Many modern Earth Science discoveries and areas of study focus on one of the most important issues of modern society: climate change. However, there are still many advances being made all the time in other areas as well. These include things such as natural disaster studies, understanding land formations like volcanoes or ocean trenches, and advances in technology. For both cases, the following topics are some of the biggest new findings of recent years to keep you up to date.
Earth Science Discoveries Relating to Climate Change
Tripling of Antarctic Ice Loss Since 2012
The general topic of this new finding in Earth Science is old news, but the confirmed rate is unprecedented. The entire study covers Antarctic Ice Sheet mass changes from 1992 to 2017 using satellite observations. During this entire time period, about 2.7 trillion tons of ice mass melted due to warming oceans and atmosphere. This corresponds to an increase in sea level of about 7.6 millimeters. And 3 of those millimeters were from ice loss between 2012 and 2017 alone.
Interestingly though, most ice loss occurs on the west side of Antarctica. The east side has actually consistently gained mass, albeit much smaller amounts. The West Antarctica loses up to 160 billion tons per year, and the East Antarctica might gain between 5 and 50 billion tons. But while overall loses grow, so does uncertainty in models. The most uncertain rates of mass growth for East Antarctica are for the most recent years.
Geoscience Discovery of Carbon Transport Methods in Rivers and Oceans
One of the biggest players in climate change is the water cycle. Water from oceans and rivers interacts with the atmosphere in many ways, including affecting atmospheric CO2 levels. Warmer oceans release CO2, in the same way soda releases the CO2 bubbles if it's warm. But oceans also act as carbon sinks which hold CO2 when they are cooler, and ocean currents act to globally redistribute the CO2 and heat.
Land also acts as a carbon sink in many ways, and rivers connect it to the ocean sink. A new discovery in Earth Science reveals that 20-100% more carbon than previously estimated may be transported by oceans and rivers. Thus, land sinks must contribute less CO2 than we thought. This would make them less significant in terms of CO2 emissions than previously thought, but emphasizes the importance of water sinks.
Earthquakes Adding Carbon to Oceans
One new finding in Earth Science changes how we see earthquakes in the context of carbon movement between land and oceans. The incredibly powerful and destructive Tohoku earthquake that hit Japan in 2011 provided the unique opportunity to study the phenomenon. It was (and still is) the fourth most powerful earthquake ever recorded, causing all of Japan to most 8 feet east and knocking the entire planet as much as 10 inches off its axis.
A 2018 study published in early 2019 showed that the subduction zone associated with the quake sucked up about a million tons of organic material during the event. This is about a fourth of the total amount added to the sea annually from the Himalayas via rivers. This huge quantity suggests a very significant role of earthquakes in the carbon cycle on Earth. However, it still remains to be seen what exactly the implications are.
Big Changes in Sulfur Dioxide Emissions
Ozone monitoring from satellites has confirmed the effectiveness of pollution control put into place in China. For decades, China was the world's top emitter of sulfur dioxide (SO2), but pollution control measures and policies have changed that. After the implementation of the policies in the early 2000s, China's emissions reduced by a whopping 75%. But India, on the other hand, increased its emissions by 50% during that time period, entirely surpassing China's emissions.
Coal energy sources are the primary emitters of SO2 and associated pollution and air quality problems. Even with the significant decrease in emissions, the related pollution such as haze in cities remains a problem. However, the changes proved previous models wrong, and continued activism in the area will have positive effects over time.
Water Distribution in the Face of Climate Change
We all know that warming temperatures affect ice sheets, glaciers, sea levels, and fresh water across the planet. But Scientists using the GRACE (Gravity Recovery and Climate Experiment) satellite are investigating water on land specifically. And they have determined that human activity and climate change triggers a global response in terrestrial water sources resulting in highly uneven terrestrial water gains, losses, and distribution.
The unevenness is caused by the different effects of warming temperatures dependent on region. In northern land regions and tropics, melting ice leads to an increased supply of freshwater. In other areas such as southern North America or the Middle East, temperatures cause extremely hot and arid conditions resulting in freshwater loss. Humans then contribute to the trends through their consumption of the water, as well as contributing to further climate change. This is an area of growing concern for evaluating and predicting changes to water and food security.
Earth Science Discoveries in Other Areas
Early Magnetic Field Model Released
Usually, scientists update the magnetic model every five years. But recent drastic changes in the magnetic field prompted them to make one this year, a year earlier than anticipated. Keeping the magnetic field model properly updated is important for navigators all over the world. The military, commercial airlines, rescue operations, and projects around the North pole all rely on the model to guide them.
The magnetic field has been moving more in terms of speed and distance since the '90s, but in this instance it lurched more than usual. In 2018 it actually went over the international date line and into the Eastern Hemisphere. Changes in the field are primarily caused by unpredictable flow of the Earth's core.
But for this particular case, one theory is that there is a jet of liquid iron under Canada which is weakening the field. Figuring out exactly how and why changes occur is still an area in need of further exploration by scientists. Studying this area will help us when the field makes more drastic changes, or even reverses, which could actually be devastating.
Geoscience Discovery of Large Quantities of Water Within Earth's Mantle
This discovery in Earth Science actually happened in 2014, but that's still pretty recent in the whole scheme of things. Experiments on the mineral ringwoodite show that part of the mantle contains huge quantities of water. As much as, or even more than, the amount on the surface of the planet.
However, the “water” is tied up as ions within the crystal structure of the mineral, rather than being actual subterranean liquid oceans. But this doesn't make it any less significant, or any less “watery.” In fact, it raises the possibility that water on the surface of the planet actually oozed out from this source within the Earth, rather than previous hypotheses that it came from meteor impacts.
The portion of the mantle which contains the trapped water is the transition zone. This is the zone between the lower and upper mantle, which interacts with tectonic certain plate subduction. Further research can help us understand the Earth's water cycle in a new way by incorporating the role of plate tectonics interacting with the transition zone.
Land Subsidence Increasing Flood Risk in San Francisco Bay
Scientists have created a new 100-year flood map of the San Francisco Bay area. The map led to a new finding in Earth Science that flood maps based solely on rising sea level underestimated flood prone areas of the Bay by at least 3.7% and up to 90.9%. This is because the map considers land subsidence in the projections.
Subsidence itself is the sinking of land due to various causes. It may occur as substances such as water or oil are removed from the underlying layers. Or natural events such earthquakes, which are common in the area, may move the soil and rock such that it sinks. It is also increasingly common in urban areas where large cities overly and drain reservoirs, causing the entire area to sink.
Subsidence of land occurs at rates of over 10 mm per year in some areas of the Bay area; a significant change that greatly changes the shape of the land and areas lower than sea level. This study emphasizes that changes to land shape will contribute to future flood risks not only as sea level rises, but also as precipitation events hit areas with significant subsidence.
Geoscience Discoveries Get Us One Step Closer to Predicting Volcano Eruptions
This Earth Science discovery makes strides in an area shrouded with mystery and uncertainty. Volcano eruptions are historically unpredictable, other than some general statistical patterns or seismic activity immediately preceding events. However, scientists in Japan have shown how volcanoes interact with one another in ways that can contribute to prediction models.
The study found that two volcanoes in Japan share a magmatic system under the crust between them. One volcano erupted in 2011, spewing significant amount of lava. The caldera (the area inside the volcanic crater) of the sister volcano had already been steadily inflating for decades. But after the eruption, its caldera then deflated. This change in inflation and the relationship to the eruptions could not be explained by changes in tectonic or volcanic stress. The scientists interpret is as a result of withdrawal of magma from the shared system during the eruption.