Eruptions Beneath the Sea

Many volcanic eruptions take place, unseen, on the ocean floor in places like the Mid-Atlantic Ridge. When lava erupts beneath the sea it produces a special form known as a Pillow Lava. You can see this happening in the video.

Video: Sea-floor eruption of pillow lava Source: Project NeMo

These pillow lavas, at Strumble Head in Wales, were formed on an ancient sea floor (over 400 million years ago) in the same way as the modern pillow lavas shown in the video clip.