지진 예측에 사용되는 균형 잡힌 바위 VIDEO: 'Rock clocks' made from delicately balanced boulders can help seismologists forecast the severity of earthquakes with 50 per cent greater accuracy, study finds

'Rock clocks' made from delicately balanced boulders can help seismologists forecast the severity of earthquakes with 50 per cent greater accuracy, study finds

Researchers calculate the age of various precariously balanced rock formations

They then work out how big of an earthquake would be required to topple them 

This allows them to predict the 'upper limit' of an past earthquake in that area

This can them be used in 'hazard' models to determine future earthquake risk 

By RYAN MORRISON FOR MAILONLINE 

PUBLISHED: 17:04 BST, 2 October 2020 | UPDATED: 17:31 BST, 2 October 2020

지진 예측에 사용되는 균형 잡힌 바위  정확도 50% 향상    정교하게 균형 잡힌 바위는 지진 예측의 정확도를 50% 향상시킬 수 있는 '록시계'를 만드는데 사용되어 왔다. 임페리얼 칼리지 런던의 연구원들은 위험할 정도로 균형 잡힌 암석(PBR)의 형성에 따른 정보를 이용하여 새로운 심각한 지진 예측 모델을 만들었다. 받침대 바위에 '슬렌더 바윗돌'을 섬세하게 얹은 암석형성물인 PBR은 부드러운 바위가 침식될 때 형성돼 단단한 바위를 상태를 유지한다 이 팀은 캘리포니아의 디아블로 캐년 원자력 발전소에서 균형 잡힌 바위를 연구하는 것으로 시작했는데, 이 바위 3D 모델을 만드는데 참여해왔다. 이를 통해 그들은 과거의 정보로부터 암석 주변 지역의 향후 대지진의 위험을 결정하는 '위험 모드'를 만들 수 있었다. 연구진은 '록시계'를 기존 모델과 결합하면 위험 추정치가 약 50% 향상된다는 사실을 발견했다. 황기철 콘페이퍼 에디터 Ki Chul Hwang Conpaper editor curator

edited by kcontents

Delicately balanced boulders have been used to create a 'rock clock' that can improve the accuracy of earthquake severity predictions by up 50 per cent. 

Imperial College London researchers created a new severe earthquake forecasting model using information from formations of precariously balanced rocks (PBRs).

 

This image shows a precariously balanced rock preserved on a tectonically uplifted marine terrace near the Diablo Canyon nuclear Power Plant in coastal Central California

PBRs, rock formations where a 'slender boulder' is delicately perched on a pedestal boulder, are formed when softer rocks are eroded, leaving the harder ones behind. 

The team started by studying balanced boulders at the Diablo Canyon Nuclear Power Plant in California - this involved dating the rocks and creating a 3D model.

They then used the 3D model to 'throw Earthquakes at the boulders' to see how strong it needed to be in order to make them topple over.

This allowed them to then create a 'hazard mode' that determines the risk of future major earthquakes in the area around the rocks from past information. 

Combining the 'rock clock' with existing models improved hazard estimates by around 50 per cent, the researchers found. 

Anna Rood collecting samples for cosmogenic surface exposure dating, which will be used to model the history of the PBR being exhumed from the surrounding softer weathered rock

As part of the study to create a 'rock clock' the team determined the age of PBRs near the Diablo Canyon Nuclear Power Plant in coastal California.

To do this they used a technique called 'cosmogenic surface exposure dating' that counts the number of beryllium atoms formed within the rocks by the long-term exposure to cosmic rays.

3D modelling was then used to digitally recreate the PBRs and calculate how much shake was needed to topple the rocks.

Having survived for thousands of years, they can be used to calculate the 'upper limit of earthquaking shaking', the point at which the boulder would topple.

This is where the 'rock clock' label comes in - by understanding how long the rocks have stood, the team can determine how long it has been since a major earthquake struck - and its maximum size - in the area surrounding that rock. 

Anna Rood measures a number of balancing rocks as part of the study into their age. This work allows the team to predict future large earthquakes and their estimated size

Anna Rood sat next to a precariously balanced rock that will be used to validate how earthquakes rupture along the San Andreas fault

The PBR overhangs its pedestal, which makes it teeter on the edge of toppling. Brightly coloured tape is used to aid the construction of 3D models of the PBR and surrounding outcrop

Anna Rood measuring the scale of an excavated section into the marine terrace. The two rock outcrops extending above the terrace surface in the background are abandoned sea stack on which the PBRs have formed

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https://www.dailymail.co.uk/sciencetech/article-8798677/Rock-clocks-balanced-boulders-improve-accuracy-earthquake-forecasts.html

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