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There have been a lot of earth sciences around this week (there are still some) and even if you are not aware of the five earthquakes of at least 6 magnitude this week, or Of the various volcanic eruptions underway, there is one aspect that you may not have missed during the week of November 15 to 21, 2018. The terrible forest fires in California are a classic example of interaction between different parties of the Earth system.
This week I'm avoiding a bit – I'm watching California, a so-called 'supervolcan' in Italy and this week's biggest earthquake. So, three articles, three continents, three natural dangers and three different aspects of the system in which we live.
Forest fires and climate change in California
The devastating wildfires in California are almost certainly linked to climate change. Image by USGS.
The California wildfires have left dozens of dead and over a thousand missing, making it the worst disaster of this nature in the history of the United States. Wildfires are natural and have existed for a long time before humans, although human intervention, careless or malicious, can be a contributing factor.
While it is likely that the magnitude of deaths and havoc is partly related to the increasing number of people living in vulnerable areas, it is also questionable whether these fires are becoming more frequent as a result of climate change.
Once again, we can say that climate change can be natural. I blame myself for not having added to a bookmark an article read a few years ago in which it was said that the California regulation had taken place during an unusually wet period and that what we now consider to be a drought is in makes a normal state. But whether or not this is the case, climate change is expected to have an impact on forest fires in the future.
It is far too early, of course, for a detailed scientific study on the current state of affairs, but my own reflections on the subject have been echoed in this week's Scientific American article. The magazine contacted climatologists who commented on the fires that followed "the hottest summer for over 100 years record keeping".
Many variables affecting the frequency and extent of these fires can be influenced by local weather conditions, but the influence of climate change is certainly part of it. A scientist interviewed observed that "we know that these events are influenced by weather and climate, as well as by drought. The climate system has been changed by people … all the time we know and what fuels these fires are climate change. "
In the footnote, it should be noted that even when fires are extinguished, interaction in the system continues. This week, the BBC has raised concerns about vegetation loss that could have adverse effects on atmospheric carbon dioxide. Forests absorb CO2, which greatly reduces their extent by fire (as by other methods), removes a carbon sink and increases atmospheric CO2 levels … by increasing global temperatures.
Campi Flegrei: the Supervolcan of Italy
The Italian "supervolcano", Campi Flegrei, is showing signs of unrest. Image of NASA.
Dr. Janine Krippner, volcanologist, science communicator and one of my scientific inspirations, was making headlines scandalous this week on Twitter. There are crackers. "A study warns that, if the Earth continues to suck its oceans, the planet could explode," warned the New York Post, while the always entertaining, though not always reliable, has opted for heightened caution: " Yellowstone VOLCANO WARNING: "Time Traveler" of the year 6491 in the prediction of apocalypse ".
I had to verify that these two titles are real (they are, although they do not exactly represent the scientific research on which they relate). But they indicate how easily we respond to the signs of imminent disaster, no matter how likely that disaster will be.
There are several supervolcans on Earth and most of them are not widely known, and they can be approached in a more measured way than tabloids tend to do. One of them is Campi Flegrei, near Naples, and this week, National Geographic reported that "The Italian government has raised the threat level of the volcano from green to yellow, or from calm to scientific scrutiny".
This change is based on the results of a study conducted in Nature Communications, which shows that Campei Flegrei is becoming more active and that "the magma could approach Campi Flegrei"That is the moment when eruptions can occur.
This is worth a bit of context here. In the first place, the authors of the study recognize that the processes they report are poorly understood. Secondly, the Campi Flegrei have a history of episodic disorders that did not result in a much-feared eruption that did not actually break out in nearly 500 years.
That said, an eruption in this area would be a significant problem, not necessarily because of its magnitude (which could be relatively minor), but because of the number of people who would be affected.
Earthquake of M6.7, Fiji
This week, an earthquake of M6.7 hit the Pacific. Image by USGS
At the same time, on the other side of the world, a major earthquake occurred between the island groups of Fiji and Tonga. It occurred at a depth of more than 530 km and the information available on the United States Geological Survey earthquake summary page suggests that it was due to lateral movement somewhere near the margin between the plates of the Pacific and Australia, the first descendant under the last Tonga pit, hundreds of kilometers to the west, or by some kind of deformation in the deepest crust
Although large, at M6.7, it was felt by only about one million people, and then only weakly. I have not seen any damage report. The reason for including it here is that it illustrates the flip side when talking about chance.
The actual example of the California wildfires and the potential example of even minor eruption, Campi Flegrei, are significant in themselves, as is the Fiji earthquake. It is the human impact that turns a natural event into a natural disaster.
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