The Kilauea volcano, the second-youngest volcano in the Hawaiian Ridge, has continued to have a significant impact on the surrounding environment and its population since its current phase of eruption started in 1983. This eruption is thought to be the longest-lasting in Kilauea’s entire history – a history between three-and sixhundred thousand years long. It is also a history that has also literally produced the island of Hawaii itself, due to the shield volcano’s gently sloping sides, which constitute fifteen hundred square kilometers, or nearly fourteen percent of the Hawaiian island (USGS, 2017)
In considering the geographical impact of Kilauea – its impact on its natural and human environments – this essay traces the development of volcanoes in general and then turns its attention to the Hawaiian volcano specifically. It first discusses the definition of and processes behind volcanoes, focuses further on the formation of the Hawaiian Ridge – of which Kilauea is a part – and then considers Kilauea to assess the impact it continues to have today. volcanoes volcano is defined as being “an opening on the surface of a planet or moon that allows material warmer than its surroundings to escape from its interior” (NASA, 2008), and their evolution on Earth has contributed to the formation of the diverse landscapes that make up the planet (Okubo et al, 1997).
These ticking time-bombs are usually formed at the convergence or divergence of tectonic plates, which move against each other and cause friction that melts the earth’s crust.
The constant movement causes the melting rock to transform into the magma that is found within volcanos. The magma then generates pressure which eventually leads it to the cracks in the plates (Perez, 1999). After a certain amount of pressure accumulates within the interior of the earth, the magma erupts at volcanoes. Most volcanic activity usually occurs in oceans because of the plate boundaries at the bottom of oceans (Okubo et al, 1997).
The geographical impact of volcanoes is due to the fact that during an eruption lava, volcanic bombs, ash, and miscellaneous gases are discharged, all of which can have a serious effect on the surrounding area. Some consequences that come from the threatening volcanic vents that discharge gas and lava include large numbers of people being forced to flee, temporary food shortages and volcanic ash landslides (Rubin, 2013). For small communities and cities that live near any type of volcano, explosive eruptions can be threatening and even fatal.
These eruptions have the ability to burst clouds of hot ash that can reach hundreds of meters in distance. These hot clouds dash down mountains, demolishing anything in their path. The ash, meanwhile, lands like powdered snow, and when it mixes with the water from streams, mudflows form – which can bury and suffocate whole communities (Mattox et al, 1993).
The Hawaiian Ridge: Volcanic hotspots (Mattox, 1993)These Hawaiian volcanoes are present on the Pacific plate. The oldest on the far left, Kauai, stands together with Oahu and, the youngest volcano, Maui. These three volcanoes together make up the Hawaiian Ridge, which is formed from the region’s solid dense rock. The Hawaiian Islands are known to be volcanic and are each composed of at least one central volcano. The distinct island known as the Big Island is made up of five primary volcanoes which include Kilauea, Mauna, Loa, Mauna Kea, Hualalai and Kohala (Rubin, 2007). Each volcano has distinct characteristics.
For example, Mauna Loa is known as the largest volcano on earth, whilst Kilauea is one of the most active and productive. Currently, there are only three active volcanoes on the island, which include the Mauna Loa, the Loihi, and the Kilauea. The Kilauea volcano has been erupting since 1983, while the Mauna Loa and Loihi volcano stopped erupting in 1984, and 1996 respectively (Rubin, 2007). It has become evident that that recent eruptions of lava have been shifting towards the east out a new vent. This new vent is called the Kupaianaha and it is slowly becoming exposed on the earth’s surface.J. Tuzo Wilson proposed a hypothesis as to why the Hawaiian Ridge is unusually placed at the center of the Pacific plate rather than on a tectonic boundary: this is known as the “hotspot theory” (Okubo et al, 1997).
He theorized that its linear geography was due to the movement of the Pacific plate, seen from right to left in the image above, which is shifted by an immobile flume of hotter magma within the Earth (Okubo et al, 1997).
As the rocky crust of the volcano is pushed over and the seafloor spreads along the plate boundary, the temperature of the localized hot spot melts the Pacific plate above the hot spot (Zerkel, 2014). The magma that is produced by the melting rock of the Pacific plate rises through the mantle and the crust as a thin thermal plume. Eventually, the thermal plume forms an active seamount beneath the ocean and causes it to increase in height until the surface penetrates and becomes an island volcano (Zerkel, 2014).
The island then pushes away from the hotspot, as the Pacific plate moves northward, and the room is made for a new island to form on top of the hotspot (Perez, 1999). A zone of magma formation is present here, known as the fixed “hot spot”, which is the source of the volcano’s power. It keeps the volcanoes running, producing harsh ash pollution to the detriment of the region’s air quality. Kilauea The Kilauea Volcano is located on the southernmost island of Hawaii and is considered the most active of the five volcanoes that make up the island of Hawaii (Heliker et al, 2004). In the Hawaiian language, its name means “much spreading” or “spewing”, which is a reference to its continual outpouring of lava (Perez, 1999)
The Kilauea volcano is about 4200 feet tall and has a 165m deep circular caldera (Perez, 1999). This historic volcano acts as a shield volcano and it emerged above sea level about 100,000 years ago: it is estimated to be around 400,000 to 600,000 years old (Perez, 1999). This unique volcano mainly flows basaltic lava but is periodically known to explode (Perez, 1999). It has only been dormant for eighteen years since 1918 between 1934 and 1952 (Hill, 2014), whilst, in 1790, the volcano had an eruption that killed at least eighty native Hawaiians – whose footprints can now be viewed in the Hawaii Volcanoes National Park (Bagley, 2014).
Clearly, the volcano’s impact has had and will continue to have, a considerable impact on both the landforms and the human populations in the surrounding area. Of the forty-five serious eruptions of Kilauea in the twentieth century (Zerkel, 2014), the Pu`u `O`o Eruption, Kilauea‘s most recent and ongoing eruption, began in January 1983 and reached its 31st year of activity on January 3, 2014 (Zerkel, 2014).
According to the U.S. Geological Survey, in this cycle, there have been more than sixty recorded eruptions. As a result of this eruption, more than 1.9 km3 of lava was created that covered 102 km2 of the landscape, and that added 205 hectares to Kilauea’s southern shore (Zerkel, 2014). Not only have the eruptions of the Kilauea volcano substantially altered the terrain, and make it difficult to transverse by car and by walking but it also fatally affected many lives in the area. In March of 1990, Kilauea was recorded that year to be experiencing the most destructive eruption period in modern history (Mattox et al, 1993). Lava flow made its way through Kalapana and its town before making it to the seat in 1986 (Mattox et al, 1993).
As a geographical consequence of the eruption, the twenty-five meters of lava demolished one-hundred and eighty-one houses and resurfaced up to thirteen kilometers of highway. This unexpected explosion also destroyed the Royal Gardens subdivision, the Hawaii Volcanoes National Park visitor center, and more than two hundred structures in the town of Kalapana (Zerkel, 2014). Despite the great risk and dangers associated with its eruptions, Kilauea seems to remain a popular attraction for tourists.
A broad cloud of toxic gas and white smoke still frequently smothers the small town of Pahala near the Volcano, which severely impacted the townspeople’s crops and health (Bagley, 2014). In 2009, the gas being released was so toxic that parts of the island have been declared a disaster area. Many of the island residents from towns nearby were notified to “not wait for an alert if they feel ill from the volcanic output” and it has essentially become completely uninhabitable (Rubin, 2013). (Rubin, 2013) (Rubin 2013)The homes of local residents in the community of Kalapana, on the Island of Hawaii, were destroyed when lava flow from the Kilauea Volcano reached them in 1990. The Island of Kalpana eventually was buried over fifty feet of lava. This has affected the region for the worse, as these volcanoes are slowly making it uninhabitable. Vegetation had been lost, homes had been lost, air quality has been lost. Who knows what is going to happen next. (Bagley, 2014). (Pleasance, 2014)
Lava Flowing Across a Road in Kilauea Kalapana, Hawaii (Pleasance, 2014) This Map prepared by the U.S Geological Survey presents the lava-flow hazard zones for the island based on expected eruption sites. It also shows the expected flows of lava and the geological past. The geographic landscapes and the ecological community of the island of Kilauea itself are also extremely threatened by the volcano’s activity. The lava flow is burning down sections of the volcanos forests and the ash that comes from the explosive eruptions that suffocate the local plant life.
This destruction becomes evident when looking at the material at the bottom of Kilauea’s ash deposits and the coatings of carbonized organic matter (Hill, 2014). Rainfall near Kilauea’s southwestern rift zone tends to mix with the volcanic sulfur dioxide resulting in acid rain (Hill, 2014). This alarming precipitation obstructs regional plant growth, making plant life in the region nonexistent (Perez, 1999). Whilst Kilauea is one of five volcanoes on Hawaii, what differentiates this volcano is the fact that it is known as a shield volcano. Shield volcanoes are usually the largest volcanoes existing on earth and have active flowing lava. In shield volcanoes, there are gentle slopes found at the summit and are produced by basaltic lava flows (Bagley, 2014). This type of lava flows for very long distances before cooling and becoming solid. The molten lava that came out of the notorious volcano when erupted ranged from 1,292 to 2,192 Fahrenheit and would incinerate anything in its path (Bagley, 2014). Along with destroying thousands of trees and plants in the distance, Kilauea suppressed most of the sandy terrain.
The picture on the right exhibits the Pu’u’O’o vent which is the source of the eruptive activity. The Healemm’uma’u which is on the left is the other one of only two active vents located on the top of the crater.ConclusionsAs the volcano is placed on a natural hot spot, volcanic eruptions in this area will never disappear. The Hawaiian hot spots that are fueled by earth’s mantle are thought to have been active for at least 70 million years, and, as an active volcano in the modern day, Kilauea has the ability to erupt at any given moment: it currently still shows frequent eruptions and outbreaks from the summit of the volcano. Although there are not immediate and critical threats to local communities, the surface flow seems to still be very active. Recently officials in the area have cautioned visitors and residents to avoid the beach by Kamokuna: they have found that a flow of over 50g of lava has been entering the ocean. The eruptions of volcanoes like Kilauea demonstrate the unique power that nature has to shape the land in a dramatic way. Not only can they create dramatic scenery and beautiful displays of erupting lava, but they can also have damaging consequences on the people, the landscape, and geography.