When it comes to earthquakes, always expect the unexpected. That’s the message coming from seismologists Prof Éric Calais, of the École Normale Supérieure (ENS) in Paris, and JeanFrançois Ritz, Director of Montpellier’s CNRS Laboratoire Géosciences.
Underpinning their advice is the reality that Earth sometimes shakes in places it shouldn’t. These mysterious events, called intraplate earthquakes, happen far from the active margins of tectonic plates and in places that are otherwise geologically quiet. Gaining a better understanding of them and an explanation for them has become the mission of the French scientists.
UNPREDICTABLE AND DESTRUCTIVE
The rocky plates that make up the brittle, outer carapace of our world are performing a slow dance across the face of the planet, moving at about the same rate that a person’s fingernails grow. While nearly all the geological action worth talking about takes place where the tectonic plates meet, intraplate quakes are different, occurring in the interiors of the plates far from the margins.
There are good, potentially lifesaving, reasons for Calais and Ritz to want to shed more light on them. Intraplate quakes are rare: the number of significant shakes is tiny compared to what happens at the edges of the plates, with Calais noting that only 20 of a magnitude of 6 and above have been recorded since 1974. That’s less than half of one per cent of the number of similarly sized quakes at plate margins over the same time.
Their rarity, and typically long return periods, makes them difficult to predict, yet they’re capable of causing immense destruction in unprepared urban centres that never regarded quakes as a problem.
Denne historien er fra December 2023-utgaven av BBC Science Focus.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
Allerede abonnent ? Logg på
Denne historien er fra December 2023-utgaven av BBC Science Focus.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
Allerede abonnent? Logg på
THE HUNGER GAME
Obesity is on the rise, but as we blame our unhealthy food-ridden environment and look to wonder drugs to get rid of unwanted fat, what role do our genetics play?
HOW THE UNIVERSE WILL END
A colossal supercollider now in the early stages of development may one day help us predict the ultimate fate of the Universe. With it, scientists will be trying to find a hidden instability built into the fabric of existence... an instability that could destroy everything
DARK ENERGY MIGHT BE ABOUT TO THROW A SPANNER IN THE WORKS
The most mysterious phenomenon in the Universe could be about to spring another surprise on us
TAKE-OFF AT LAST
AFTER A LONG WAIT, THE WORLD'S FIRST ZERO EMISSIONS AEROPLANES ARE FINALLY TAXIING TO REALITY. BUT ARE THEY THE SOLUTION WE NEED?
INSIDE THE 3D, NANOSCALE ATLAS THAT REVEALS A FRACTION OF THE HUMAN BRAIN
The map is now the highest-resolution picture of the human brain ever created
HOW THE LATEST DEVELOPMENT IN NUCLEAR FORENSICS MAY HELP CLEAN UP CHERNOBYL
Contrary to popular belief, radioactive material doesn't glow. But a team of nuclear forensics experts are working on a device to make it do just that. BBC Science Focus's Noa Leach meets the scientists behind the innovative device
MAJOR STUDY SHOWS HOW ULTRA-PROCESSED FOODS CHANGE YOUR LIFESPAN, IF YOU'RE NOT EATING YOUR VEG
While ultra-processed food is bad for your health, a decades-long study suggests it may not be as harmful as previously thought
ORIGIN OF EARTH'S 'SECOND MOON' DISCOVERED
Asteroid sampling mission will confirm whether moon-like Kamo'oalewa came from our Moon
INTERMITTENT FASTING AND CORRECTLY TIMED WORKOUTS ARE KEY TO FAT LOSS, SAYS STUDY
A new approach to dieting and exercise could help you lose weight and enhance your health
MASSIVE EXPLOSION SPOTTED ON MYSTERIOUS DEAD STAR
A satellite in the right place at the right time captured an important cosmic sight