Geology of HawaiiGeology of Hawaii

By: Katie DonovanBy: Katie DonovanRachel SeesanRachel Seesan

SCI 210 4/5/04SCI 210 4/5/04Dr. SandyDr. Sandy

• Hawaii has an area ofHawaii has an area of 6,435 square 6,435 square miles and the shoreline are 1,022 miles miles and the shoreline are 1,022 miles longlong

• There are actually 132 islands in the There are actually 132 islands in the Hawaii Island ChainHawaii Island Chain

• The big island has five above the ocean The big island has five above the ocean volcanoes which are oldest to the volcanoes which are oldest to the northwest and youngest to southeast. northwest and youngest to southeast.

• 82 volcanoes in the Hawaii chain82 volcanoes in the Hawaii chain

•   Mauna Kea is the tallest mountain in Mauna Kea is the tallest mountain in

Hawaii at 13,796 feetHawaii at 13,796 feet • 8,800 different species of animals… most 8,800 different species of animals… most

of which are endangeredof which are endangered

• 1,193,0011,193,001 live in Hawaii.. Less then 1% live in Hawaii.. Less then 1% are pure Hawaiianare pure Hawaiian

• Hawaii was formed when a Hawaii was formed when a molten 'hot spot' weakened molten 'hot spot' weakened the Earth’s crust until it the Earth’s crust until it broke open and molten lava broke open and molten lava started pumping out. started pumping out.

• That one 'hot spot' stays in That one 'hot spot' stays in the same place as the the same place as the Pacific Tectonic Plate moves Pacific Tectonic Plate moves slowly northeast towards slowly northeast towards Japan and has created all of Japan and has created all of the Hawaiian Islands the Hawaiian Islands

• A volcano is defined as a A volcano is defined as a place where magma/or gas place where magma/or gas from within the earth from within the earth surfacesurface

• Explosions depend on two Explosions depend on two characteristics:characteristics:1.1. The amount of gas in The amount of gas in

proportion to liquid rockproportion to liquid rock2.2. The viscosity The viscosity

(stickiness) of the liquid (stickiness) of the liquid lavalava

““Hawaiian type” eruptions Hawaiian type” eruptions are unique compared to are unique compared to other typesother types

• Rocks ejected from volcanic eruptions are Rocks ejected from volcanic eruptions are known as volcanic ejectaknown as volcanic ejecta

• Hawaiian ejecta is known as pyroclastic Hawaiian ejecta is known as pyroclastic (“fire-broken”) rocks(“fire-broken”) rocks

• Ejecta classified according to size.Ejecta classified according to size.• Rocks found in Hawaii are also found in Rocks found in Hawaii are also found in

other central Pacific islandsother central Pacific islands• Hawaiian rocks differ in the processHawaiian rocks differ in the process

• Most abundant mineral is Most abundant mineral is feldsparfeldspar– White/gray with glassy or White/gray with glassy or

pearly lusterpearly luster– Cleavage seen on broken Cleavage seen on broken

surfacesurface– Made of anorthite and albite Made of anorthite and albite

chemicalschemicals

Most abundant limestone is Most abundant limestone is CalciteCalcite

– Rhombohedral cleavageRhombohedral cleavage

Quartz is the rarest mineralQuartz is the rarest mineral– Glassy appearance and Glassy appearance and

little/no cleavagelittle/no cleavage

• Serves multiple Serves multiple purposes to the purposes to the Hawaiian islandsHawaiian islands

• Least known part Least known part of the earth’s of the earth’s surfacesurface

• The shoreline is The shoreline is gradually cut back gradually cut back by the horizontal by the horizontal direct attack of the direct attack of the waveswaves

• Rock debris is Rock debris is produced by this produced by this processprocess

• Series of elastic wavesSeries of elastic waves

• One of the most feared natural One of the most feared natural disasters of Hawaiidisasters of Hawaii

• Caused by sudden displacement of Caused by sudden displacement of rock in the oceanrock in the ocean

• Waves spread out and cause tidal Waves spread out and cause tidal waveswaves

http://www.geophys.washington.edu/tsunami/general/historic/images/64800111.jpg

• Pele the goddess and creator of the Pele the goddess and creator of the Hawaiian Islands can create/destroy with Hawaiian Islands can create/destroy with firefire

• Bad luck to steal a piece of rock from the Bad luck to steal a piece of rock from the Island… Pele will find revenge on you!Island… Pele will find revenge on you!

• Includes sand, rocks, and lava rocks, and Includes sand, rocks, and lava rocks, and shellsshells

• http://www.volcanogallery.com/lavarock.htmhttp://www.volcanogallery.com/lavarock.htm