Items on the Japan earthquake and ensuing tsunami in Japan consistently ranked among the top spots in Twitter's most-popular topics in the United States Friday morning.
The poll tracks in real time the words or phrases repeated most frequently over the social-networking site.
Among nonprofits, only American Red Cross' mobile-giving campaign made the list, with celebrities such as George Takei asking readers to "Text REDCROSS." As it has during previous disasters, the organization is allowing donors to give $10 at a time by sending text messages.
After the 2010 Haiti earthquake, the American Red Cross raised more than $8-million from text messages in the first 48 hours, and saw similar prominence over Twitter feeds.