want to see what the GLRI has done for your town or county? You can find an interactive map and list of projects here: www.glri.us

-CEL

Sources: https://www.glri.us/ http://bit.ly/2nwXAcI http://bit.ly/2oxuif0 http://nyti.ms/2n1o7CH http://bit.ly/2ns1fw2 http://bit.ly/2nLt5Rv http://bit.ly/2nZDMll http://bit.ly/2nOd3HX Images: 1. NASA (https://go.nasa.gov/2opXeZM), 2. An algal bloom in Lake Erie. 3. A water snake in Lake Erie. 2&3: NYT (http://nyti.ms/2n1GyXZ)

Huntington Beach Ohio

This photographer was in the right place at the right time as he captured this stunning shot of lightening striking off shore at Huntington Beach, Ohio.

-LL

Image; James Larkin

Nice view of Lake Erie through the trees.

Niagara Falls

We all know it; we are all impressed with its beauty. But do we all know how it was actually formed?

Towards the end of the last Ice Age, something like 12,000 years ago, retreating glaciers gouged out what would become the Great Lakes and caused the formation of the Niagara River, which runs between Lake Erie and Lake Ontario. The course of the river has changed a number of times since its formation, settling into the present one about 5,000 years ago. This flows over the Niagara Escarpment and, because the river is split into channels by Goat Island, the water forms three waterfalls, the Horseshoe, or Canadian, Falls, the American Falls and the smaller Bridal Veil Falls. Immediately below the falls themselves, the river turns at an abrupt right angle, forming the Whirlpool, and continues through the Whirlpool rapids. Both the falls and the rapids are the largest such features in North America and, although the falls themselves are not particularly high, at about 170ft (52m), they are very wide. The largest, the Horseshoe Falls, are about 2,600ft (790m) wide and get their name from their shape, where the rock of the escarpment has eroded to form a semicircular drop.

The name is an adaptation of the original Native American name of Onguiaahra, which means ‘Thunder of Water’ and refers, of course, to the huge noise of such a large volume of water crashing over the falls. The water itself is famously blue-green in colour, a feature remarked upon by Charles Dickens when he visited in 1842, and is caused by its high mineral content, gained from the eroding properties of its turbulence. This erosion was causing the falls to retreat by about 4ft (1.2m) a year until, at the start of the 20th century, water began to be diverted away from the falls to power hydroelectric generating plants. The amount of water diverted has increased over the years, particularly at night, and this, together with preventative engineering measures, has reduced the erosion considerably.

The edges of the falls have been strengthened and weirs built to redirect the most destructive currents. In 1969 the Niagara River was directed away from the American Falls for several months, by an earth dam constructed across the mouth of the channel leading to it, while faults in the rock were stabilised. The faults had previously led to a huge rock fall from the face of the falls, forming a large pile of scree (a mass of small loose stones that form or cover a slope on a mountain) that can be seen at the base of the falls today. Luna Island, the small piece of ground separating the American Falls from the Bridal Veil Falls, has been off-limits to the public for years because it is thought to be unstable as a result of cracking in the rock and it could collapse at any time.

~ JM

Image Credit: Labelled for reuse: http://bit.ly/1Hsqg9A Accessed on 26/06/16

More info: Niagara Parks. Facts & Figures: http://bit.ly/R0g1WJ Tesmer, I. H., & Bastedo, J. C. (1981). Colossal Cataract: The Geologic History of Niagara Falls. SUNY Press. Grabau, A. W. (1901). Guide to the geology and paleontology of Niagara Falls and vicinity (Vol. 7, No. 1). University of the State of New York. Philbrick, S. S. (1970). Horizontal configuration and the rate of erosion of Niagara Falls. Geological Society of America Bulletin, 81(12), 3723-3732.

Phosphorus storage

Phosphorus is a nutrient in high demand by life. It’s a major component of fertilizers and a component of sewage, so there are huge supplies of it carried downstream by rivers. Phosphorus is also a nutrient for organisms that live in lakes, rivers, and the ocean, so too much phosphorus also causes blooms of algae, using up oxygen other organisms need and sometimes releasing toxins that can make people sick. Managing phosphorus therefore is a major environmental issue, particularly in heavy agricultural areas.

In many areas, phosphorus usage has gone through a cycle. After phosphorus based fertilizers were developed in the early part of the 20th century, phosphorus usage skyrocketed in areas like Europe and the US. However, after environmental regulations were established and costs of fertilizers began increasing, phosphorus deployment decreased.

To understand how this deployment cycle affected pollution in the oceans, scientists led by Dr. Powers from the Center for Environmental Research, Education, and Outreach in Washington conducted a survey of phosphorus flows recorded leaving three rivers and combined it with a survey of phosphorus usage in the river basin.

The Thames River basin saw a rapid increase in phosphorus usage starting in the first half of the 20th century, but for the next 5 decades more phosphorus was used on the land than came out of the river. Around the year 1990, phosphorus usage in the Thames basin began declining, but interestingly phosphorus kept flowing out of the river. Total phosphorus in Thames River sediment did start to decline, but nowhere near as fast as phosphorus usage on land. Today, more phosphorus is leaving the Thames basin than is used as fertilizer.

Records for the Maumee River in Ohio, which contributes directly to algal blooms in Lake Erie, show a similar effect. Phosphorus usage in the basin has been declining since the 1970s, but phosphorus flows in the river have been increasing the entire time, and today more phosphorus flows into the lake than is used in the basin.

The measurements from these rivers suggest phosphorus has a long residence time in the river basins. It gets stored for some time, either in the sediments, soil, or in the groundwater, and releases gradually over time. Even dramatic cuts in phosphorus usage will take decades to translate to substantial cuts in nutrient pollution to lakes and oceans.

The most extreme location found by the researchers is the Yangtze River (Cháng Jiāng) in China. Phosphorus usage in that basin has skyrocketed since 1990 and as of right now the flows from the river represent only about 40% of the total phosphorus usage in the basin. Even if phosphorus usage started dropping today, outflows down that river will likely increase for years to begin removing the nutrient already present in that river basin.

-JBB

Image credit: Chelys http://bit.ly/1Txx6zT

Reference/Original Paper: http://bit.ly/1UL1V9k

More: https://www.epa.gov/nutrientpollution/problem

Sunset over Lake Erie, note the waves in the clouds overhead.

Are extreme Algal blooms about to become a common occurrence?

An algal bloom is the rapid accumulation of (usually microscopic) algae in an aquatic system. This can be either marine of freshwater based. Usually only 1 species is involved in an algal bloom, and many blooms are recognised due to the discolouration of large areas of water. There's no recognised number for what constitutes an algal bloom, but typically blooms occur when cells reach thousands to hundred of thousands per millilitre, although, some blooms have recorded up to millions of cells per millilitre. Depending on species the colour of blooms can differ, but typically they are a bright green. Cyanobacteria (also known as blue-green algae) are responsible for bright green blooms, and those blooms that are harmful, known as "red tides" are caused by the dinoflagellate genus Alexandrium and Karenia or diatoms of the genus Pseudo-nitzschia.

Freshwater algal blooms are usually the result of an excess of nutrients (normally phosphorous) entering the system. The origins of the excess nutrients vary, but common culprits include pesticides (from agriculture) and run off water containing chemicals from house hold cleaning products. Excess amounts of nitrogen and carbon have also been implicated in various studies.

The excess of nutrients causes increased growth in algae, and when the algal dies, conditions can be anoxic and levels of oxygen can become to low for normal aquatic life to survive.

In 2011 Lake Erie (located in North America) experienced a record breaking algal bloom, caused by the algae microcystis aeruginosa. This algae can be harmful to mammals, and produces a liver toxin that can be fatal to dogs that have swum in affected waters. The cause of the bloom is complex and not fully understood, but some causes cited are increased rainfall in Spring (increasing run off) and an invasive species of mussel that was found in the lake. After the bloom began, several days of low surface winds across the lake coupled with increased temperatures caused the algae to "boom" and their numbers increased on the surface.

New research conducted by the Carnegie institutes Anna Michalak has concluded that unless agricultural practices are reviewed, the algal bloom seen at Lake Erie in 2011 may not longer become a record breaking rare occurrence, but rather a common "normal" event. Research has also suggests that wind patterns, and the overall amount of wind is decreasing across the United States. This is turn will effect the amount of mixing occurring in the water column, and will see conditions optimal for algal blooms likely to increase.

-LL

Links; http://www.sciencedaily.com/releases/2013/04/130401151026.htm

http://earthobservatory.nasa.gov/IOTD/view.php?id=76127

http://www.sciencedaily.com/articles/a/algal_bloom.htm

http://www.nrm.qld.gov.au/water/blue_green/

Image; NASA

Year to year

It’s a little bit cold in the frame of this image tonight. However, it’s pretty clear that the current winter is no where near measuring up to how cold it was last winter. In January and February of 2015, temperatures plummeted across North America consistently, locking the area around the Great Lakes in an Arctic Deep Freeze. By the end of winter in 2015 Lake Erie was about 95% frozen. This year, it has stayed around 10%.

Ice cover on these lakes is a major contributor to the weather in the surrounding area. When the lake water is exposed, it evaporates, creating a water supply that can cause lake effect snow downwind of the lakes. We’re getting plenty of that today, since it’s cold and windy over these unfrozen lakes. When the lakes freeze over, evaporation nearly stops, cutting off lake effect snow (and in fact, keeping the lake levels higher throughout the year).

-JBB

Image credit: NASA/NWS/Tom Nizol https://twitter.com/TomNiziol/status/697442395177295873

Reference: http://www.glerl.noaa.gov/res/glcfs/glcfs-ice.php?lake=e&type=N&hr=00

Geology of New England, 1826 #tbt

I was so excited when I found this image that I wasted time I should have been working on an abstract. Oops. This was just too neat.

This is a gigantic geologic cross section of New England drawn about 130 years before the acceptance of plate tectonics. It starts on the left in Boston Harbor and ends in the right at Lake Erie. Some noteable places like Boston, Syracuse, and Utica give context for the cross section.

There’s so much content on here that gives insight to how early geologists viewed this continent – rocks that were gradually folded, single units of shale or greywacke running across half the section, missing faults, but mostly granite/gneiss bodies rising upwards inexplicably to make up the cores of mountain ranges. The Old Red Sandstone, one of the most famous units from Great Britain, even makes an appearance. Today we understand that plate tectonic processes have often caused those igneous cores to be thrust upwards by faults and that some of the igneous rocks west of Boston actually are an accreted island arc terrane.

This file was published last week and made available under a creative commons license from the collections of the New York Public Library. Look closer and see what else you can find.

-JBB

Image credit: The Miriam and Ira D. Wallach Division of Art, Prints and Photographs: Print Collection, The New York Public Library. "Geological profile extending from the Atlantic to Lake Erie." New York Public Library Digital Collections. http://digitalcollections.nypl.org/items/510d47d9-7f0e-a3d9-e040-e00a18064a99

Couple excellent frames of Niagara Falls.