Credit: Greenpeace

Major cities are flooding more than was previously thought. This news comes from a new study published in the journal Nature Communications that used Twitter to measure the impact of tidal flooding along the U.S. Gulf and East coasts. The data show that flooding happens more frequently in some areas than what current flood monitoring tech has been able to detect.

The study analyzed data from 473,000 tweets sent by more than 5 million Twitter users from at least 273 different counties. With the data, researches were able to see a trend in which 22 counties had flooding at tide heights lower than the areas’ existing flood thresholds. Miami, Boston, and New York were among the large cities that were mentioned in the study. These were identified as locations that have been seeing nuisance flooding that has often gone undetected by tide gauges.