Hawaii’s Geology, Cultural and Geologic Accretions, and Terranes

Most people seem to go to Hawaii for the beaches. I am not a beach person. Many people consider it a vacation when they can sit and read. I can sit and read at home. Thus, I finally went to Hawaii on a trip with the American Scientific Affiliation to look at volcanic geology that required hikes down into calderas and up to craters. Having done research in New Zealand involving the Maori, I was also interested in Hawaii’s Polynesian indigenous culture and history.

How does one understand Hawaii? I began to use some key geologic concepts as lenses through which to see the land and its complex history. Bear with me as I use geologic concepts “loosely” at times as I think about Hawaii!

Hawaii sits in the Pacific Ocean and is over a Hot Spot, a place where there is a plume of hot lava that rises to the surface. Tectonic plates move over the somewhat stationary hot spots, creating a string of volcanoes.  In the case of Hawaii, the Pacific plate is moving toward the NW with the presently active volcanic activity over the hot spot—primarily the Big Island of Hawaii. As you go west the islands get older and more eroded. In other words, you can see the progressive geologic history of Hawaii in its islands, from the Big Island which is still being created, to the western most islands that have moved away from the hot spot long ago and had time to be acted upon and eroded by other forces of nature.

Originally called the Sandwich Islands by European explorers, this location, in the middle of the Pacific, has made Hawaii a strategic location for those that navigated the expansive Pacific Ocean. Hawaii, as a place, has been created through its location in the middle of the Pacific Plate over a hot spot, and in the middle of the Pacific Ocean, as an important stop-over for ships.

In geology, accretion is a process by which material is added to a geologic plate at a place where one tectonic plate collides with another, usually on the edge of continental land masses. The plate grows as material is added at the point of collision. I am not sure that the growth of the Big Island is considered accretion by the strict definition, since the process does not involve plate collisions, but the active volcanic processes do involve the creation of more land.

We spent time in the Puna District and the Eastern Rift Zone on the southeast side of the Big Island, the leading edge of land creation. This is a geologically active zone with large flows as recently as 2018. At that time, homes were destroyed and more than 875 acres added to the coastline. Viewing places where the lava flow stopped and cooled gives you the sense of being frozen in time. When we visited, landowners were in the process of re-inhabiting this stark landscape. We asked some locals about insurance for the risk of lava and were told that you couldn’t really get insurance for the lava, but if you were lucky enough to have your house catch fire from the lava bombs first, it would be covered. The rebuilding of houses on the landscape looked like a form of accretion, human materials being melded back onto the landscape, precarious as it was.

We saw the new land that had been created in Isaac Hale State Park, extending the coastline into the ocean. As the lava reached the coastline, it became fractured by the encounter with water, breaking into fragments, that then were picked up by the wave forces of long shore drift, another geologic process, totally burying and reshaping the coastline. I had seen the process of long shore drift with sand, but the speed of this accumulation of sediment and the size of the particles in this case was beyond what I could have imagined. The heat of the lava is still felt in the pool of water within the debris so we had to spend some time giving our feet a rest.

The Big Island continues to be active geologically. We visited Volcanoes National Park and stayed at the Volcano House on the edge of the Kilauea Caldera. We made two hikes, one across the floor of the Kilauea Caldera on land created in 1974, and the other up to the edge of the Kilauea Iki Crater. The enormity of the Kilauea Caldera became evident from the view from above, barely being able to see those hiking on the caldera floor. Crossing the caldera we were guided by cairns scattered across the stark landscape and we could feel heat in some of the cracks in the caldera floor.

While we had to stay away from the edge of the Kilauea crater below the floor of the larger caldera, we could walk up to the edge of the Kilauea Iki Crater and look in. Along the way up to the crater we saw the forms left by lava flowing around trees. The cracks and the heat at the top made me pause.

The volcanic processes that create such stark landscapes also raise up shield volcanoes which accentuate the climatic contrasts between the windward and leeward sides of the Big Island. At this latitude, the trade winds blow from NE to SW, leading the easterly sides of the island (windward) to capture most of the rainfall and develop rainforests and waterfalls. The westerly side (leeward) is dry with few flowing streams. On the Big Island, Kona is on the dry side and Hilo is on the wet side. Kona coffee grows at particular elevations on the dry side, with just the right temperature and moisture. At Kealakekua Bay, on the dry side, we visited the site of the first contact between Hawaiians and the West with the arrival of Captain Cook in 1779, and an important religious site for Hawaiians where the dry climate and rocky terrain were evident.

Hilo, on the windward side of the Big Island, is tropical and wet. This side of the Big Island felt like the classic Hawaii from travel brochures—waterfalls and rainforests. We visited Akaka Falls, Waipi o Valley lookout, and Laupahoehoe Point…in the rain. In the local market in Hilo we bought fruits that we had never seen and could not identify. Most were quite tasty!

Just as land has been added to the Big Island, so people groups have been added to Hawaii over time.  Native Hawaiians are part of the Polynesian culture region. I heard an echo of New Zealand Maori concepts while reading about Hawaii, with slightly different twists, such as “mana,” authority or power, and “tapu,” something sacred that implies a prohibition. Hawaiian culture was based on an elaborate class system. The islands were unified by King Kamehameha in 1810, and later became a constitutional monarchy. Hawaiians were creatively adaptive as they added technology, constitutions, and political structures. However, rulers, subsequent to Kamehameha, had difficulty managing relations with external parties, particularly the U.S. and British, who vied for influence.

Cultural accretion happened over time. American New England Congregationalists came and their children often identified as primarily citizens of Hawaii. For example, Sanford Dole, a missionary’s son and sugar planter was a prominent politician and was justice of the Supreme Court in Hawaii, the body charged with maintaining the constitution. We attended a congregational church in Hilo and it was a wonderful mix of Hawaiian and New England culture melded together.

Forces worked to limit the power of Native Hawaiians and large blocks of land were obtained by Americans through intermarriage with members of Hawaiian royalty or through business dealings with the government.  For example, Parker Ranch in Waimea on Hawaii’s Big Island was founded in 1847 and has approximately 150,000 acres. The land holding originated with John Parker who was a sailor with Captain James Cook on his first encounter with Hawaii. Parker jumped ship and eventually settling permanently in Hawaii. He married the daughter of a high-ranking chief and developed the salt beef export industry. The Parker Ranch continues to this day but as a trust to benefit the Waimea community.

In the 1870s the sugar industry expanded, with large land holdings developed into plantations. Labor was needed, so Asian migration to Hawaii began on a large scale. Portuguese also came to work in sugar plantations but quickly developed a dairy industry and also brought ukulele and slack key guitar as accretions to Hawaiian culture.

The areas of Hawaii that reflect the sugar plantation period, with sugar growing wild, isolated farms, rural churches, and Asian influence, are called “Old Hawaii.” We visited Honomu, one such old sugar plantation town, which is trying to attract tourists. The multi-ethnic flavor was evident and the architecture of the houses was clearly adapted to the wet and hot climate.

David Kalākaua, the last king of Hawaii, ruled from 1874 to 1891. In 1885, he signed a trade reciprocity treaty with the United States that allowed for sugar to be sold to the U.S. market tax-free. The Kingdom of Hawaii was soon overtaken by white landowners, missionaries, and businessmen. Even though the King promoted Hawaiian culture and traditions, Hawaiian sovereignty suffered. Eventually he was forced to sign a new constitution that stripped him of authority and many native Hawaiians of their rights. Non-native politicians and businessmen dominated the political system.

Queen Liliuokalani, the last monarch, again asserted Hawaiian independence and nationalism through a new constitution in 1893 that restored the monarchy’s powers and returned the franchise to Native Hawaiians. In spite of protests by the majority of Native Hawaiians, the U.S. took control of the islands and officially annexed the Hawaiian Islands in 1898, based on the argument that the Hawaiian Islands were strategic as a mid-Pacific fueling station and as a naval base.

After visiting the Big Island, we flew to Kauai to see the western most of the main islands. Here time and climate had shaped and eroded the original volcanic landscape. Here also, the economic and cultural forces, post World War II, have shaped the place. During this time period, agriculture declined as the economy has become focused on construction, service industries and tourism. Traffic and luxury resorts dominate large parts of the coastline. We spent little time among the resorts but rather headed up with Waimea Valley to see the affects of time and climate.

The northwest part of the island is a wilderness park where streams, stream-cut valleys and forests dominate. From the head of the Waimea Valley, we looked down into the Kalalau Valley to get a view of this remote wilderness, so close to the intense tourism of the other parts of the island.

In geology, a terrane is a crust fragment that becomes accreted to crust lying on another plate. For example, the Hawaiian Islands could, in millions of years, be sutured into the Eurasian Plate, since it is moving in that direction. Its fragments would preserve its distinctive geologic history and origins. Because it would be different than what is surrounding it, and far from its origins, it would be called an "exotic" terrane. My trip to Hawaii has made me think about the “exotic” cultural terranes that have been accreted to Hawaii—New England Congregationalism, tourism on a massive scale, Americanism, Asian immigration and large landholdings.

Magmatic differentiation is a process that we discussed on our trip to Hawaii. It is the geologic process by which chemically different igneous rocks, such as basalt and granite, can form from the same initial magma. Because the earth’s mantle is composed of many different minerals, it does not melt uniformly. As minerals with lower melting points turn into liquid magma, those with higher melting points remain as solid crystals. The magma rises to the surface because it is more buoyant, leaving the other minerals behind. In Hawaii they are going through cultural magmatic differentiation. Out of this mix of exotic terranes, chemically interacting, what will rise to the surface, and what will solidify into a cultural identify that can exist within the larger United States but also be differentiated and find continuity with the long history of the place?

The annexation of Hawaii has been recognized as an illegal act on the part of the U.S. Most recently, a joint resolution on the 100th anniversary of the 1893 overthrow of the Kingdom of Hawaii offered an apology to Native Hawaiians on behalf of the United States for the overthrow of the Kingdom of Hawaii. Native Hawaiians have a renewed appreciation and desire to restore some of their influence and power. I want to support them in this journey.