The sea receded by about 50 metres in the Eravipuram-Kulathumpadu coastal area, near here, on Sunday night. It caused panic among residents in the coastal belt as the sea had similarly receded on December 26, 2004 shortly before the tsunami on that day.

The sea continued to remain in a receded state on Monday. However, experts said there was no need for panic. Environment researcher Sainudeen Pattazhy said a similar phenomenon had occurred in the coastal belt in Kozhikode, Thrissur and Kollam in 2002 and 2005. He attributed it to the expansion of the earth and a corresponding spreading of the seabed.

However, fishermen in the area said though not on a regular annual basis, they had witnessed this phenomenon during the Malayalam month of Kanni.

Dr. Pattazhi said the earth's expansion was a geological phenomenon and the expansion made the sea recede from shorelines. The process had been taking place for millions of years. Every time the earth goes through some pole shift, the earth expands and the oceans recede. When the pole ice caps melt, depending on the shift distance, more water is added to the ocean again, said Dr. Pattazhy. Then the ice on the new pole position builds up at a new location. Coinciding with the expansion of the earth, sea floor spreading occurs causing the sea to recede. In some places, such receding is permanent while in other areas, the sea returns to the previous state in two to seven days, he said..