Nearly 75 per cent of the us is at risk from earthquakes

2 min read

PLANET EARTH

WORDS BEN TURNER

Nearly 75 per cent of the US could be struck by damaging earthquakes, the US Geological Survey (USGS) has discovered. The new finding, made by a model used to build a colour-coded earthquake map, reveals that millions of Americans live in areas with a high earthquake risk. That includes known earthquake hazard zones such as Los Angeles, San Francisco, Portland and Seattle, but also locations like Salt Lake City and Memphis.

According to the new model, 37 US states have experienced earthquakes greater than magnitude 5.0 in the last 200 years. The new information helps update the odds of harmful earthquakes in the seismically active regions of Alaska and California and highlights the possibility of more damaging earthquakes along the central and northeastern Atlantic coastal corridor, which includes the cities of Washington DC, Philadelphia, New York and Boston. “Earthquakes are difficult to forecast, but we’ve made great strides with this new model,” said Mark Petersen, a geophysicist at the USGS. “The update includes more faults, better characterised land surfaces and computational advancements in modelling that provide the most detailed view ever of the earthquake risks we face.”

Earthquakes occur because tectonic plates get locked together as they move over the mantle. The forces that caused them to collide continue to build up until the plates suddenly shift. This creates a gigantic rupture, releasing energy in the form of potentially devastating seismic waves that violently shake the ground. Scientists have searched for patterns that could forecast major earthquakes for decades, but without a precise map of Earth’s subterranean crust, these efforts have come up short. Instead, geophysicists collate data on past earthquakes’ locations and magnitudes to create risk maps indicating where the strongest and most frequent temblors could hit.

The new map is the first National Seismic Hazard Model to chart this risk across all 50 states, and is the result of a collaborative effort between federal, state and local officials. Notably in the new model, the strength of the earthquakes in Hawaii have been upgraded – a consequence of increased volcanic activity witnessed in recent years in the region. ��

This article is from...

How It Works Magazine

15 February 2024

National Geographic Traveller

Greek islands

From the gastronomic isles of the Cyclades to the enigmatic ruins of the Dodecanese, each of the six main Greek island groups has its own distinct character. Choose your own adventure and discover them yourself

All About Space

Become an astronomer

Part two

BBC Wildlife Magazine

On thehunt

S ince 2009, Amy Dickman has come across some horrific sights on the edge of Ruaha National Park in Central Tanzania where she studies, and tries to resolve, conflict between people and predators. The

BBC Science Focus Magazine

Bed bugs vs the world

Bed bugs have been around longer than humans. When researchers used bed bug DNA to get an idea of when they first evolved, they found that the ancestors of today’s bed bugs were already tiny but succe

BBC Sky at Night Magazine

Touching thesun

On 12 August 2018, NASA’s Parker Solar Probe (PSP) blasted off from Cape Canaveral Air Force Station into the pre-dawn Florida sky on a mission to become the first-ever spacecraft to ‘touch the Sun’.