Lava from the Cumbre Vieja volcano on Spain's La Palma poured into the Atlantic Ocean for a second day on Thursday, creating a rocky outcrop more than 500 metres wide that extends the island's coastline farther to the west.
Vicente Soler, a volcanologist with Spain's National Research Council, said by flowing into the sea the lava was less likely to cause damage than it would on land.
Thousands of people were evacuated from their homes and La Palma airport was temporarily closed after the volcano erupted on September 19. The lava flow destroyed more than 800 buildings, as well as banana plantations, roads and other infrastructure.
"This outlet ... represents the most favourable situation for the lava flow not to keep invading new territory as it has been doing until now," Mr Soler said in a video on social media.
After meandering downhill to the coast for nearly 10 days, the lava reached the ocean just before midnight on Tuesday near the town of Tazacorte. On reaching the water, the lava cools rapidly, binding to the cliffside and enlarging the island's territory.
Despite fears of toxic gases from the lava reacting with the seawater, authorities said the air inland was fine to breathe.
Emergency services said that ash thrown out from the crater was blocking sunlight and reducing visibility.
Several villages near the coastline are locked down as a precaution, but banana farmers in several villages were allowed access to their plantations to tend their crops.
The eruption appears to have calmed and no lava was being expelled from the crater, Reuters reported, although smoke continued to billow from the volcano.