Strange Precariously Balanced Rocks Provide Earthquake Forecasting Clues

scitechdaily ^ | October 1, 2020 | Imperial College London

[BenLurkin]

Precariously balanced rocks (PBRs) are formations found throughout the world where a slender boulder is balanced precariously on a pedestal boulder. They form as blocks preserved on cliffs, or when softer rocks erode and leave the harder rocks behind. They can also form when landslides or retreating glaciers deposit them in strange positions.

Despite their delicate balancing act, many PBRs — like the Brimham Rocks in Yorkshire, or Chiricahua National Monument in Arizona — have survived earthquake shaking over thousands of years. They can therefore tell us the upper limit of earthquake shaking that has occurred since they were first formed — shaking that, were it strong enough, would have caused them to topple.

By tapping into ancient geological data locked within Californian PBRs, Imperial College London researchers have broken ground on a new technique to boost the precision of hazard estimates for large earthquakes by up to 49 percent.

Earthquake hazard models estimate the likelihood of future earthquakes in a given location. They help engineers decide where bridges, dams, and buildings should be built and how robust they should be — as well as informing earthquake insurance prices in high-risk areas.

Current earthquake hazard estimates rely largely on observations like proximity to fault lines and how seismically active a region has been in the past. However, estimates for rarer earthquakes that have occurred over periods of 10,000 to 1,000,000 years are extremely uncertain due to the lack of seismic data spanning those timescales and subsequent reliance on rocky assumptions.

By counting rare cosmic ray-generated atoms in PBRs and digitally modeling PBR-earthquake interactions, Imperial researchers have created a new method of earthquake hazard validation that could be built into existing models to finetune their precision

[Revel]

Reminds me of Hillary walking down stairs.

[SunkenCiv]

Precariously balanced rocks (PBRs) are formations found throughout the world where a slender boulder is balanced precariously on a pedestal boulder... Despite their delicate balancing act, many PBRs... have survived earthquake shaking over thousands of years... estimates for rarer earthquakes that have occurred over periods of 10,000 to 1,000,000 years are extremely uncertain due to the lack of seismic data spanning those timescales and subsequent reliance on rocky assumptions. By counting rare cosmic ray-generated atoms in PBRs and digitally modeling PBR-earthquake interactions, Imperial researchers have created a new method of earthquake hazard validation that could be built into existing models to finetune their precision...

Thanks BenLurkin.

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[grey_whiskers]

https://www.youtube.com/watch?v=BJvHc65knmU

[Tallguy]

[Tallguy]

[norwaypinesavage]

If you’re from the Midwest, you know that enough PBRs explain almost everything. They even make ugly girls look good.

(PBR - Pabst Blue Ribbon)

[COBOL2Java]

Reminds me of Hillary walking down stairs.

"6.5 on the Richter Scale!"

[SunkenCiv]

:^)