The Kaū Desert is a leeward desert in the district of Kaū, the southernmost district on the Big Island of

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state ...

, and is made up mostly of dried lava remnants,

volcanic ash Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to refer ...

, sand and gravel. The desert covers an area of the

Kīlauea Kīlauea ( , ) is an active shield volcano in the Hawaiian Islands. Located along the southeastern shore of the Big Island of Hawaii, the volcano is between 210,000 and 280,000 years old and emerged above sea level about 100,000 years ago. His ...

Volcano A volcano is a rupture in the Crust (geology), crust of a Planet#Planetary-mass objects, planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and volcanic gas, gases to escape from a magma chamber below the surface. On Ear ...

along the Southwest rift zone. The area lacks any vegetation, mainly due to acid rainfall. Kau desert

Climate

Kaū desert is not a true desert in that rainfall exceeds per year. However, rain combines with sulfur dioxide, released by volcanic vents, and forms acid rain. The pH level of the rain, as low as 3.4 during an eruption, inhibits plant growth. Furthermore, water evaporates quickly on the ground and the

tephra Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size, or emplacement mechanism. Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, they re ...

soil is extremely permeable.

Visiting

The Kaū Desert is popular for walking and hiking tours during inactive periods. It can be reached by following Highway 11 counterclockwise from Kona to the volcano. The trailhead is on Crater Rim Drive, coordinates . By traversing the desert, one can cross the Great Crack and the Southwest Rift Zone, a major fault zone that looks like a giant groove in the earth, before reaching

. From the city of Hilo, take Highway 11 about 30 miles (48 km) west. The area is part of

Hawaii Volcanoes National Park Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state ...

, but often is closed during periods of high volcanic activity, due to the potential for poisonous gas blown southwest by the

tradewinds The trade winds or easterlies are the permanent east-to-west prevailing winds that flow in the Earth's equatorial region. The trade winds blow mainly from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisph ...

from

Halemaʻumaʻu Halemaumau (''six syllables: HAH-lay-MAH-oo-MAH-oo'') is a pit crater within the much larger Kīlauea Caldera at the summit of Kīlauea volcano on island of Hawaiʻi. The roughly circular crater was x before collapses that roughly doubled ...

.Closed Areas and Advisories
on Hawaii Volcanoes National Park web site

The 1790 eruption

One of most devastating explosions in Hawaiian history occurred in 1790. The eruption released

, which formed spheres of

known as accretionary lapilli due to the effect of electrostatic forces and moisture. Chief Keōua Kuahuula was traveling then around Kīlauea to Kaū, after battling the dominant chief

Kamehameha I Kamehameha I (; Kalani Paiea Wohi o Kaleikini Kealiikui Kamehameha o Iolani i Kaiwikapu kaui Ka Liholiho Kūnuiākea; – May 8 or 14, 1819), also known as Kamehameha the Great, was the conqueror and first ruler of the Kingdom of Hawaii. Th ...

. At least 80 Hawaiian warriors suffocated when volcanic ash entered their lungs. The

footprints Footprints are the impressions or images left behind by a person walking or running. Hoofprints and pawprints are those left by animals with hooves or paws rather than feet, while "shoeprints" is the specific term for prints made by shoes. The ...

preserved in the ash were supposedly of these warriors. However, recent research indicates a variety of people used this area for hundreds of years.Keonehelelei – the falling sands
''Hawaii Volcanoes National Park Archaeological Inventory of the Footprints Area'', Jadelyn Nakamura, 2003

References

External links

General description of Kaū Desert
{{DEFAULTSORT:Ka'u Desert Geography of Hawaii (island) Deserts of the United States Deserts of Oceania Hawaiʻi Volcanoes National Park Volcanic deserts