AP Biology class blog for discussing current research in Biology

Tag: ice age

Glaciers Hold Less Water than Previously Thought. Is this Good?

Last summer in Alaska, I was kayaking up to the Holgate Glacier when I noticed the water getting colder. I began to feel the katabatic winds as I got even closer to the massive wall of ice. Small ice chunks began to surround the kayak, and I could see the fast moving silt deposits flowing beneath me. I then heard a noise which boomed and echoed off of the surrounding mountains, and I saw a massive chunk of ice break off (“calve”) from the glacier and plummet into the sea. I’ve always known that climate change was happening, but seeing it before my eyes reaffirmed my fears.

Aialik glacier pano 2

Holgate Glacier, Aialik Bay, Kenai Fjords National Park, Seward, Alaska

I’m not here to talk about my fantastic trip to Alaska, but rather to talk about the new scientific findings which will further predict the climate change battle. Previously, scientists believed that warmer-than-average temperatures can begin to melt glaciers, causing the sea levels to rise and cause disastrous flooding. Just recently, satellite image glacier research spearheaded by Romain Millan of Grenoble Alpes University in France has determined that glaciers hold 20% less water than previously thought. This means that, if all of the glacier ice were to melt, that the seas are predicted to rise 10 inches instead of 13 inches.

This is great news, right? Well, some could argue that less flooding means less disaster (landslides, wipe out infrastructure, etc), and that it’s good news. But it’s not, because even if the sea levels were to rise just a few inches lower, still 29% of the entire world’s population would be predicted to be immediately affected by flooding, and within a few days, 99.9% of the entire world’s population would feel the indirect effects through shortages or outages. In addition, less water quite literally means “less water.” 2 billion people currently rely on glaciers as their primary source of water, so “less water” would effect them through a drought. As

Parque estatal Chugach, Alaska, Estados Unidos, 2017-08-22, DD 94

Glacier at Chugach State Park, Alaska (which I too visited)

we’ve learned in AP Biology, water is one of the most, if not the most, important molecules to biological existence. A drought can affect human life from hundreds of angles, such as famine, or more immediately, dehydration. Water is extremely crucial to performing catabolic reactions such as hydrolysis, which we learned in AP Biology.

Factoring in mountaintop glaciers and their water content, Millan is able to determine the rate at which communities will run out of water. But for the non-alpine communities, these mountaintop glaciers are only a tiny drop in a large bucket. Millan’s research lacks one major component: the antarctic and arctic glaciers. If these unbelievably large ice fields continue to melt at the current pace, 90% of the United States is predicted to be underwater by 2050. To be honest, I believed this statistic was exaggerating until just recently. In Alaska, one of the glaciers named “Exit Glacier” had markers at the glacier’s terminus for each year. As I got closer to the glacier, I noticed the markers getting further and further away, signaling that the glacier was melting quicker and quicker. Take a look at the graph below, specifically how the year intervals begin to get smaller, and let me know how it makes you feel in the comments. Although it does not take a trip to Alaska to realize that climate change is really happening, new and emerging headline-worthy research like Millan’s is truly highlighting the immediate issue we all could face soon.

Exit Glacier Terminus Position From 1950-2020



Melting Glaciers & Rising Sea Levels

Because of ocean warming and melting of land ice, sea levels have risen all over the world. However, sea levels have not risen by the same amount everywhere. Along the coast of North Carolina, for example, the sea level has risen by about 18 inches (a foot and a half). Along Miami and New York City, the sea has risen by approximately 12 inches. And in Portland Maine, the sea has only risen by 6 inches. According to a study done by the Woods Hole Oceanographic Institution (WHOI), these variations can be attributed to a “post-glacial rebound.”

Image result for picture of the ocean“View of the ocean from Zamami Island, Okinawa, Japan. October 2015.”

In short, during the most recent Ice Age, Canada and parts of the Northeast United States were covered by colossal “sheets of ice.” The immense weight of the ice caused the land to sink. Areas on the periphery of these ice sheets, however, began to rise. Once the ice sheets began to melt approximately 26, 500 years ago, the “weighed-down” land gradually rose, whereas the peripheral lands started to sink. The ice sheets melted away about 7,000 years ago, but this “post-glacial rebound” is still taking place.

File:Icebergs.jpgIcebergs | St. Anthony, Newfoundland

The lead author of a study published in the journal Nature, Chris Piecuch, wanted to determine why sea levels rose at quicker rate in certain areas during the last century. He and his colleagues used advanced technology to take sea level measurements and combined “observational data with complex geophysical models — something that has not been done before — to give a more complete view of sea level changes since 1900.” The team ultimately determined that most of the sea level changes have been due to “post-glacial rebound,” and that “sea level trends increased steadily from Maine all the way down to Florida.” Pieuch attributes these changes to groundwater extraction, as well as to more recent melting of glaciers and ice sheets. These occurrences can cause masses of water around the Earth to move, and affect the planets crust. Although Piecuch is uncertain as to why water is redistributed to certain locations, he is pleased with his findings, stating: “Post-glacial rebound is definitely the most important process causing spatial differences in sea level rise on the U.S. East Coast over the last century. And since that process plays out over millennia, we’re confident projecting its influence centuries into the future.”


Global Warming is now affecting the next Ice age

Carbon dioxide emissions in our atmosphere are not only creating global warming but are disrupting the earth’s environmental cycle. Ice ages  occur very rarely in the earths history but it is essential to the earths environmental cycle. According to a study done at Cambridge University, University College London, the University of Florida and Norway’s University of Bergen, the high levels of carbon dioxide emissions in the atmosphere has disrupted this cycle and the next ice age is delayed to at least 1500 years

An Ice Age is a period of time where the earth’s temperature is consistently low resulting in ice sheets and glaciers. Long-term reduction in the earth’s surface temperature and atmospheric temperature creates ice sheets and glaciers. The glaciers reflect the suns energy and absorb less energy. Earth is currently in an interglacial period, warm period, for 10,000 to 15,000 years.

The study was conducted at Cambridge University, University College London, the University of Florida and Norway’s University of Bergen; they used rock samples and information about the variations in the earths orbit. Through research they figured out that the next ice age will not be until 1500 years. However, it will only occur in the next 1500 years if carbon dioxide emissions do not exceed 240 ppmv and we are currently at 390 ppmv. Carbon Dioxide emissions are rising not decreasing so the next ice age might be delayed longer than 1500 years if we do not reduce carbon emissions.

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