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PAESTA - The Pennsylvania Earth Science Teacher Association

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PAESTA - The Pennsylvania Earth Science Teacher Association

    How do salmon know where to return to spawn? - PAESTA Podcast Series: Episode 45

    How do salmon know where to return to spawn? - PAESTA Podcast Series: Episode 45

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    Transcript of the podcast





    Good morning listeners! This is Matthew Merrone, an undergraduate student at Penn State Brandywine, and I am here today to introduce this new episode of the PAESTA Podcast Series – How do salmon know where to return to spawn?

    A growing mystery for scientists revolves around the idea of salmon being able to know exactly how to return to their home stream to spawn. Salmon are a very unique type of fish that are born in a stream and eventually venture off into the vast oceans before coming home to give birth. For something that seems so far-fetched, salmon are somehow able to migrate thousands of miles into the open ocean for years at a time, and then they miraculously swim all the way home to the stream they were hatched in.  For years, scientists have speculated many different possible explanations for this odd phenomenon. Now, they may have finally broken the code to understanding how the salmon manage to do such a difficult task.

    One of the tools that salmon use to migrate back to their home stream is their brains. [1] Experiments and research taken through the Institute of Creation Research state that salmon remember the water and its components while traveling downstream into the ocean. They claim that the fish have a flexible system for learning olfactory waypoints at appropriate time and places. [2] With the use of their brains, salmon are able to comprehend important oceanic factors including the ocean currents, length of the days, amount of sun exposure, water salinity, and the temperatures of the waters. These unique abilities allow the salmon to be able to recognize the water in which they are swimming in and navigate with the conditions of the ocean on their journey making it easier to migrate home.

    Beyond their excessive use of their brains, scientists knew that salmon had a keen sense of smell that aided them in finding their way to their original stream. [2] It was observed that salmon use their sense of smell to imprint on their hatching stream for future reference. These fish imprint on the odor of the stream that they are hatched in and can remember that odor for the duration of their life. In an experiment, several salmon were moved from their home streams during their hatching periods. The scientists observed as the salmon migrated back into their home streams, concluding the importance of the fish’s ability to imprint early on in its life. This experiment later led to the discovery that salmon imprint at other important time periods of their lives like when the emerge from their gravel nets. [3] A hatchery research center for salmon in Oregon spent time digging their own fake streams for research. What they did was they took water from the salmon’s home stream and put it upstream while using regular water for the downstream. What they observed was that the salmon were using pheromones to sense their water. Almost all of the salmon were found migrating upstream to the water at which they were born into. The Oregon hatchery then confirmed that salmon’s sense plays a big role in the migrating process, and they wanted to repeat the experiment several more times with stronger sensing water. 

    The newest discovery that scientists have made referring to the ability for salmon to migrate to their home stream correlates to the Earth’s magnetic fields. [4] A team of researchers from the National Science Foundation put together data from patterns in salmon migration out of the Fraser River in British Columbia, Canada for the last 56 years. Coming into the experiment, the scientists knew that Earth’s magnetic field changes each year and it is weakened with proximity to the equator and the Earth’s poles.  Vancouver Island sits at the mouth of the Fraser River, and blocks the salmon from entering their home stream. The scientists were a

    • 5 min
    What are the impacts of climate change on water resources? - PAESTA Podcast Series: Episode 44

    What are the impacts of climate change on water resources? - PAESTA Podcast Series: Episode 44

    You Asked, We Answered!

    Transcript of the podcast





    Hello my name is Nick Malorgio and today I will be answering the question: what are the impacts of climate change on water resources?

    On earth, ninety-eight percent of our water is salty and two percent is fresh water. Seventy percent of fresh water is snow, and the remaining thirty percent is ground water [1]. Climate change has negatively impacted the sparse amount of fresh water on Earth. It is important to discuss the key factors that contribute to climate change and global warming as we work to preserve the world’s fresh water.

    Water makes up over three-quarters of Earth so 2% of that sounds like a significant amount of fresh water… So why are we so worried about preserving it? Well, water scarcity is actually a major problem caused by climate change. As of right now 1.6 billion people live with water scarcity and by the year 2025 this is expected to increase to 2.8 billion people.

    As the earth’s temperature continues to rise it causes a negative impact on our fresh water sources. Glaciers are one of the important sources of fresh water that many people depend on in the world. As global temperatures continue to rise, these glaciers are melting away with some of them predicted to vanish within this century [2]. Regions that use these glaciers as sources of fresh water will need to seek new fresh water because once these glaciers are gone they cannot be restored.

    Climate change is also causing our water cycle to act differently than in the past. Scientists now agree that these changes are going to affect water vapor, concentrations, clouds, precipitation patterns, and runoff stream flow patterns [3]. If the lower portion of the atmosphere continues to become warmer, the evaporation rate will increase. The change will cause certain areas to dry out and others to have too much rainfall. These warmer climates cause more water to evaporate from the land and oceans. The excessive rainfall and snow melting will result in fewer places to store the water as it exceeds its holding capacity. This will cause flooding and the additional fresh water will run off into our oceans becoming new salt water. The runoff also makes the ocean level rise; this creates more problems as the rising level makes the salt water drive into freshwater aquifers. At this point, in order to make the water usable in the aquifers we would to need to move it and then treat it. This increased ocean level is also forcing pollutants and waste to wash into our water. This makes the water be unusable because it is not safe [4]. The change in the water cycle is going to cause more droughts to occur and for longer periods of time. The Western side of the United States is having the worst droughts in history. With water already being limited in the west, the fast growing population is making the demand for water to increase.

    Energy is another thing being affected because of the impacts on water. The north western part of the United States also relies on water to create energy through hydropower. However due to the water flow becoming lower it is reducing the amount of energy that can be produced. The weaker water flow also makes it harder to cool fossil fuels and nuclear power plants. Energy being produced from different ways is making it worse as the constant burning of coals, gas, and fossil fuels are actually accelerating the climate change to become worse.

    Finally, due to climate change, countries such as Turkey, Israel, and Morocco will be greatly affected, with more than fifty percent of their water sources vanishing [5]. These are countries where agriculture is popular and farmers will have a hard time farming with the climate change. The increased amount of rainfall is causing crops to be damaged from the floods and this increases soil erosion. Areas that are already effected by dro

    • 3 min
    How much water does it really take to grow almonds? - PAESTA Podcast Series: Episode 43

    How much water does it really take to grow almonds? - PAESTA Podcast Series: Episode 43

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    Transcript of the podcast





    Hello, on today’s episode of the PAESTA Podcast Series, we’ll be talking about whether almonds really take too much water to be worth growing, especially during a water shortage. This is a common misconception that we hopefully can clear up. The almond industry brings in an astounding 11 billion dollars annually since the popularity of almonds has gone up over the past couple years because of  almonds’  many health benefits. California supplies about 80% of the United States almonds, and dedicates 10%, or 80 million gallons, of its state’s water to grow the nut. To grow one almond  requires 1.1 gallons of water, and to grow a pound takes 1,900 gal/ lb[1]. The crazy thing about that is that walnuts, hazelnuts, pistachios, and cashews all use roughly the same amount of water to grow as well, but it is the almond which is in such high demand at this time. Currently, California is in the midst of a 5 year drought that has everyone looking at the nut industry to blame. Because people are buying more almonds and nuts in general, farmers are shifting towards growing more of them, which can lead to pointing the blame at them for the water crisis in California. And because of the drought, the price per pound of almonds has gone way up to $6 a pound, as opposed to $2 a pound back in 2010 [2]. This gives farmers even more incentive to grow them, even with the water crisis going on.

    Recently, a group of farmers were invited to talk on NPR about California’s drought and they had an interesting take on the situation. One farmer said that almonds really aren't any more thirsty than any of his other crops and shook his head when hearing that one almonds takes a gallon to produce. This same farmer then goes on to say that they've reduced the amount of water almonds require by 33% [3]. Another farmer then adds that almond trees require 10% of California's water supply and thinks that it “is a lot to devote to just one crop” but that they are working on reducing that number.

    The LA Times wrote an article about growing almonds and they also had a different take on them by saying  it isn’t as big of a problem as people are making it out to be. It states that although almonds trees use a lot of water to grow, these trees can be ground up and used as biomass fuel for cogeneration plants, essentially helping make electricity. It also says that almond farmers are working to reduce the amount of water that each plant consumes with techniques like drip irrigation. Farmers in this article also defend the almond by saying, “People need to understand that everything you eat takes water”. This same farmer goes on to say that "Now, we're feeling like a scapegoat for over 30 years of water mismanagement in this state” because of how much criticism her farm and other almond farmers are taking. This article concludes with a great point that “ the water it takes to grow any vegetable, fruit or nut is a mere fraction of what is required to raise animal protein” and goes on to say “It takes more than 106 gallons of water, experts say, to produce one ounce of beef”, so just imagine how much water a whole herd of cattle would use![4]

    So to answer the question, “How much water does it really take to grow almonds?,” I can conclude that the answer is widely debated between farmers and the media. On one hand, farmers believe that they don't use substantially the amount of water that the media thinks they do. Farmers all over agree that although almonds use a more than an average amount of water, they want the public to remember that all crops use water to grow. They also completely disagree that one almond takes 1.1 gallons of water to grow and are appalled to think people would believe that. On the other hand, there are countless articles that stand behind the fi

    • 4 min
    What are the differences between weather and climate? - PAESTA Podcast Series: Episode 42

    What are the differences between weather and climate? - PAESTA Podcast Series: Episode 42

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    Transcript of the podcast





    Hello, my name is Vipul Kapoor and I will be hosting this podcast. Today, we will discuss the differences between weather and climate. Our main focus will be the primary differences. Then we will go in depth on how each are studied and how they affect the world. To put it simply, the main difference between weather and climate is the measurement of time. [1] Weather affects a given area and contributes to shaping the Earth's features, while climate helps scientists to determine how the Earth will change—and has changed—over a long period of time. [2] Now, as we all know, weather is always changing. A period of time in which we measure weather can be as little as 5 minutes to as long as weeks. Throughout this time, there are many changes in weather. In the span of just 10 days, weather goes through big changes. From thunderstorms to heavy rain to heat waves. [3] These are conditions in the atmosphere at a given time and place; however, they only last for a short period of time.

    It is very important to understand that weather and climate are not the same. We define climate as the long-term trends of the weather, while weather is just what's happening now. [4] Weather and climate each have separate elements used by scientists all over the world. [5] The main elements for weather are temperature and climate, while the main elements for climate are latitude, wind, ocean currents, proximity to coastlines, and altitude. [6] Everyday Americans like you and me tend to care and know more about the weather rather than the climate. After all, we use the weather forecasts to determine our plans and even what to wear. A big difference between weather and climate are how they are predicted. Weather forecasts try to answer questions such as, how much will it rain tomorrow, or, how cold will it be tomorrow. [7] The forecasts are based on models, incorporating observations of air pressure, humidity, temperature, and wind to give the best estimates of future weather conditions. These forecasts tend to be short-term. On the other hand, climate predictions take a much longer-term view. Climate predictions attempt to answer questions like, how much warmer will the Earth be 50 years from now? or how much will the sea level rise in the next 10 years? Such predictions are made using global climate models.

    Now, although we do not pay much attention to climate, it is still a very important topic to study. Studying climate is crucial as it affects people around the world. Studying climate gives us information about rising global temperatures and how they raise sea levels, or how long term changes in precipitation have detrimental effects on water supply and crop yields. [8] Climate can also have a big effect on humans and other animals. Change in climate can cause deserts to expand into rangelands and National Parks and Forests to be altered, leaving animals in an unknown environment. These changes can also cause some animals to go extinct.

    The difference in essence comes down to climate is what you expect, while weather is what you get. When compared to weather, climate is fairly easy to model.  Experts can model physical principles of average temperature and rainfall in a fair amount of detail. On the other hand, weather changes quickly and chaotically, but still exists within a range of expected values. Climate and weather both differ around the planet, and are principally controlled by the energy from the sun. [9]

    Climatology is the study of climate characteristics in addition to the more complex behavior of the atmosphere which is heavily influenced by the land, oceans, and chemical reactions. [10] Scientists then investigate records to identify and find patterns of normal and extreme conditions, as well as to predict whether storm activity is likely to increase. Overall, un

    • 5 min
    Why did the water in the Rio Olympics turn green? - PAESTA Podcast Series: Episode 41

    Why did the water in the Rio Olympics turn green? - PAESTA Podcast Series: Episode 41

    You Asked, We Answered!

    Transcript of the podcast





    Hello my name is Laura Delgadillo, I am a student at Penn State Brandywine and today I’d like to answer the question: Why did the water in the Olympic pools in Rio this past summer turned green? The issue started because [1] a local pool maintenance worker applied hydrogen peroxide to the pool when it already had chlorine. Hydrogen peroxide is good for cleaning pools but not when it is combined with chlorine. It was a chemical misbalance. [2] Hydrogen peroxide was dropped into the pools by the contractor and hydrogen peroxide undoes what chlorine is supposed to do which is kill germs and keep the water clean. Nonetheless, since the water had to be clean for synchronized swimmers to be able to see each other under water, for water polo players, and for divers, the solution was to drain both pools off of all their water and refill them with clean water from the practice pools in time for these events to be able to happen.

    Now after the public saw and heard what was happening in Rio, there were people who argued that the pools’ dirty water was due to the fact that all water in Rio is unclean. [3] The problem of contaminated waters during the Rio Olympics was not only a problem in the swimming pools but in the sewage of the city, and country as a whole, and the outlets for all the water waste of the city, which are the rivers in Rio. The fact that the waste water goes to the rivers of Rio means the outdoor swimmers and rowers were at risk of contracting diseases from these waters. The waste from the poor favelas in Rio often does not get picked up by the government and it ends up in the rivers. If the government of a country cannot keep the rivers of its cities clean, then it would be easy for swimming pool managers at the Rio Olympics to neglect the treatment of the swimming pools and not apply the proper amount of chemicals into the competition pools. After I did a little more research however, I found an opposing viewpoint on a Forbes article about how the chemical misbalance everyone had been talking about had nothing to do with the water turning green. [4] The hydrogen peroxide and chlorine combination had nothing to do with the water turning green. The actual cause of it was copper(II) sulfate, a blue crystal that is used in tiny quantities to control the growth of green algae in large public pools and in municipal water supplies. It was added to the pool water; it dissolves quickly and it is to prevent algae from growing. It is toxic to algae, fish and other aquatic life; it can also be toxic to humans in large amounts. Another chemical reaction, which is the copper(II) sulfate dissolved in water that has to do with a poisonous stinky gas, which could be smelled from the pool water. This is how that chemical reaction works; the copper ions combine with four chlorine ions in the water, creating a copper(II) tetrachloro complex, which is green, and if it’s present in high enough concentrations, it turns the water green. The sulfate ions are reduced to hydrogen sulfide, a poisonous stinky gas, which is the source of the rotten egg smell associated with raw sewage smell people claimed was in the air. If the aquatic center for the Rio Olympics had a smell of raw sewage, or to vulgarly describe it: a smell of farts, then the opposing viewpoint seems to be the answer to the question we asked ourselves in the beginning.

    These two reasons seemed like they both were the right answer, in one hand there are managers and pool supervisors saying that chemistry is not an exact science and it could have happened to anyone and the chemical misbalance of hydrogen peroxide being mixed in with chlorine was the reason for the green water. In the other hand there is a viewpoint in a Forbes article that talks about another chemical misbalance but that has to do with copper

    • 4 min
    What are the mental impacts of weather and climate disasters? - PAESTA Podcast Series: Episode 40

    What are the mental impacts of weather and climate disasters? - PAESTA Podcast Series: Episode 40

    You Asked, We Answered!

    Transcript of the podcast





    Hello my name is Allysa and I am a student at Penn State Brandywine. Today I will be answering the question “What are the mental impacts of weather and climate disaster?”. First off, weather and climate disasters are like natural disasters. They are major adverse events resulting from a natural process of the earth and can include floods, hurricanes, tornadoes, volcanic eruptions, earthquakes, tsunamis, and natural processes of the earth.  We hear about natural disasters often on the news or weather channels where they try to predict when a storm or something of the sort is coming our way and warn us, the people, to evacuate if they feel it’s going to really bad. Some natural disasters that made big news include The tsunami in Thailand in 2004 and hurricane Katrina that hit New Orleans hard in 2005.

    Natural disasters are something we can’t control but that can come quickly and shake our lives forever. People who are involved have most likely seen, experienced, and lost things that are unimaginable to us. First, people can experience shock immediately after. This reaction can be a combination of shock and denial. [1] This can last for a bit of time, maybe days or weeks. After that people usually have feelings of insecurity. Home is supposed to be a safe place and when that’s taken from you, it is hard to feel secure again. Some things that come from this feeling of insecurity are nightmares, anxiety, or extreme preparation in fear for the next storm. [2] With this anxiety and stress, posttraumatic stress disorder or PTSD can follow. PTSD is a mental health condition that’s triggered by a terrifying event. The symptoms include flashbacks, nightmares, and severe anxiety. [3] Other long-term issues that can come from these events are depression, issues with eating and obsessive compulsive disorder also known as OCD.

    Those whose homes were affected are not the only ones subject to these possible aftermath symptoms. It has been reported that many people who help clean up on scene or first responders experience many of these psychological symptoms as well. [4] A lot of first responders say that they can be haunted from the wounded people they saw and saved as well as all of those that they were unable to save. [5] Even though they were not there for the actual event, they’re the ones that come in right after it and can see some of the worst of it.

    So, we know how natural disasters can affect people, their homes, communities, and families. However it can also affect their relationships with people. Many of those who are victims of an event like this suffer with relationships at school, work, friendships, marriage, or struggle as a parent. [2] With this usually comes distrust, irritability, conflict, withdrawal, isolation, feelings of rejection or abandonment, judgment, or being over controlling. [6]

    Although all of these things mentioned are normal reactions to extreme stress like a natural disaster,  there are times when those who are affected may need to seek help if certain symptoms do not go away. As we mentioned before, shock and disbelief are normal. People may have a hard time accepting the reality of what happened.  There are ways to help reduce these feelings like staying away from media exposure and avoiding distressing images. [4] Watching these things can bring memories back that you’re trying to avoid.

    Another suggestion is to accept your feelings by mourning the losses and not forcing the healing process. [2] It may take a long time but by accepting your emotions it is easier to move on and reconnect with uncomfortable emotions with little or no stress and anxiety.  It is also encouraged for people to reach out to others because, like I mentioned, it is easy to withdrawal from people after an event like this.

    If people surround t

    • 5 min

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