The Icelandic volcano which has been disrupting air traffic for more than a month is showing a marked drop in activity. A leading volcanologist said heat camera footage from yesterday indicated the temperature in the crater had fallen to just 100 degree Celsius.He said, this means Eyjafjallajokull is now producing steam, not magma. But he warned that it was too early to say whether the eruption was over completely. Huge ash clouds from the volcano grounded thousands of flights in Europe during the early part of the eruption, and there has been fresh disruption since then.