The massive quake rattled buildings after striking at a depth of 32km around 12 miles southeast of Oaxaca in southern Mexico, according to US Geological Survey.
The earlier September 7 quake killed almost 100, mostly in Oaxaca and neighboring Chiapas state.
It was so strong that shakes were felt as far away as Austin, Texas, some 1,100 miles away.
She has put her nose to work in disasters such as an quake in Ecuador previous year, another one in southern Mexico two weeks ago, a landslide in Guatemala in 2015 and a Mexico City gas explosion in 2013.
More than 400 fatalities have been caused by the two September quakes.
Along a 60-foot stretch of a bike lane in Mexico City, families huddled under tarps and donated blankets, awaiting word of loved ones trapped in the four-story-high pile of rubble behind them. “I feel afraid even when a vehicle passes by”, said Dulce Bueno, who came Saturday morning with her husband and daughter to the hard-hit Condesa neighborhood.
Earlier on September 19, an natural disaster of magnitude 7.1 on the Richter scale that struck Mexico having epicentre 4.5 kilometers from east-northeast of San Juan Raboso and 55 km southwest of the city of Puebla.
At least 305 people died in the quake on Tuesday. It was powerful enough to once again send residents running into the streets. No reports of additional damage or injuries have been received.
The rest of the deaths occurred in the states of Morelos, Mexico, Puebla, Guerrero and Oaxaca. That frustrated rescue workers that continued battling the clock to find any possible survivors.
Search and rescue efforts in the Mexico City area could last “for at least two more weeks”, Luis Felipe Puente, Mexico’s civil protection coordinator, told CNN affiliate Foro TV. “They are all moments that you wouldn’t wish on anyone”.
They were told that water and food had been passed along to at least some of those trapped inside. Using the information to pinpoint their location, rescuers freed Pacheco, 30, and the three other survivors shortly after 6 am on Wednesday.