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The surface of the lava

cools to form a wrinkled or

rough, fractured skin of

solid black rock

The lava that erupts on Hawaii solidifies into black basalt – a heavy, iron-rich rock

Lava flows downhill

at speeds of up to 100 km/h (60 mph)

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ERUPTION

When Kilauea erupts, basalt lava and gas are forced up from deep within the volcano. Basalt lava is very fluid, so a lot of it just spills over the rim of the crater. Erupting gas can also cause explosive “fire fountains” of gas and red-hot lava, like this one.^2

CRATER

Lava boils up through a vent to

build up a cone of rocky debris. More eruptions make the inside of the cone collapse or even explode upwards to create a roughly circular crater. Its almost sheer walls reveal layers of cinders, ash, and solidified lava.^3

CONE

This small volcanic cone is just the summit of a huge, dome-shaped shield volcano, which rises all the

way from the ocean floor 7,277 m (23,875 ft) below. The dome is built up by the fluid lava that erupts on Hawaii. Volcanoes that erupt stickier, less fluid lava have steeper sides.

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LAVA FLOW

The lava that erupts from Kilauea is extremely hot, and is so fluid that it flows downhill away from the crater like a river of fire. Since 1983 the volcano has been erupting almost constantly, spilling lava over more than 100 sq km (40 sq miles).^5

TYPES OF LAVA

Hawaiian lava is molten basalt rock pushed up from beneath the ocean floor. It is fluid because it contains very little silica (the mineral used to make glass). Other volcanoes erupt lava that is high in silica, which is much stickier and does not flow far.^6

LAVA TUBE

As the lava streams away from the active crater of Kilauea, the surface of the flow cools and hardens. Underneath, however, the hot lava keeps flowing. This creates “lava tubes” that extend to the coast, where the lava spills into the sea in clouds of steam.

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