By Seán Federico O'Murchú
From CNN's Mohammed Tawfeeq
At least 296 people have been killed, and more than 150 wounded after an earthquake of magnitude 6.8 hit Morocco on Friday night, state-run Al-Aoula television reported on Saturday.
From CNN's Sharif Paget and Mohammed Tawfeeq
Multiple buildings collapsed following Friday night's quake southwest of Marrakech city in Morocco, footage aired by the state-run Al-Aoula TV station showed.
Thousands of people fled their houses and residential buildings after the country's National Institute of Geophysics warned of aftershocks.
The epicenter of the quake was in the town of Ighil in Al Haouz Province of the Marrakech-Tensift-El Haouz region of Morocco.
The quake struck shortly after 11 p.m. local time at a relatively shallow depth of 18.5 kilometers (11.4 miles), according to the US Geological Survey.
The epicenter was in the High Atlas mountains located about 72 kilometers (44.7 miles) southwest of Marrakech, a city of some 840,000 people and a popular tourist destination.
“Earthquakes of this size in the region are uncommon, but not unexpected. Since 1900, there have been no earthquakes M6 (magnitude 6) and larger within 500 km of this earthquake, and only nine M5 (magnitude 5) and larger earthquakes,” USGS said.
The US body predicted that “significant damage is likely and the disaster is potentially widespread”, noting that many people in the area reside in structures that are “highly vulnerable to earthquake shaking.”
From CNN's Jennifer Gray
Measuring earthquakes is no easy task, given they strike suddenly and sometimes at global scale.
When the Earth’s crust shifts abruptly, an earthquake occurs, with energy radiated out as seismic waves and shaking that’s sometimes experienced by people, buildings and infrastructure.
Seismic waves and factors related to the shifting ground determine an earthquake’s magnitude, as measured through 10 on the scale most commonly used to describe quakes.
How strong the shaking feels is an earthquake’s intensity, as measured on a scale that uses Roman numerals to assign categories based on assessed damage and people’s observations.
Here’s what the scales indicate:
Scientists largely use the moment magnitude scale to categorize earthquakes’ strength and size in a way that’s more accurate than the long-used Richter scale, the US Geological Survey says.
This moment magnitude scale is based on the earthquake’s “seismic moment,” which accounts for how far the Earth’s crust shifts in a quake, the size of the area along the crustal crack and the force required to overcome friction at that spot, along with the seismic waves the shift creates.
The moment magnitude will be larger if there is more friction and shifting across a longer distance. Seismic waves are measured by seismometers, which use a pendulum attached to a spring that moves with the shaking of the Earth, generating a kind of graph called a seismogram.
Magnitude is ranked through 10, with each whole-number increase equal to 32 times more energy released.
At least 296 people have been killed, and more than 150 wounded after an earthquake of magnitude 6.8 hit Morocco on Friday night, state-run Al-Aoula television reported on Saturday.
Multiple buildings collapsed following Friday night's quake southwest of Marrakech city in Morocco, footage aired by the state-run Al-Aoula TV station showed.
Thousands of people fled their houses and residential buildings after the country's National Institute of Geophysics warned of aftershocks.
The epicenter of the quake was in the town of Ighil in Al Haouz Province of the Marrakech-Tensift-El Haouz region of Morocco.
The quake struck shortly after 11 p.m. local time at a relatively shallow depth of 18.5 kilometers (11.4 miles), according to the US Geological Survey.
The epicenter was in the High Atlas mountains located about 72 kilometers (44.7 miles) southwest of Marrakech, a city of some 840,000 people and a popular tourist destination.
“Earthquakes of this size in the region are uncommon, but not unexpected. Since 1900, there have been no earthquakes M6 (magnitude 6) and larger within 500 km of this earthquake, and only nine M5 (magnitude 5) and larger earthquakes,” USGS said.
The US body predicted that “significant damage is likely and the disaster is potentially widespread”, noting that many people in the area reside in structures that are “highly vulnerable to earthquake shaking.”
Measuring earthquakes is no easy task, given they strike suddenly and sometimes at global scale.
When the Earth’s crust shifts abruptly, an earthquake occurs, with energy radiated out as seismic waves and shaking that’s sometimes experienced by people, buildings and infrastructure.
Seismic waves and factors related to the shifting ground determine an earthquake’s magnitude, as measured through 10 on the scale most commonly used to describe quakes.
How strong the shaking feels is an earthquake’s intensity, as measured on a scale that uses Roman numerals to assign categories based on assessed damage and people’s observations.
Here’s what the scales indicate:
Scientists largely use the moment magnitude scale to categorize earthquakes’ strength and size in a way that’s more accurate than the long-used Richter scale, the US Geological Survey says.
This moment magnitude scale is based on the earthquake’s “seismic moment,” which accounts for how far the Earth’s crust shifts in a quake, the size of the area along the crustal crack and the force required to overcome friction at that spot, along with the seismic waves the shift creates.
The moment magnitude will be larger if there is more friction and shifting across a longer distance. Seismic waves are measured by seismometers, which use a pendulum attached to a spring that moves with the shaking of the Earth, generating a kind of graph called a seismogram.
Magnitude is ranked through 10, with each whole-number increase equal to 32 times more energy released.
