UCSB Science Line
Sponge Spicules Nerve Cells Galaxy Abalone Shell Nickel Succinate X-ray Lens Lupine
UCSB Science Line
How it Works
Ask a Question
Search Topics
Our Scientists
Science Links
Contact Information
I saw a picture yesterday on the newspaper online of lava flowing from rocks in Hawaii. How is this possible?
Answer 1:

Lava flows in Hawaii are generally really slow moving and extremely hot! As they emerge from the volcano, the lava flows begin to immediately cool as they interact with the much cooler air around us. As the outer edges of the lava flows cool, they begin to form a crust but the center of the lavas flows remain very hot and have the ability to continue moving. Think about a hot lava cake, a chocolate crust encases a gooey chocolate inside; this is just like Hawaiian lava flows! The crust that forms actually protects the inside of the lava flows from the air outside, keeping the inside warm and gooey. Sometimes, lava can pool up beneath that crust creating so much pressure that it will actually burst through the edge of the crust! When this happens the flows emerge from beneath the crust and flow in a different direction and then form a new crust.

So the lava isn’t actually flowing FROM the rocks in Hawaii, the flows are actually flowing beneath this sometimes-thick crust of hardened lava. This crust can become very thick and sometimes the lava flowing beneath can form tunnels, or lava tubes, in which the lava can freely flow and maintain its heat and eventually may emerge from beneath these rocks once they make it to the ocean.

Answer 2:

The Hawaiian islands are thought to be formed through a process called hotspot volcanism, whereby each island is formed from one or more volcanoes. Geoscientists think that a hot plume of material originating from near the core/mantle boundary (~2900 km below the Earth's surface) has built the islands over time. This material is heated and rises buoyantly - like material in a lava lamp - until it erupts onto the ocean floor. Once this happens, later eruptions 'grow' each volcano over time, leading some to emerge from the ocean and become islands.

The island of Hawaii (called "the Big Island") is actually built from multiple volcanoes, and some are still active. The photo you saw likely came from one of these active volcanoes. The eruptions at this stage are not explosive and are therefore not dangerous; this allows people to get very close to the lava as it erupts. Once the lava cools, it forms basalt - the same type of rock the islands are made of. In summary, these lava flows are the result of active volcanism in the Hawaiian Islands.

Answer 3:

Rocks are kind of like ice cream. Sometimes rocks get really hot and can melt and become lava. When they get cold they turn into solid rock again.

Some rocks are easier to melt than others. Those which melt easily usually aren't as hot when they come out as lava on the surface. The rocks in Hawaii are harder to melt, and they come out at a higher temperature than other kinds of lava.

When I was a kid I visited some of my family in Hawaii and saw the volcanoes there. The lava was hotter than a campfire. If people threw any sticks into the lava, they would burn right up.

Answer 4:

Answer # I don't know exactly what you saw, but remember that lava is molten because it is hot, and freezes when it is colder. The air is colder than the lava, so molten lava touching air will form a layer of frozen rock on the surface, with still molten lava underneath. The frozen lava on the surface looks like a rock because it is a rock , but it can still flow or the still-molten lava can break out because it is hotter underneath the surface.

Answer 5:

Lava is melted rock. If you heat rocks above 1112 F (600 or 700 degrees Celsius) they start to melt, just like ice/snow starts to melt when you heat it above 32 degrees F (0 degrees C). The lava that you saw pictures of in Hawaii is extremely hot, which is why it is liquid.

There aren't very many places on Earth that are hot enough to melt rocks, but Hawaii is one of them. This is because Hawaii has volcanoes. Volcanoes are where very hot lava from inside the earth (the mantle) comes to the surface of the earth. It is still very hot when it gets to the surface of the earth, but it starts to cool.

That lava that you saw in the photo will only be liquid for a few hours before it starts to cool and become solid.This is how rocks are formed!

Click Here to return to the search form.

University of California, Santa Barbara Materials Research Laboratory National Science Foundation
This program is co-sponsored by the National Science Foundation and UCSB School-University Partnerships
Copyright © 2015 The Regents of the University of California,
All Rights Reserved.
UCSB Terms of Use