All the volcanoes in Hawaii are shield volcanoes. This means they are relatively large and have shallow-sloping sides - much like a warrior's shield. They are formed by low-viscosity (very runny) lava which, over time, runs down the side of the volcanic mountain and builds up a broad profile. It is like as if you had a steep, tall mountain of sand and you poured more sand on top of the mountain. The sand would run down the sides and, if you pour enough sand, your once steep and tall mountain will now be a shallow and broad hill. The shield volcanoes Hawaii erupt magma as hot as 1,200 °C (2,200 °F) compared with 850 °C (1,560 °F) for most other volcanoes around the world.

The Big Island of Hawaii is totally made up of volcanoes. From oldest to youngest these are: Kohala, Mauna Kea, Hualalai, Mauna Loa, and Kilauea.

Mauna Loa

Mauna Loa is the largest volcano in the world. It covers half the Big Island of Hawaii yet the slope of Mauna Loa ranges only 3-6°. Its flank spans across the Big Island of Hawaii which makes it unpredictable and dangerous because the eruptions can be in any direction. Historically, Mauna Loa erupted frequently (about once every decade) however since 1949 it has slowed down and has only erupted three times since then. Its last eruption was in 1984. Scientists now watch the volcano very carefully fro any signs of an impending eruption.

Mauna Kea

Did you know Mt Everest is NOT the tallest mountain in the world? In fact Mauna Kea, a volcano in Hawaii, is the tallest mountain (more than 9km high) when measured from its base which extends below sea level. The word 'mauna kea' in Hawaiian means 'white mountain' because of the white snow-cap seen at the summit during winter. Mauna Kea has erupted several times in the past 10,000 years, however the most recent eruption was 3,500 years ago. This makes it a dormant volcano but scientist still expect it to erupt again someday. Numerous observatories have sprung up on the summit of the volcano because Mauna Kea is considered the best place to view the sunset and the stars.

Kilauea

Kilauea is one of the world's most active volcanoes. This is what active means:

• Kilauea had continuous eruptions during 19th and 20th centuries.
• Kilauea has had 34 eruption cycles since 1952.

• The last eruption cycle started in 1983, continues even today, and has no indication of stopping in the near future.
• The lava flow from Kilauea has added more than 500 acres to the shoreline of the Big Island of Hawaii.
• The lave flow has destroyed a 700 year old Hawaiian temple and the old National Park Visitor Center, overrun many houses, and permanently blocked several highways.

No wonder why Hawaiian tradition says that the angry volcano goddess, Pele, resides in Kilauea!

Kohala

Kohala is the oldest of the volcanoes in Hawaii. It emerged from the sea more than 500,000 years ago and has not erupted for 60,000 years. Kohala is slowly sinking into the sea and is being covered by the lava flows from the two largest volcanoes, Mauna Loa and Mauna Kea. More than 200,000 years ago, a massive landslide occurred on the northern flank of the volcano forming magnificent cliffs which can be seen today.

Hualalai

Hualalai is situated in the west of the Big Island of Hawaii. The most recent eruption occurred during 1800-1801. The flanks of Hualalai have sprung full of life - houses, resorts, buildings, farms, and an airport. However in 1929, the place was hit by a chain of intense earthquakes which lasted a month. For this reason, scientists are now expecting an eruption in the next 100 years.