Rip Currents

• Context (TH): Indian National Centre for Ocean Information Services (INCOIS) and ISRO have embarked on a project to monitor and issue operational forecast alerts of rip currents.
• Rip current is a narrow, powerful current of water running perpendicular to the beach, out into the ocean.
• They typically extend from near the shoreline, through the surf zone and past the line of breaking waves.
• Rip currents move along the surface of the water, pulling one straight out into the ocean.

Surf zone is the area between the high tide level on the beach to the seaward side of breaking waves.

How do rip currents form?

• They are caused by the shape of the shoreline itself, and they may be sudden and unexpected.
• They can occur in areas with hard-bottom (rocky) or soft-bottom (sand or silt) beach topography.
• Rip currents form when waves break near the shoreline, piling up water between the breaking waves and the beach.
• One of the ways this water returns to sea is to form a rip current, a narrow stream of water moving swiftly away from shore, often perpendicular to the shoreline.

How fast are rip currents?

• Rip currents typically reach speeds of 1 to 2 feet per second. However, some rip currents have been measured at 8 feet per second—faster than any Olympic swimmer ever recorded.

How big are rip currents?

• Rip currents can be as narrow as 10 or 20 feet in width though they may be up to ten times wider.
• Rip currents begin to slow down as they move offshore, beyond the breaking waves, but sometimes extend for hundreds of feet beyond the surf zone.

Are all rip currents dangerous?

• Rip currents are present on many beaches every day of the year, but they are usually too slow to be dangerous to beachgoers.
• They are one of the most well-known coastal hazards on beaches around the world.