The Canary Islands are a chain of seven volcanic islands that stretch ENE to WSW off the northwest coast of Africa. Like the Hawaiian Islands, they have formed over an oceanic hotspot.
As the Atlantic Ocean opened and the Tethys Sea closed, the African Plate has moved to the ENE, passing over the hotspot (an upward plume of the Earth's mantle). The oldest of the Canary Islands are thus at the northeast end of the chain and are now devoid of active volcanism (i.e. they are in the erosional phase of their natural history). The middle islands of the archipelago now lie northeast of the hotspot and are unlikely to experience active volcanism. The southwestern islands, including La Palma, sit above the hotspot and, as we have seen this week, are prone to volcanic eruptions.
The current eruption and basalt flows on La Palma could last for months, if not longer. After all, the eruption of Kilauea, on the Big Island of Hawaii, has continued since 1983.
