Hawaiian Islands

The Hawaiian Islands (Hawaiian: Mokupuni Hawaiʻi) are an archipelago of eight major volcanic islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some 1,500 miles (2,400 kilometers) from the island of Hawaiʻi in the south to northernmost Kure Atoll. They used to be called the Sandwich Islands by Europeans, but now they are known by the name of their largest island, Hawaiʻi.

These islands sit on the Pacific Plate. They are the tops of a huge underwater mountain range called the Hawaiian–Emperor seamount chain, created by volcanic activity over the Hawaiian hotspot. The islands are about 1,860 miles (3,000 km) from the nearest continent and are part of the Polynesia area of Oceania.

The U.S. state of Hawaii covers nearly all of the islands, except for Midway Atoll, which belongs to the United States Minor Outlying Islands. Hawaii is the only U.S. state that is made completely of islands, and it is also the only state not connected to North America. The northwestern islands and the waters around them are protected as a national monument and World Heritage Site.

Islands and reefs

The Hawaiian Islands cover a land area of 6,423.4 square miles (16,636.5 km²). Besides Midway, which is an area of the United States without its own local government, these islands and small land pieces are part of Hawaii, the 50th state of the United States.

The eight main islands of Hawaii are listed above. All of these islands have people living on them except Kaho'olawe.

Hawaii counts 137 "islands" in its chain. This includes all smaller islands, tiny islands just off the shore of the main islands, and individual tiny islands in each group of islands joined together. Some of these are:

• Kaʻula
• Kāohikaipu
• Lehua
• Mānana
• Mōkōlea Rock
• Mokoliʻi
• Moku Manu
• Mokuauia
• Moku o Loʻe
• Moku Ola
• Mokuʻumeʻume
• Molokini
• Nā Mokulua

Partial islands, groups of islands joined together, and coral reefs—those west of Niʻihau are not lived on except Midway Atoll—make up the Northwestern Hawaiian Islands. These include:

• Nīhoa (Mokumana)
• Necker (Mokumanamana)
• French Frigate Shoals (Kānemilohaʻi)
• Gardner Pinnacles (Pūhāhonu)
• Maro Reef (Nalukākala)
• Laysan (Kauō)
• Lisianski Island (Papaʻāpoho)
• Pearl and Hermes Atoll (Holoikauaua)
• Midway Atoll (Pihemanu)
• Kure Atoll (Mokupāpapa)

Geology

Main article: Hawaii hotspot

Further information: List of rivers of Hawaii

This group of islands, called an archipelago, formed as the Pacific Plate moved slowly over a hot spot in the Earth's mantle. The southeast island is still active with volcanoes, while the islands at the northwest end are older and smaller because they have been worn down by erosion. The oldest island, Kure Atoll, is about 28 million years old. The youngest, Hawaiʻi, is only about 400,000 years old. The only recent volcanic activity has been on Hawaiʻi and on a growing underwater volcano called Kamaʻehuakanaloa (formerly Loʻihi). The Hawaiian Volcano Observatory of the USGS keeps track of volcanic activity. Kīlauea erupted many times from 1983 until it stopped in 2018.

Most of the magma that feeds these volcanoes is a type of rock called basalt, which makes the eruptions usually not too explosive. Hawaiʻi, the Big Island, is the largest and youngest. It has five volcanoes, with Mauna Loa being the largest shield volcano on Earth. From the ocean surface to its top, Mauna Loa is more than 2.5 miles (4 km) high.

Earthquakes

Main article: List of earthquakes in Hawaii

The Hawaiian Islands often have earthquakes linked to volcanic activity. These earthquakes happen most often near active volcanoes like Mauna Loa and Kilauea. The shaking can be caused by the movement of magma and the land sliding. Earthquakes can sometimes cause tsunamis.

People have kept records of earthquakes in Hawaii since the 1800s. Today, the Hawaiian Volcano Observatory run by the USGS monitors them. Hawaii has many earthquakes, ranking third among U.S. states from 1974 to 2003.

On October 15, 2006, there was an earthquake with a strength of 6.7 near the island of Hawaii. It caused some damage but no serious injuries. On May 4, 2018, there was a 6.9 earthquake near Kīlauea.

Earthquakes are watched closely by the Hawaiian Volcano Observatory run by the USGS.

Tsunamis

The Hawaiian Islands can be hit by tsunamis, big waves caused by earthquakes far away in the Pacific. These waves move very fast and can affect the islands even if the earthquake is thousands of miles away.

Sometimes, tsunamis can start in Hawaii too. Big volcanic explosions or underwater landslides can create them. The city of Hilo has felt the effect of tsunamis strongly because of the shape of its bay. Coastal areas have warning sirens.

A tsunami from an earthquake in Chile reached the islands on February 27, 2010. It was small, but people prepared for a bigger one. A tsunami from an earthquake in Japan came on March 11, 2011. It caused about $30.1 million in damages.

Volcanoes

Main article: List of volcanoes in the Hawaiian–Emperor seamount chain

Only the two southeast islands, Maui and the Big Island, have active volcanoes. These include Haleakalā on Maui and Mauna Loa, Mauna Kea, Kilauea, and Hualalai on the Big Island. The other islands’ volcanoes are no longer active. An underwater volcano called the Kamaʻehuakanaloa Seamount may become the next island in about 10,000 to 100,000 years. Volcanoes can cause lava flows, gases, earthquakes, and tsunamis.

History

Main article: History of Hawaii

The Hawaiian Islands were first settled by people from Tahiti or the Marquesas Islands. The exact date of the first settlements is still debated, but it is believed to have happened between 940 and 1130 C.E.

In January 1778, British explorer James Cook was the first European to see the islands. With help from new European tools, Kamehameha I brought the islands together into one kingdom in 1795. This kingdom grew strong through farming and its important place in the Pacific Ocean.

After Cook’s visit, many people from different places moved to Hawaii. Farmers from Japan, China, and the Philippines came to work on plantations. The kingdom allowed everyone equal rights, no matter their background. Sadly, the number of Native Hawaiians got smaller over time but began to grow again in the late 1900s. In 1893, Queen Liliʻuokalani was removed from power, and Hawaii became a U.S. territory in 1898. Finally, in 1959, Hawaii became the 50th American state.

Ecology

See also: Endemism in the Hawaiian Islands, List of animal species introduced to the Hawaiian Islands, and List of invasive plant species in Hawaii

The Hawaiian Islands are home to many special animals and plants that are found only there. When humans first arrived, they brought new animals like rats and pigs. These new animals hurt the native birds and insects that had never had to deal with predators before. As more people came, especially from Europe and America, forests were cut down for farming and building towns. This caused many forest animals to disappear, and many others are now in danger of disappearing forever.

The way people farmed changed a lot when Europeans arrived. They cleared more forests to grow single crops and raise animals, which hurt even more native species. As of 2009, many of the special plants and animals of Hawaii were still at risk.

National Monument

On June 15, 2006, President George W. Bush created Papahānaumokuākea Marine National Monument using special powers given by law. This area includes the northwestern Hawaiian Islands and the waters around them, making it the biggest marine reserve in the world. Later, in August 2010, a group of experts named it one of the most important places in the world. Then, on August 26, 2016, President Barack Obama made it four times bigger than before.

Climate

Main article: Climate of Hawaii

The Hawaiian Islands have a tropical climate but have many different weather patterns depending on height and location. The islands get most of their rain from winds that come from the north and east. Areas on the south and west sides are usually drier.

The islands are driest from May to September and get more rain during the winter months from October to April. Sometimes tropical storms and hurricanes can happen from July to November. Summer temperatures are around 84 °F (29 °C), and winter temperatures are about 79 °F (26 °C). The temperature doesn’t change much during the year, so severe thunderstorms are rare.