WASHINGTON (Reuters) - Just one minute after the 5.8 magnitude earthquake struck in the state of Virginia on Tuesday and shook much of the U.S. eastern seaboard, an online aftershock of 40,000 tweets hit the internet.
Meanwhile, the National Hurricane Center got an additional 15,000 "likes" on Facebook ahead of Hurricane Irene's advance.
Social networking sites are increasingly critical to reporting and responding to such disasters, the Department of Health and Human Services, the American Red Cross, and the U.S. National Weather Service said in a Facebook Live event.
Surveys have shown that a majority of Americans believe response agencies should be monitoring social media, Director of Disaster Services at the American Red Cross Trevor Riggen said in the videoconference.
Nearly 40 percent of the American public expected help to come in less than an hour when such a request was posted after a disaster, and the American Red Cross said the Internet has become the third most used tool for disaster reporting.
"As you can imagine the influx of social media and use of social media in disasters has really sprung up over the last few years," said Riggen, who reported that just after Tuesday's earthquake he texted, posted on Facebook and then tweeted.
"I think that's the sequence the public is going through."
Almost a fifth of the American public uses Facebook as a trusted source during disasters and nearly a quarter uses social media to communicate with loved ones after an event.
NWS Deputy Director Laura Furgione said each of its 120 offices now have Facebook, along with the National Hurricane Center which had 69,054 "likes" on Wednesday afternoon and is currently monitoring Hurricane Irene.
"They have been using social media to help us get the message out," said Furgione. "Hurricane Irene is coming up the East coast and folks need to be thinking about - hopefully they're already thinking about - 'what is our plan?'"
The NHC has upgraded Irene to a Category 3 storm and projected it to hit North Carolina's Outer Banks Saturday.
Health and Human Services posted a $10,000 contest Monday to create a Facebook application for disaster preparedness.
Stacy Elmer, special assistant to the assistant secretary for preparedness and response of HHS, noted telecommunication challenges following the quake as a social media advantage.
"We're trying to decompress our communication systems," she said. "And then the people that really need to use them - our emergency responders, people trapped in the rubble - can have a chance to use them."
Authorities anticipate social networking will continue to be critical to the public's preparedness for disasters.
"Preparedness has always been a challenge, for years," said Riggen. "On a day like yesterday when you had both the earthquake and the hurricane coming up the east coast, that gets people's attention."
Like the weather, the social media technology is constantly changing, Elmer said. "If this is constantly evolving, we are thinking, how do we keep up with the change, instead of being behind it?"
Editing by Cynthia Johnston