Earthquake : aftershocks count in the thousands – .

Earthquake :

(Photo by Mario Tama / .)

(.) – The earth continued to rumble.

Communities in Southern California had just begun repairs after the quake struck on the morning of July 4, when an even stronger quake struck the area just over 24 hours later.

READ: A devastating California earthquake by 2030 is possible and this is the reason

(Photo by Mario Tama / .)

The two earthquakes have been the strongest in the region in decades. This is how they compare.

The second earthquake was 11 times stronger

The 6.4 magnitude earthquake that occurred Thursday morning had its epicenter near Ridgecrest, a community west of the Mojave Desert and approximately 150 miles (240 km) north of Los Angeles.

He had residents run out of their homes, and the thousands of aftershocks that followed had them on alert for hours.

A 7.1 magnitude quake struck the same area on Friday night, shaking buildings and leaving cracks in the streets.

It was 11 times more powerful than the first quake, according to the United States Geological Survey (USGS).

And it was 5 times bigger

Friday’s quake was not only 11 times more powerful than Thursday’s, it was also five times larger.

What does that mean exactly?

“Five times larger” refers to the scientific measure of the earthquake. On the seismograph, Friday’s quake is five times the size of Thursday’s quake.

“Eleven times stronger” refers to the intensity of the earthquake. Friday’s quake released 11 times as much energy as Thursday’s.

But strength, not size, is the most important number. The energy released in an earthquake is what causes the damage. Or, as the USGS puts it: “It really is energy or force that knocks down buildings.”

Here’s how to interpret the magnitude of an earthquake in terms of the amount of damage it causes:

Magnitude Damage

Micro 3.0 Little or nothing

Less 3.0 to 3.9 Little or nothing

Light 4.0 to 4.9 Moderate

Moderate 5.0 to 5.9 Considerable

Strong 6.0 to 6.9 Severe

Higher 7.0 to 7.9 Extensive, severe

Huge 8.0 and more Immense

READ: Earthquakes in California: the earth shakes with almost one aftershock per minute

It was also longer

Bakersfield resident Giovanna Gomez was at home with her family on Friday when her house wobbled and the water in her pool overflowed.

“It lasted about a minute,” he said. “Much longer than yesterday’s.”

Bakersfield is in Kern County, about 110 miles (177 km) from Ridgecrest.

Donald Castle, who lives in Porterville, west of Ridgecrest, said his house shook for almost 25 seconds.

“It was more of a jolt than the one we had on the 4th (July). It lasted longer and moved more, “she said.

Both earthquakes caused damage

(Photo by Mario Tama / .)

The two earthquakes caused damage to communities, including fires, power and water outages.

READ: What we know so far about the powerful second earthquake in California

They happened close to each other

Friday’s earthquake occurred 11 miles (17 km) northeast of Ridgecrest, according to the USGS. Its epicenter was located just northwest of the quake on Thursday, also near Ridgecrest.

They are part of an ongoing system

Seismologist Lucy Jones of CalTech said Friday that the two earthquakes are part of an ongoing sequence, of a “very energetic system.”

USGS geophysicist John Bellini told . that more than 4,700 tremors of all magnitudes have been recorded since Thursday’s earthquake.

READ: More than 4,700 earthquakes have been registered since Thursday in California

“They come every 30 seconds, every minute,” he said.

Since the 7.1 magnitude earthquake on Friday night, there have been three earthquakes with magnitudes of 5 or more.

On its website, the USGS looked at the possibility of more aftershocks in the coming week (until July 13). Here is the forecast:

The probability of an earthquake of magnitude 3 or greater is more than 99%. The probability of an earthquake of magnitude 5 or greater is 96%. The probability of an earthquake of magnitude 6 or greater is 27%. The probability of an earthquake of magnitude 7 or greater is 3%.

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These probabilities will continue to decrease as time passes.

Jay Croft, Braden Goyette, Christina Maxouris, Paul Vercammen, Haley Brink and Meg Wagner contributed to this report.