California's eerie "earthquake break" is over. There should have been some "big ones". All the pressure has to go somewhere. Geologists are now nervously observing eight nearby volcanoes. And why did Yellowstone Supervolcano behave so funny?
The US Geological Survey (USGS) has warned Southern California that further severe earthquakes are to be expected. Some, they say, could be even more powerful than those they have experienced in the last few days.
"(These quakes are no less likely to make (the big one)," local seismologist Lucy Jones told the Los Angeles Times, "and there is a one in twenty probability that this place will have an even bigger earthquake in the next few days and that we have not yet seen the episode's biggest earthquake. "
In part, because California is so overdue for" the Great. "
The past century was unusually calm with regard to large, ground-breaking earthquakes.
The last "major" occurred in 1
And US geologists are starting to suspect that this is not just a godsend.
Somewhat deep California seems to be changing and the implications are still unclear.
The earthquakes last week were the most significant events in Southern California since 1999. Then a magnitude 7.1 event ripped apart the remote Mojave Desert.
It was an isolated case. And it was not a surface quake.
"We are unusually quiet," co-author of a recent study, Glenn Biasi, told Live Science in April. "The biggest mistakes and the mistakes that carry most of the slippage did not come up."
Something has broken the geological pattern.
The USGS has carefully scanned California for evidence of past earthquakes. They know how many lives could possibly be at stake. And forewarned is prepared.
They have compiled seismic records at 12 key points along the Golden State's main fault line, dating back some 1,000 years – the widespread rejection of San Andreas, the rejection of Hayward and the rejection of San Jacinto.
Data shows that the likelihood that all three errors are silent for 100 years is close to zero.
Instead, according to USGS, California would have had to expect six "big ones".
"We do not believe that this happened in 19659005 a thousand years ago," Mr Biasi said.
The quake break remains a mystery. Speculation that the dislocations in an unusually active 19th century would have reduced much of their pent-up tension remains speculation.
Another possibility remains: that there is something even deeper, something so big that it causes the activity of the state. Five main lines of "synchronizing".
"The potential to damage earthquakes, landslides, floods, tsunamis and forest fires is well known in California," states a recent USGS report. "The same is not true for volcanic eruptions, although they occur in the state about as often as the largest earthquakes in the San Andreas Fault."
Of the eight volcanoes in the state, seven were found to be "active." Magma chambers.
It is worrying that 200,000 people are considered vulnerable should an outbreak occur. And it is claimed that the likelihood of such an event is 16 percent over the next 30 years.
Like the faulting studies, geologists have drawn clues from the California landscape to determine volcanic activity over the past 5,000 years.
It's been over the last 3000 years that five volcanoes erupted – Mount Shasta, Medicine Lake, Lassen, Long Valley and Salton Buttes. Clear Lake Volcanic Field near San Francisco – although it is considered potentially very high risk – was no longer blown up.
The trick is to predict when the next outbreak will likely be.
It's an inaccurate science. But there are hints.
GPS sensors and satellite radars measure volcanic surface deformation. Seismometers detect underground movements. Gas emissions are regularly checked for changes in salary.
So far, all eight are quiet.
The melted heart of the earth is always in motion. Movements are thought to be deep below the crust behind the changing magnetic field of the North Pole. There is a magnetic "anomaly" in the South Atlantic that causes even some satellite problems.
The geysers in Yellowstone National Park, located above the largest "super volcano" in the world, behave erratically.
Is there a connection?
Seismologists say that there is simply no evidence. And a surface quake in California will not affect Yellowstone, which is about 1,000 km away.
However, speculation remains widespread: there is a lot of talk about super volcano in social media.
What do the experts think? The USGS unit, which was specifically tasked with monitoring the famous geysers and the monster, was puzzled by the change in patterns in normally regular geyser eruptions. Instead, it is believed that changes in a "Crystal Mash" in the Yellowstone Chamber itself disrupt the hydrothermal channels that supply the park's biggest attractions again for several hundred thousand years.
This story originally appeared in news.com.au.