LOS LLANOS DE ARIDANE, Canary Islands (AP) — Lava flowing from a volcano in Spain’s Canary Islands has picked up its pace on its way to the sea. But scientists say it’s impossible to estimate when the stream of molten rock would reach the Atlantic Ocean off the island of La Palma, an event that could trigger explosions and the release of toxic gas. Authorities said the lava had moved to within 800 meters (875 yards) of the Atlantic Ocean as of Tuesday morning, nine days after the volcano’s eruption. The National Geographic Institute detected six earthquakes in the area of the eruption. No flights went in or out of La Palma’s airport for a fourth day because of a huge ash cloud.