Dogs are animals of integrity. We have much to learn from them.
Category: Environment
Back to more dog pictures from Unsplash.
Photo by Ramin Talebi on Unsplash
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Photo by Ramin Talebi on Unsplash
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Photo by Erin Minuskin on Unsplash
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Photo by Dylan Shaw on Unsplash
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Photo by Anantha Krishnan on Unsplash
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Photo by Hope Frock on Unsplash
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Photo by Karen Mork on Unsplash
That is all for this week. Be safe!
The atmospheric river in California is reaching up to Southern Oregon
After we had the thick end of twelve inches of rain in January, February has kept up the downpours; as of yesterday morning we had had 0.52 inches (1.32 cm) for the month and it was still raining. (And 0.8 in at 08:00 this morning.)
Here’s an item from yesterday about the situation in California.
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By Qian Cao, University of California, San Diego
A series of atmospheric rivers is bringing the threat of heavy downpours, flooding, mudslides and avalanches to the Pacific Northwest and California this week. While these storms are dreaded for the damage they can cause, they are also essential to the region’s water supply, particularly in California, as Qian Cao, a hydrologist at the University of California, San Diego, explains.
An atmospheric river is a narrow corridor or filament of concentrated water vapor transported in the atmosphere. It’s like a river in the sky that can be 1,000 miles long. On average, atmospheric rivers have about twice the regular flow of the Amazon River.
When atmospheric rivers run up against mountains or run into local atmospheric dynamics and are forced to ascend, the moisture they carry cools and condenses, so they can produce intense rainfall or snowfall. https://www.youtube.com/embed/w3rtYM0HtIM?wmode=transparent&start=0 A satellite view of atmospheric rivers.
Atmospheric rivers occur all over the world, most commonly in the mid-latitudes. They form when large-scale weather patterns align to create narrow channels, or filaments, of intense moisture transport. These start over warm water, typically tropical oceans, and are guided toward the coast by low-level jet streams ahead of cold fronts of extratropical cyclones.
Along the U.S. West Coast, the Pacific Ocean serves as the reservoir of moisture for the storm, and the mountain ranges act as barriers, which is why the western sides of the coastal ranges and Sierra Nevada see so much rain and snow.
Consecutive atmospheric rivers, known as AR families, can cause significant flooding.
The first heavy downpours saturate the ground. As consecutive storms arrive, their precipitation falls on soil that can’t absorb more water. That contributes to more runoff. Rivers and streams fill up. In the meantime, there may be snowmelt due to warm temperatures, further adding to the runoff and flood risk.
California experienced a historic run of nine consecutive atmospheric rivers in the span of three weeks in December 2022 and January 2023. The storms helped bring most reservoirs back to historical averages in 2023 after several drought years, but they also produced damaging floods and debris flows.
The cause of AR families is an active area of research. Compared with single atmospheric river events, AR families tend to be associated with lower atmospheric pressure heights across the North Pacific, higher pressure heights over the subtropics, a stronger and more zonally elongated jet stream and warmer tropical air temperatures.
Large-scale weather patterns and climate phenomena such as the Madden-Julian Oscillation, or MJO, also play an important role in the generation of AR families. An active MJO shift occurred during the early 2023 events, tilting the odds toward increased atmospheric river activity over California.
A recent study by scientists at Stanford and the University of Florida found that storms within AR families cause three to four times more economic damage when the storms arrive back to back than they would have caused by themselves.
I’m a research hydrologist, so I focus on hydrological impacts of atmospheric rivers. Although they can lead to flood hazards, atmospheric rivers are also essential to the Western water supply. Atmospheric rivers have been responsible for ending more than a third of the region’s major droughts, including the severe California drought of 2012-16.
Atmospheric rivers provide an average of 30% to 50% of the West Coast’s annual precipitation.
They also contribute to the snowpack, which provides a significant portion of California’s year-round water supply.
In an average year, one to two extreme atmospheric rivers with snow will be the dominant contributors to the snowpack in the Sierra Nevada. Together, atmospheric rivers will contribute about 30% to 40% of an average season’s total snow accumulation there.
That’s why my colleagues at the Center for Western Weather and Water Extremes at the Scripps Institution of Oceanography, part of the University of California, San Diego, work on improving atmospheric river forecasts and predictions. Water managers need to be able to regulate reservoirs and figure out how much water they can save for the dry season while still leaving room in the reservoirs to manage flood risk from future storms.
As global temperatures rise in the future, we can expect more intense atmospheric rivers, leading to an increase in heavy and extreme precipitation events.
My research also shows that more atmospheric rivers are likely to occur concurrently during already wet conditions. So, the chance of extreme flooding also increases. Another study, by scientists from the University of Washington, suggests that there will be a seasonal shift to more atmospheric rivers earlier in the rainy season.
There will likely also be more year-to-year variability in the total annual precipitation, particularly in California, as a study by my colleagues at the Center for Western Weather and Water Extremes projects.
Qian Cao, Hydrologist, Center For Western Weather and Water Extremes, University of California, San Diego
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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PBS have also presented an item on what is an atmospheric river. Their article starts:
Forecasters warned of dangerous flooding, heavy mountain snow and a heightened risk of mudslides and avalanches Feb. 4-6, 2024, as a powerful atmospheric river took aim at California. It’s the latest in a series of atmospheric rivers to bring extreme rainfall to the West Coast.
Qian Cao
I sense many things are changing and the challenge is not to let one’s imagination go into overdrive.
Man’s First Friend
Last Sunday Jean and I watched a Top Documentary Film about the origins of dogs. It was filmed in 2018 and was precious.
Here are the words that accompanied the film:
He has been an integral part of our existence for over 20,000 years. Throughout history, his contributions have been diverse and invaluable. He’s aided us in procuring sustenance, safeguarded our domesticated animals, served as a shield against adversaries, provided navigation during harsh conditions, and rescued us from imminent danger.
Presently, he offers solace, alleviating solitude and assisting us in managing the challenges of advancing age. He has evolved into an unwavering comrade. The origins of dogs raise intriguing questions: How did these remarkable creatures emerge? How did they ascend to such prominence in our lives? How did we forge a collaborative relationship, leveraging their distinct abilities? Moreover, what remarkable feats do they accomplish for us in contemporary times?
Prepare to embark on a journey that unveils the extraordinary escapades of these exceptional beings, showcasing their heroic deeds. Transitioning from wild wolves to beloved companions, from predatory instincts to steadfast friendship, we will traverse the globe to narrate the captivating narrative of how dogs earned their title: man’s first friend.
Director: Frédéric Fougea
Luckily the film, that runs for 90 minutes, is available on YouTube.
Here it is:
If you haven’t seen the film then, please, put some time aside to watch it. You will not be disappointed.
We pass from 2023 into 2024.
So here we are, 2024, and the year when I become 80! However, I still have eleven months before that happens. Like an amazing number of people, I do not really think long about this New Year but there are plenty that do.
Here is an article that explains much more. It is from The Conversation.
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Rosalyn R. LaPier, University of Montana
On the day of winter solstice, many Native American communities will hold religious ceremonies or community events.
The winter solstice is the day of the year when the Northern Hemisphere has the fewest hours of sunlight and the Southern Hemisphere has the most. For indigenous peoples, it has been a time to honor their ancient sun deity. They passed their knowledge down to successive generations through complex stories and ritual practices.
As a scholar of the environmental and Native American religion, I believe, there is much to learn from ancient religious practices.
For decades, scholars have studied the astronomical observations that ancient indigenous people made and sought to understand their meaning.
One such place was at Cahokia, near the Mississippi River in what is now Illinois across from St. Louis.
In Cahokia, indigenous people built numerous temple pyramids or mounds, similar to the structures built by the Aztecs in Mexico, over a thousand years ago. Among their constructions, what most stands out is an intriguing structure made up of wooden posts arranged in a circle, known today as “Woodhenge.”
To understand the purpose of Woodhenge, scientists watched the sun rise from this structure on winter solstice. What they found was telling: The sun aligned with both Woodhenge and the top of a temple mound – a temple built on top of a pyramid with a flat top – in the distance. They also found that the sun aligns with a different temple mound on summer solstice.
Archaeological evidence suggests that the people of Cahokia venerated the sun as a deity. Scholars believe that ancient indigenous societies observed the solar system carefully and wove that knowledge into their architecture.
Scientists have speculated that the Cahokia held rituals to honor the sun as a giver of life and for the new agricultural year.
Zuni Pueblo is a contemporary example of indigenous people with an agricultural society in western New Mexico. They grow corn, beans, squash, sunflowers and more. Each year they hold annual harvest festivals and numerous religious ceremonies, including at the winter solstice.
At the time of the winter solstice they hold a multiday celebration, known as the Shalako festival. The days for the celebration are selected by the religious leaders. The Zuni are intensely private, and most events are not for public viewing.
But what is shared with the public is near the end of the ceremony, when six Zuni men dress up and embody the spirit of giant bird deities. These men carry the Zuni prayers for rain “to all the corners of the earth.” The Zuni deities are believed to provide “blessings” and “balance” for the coming seasons and agricultural year.
As religion scholar Tisa Wenger writes, “The Zuni believe their ceremonies are necessary not just for the well-being of the tribe but for “the entire world.”
Not all indigenous peoples ritualized the winter solstice with a ceremony. But that doesn’t mean they didn’t find other ways to celebrate.
The Blackfeet tribe in Montana, where I am a member, historically kept a calendar of astronomical events. They marked the time of the winter solstice and the “return” of the sun or “Naatosi” on its annual journey. They also faced their tipis – or portable conical tents – east toward the rising sun.
They rarely held large religious gatherings in the winter. Instead the Blackfeet viewed the time of the winter solstice as a time for games and community dances. As a child, my grandmother enjoyed attending community dances at the time of the winter solstice. She remembered that each community held their own gatherings, with unique drumming, singing and dance styles.
Later, in my own research, I learned that the Blackfeet moved their dances and ceremonies during the early reservation years from times on their religious calendar to times acceptable to the U.S. government. The dances held at the time of the solstice were moved to Christmas Day or to New Year’s Eve.
Today, my family still spends the darkest days of winter playing card games and attending the local community dances, much like my grandmother did.
Although some winter solstice traditions have changed over time, they are still a reminder of indigenous peoples understanding of the intricate workings of the solar system. Or as the Zuni Pueblo’s rituals for all peoples of the earth demonstrate – of an ancient understanding of the interconnectedness of the world.
(This article is republished from The Conversation under a Creative Commons license. Read the original article.)
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Jean and I wish you all a Very Happy 2024. Please be safe and careful, and be happy!
A woman who knew no bounds when it came to rescuing three large dogs.
This is such a beautiful account of Veronica Shea taking action, and personal risks, to provide, firstly trust, and then love for Princess George, Grace and Steve, as they were named. The story was published on The Dodo.
Please read for yourself.
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Woman Visits Mountain Every Day To Convince Huge Dogs To Let Her Rescue Them
Published on the 26th October, 2023
In 2020, Veronica Shea was out hiking with her dog in the Angeles National Forest in California, when she spotted something strange moving ahead of them.
“We whip around the curve, and I look over and there was this huge black thing,” Shea told The Dodo. “He went up the side of a cliff.”
Shea followed the furry animal and came face to face with three malnourished dogs alone in the wilderness. Realizing the dogs had been abandoned, she knew she had to help them. Every day for several weeks, Shea trudged up the mountain to feed the dogs and work on gaining their trust.
Slowly, the dogs got used to her and even began eating out of her hand. But Shea had no idea how to get them off the mountain. If she trapped one dog, would the others flee? She knew she couldn’t do it alone.
When she asked for help, a whole team of rescuers stepped forward. Together, they carried equipment up the mountain and put together a makeshift cage. The rescuers carefully lured the dogs inside and carried them down the mountain.
The three dogs —mastiffs named Princess George, Grace and Steve, who are believed to be siblings — were safe now. But they still had a long journey ahead.
The rescuers approached Cheri Wulff Lucas, a well known dog behaviorist and trainer in California, to see if she could help the nervous dogs learn to trust again.
“They weren’t adoptable the way they came,” Lucas told The Dodo. “They couldn’t be touched. They couldn’t be leashed. They were just terrified.”
Princess George, Grace and Steve responded well to Lucas’ training. Still, they continued to have a “very strong startle reflex,” said Lucas. This made it difficult to find them the perfect home.
“It was going to take a very special home for them to go into because they’re not the kind of dogs that are going to go to the dog park,” Lucas said. “Even walking them on city streets would be a lot for them. And if they do spook, they weigh 125 pounds, so [they would be] very hard to contain.”
But Lucas knew the dogs were safe on her own property.
“I’m out in the middle of nowhere,” Lucas said. “There’s no traffic around here. You can’t even see another home from here. So if they did get out, they would just come back here to me.”
While Lucas never planned on keeping the dogs herself, that’s exactly what she ended up doing. This turned out to be the best decision for everyone. Princess George, Grace, and Steve continued to live in a safe and supportive environment. And Lucas discovered that the dogs could help her with her work as a trainer.
“If I get dogs that needs socialization — to be more familiar and less reactive with other dogs — I use my pack to help rehabilitate them,” Lucas said. “And all three of them are highly social with dogs. They know how to smell properly, how to not overpower the dog that needs the socialization. They’re just flawless. And that’s not something I taught them — they came that way.”
The threesome were particularly helpful when Lucas started working with another dog named Andi, who was rescued from a hoarding case.
“She had lived in a pen for seven years without human touch or being leashed or anything and she was terrified,” Lucas said. “They just came in and really made her feel comfortable. It was really sweet to see. They brought her around in a way that I never could as a human.”
Lucas ended up adopting Andi as well, bringing her personal pack of dogs to 12.
Princess George, Grace and Steve have been living with Lucas now for over three years, and they’re completely different dogs now.
“They’re incredibly playful,” Lucas said. “If you came to my house and did not know their backstory, you would think they were like any other dog.”
Lucas describes George as a “couch potato” who loves hanging around the house and socializing with the other dogs. Steve is the one who likes to play endless games of “chase” out in the yard. Grace remains a bit timid, but she shares a very close relationship with Steve.
“They’re pets — they’re really pets now,” she said. “They’re not cases for me anymore.”
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Lucas sums it up perfectly in that last sentence; “They’re pets – they’re really pets now,“
Lucas reminds me of Jean for when we first met, in December 2007, Jean had more than twenty dogs at home, all rescues, and led to me publishing my first book in 2009: Learning from Dogs.
Some fantastic photographs of owls!
This is a change of subject for today’s Picture Parade.
I have been for some time complimenting my son on his brilliant photographs. I have been admiring them on Instagram but, of course, one cannot copy them from there. So Alex sent me the following by email.
Plus, Alex has rightly copyrighted these photographs and also states that his Instagram profile is @Alex_handover_photography. There are more of Alex’s photographs to admire over on Instagram.
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These are fabulous and just endorses the care and attention that Alex puts into his photography.
Hannah Ritchie raises a very important question.
I was born in London before the end of World War II and to a great extent my upbringing was in the times of yesterday. But the world has moved on in many, many ways. It is too easy to say that we live in very strange times.
Thus it was enlightening to come across this talk, under the TED Talks banner, quite recently. I have great pleasure in sharing it with you. Plus, Hannah’s website is here. (From which I have taken the following words!)
(P.S. The YouTube video is just over thirteen minutes long. It automatically runs into the next video so you will have to stop it yourself.)
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The word “sustainability” gets thrown around a lot these days. But what does it actually mean for humanity to be sustainable? Environmental data scientist Hannah Ritchie digs into the numbers behind human progress across centuries, unpacking why the conventional understanding of sustainability is misleading and showing how we can be the first generation of humans to actually achieve it.
Hannah Ritchie is deputy editor and research lead at Our World in Data, an online publication making data and research on the world’s largest problems accessible and understandable for non-experts. She is a senior researcher at the University of Oxford, where she studies how environmental issues intersect with others like poverty, global health and education. She has also done extensive research into the question of how to feed everyone in the world a nutritious diet without wrecking the planet. Her work has appeared in The New York Times, The Washington Post, Vox, Wired, BBC, Al Jazeera, The Economist and New Scientist.
In 2022, Ritchie was named Scotland’s Youth Climate Champion. She is also an honorary fellow at the University of Edinburgh and Edinburgh Centre for Carbon Innovation, and a fellow at the Energy for Growth Hub, focused on ending global energy poverty. Her forthcoming book, The First Generation, makes an evidence-based case for why we have a meaningful chance to solve global environmental problems for the first time in human history.
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It is a very inspiring talk; please watch it!
I am reproducing a recent article published by The Conversation.
It is a reflection of the latest research undertaken by NASA, it is beyond fascinating!
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Ryan Keeley, University of California, Merced
Astronomers have known for decades that the universe is expanding. When they use telescopes to observe faraway galaxies, they see that these galaxies are moving away from Earth.
To astronomers, the wavelength of light a galaxy emits is longer the faster the galaxy is moving away from us. The farther away the galaxy is, the more its light has shifted toward the longer wavelengths on the red side of the spectrum – so the higher the “redshift.”
Because the speed of light is finite, fast, but not infinitely fast, seeing something far away means we’re looking at the thing how it looked in the past. With distant, high-redshift galaxies, we’re seeing the galaxy when the universe was in a younger state. So “high redshift” corresponds to the early times in the universe, and “low redshift” corresponds to the late times in the universe.
But as astronomers have studied these distances, they’ve learned that the universe is not just expanding – its rate of expansion is accelerating. And that expansion rate is even faster than the leading theory predicts it should be, leaving cosmologists like me puzzled and looking for new explanations.
Scientists call the source of this acceleration dark energy. We’re not quite sure what drives dark energy or how it works, but we think its behavior could be explained by a cosmological constant, which is a property of spacetime that contributes to the expansion of the universe.
Albert Einstein originally came up with this constant – he marked it with a lambda in his theory of general relativity. With a cosmological constant, as the universe expands, the energy density of the cosmological constant stays the same.
Imagine a box full of particles. If the volume of the box increases, the density of particles would decrease as they spread out to take up all the space in the box. Now imagine the same box, but as the volume increases, the density of the particles stays the same.
It doesn’t seem intuitive, right? That the energy density of the cosmological constant does not decrease as the universe expands is, of course, very weird, but this property helps explain the accelerating universe.
Right now, the leading theory, or standard model, of cosmology is called “Lambda CDM.” Lambda denotes the cosmological constant describing dark energy, and CDM stands for cold dark matter. This model describes both the acceleration of the universe in its late stages as well as the expansion rate in its early days.
Specifically, the Lambda CDM explains observations of the cosmic microwave background, which is the afterglow of microwave radiation from when the universe was in a “hot, dense state” about 300,000 years after the Big Bang. Observations using the Planck satellite, which measures the cosmic microwave background, led scientists to create the Lambda CDM model.
Fitting the Lambda CDM model to the cosmic microwave background allows physicists to predict the value of the Hubble constant, which isn’t actually a constant but a measurement describing the universe’s current expansion rate.
But the Lambda CDM model isn’t perfect. The expansion rate scientists have calculated by measuring distances to galaxies, and the expansion rate as described in Lambda CDM using observations of the cosmic microwave background, don’t line up. Astrophysicists call that disagreement the Hubble tension.
Over the past few years, I’ve been researching ways to explain this Hubble tension. The tension may be indicating that the Lambda CDM model is incomplete and physicists should modify their model, or it could indicate that it’s time for researchers to come up with new ideas about how the universe works. And new ideas are always the most exciting things for a physicist.
One way to explain the Hubble tension is to modify the Lambda CDM model by changing the expansion rate at low redshift, at late times in the universe. Modifying the model like this can help physicists predict what sort of physical phenomena might be causing the Hubble tension.
For instance, maybe dark energy is not a cosmological constant but instead the result of gravity working in new ways. If this is the case, dark energy would evolve as the universe expands – and the cosmic microwave background, which shows what the universe looked like only a few years after its creation, would have a different prediction for the Hubble constant.
But, my team’s latest research has found that physicists can’t explain the Hubble tension just by changing the expansion rate in the late universe – this whole class of solutions falls short.
To study what types of solutions could explain the Hubble tension, we developed statistical tools that enabled us to test the viability of the entire class of models that change the expansion rate in the late universe. These statistical tools are very flexible, and we used them to match or mimic different models that could potentially fit observations of the universe’s expansion rate and might offer a solution to the Hubble tension.
The models we tested include evolving dark energy models, where dark energy acts differently at different times in the universe. We also tested interacting dark energy-dark matter models, where dark energy interacts with dark matter, and modified gravity models, where gravity acts differently at different times in the universe.
But none of these could fully explain the Hubble tension. These results suggest that physicists should study the early universe to understand the source of the tension.
Ryan Keeley, Postdoctoral Scholar in Physics, University of California, Merced
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Ryan Keeley explains it above. Hopefully most of you who read this understand the physics involved. Ryan has a website here.
As I said at the start it is beyond fascinating! In the truest sense, out of this world!
A fascinating subject.
We take it for granted! Of that I am sure. But the question of how oxygen first came to be built up in our atmosphere is fascinating. There was a recent article written by Elizabeth Swanner, who is Associate Professor of Geology, Iowa State University that was published in The Conversation. It makes for a very interesting read.
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Elizabeth Swanner, Iowa State University
Little Deming Lake doesn’t get much notice from visitors to Itasca State Park in Minnesota. There’s better boating on nearby Lake Itasca, the headwaters of the Mississippi River. My colleagues and I need to maneuver hundreds of pounds of equipment down a hidden path made narrow by late-summer poison ivy to launch our rowboats.
But modest Deming Lake offers more than meets the eye for me, a geochemist interested in how oxygen built up in the atmosphere 2.4 billion years ago. The absence of oxygen in the deep layers of Deming Lake is something this small body of water has in common with early Earth’s oceans.
On each of our several expeditions here each year, we row our boats out into the deepest part of the lake – over 60 feet (18 meters), despite the lake’s surface area being only 13 acres. We drop an anchor and connect our boats in a flotilla, readying ourselves for the work ahead.
Deming Lake is meromictic, a term from Greek that means only partially mixing. In most lakes, at least once a year, the water at the top sinks while the water at the bottom rises because of wind and seasonal temperature changes that affect water’s density. But the deepest waters of Deming Lake never reach the surface. This prevents oxygen in its top layer of water from ever mixing into its deep layer.
Less than 1% of lakes are meromictic, and most that are have dense, salty bottom waters. Deming Lake’s deep waters are not very salty, but of the salts in its bottom waters, iron is one of the most abundant. This makes Deming Lake one of the rarest types of meromictic lakes.
The lake surface is calm, and the still air is glorious on this cool, cloudless August morning. We lower a 2-foot-long water pump zip-tied to a cable attached to four sensors. The sensors measure the temperature, amount of oxygen, pH and amount of chlorophyll in the water at each layer we encounter. We pump water from the most intriguing layers up to the boat and fill a myriad of bottles and tubes, each destined for a different chemical or biological analysis.
My colleagues and I have homed in on Deming Lake to explore questions about how microbial life adapted to and changed the environmental conditions on early Earth. Our planet was inhabited only by microbes for most of its history. The atmosphere and the oceans’ depths didn’t have much oxygen, but they did have a lot of iron, just like Deming Lake does. By investigating what Deming Lake’s microbes are doing, we can better understand how billions of years ago they helped to transform the Earth’s atmosphere and oceans into what they’re like now.
Two and a half billion years ago, ocean waters had enough iron to form today’s globally distributed rusty iron deposits called banded iron formations that supply iron for the modern global steel industry. Nowadays, oceans have only trace amounts of iron but abundant oxygen. In most waters, iron and oxygen are antithetical. Rapid chemical and biological reactions between iron and oxygen mean you can’t have much of one while the other is present.
The rise of oxygen in the early atmosphere and ocean was due to cyanobacteria. These single-celled organisms emerged at least 2.5 billion years ago. But it took roughly 2 billion years for the oxygen they produce via photosynthesis to build up to levels that allowed for the first animals to appear on Earth.
At Deming Lake, my colleagues and I pay special attention to the water layer where the chlorophyll readings jump. Chlorophyll is the pigment that makes plants green. It harnesses sunlight energy to turn water and carbon dioxide into oxygen and sugars. Nearly 20 feet (6 meters) below Deming’s surface, the chlorophyll is in cyanobacteria and photosynthetic algae, not plants.
But the curious thing about this layer is that we don’t detect oxygen, despite the abundance of these oxygen-producing organisms. This is the depth where iron concentrations start to climb to the high levels present at the lake’s bottom.
This high-chlorophyll, high-iron and low-oxygen layer is of special interest to us because it might help us understand where cyanobacteria lived in the ancient ocean, how well they were growing and how much oxygen they produced.
We suspect the reason cyanobacteria gather at this depth in Deming Lake is that there is more iron there than at the top of the lake. Just like humans need iron for red blood cells, cyanobacteria need lots of iron to help catalyze the reactions of photosynthesis.
A likely reason we can’t measure any oxygen in this layer is that in addition to cyanobacteria, there are a lot of other bacteria here. After a good long life of a few days, the cyanobacteria die, and the other bacteria feed on their remains. These bacteria rapidly use up any oxygen produced by still photosynthesizing cyanobacteria the way a fire does as it burns through wood.
We know there are lots of bacteria here based on how cloudy the water is, and we see them when we inspect a drop of this water under a microscope. But we need another way to measure photosynthesis besides measuring oxygen levels.
The other important function of photosynthesis is converting carbon dioxide into sugars, which eventually are used to make more cells. We need a way to track whether new sugars are being made, and if they are, whether it’s by photosynthetic cyanobacteria. So we fill glass bottles with samples of water from this lake layer and seal them tight with rubber stoppers.
We drive the 3 miles back to the Itasca Biological Station and Laboratories where we will set up our experiments. The station opened in 1909 and is home base for us this week, providing comfy cabins, warm meals and this laboratory space.
In the lab, we inject our glass bottle with carbon dioxide that carries an isotopic tracer. If cyanobacteria grow, their cells will incorporate this isotopic marker.
We had a little help to formulate our questions and experiments. University of Minnesota students attending summer field courses collected decades worth of data in Itasca State Park. A diligent university librarian digitized thousands of those students’ final papers.
My students and I pored over the papers concerning Deming Lake, many of which tried to determine whether the cyanobacteria in the chlorophyll-rich layer are doing photosynthesis. While most indicated yes, those students were measuring only oxygen and got ambiguous results. Our use of the isotopic tracer is trickier to implement but will give clearer results.
That afternoon, we’re back on the lake. We toss an anchor; attached to its rope is a clear plastic bag holding the sealed bottles of lake water now amended with the isotopic tracer. They’ll spend the night in the chlorophyll-rich layer, and we’ll retrieve them after 24 hours. Any longer than that and the isotopic label might end up in the bacteria that eat the dying cyanobacteria instead of the cyanobacteria themselves. We tie off the rope to a floating buoy and head back to the station’s dining hall for our evening meal.
The next morning, as we wait for the bottles to finish their incubation, we collect water from the different layers of the lake and add some chemicals that kill the cells but preserve their bodies. We’ll look at these samples under the microscope to figure out how many cyanobacteria are in the water, and we’ll measure how much iron is inside the cyanobacteria.
That’s easier said than done, because we have to first separate all the “needles” (cyanobacteria) from the “hay” (other cells) and then clean any iron off the outside of the cyanobacteria. Back at Iowa State University, we’ll shoot the individual cells one by one into a flame that incinerates them, which liberates all the iron they contain so we can measure it.
Our scientific hunch, or hypothesis, is that the cyanobacteria that live in the chlorophyll- and iron-rich layer will contain more iron than cyanobacteria that live in the top lake layer. If they do, it will help us establish that greater access to iron is a motive for living in that deeper and dimmer layer.
These experiments won’t tell the whole story of why it took so long for Earth to build up oxygen, but they will help us to understand a piece of it – where oxygen might have been produced and why, and what happened to oxygen in that environment.
Deming Lake is quickly becoming its own attraction for those with a curiosity about what goes on beneath its tranquil surface – and what that might be able to tell us about how new forms of life took hold long ago on Earth.
Elizabeth Swanner, Associate Professor of Geology, Iowa State University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Nothing I can add to this very erudite article. Please read it and be fascinated by the findings.
Well, just two rainbows!
I just ran out of time yesterday to publish a proper blog post so I am sharing this photograph with you. It shows Mount Sexton in the distance, just to the right of the fir tree, and two rainbows, it being a rainy afternoon. The camera is facing North-East and the picture was taken at the north end of our rear deck.
Learning from Dogs 
