A recent study investigated around 100,000 localized seismic events to search for patterns in the data. University of Tokyo Professor Satoshi Ide discovered that earthquakes of differing magnitudes have more in common than was previously thought.

This suggests development of early warning systems may be more difficult than hoped. But conversely, similarities between some events indicate that predictable characteristics may aid researchers attempting to forecast seismic events.

Since the 1980s seismologists - earthquake researchers - have wondered how feasible it might be to predict how an earthquake will behave given some information about its initial conditions.

In particular whether you can tell the eventual magnitude based on seismic measurements near the point of origin, or epicenter. Most researchers consider this idea too improbable given the randomness of earthquake behavior, but Ide thinks there's more to it than that.

"Taking inspiration from a study comparing different-sized earthquakes, I decided to analyze a seismic data set from a region known as the Tohoku-Hokkaido subduction zone in eastern Japan," said Ide. "A systematic comparison of around 100,000 seismic events over 15 years leads me to believe earthquakes are not different in random ways but share many similarities."

To draw comparisons between different earthquakes, Ide first selected the larger examples from the data set with magnitudes greater than 4.5. He also selected smaller earthquakes in the same regions as these larger ones.

Ide then ascertained mathematically how similar seismic signals were between pairs of large and small earthquakes. He used a statistical function for the comparison of signals called a cross-correlation on data from 10 seismic stations close to the pairs of earthquakes in each case.

"Some pairs of large and small earthquakes start with exactly the same shaking characteristics, so we cannot tell the magnitude of an earthquake from initial seismic observations," explained Ide.

"This is bad news for earthquake early warning. However, for future forecasting attempts, given this symmetry between earthquakes of different magnitudes, it is good to know they are not completely random."

Research paper

Related Links
University of Tokyo
Bringing Order To A World Of Disasters
When the Earth Quakes
A world of storm and tempest

Tweet

Thanks for being here; We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor $5 Billed Once credit card or paypal		SpaceDaily Monthly Supporter $5 Billed Monthly paypal only

Stanford researchers explain earthquakes we can't feel
Stanford CA (SPX) Aug 23, 2019
The Earth's subsurface is an extremely active place, where the movements and friction of plates deep underground shape our landscape and govern the intensity of hazards above. While the Earth's movements during earthquakes and volcanic eruptions have been recorded by delicate instruments, analyzed by researchers and constrained by mathematical equations, they don't tell the whole story of the shifting plates beneath our feet. Over the past two decades, the advent of the global positioning system - ... read more