Hurricanes, like Irma, lose potency when winds near the ocean surface blow at one speed and direction while winds in the upper atmosphere blow another. This difference — or shear — causes a hurricane to physically tilt, like a top, which dampens the force of the winds emanating from it.
“Right now, the shears are pretty low, and as you can see the storm looks pretty symmetrical,” Philip Klotzbach, an atmospheric scientist at Colorado State University, told the NewsHour.
A lone man stands on a beach in Khao Lak as a huge wave engulfs him during the 2004 Boxing Day Tsunami. It is estimated that 227,898 people lost their lives that day, making it the single worst tsunami in recorded history.