Plant life explosion seen from space

Weather systems such as El Nino and La Nina have triggered a plant life explosion in the sea which can be seen from space.

The survey of plant life on Earth was possible because of a new sensor orbiting the planet for the past three years, Nasa says.

The study, whose findings are reported in the journal Science, claims to have produced the most comprehensive global biological record ever assembled.

It represents the "first continuous global observations of the biological engine that drives life on Earth", Nasa said.

Researchers believe the record of plant life on Earth could reveal as much about the way the planet works now as fossils do about the planet's history.

Leading Nasa oceanographer Michael Behrenfeld said: "This is a period of exploration for us. We've never been able to see the Earth this way before."

The sensor, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), monitors levels of photosynthesis - the process in which plants use light, carbon dioxide and water to produce oxygen and carbohydrate.

A ship monitoring ocean plant life would take more than 4,000 years to gather the information that a single image from the sensor could offer, SeaWiFS project manager Gene Carl Feldman said.

The research was conducted by Nasa's Earth Science Enterprise, a long-term research effort dedicated to studying how human-induced and natural change affects the global environment.

The sensor was launched in 1997 and orbits the Earth from pole to pole 14 times a day, providing a complete global view every two days. More than 1,600 scientists representing 35 countries have registered to use the data.