But now that relief efforts are getting under way, social media is stepping up to play another key role: helping the world support the rebuilding.
Whether it's through gaming or texting, tweeting or Facebooking, social media start-ups are working with non-profit organizations to help raise money for the cause.
If you're looking for high-tech ways to support earthquake relief efforts in Japan, take a look below.
To find other ways to help, click here.
To help victims of Japan's record-breaking earthquake, Chicago-based Groupon has turned its attention from deals to donations.
In addition to its daily deals in thousands of cities around the world, Groupon introduced an online offer Friday evening to let customers donate $5, $10 or $25 to support humanitarian aid group International Medical Corps' emergency relief efforts in Japan and other areas affected by the earthquake.
Since the deal went live Friday, the company said it has already generated $16,000 in donations.
Groupon also issued a tongue-in-cheek warning to its customers: ""Buyers beware," when you click "Buy" to donate your time or money to a worthwhile G-Team cause, the only discount you may receive is 100% off free, priceless karma."
Pledge Money With Your Facebook Posts, Tweets
If you're a social media addict, you can use your tweets and Facebook posts to raise money for Japan with HelpAttack.
Launched last year, the Austin, Texas-based start-up lets users pledge money for every action they take online. Similar to pledge models associated with marathons, in which runners raise money with every mile they run, HelpAttack lets users pledge an amount of money for every tweet and Facebook post they make.
You choose the amount of money you want to pledge with each post (as little as 10 cents or as much as $10 or more) and at the end of a 30-day cycle, your credit card gets charged with the amount you raised.
Your cell phone is another high-tech humanitarian tool. Just type in a few numbers and you can text a donation to one of several non-profit groups helping earthquake victims.
The Mobile Giving Foundation announced an initiative Friday that lets people use their cell phones to donate $5 or $10 to relief efforts.
Text "JAPAN" or "TSUNAM" to 20222 to donate $10 on behalf of Save the Children Federation, Inc.
Text "4JAPAN"or "4TSUNAMI" to 20222 to donate $10 on behalf of World Vision, Inc. Text "MERCY" to 25283 to donate $10 on behalf of Mercy Corps
The Red Cross has its own mobile giving program, in which supporters can text "REDCROSS" to 90999 to donate $10.
If you want to support The Salvation Army USA, you can text "JAPAN" to 80888 to make a $10 donation to the organization.
If you're a diehard FarmVille fan, you can support children affected by the earthquake just by playing your favorite game.
Zynga, the company behind the wildly popular Facebook game, announced Saturday that it was partnering with Save the Children to support earthquake and tsunami relief efforts.
In eight of the company's most popular games -- Cafe World, CityVille, FrontierVille, FarmVille, YoVille, Zynga Poker, Words With Friends and zBar -- players will have the opportunity to donate.
In FarmVille, for example, players can purchase a limited edition daikon radish crop. In Cafe World, players can buy Japanese-inspired decorations for their cafe. In each game, 100 percent of the purchase price goes to Save the Children's Japan's Earthquake and Tsunami Children Emergency Fund.
Japan Earthquake: Facebook Causes
Through Facebook causes, the social network's activism application, Facebook fans can support relief efforts by donating to the American Red Cross and Save the Children.
So far, the Help Japanese Earthquake and Tsunami Victims fundraising project has raised more than $17,000 for the American Red Cross. Online activists have raised nearly $1,000 for Save the Children's Japan Earthquake and Tsunami Emergency Fund.
On its disaster relief page -- http://www.facebook.com/DisasterRelief -- Facebook users are sharing fundraising projects, videos and other information related to the earthquake and tsunami.
The technology world's annual social media extravaganza, the South by Southwest Interactive Festival, is currently under way. But, on Friday, as the festival was just beginning, the event director tweeted that some social media mavens had launched a website to raise money for victims of the tragedy.
The sxsw4.japan.org web site was launched Friday with the goal of raising $10,000 by the end of the four-day festival. By Saturday afternoon, it had already raised more than $8,000.
"At SXSW this year, there's a lot of discussion and debate about influence. Now it's time to stand up and be truly influential as we raise support for tsunami relief," the site says.
Although the web site is focused on rallying conference attendees, anyone can donate and take part in support efforts.
In addition to featuring a way for people to donate money through the site, it also includes tips for launching individual fundraising pages.