The disaster in Burma is a stark reminder of the dangers of cyclones in the Bay of Bengal. These waters are a cauldron that brew up some of the world’s most destructive storms, causing more than half the world’s deaths from cyclones each year.

The premonsoon season, from April to May, is a dangerous time. If the sea reaches a temperature of 27C (81F), clusters of storm clouds can join together into a much larger, rotating storm that takes on a life of its own. It feeds voraciously off the warm sea and turns the humid air into monstrous clouds, exploding with heat that fuel a vortex of low pressure, which sucks in raging winds. The winds and torrents of rain turn into a frenzied whirlpool around a calm eye at the centre, and a cyclone is born.

This year extra trouble was expected from La Niña, a cooling of the tropical waters in the Pacific, so it was perhaps little surprise that Cyclone Nargis was a ferocious beast. On Saturday it smashed into the coast of Burma with winds reaching 190km/h (120mph) – equivalent to a Category 3 hurricane in the Atlantic. Cyclones in the Bay of Bengal wreak most of their havoc from storm surges, where a great bulge in the sea is whipped up by the winds and the storm’s intense low pressure and is rammed into a shallow coastline. On Saturday the storm surge from Cyclone Nargis, estimated at 3.7 metres struck the lowlying delta of the Irrawaddy river, obliterating the towns and villages there.

Cyclone Nargis was on much the same scale as Hurricane Katrina, which devastated New Orleans and the Louisiana coastline in 2005 and caused about 1,800 deaths. The death toll in Burma is far higher because there was little advance warning, evacuation or flood defence in an extremely densely populated region. As Bangladesh found to its cost after decades of cyclone disasters, with the right preventative measures the death toll can be reduced significantly.

Explore World News

• Iraq News

• US & Americas News

• Europe News

• Middle East News

• Asia News

• Africa News

• Ireland News

Times Recommends

• The Afghan grave that began decades of war
• Science thinks big for better IVF
• China jails monks to silence Olympic protests