Our directory of things of interest

University Directory

California’s long-term quake forecast

  • Written by  Tom Hart
  • Published in Tectonics
San Francisco’s Palace Hotel on fire during a major earthquake in 1906 San Francisco’s Palace Hotel on fire during a major earthquake in 1906 Everett Historical
11 Mar
2015
Outlook is for fewer small quakes, but an increased risk from the ‘Big One’

California’s long-term earthquake forecast, the first in seven years, has been released. The study, known as the Third Uniform California Earthquake Rupture forecast, teams the US Geological survey with three other state authorities on tectonics to work out the region’s risk from earthquakes.

The good news is that the risk from magnitude 6.7 earthquakes has reduced by around 30 per cent, and the frequency rate for these quakes has dropped from an average of one per 4.8 years to one per 6.3 year.

A 6.7 earthquake is the same magnitude as the 1994 Northridge quake that killed 57 people, injured more than 8,500, and cost California some $20billion in damages.

6990B6C47C9B11DAThe 1994 Northridge earthquake caused serious damage to California’s transport infrastructure (Image: USGS)

But the study also shows that the risk from the ‘Big One’ – a magnitude 8 or greater quake – has increased from 4.7 per cent to seven per cent over the next 30 years.

A 2008 USGS report, ShakeOut Scenario, outlined the possible impacts from a 7.8 magnitude earthquake in California. The study suggested the state could expect 10,000–100,000 individual landslides and 1,600 fires. Total losses to buildings alone were valued at $33billion , with a total economic cost reaching $213.3billion. Casualties were estimated at 1,800 deaths, and 50,000 injuries.

ShakeOut scenario gets the Hollywood treatment

‘There are dozens more actions and policies that could be undertaken at the individual and community levels to further reduce these losses,’ the report concluded.

It’s a warning some Californian cities have heeded. In San Francisco, the Advanced Community Disaster Resilience Project aims to make the city’s neighbourhoods better prepared for an earthquake. The city has also introduced legislation to earthquake-proof older buildings.

‘The new likelihoods are due to the inclusion of possible multi-fault ruptures, where earthquakes are no longer confined to separate, individual faults, but can occasionally rupture multiple faults simultaneously,’ says Ned Field, lead author on the Third Uniform report.

Two models are used to understand California’s complex fault system. The Earthquake Rupture Forecast indicates when and where there might be a slip on the state’s faults while the Ground Motion Prediction model estimates ground shaking at a given fault.

Read the full Third Uniform Earthquake Rupture Forecast.

Related items

Subscribe to Geographical!

Geographical Week

Sign up for our weekly newsletter today and get a FREE eBook collection!

University of Winchester

EDUCATION PARTNERS

Aberystwyth University University of Greenwich The University of Derby

TRAVEL PARTNERS

Ponant

Silversea

Travel the Unknown

DOSSIERS

Like longer reads? Try our in-depth dossiers that provide a comprehensive view of each topic

  • The Human Game – Tackling football’s ‘slave trade’
    Few would argue with football’s position as the world’s number one sport. But as Mark Rowe discovers, this global popularity is masking a sinister...
    Essential oil?
    Palm oil is omnipresent in global consumption. But in many circles it is considered the scourge of the natural world, for the deforestation and habita...
    National Clean Air Day
    For National Clean Air Day, Geographical brings together stories about air pollution and the kind of solutions needed to tackle it ...
    REDD+ or Dead?
    The UN-backed REDD+ (Reducing Emissions from Deforestation and Forest Degradation) scheme, under which developing nations would be paid not to cut dow...
    Diabetes: The World at Risk
    Diabetes is often thought of as a ‘western’ problem, one linked to the developed world’s overindulgence in fatty foods and chronic lack of physi...

MORE DOSSIERS

NEVER MISS A STORY - Follow Geographical on Social

Want to stay up to date with breaking Geographical stories? Join the thousands following us on Twitter, Facebook and Instagram and stay informed about the world.

More articles in NATURE...

Energy

The Treasury has announced that it is considering imposing a…

Tectonics

Major earthquakes are triggering seismic activity half the world away

Climate

Marco Magrini finds that a warming world also means a…

Wildlife

Unchecked tourism is potentially reducing the number of cheetah cubs that…

Oceans

A relocated military base in Okinawa, Japan will cause ‘irreversible’…

Climate

The ongoing recovery of the planet’s ozone layer is being…

Oceans

The Ocean Cleanup has launched System 001, a floating barrier…

Nature

New videos reveal how plants respond to wounds, sending forth…

Geophoto

The recent heatwave had everyone longing for a drop of…

Wildlife

The demand for horseshoe crab blood – vital for testing…

Climate

One of the problems in getting accurate climate science out…

Wildlife

Italy is divided over the future of its wolves and…

Energy

A Scottish tidal power project in the Pentland Firth has…

Oceans

The world’s first full global analysis of beaches reveals the…

Geophoto

With the recent Saddleworth Moor fire, it can be easy…

Wildlife

Whale sharks have been found to not travel far from…

Wildlife

The Lone Star tick is spreading across North America, carrying…

Tectonics

Earlier this week, Indonesia was struck by a series of…

Energy

Efforts to reduce the energy drain of the internet are…

Energy

Coal’s rising popularity among climate-apathetic leaders is a worrying trend,…