Hawaii Volcano, Research Paper Example

Mauna Loa, or “long mountain” (Hawaii Center for Volcanology, 2014, para. 1) is a volcano located on the main island of Hawaii. The first eruption was recorded in 1780 and since then it has been an active volcano with many years of dormancy. This paper will focus on Mauna Loa’s eruptive cycle and what scientists have recognized as eruptive precursors. The paper will also focus on eruptive patterns and it’s importance to hazard mitigation.

From the Mauna Loa’s first recorded eruption in 1780 it has erupted a total of thirty nine times (Seach, n.d., para. 45) in the following years: 1984, 1975, 1950, 1949, 1942, 1940, 1935-36, 1933, 1926, 1919, 1916, 1914-15, 1907, 1903, 1899, 1896, 1892, 1887, 1880-81, 1880, 1879, 1877, 1876, 1875, 1873-74, 1873, 1872-73, 1871, 1868, 1865-66, 1859, 1855-56, 1852, 1851, 1849, 1843, 1832, 1803, 1780 (Seach, n.d., para. 45). With all of these previous dates of eruption, it is noted that Mauna Loa is currently in its longest running inactive period (having lasted for over 25 years).

In the one of the first documented eruptions (1832), observers documented that the volcano continued eruption or 4 weeks and that this eruption was paralleled with lava flanking both sides of the volcano (Seach, n.d., para. 42). Twenty-three years passed before the volcano erupted again (an eruption documented by John Turnbull, who, at the time, was going on a voyage around the world). Another nineteen years would pass before the volcano would erupt again in 1832. The volcano lay inactive for nearly a decade (1843) before it was followed by another eruption that lasted for 90 days. The eruption was marked with another volcano erupting (Kilauea volcano) but it was discovered that the two volcanoes do not share a magma reservoir, making them independent of each other. Six years later the volcano erupted and a brilliant light (lava fountaining) was seen from the volcano, a light that lasted for three weeks. Another six years passed and in 1935 the Mauna Loa lava was noted to have flowed at an extraordinary rate; in fact, the lava flowed from the old crater pit and then was noted to have reappeared more than “6.5 km downslope” (Seach, n.d., para. 40). The 1851 (16 years between eruptions) eruption was noted by observers to have “white pillar of smoke by day and a brilliant fiery pillar by night” (Seach, n.d., para. 39). The next eruption occurred a mere six months after the 1851 eruption, and wherein lava was noted to have flowed into the nearby forest (in Hilo). Three years later from 1855-1856 Mauna Loa reportedly erupted for a period of over 16 months and lava was documented to have flown over 60 miles. Three years after this tremendous out flowing of lava, Mauna Loa engaged in another impressive and massive eruption that lasted for a period of 10 months and saw lava flow 12 miles. Seach (n.d.) states that the lava flowed for an approximate 300 days. Six years later Mauna Loa erupted for a “four month long summit”. Hawaii witnessed two volcanoes erupt in 1868 when both Mauna Loa and Kilauea erupted simultaneously again (in 1843 and 1868 both of these volcanoes simultaneously erupted, 25 years spanning the distance between these two time periods). Together, lava flow reached the sea and “The eruption of Mauna Loa volcano created an earthquake swarm with a maximum magnitude 8, which was is the largest historical earthquake in Hawaii. The earthquake caused a tsunami which hit from Hilo to South Cape. The eruption began at the summit followed by the southwest rift. On 7th April lava erupted from a fissure at 5,600 ft altitude. The lava flow lasted 4 days and destroyed 37 houses” (Seach, n.d., para. 35). A mere three years later Mauna Loa erupted again. A year after this the volcano erupted for a period of 18 months but was confined to the summit caldera. Mauna Loa had a mere six month rest period between eruptions, for in January, 1873, the volcano erupted again for a period of 2-3 weeks then the volcano erupted again in April (having had a rest period of three months). This last erupted lasted into 1874: “Lava fountains were recorded to a height of 200 ft above the summit. Geologist William Green climbed to the summit of Mauna Loa on 6th June 1873 to view the eruption” (Seach, n.d., para. 32). The volcano lay inactive until January 1875, a year in which the volcano erupted twice: in January and in August, each eruption lasting a very short amount of times (Augusts’ eruption lasted for a week). In 1877 the volcano erupted and this eruption was followed by a submarine eruption that occurred three miles south of Kealakekua which is located one mile offshore: The submarine eruption ejected steam, pumice, and scoria into the air. A tsunami reached Kona. The locals reported “red, blue, and green lights dancing in the waters” (Seach, n.d., para. 30). Another summit eruption was witnessed in 1879 (two years later). Mauna Loa lay inactive for twenty-one years and then in 1880 there was another summit eruption which observers reported to have sounded like thunder. Six months later in November 1880 Mauna Loa erupted again with very intensely and with great volume. This eruption lasted for 9 months and was juxtaposed with three main lava flows, however, was not accompanied with any earthquakes (MacDonald, 1950, p. 211) or with any ash emission: “The first eruption occurred west of Red Hill at the pit crater Puka Uahi. A second lava flow diverted around Red Hill and flowed towards Kau. A third lava flow moved towards Hilo and flowed between 1852 and 1855 eruptions. This flow stopped only a quarter of a mile from Hilo” (Seach, n.d., para. 25). In 1887 Mauna Loa’s eruption is noted with strong earthquakes that originated in the crater south of the summit caldera. For the second time in its eruption history, Mauna Loa’s lava reaches the sea sometime in January. Five years later in 1892 the volcano erupts for a period of three days (no earthquakes were reported). In 1896 an eruption lasts for a period of 16 days. Three years later in 1899 a flank eruption begins. There were two lava flows. The eruption site was near the “crest of a ridge and small changes in eruption sent lava in different directions” (Seach, n.d., para. 10). Four years later in 1903, Mauna Loa erupts for a period of four months. Four years later in 1907 the volcano erupts with lava flow lasting for a period of 15 days. Between 1907 and 1940 there are six eruptions without earthquakes (1935-36, 1933, 1926, 1919, 1916, 1914-15 with respected inactivity periods as follows: four years, three years, six years, six years, three years, and finally two years). In 1940 there is a summit eruption four years after the last eruption. This eruption consisted of “a summit eruption followed by a flank eruption. The eruption began with a continuous line of lava fountains from a series of fissures 5 km long, extending from the centre of Mokuaweowo caldera, to a point over the SW caldera rim” (Seach, n.d., para. 8). A plume rose from the summit and from the caldera floor there was a fluid spread of pahoehoe. This summit eruption was also witness to earthquakes (though reportedly small in number). Two years later in 1942 there was a flank eruption. This flank eruption was equipped with lava erupting from fissures (at 285 m altitude) in the North Bay and is described as thus, “Like most flank eruptions of Manna Loa, the 1942 eruption began with a brief period of eruption in and near the summit caldera. The summit phase of the eruption commenced at approximately 17:05 on 26th April, with the opening of a fissure part way up the cliff along the western side of Mokuaweoweo caldera, across North Bay, and about 4 kilometers down the northeast rift zone. A voluminous amount of fluid, gas rich pahoehoe lava cascaded down the western wall of the caldera” (Seach, n.d., para. 4-6). The flank eruption also consisted of lava coming out of the fissures in the rift zone with these fissures erupting continually during this period (it is reported that the fissure grew in length to about a mile). The lava fountain was measured to have been around 160 meters in height. A lava river accompanied the flank eruption and was measured at about 16 meters wide (having erupted from the east-northeast side with an estimated 25-30 km per hour). During this flank eruption, the lava river flowing at an altitude of 840 meters was diverted through the efforts of US Air force personnel who dropped bombs on it and diverted its course. A decade later in 1950, there was another flank eruption, this time from the southwest rift zone. This eruption lasted for a period of 23 days and consisted of lava flows (the lava flow, Honokua, went into the ocean in less than three hours) and was measured at approximately 387 million cubic meters (not including the amount that was dropped into the sea which was estimated at about 76 million cubic meters). Twenty-four years later, in 1975, Mauna Loa erupted again with a line of lava fountains occurring at the summit caldera. Nearly a decade past before another eruption occurred in 1984 that was accompanied by a magnitude 4 earthquake with lava fountains visible in Mokuaweoweo caldera. This eruption also saw fissures opening (this was near the northeast rift zone) (Klemetti, 2009, para. 1). Twenty-five years later inflation stopped on Mauna Loa volcano that is the longest time period in it’s recorded history that it has remained inactive. Some patterns that occur in the volcano’s history include the most common time period between eruptions has been five-six years (Seach, n.d., para. 1-42).

One thing of note is that as eruptions from the summit of the volcano increase in size and frequency the eruptions form the rift zone decline (USGS, 2006, para. 1). Cycles of the summit-flank alternation “suggest that such shifts may cycle every 2,000 years” (USGS, 2006, para. 2) meaning that there may be a period of time in which this shift will precursor a period of “long-lived lava-lake activity, shield-building, increased summit overflow, and diminished rift zone eruptions” (USGS, 1998, para. 5). Further research on the volcano began in 1958 with CO2 emission rates. Research done by the US Department of Commerce/National Oceanic & Atmospheric Administration/NOAA Research has shown that there is a pattern to these emissions. This pattern shows that CO2 emissions drastically decreases after each eruption period with the lowest levels of reported CO2 occurring currently with this period of twenty-five year inactivity (at least this pattern holds firm since the research began) (Earth System Research Laboratory, n.d., para 5). The volcano also emits significant levels of sulfur dioxide (SO2) (Ryan, 2010, para., 1).

MacDonald (1950) states that there appears to be precursors to Mauna Loa’s eruption: these precursors are in the form of earthquakes. The author notes that this pattern of earthquakes, however, is less definitive or volcanic activity. As the above information has listed, many times, when Mauna Loa erupted, there were no earthquakes (p. 211). In fact, MacDonald states that “No cycle of activity of any great value in predicting activity has been recognized in Hawaii” (p. 211). MacDonald notes the difference between the summit and the flank eruptions but states that there is no sequence between these two different types of eruptions and seismic activity and goes on to state that, “Astronomical and tidal cycles have been studied in relation to both time of outbreak and strength of eruption, but without demonstration of any very definite relationship. Eruptions have occurred in every month of the year, but there is a slight tendency for them to cluster just before and after solstice, particularly winter solstice” (p. 211). There is, however, new data presented by Scientific American that suggests a telling sign of volcanic activity.

Oskin (2014) reports that the Hawaii Volcano Observatory has witnessed signs of activity in the volcano (as observed in June 2014). The Hawaii Volcano Observatory is concentrating on points on a graph that indicated tiny jolts of seismic activity, that they say, may be a precursor for Mauna Loa activity. The Hawaii Volcano Observatory stated that there were four separate earthquake “swarms” (Oskin, 2014, para. 3) or “clusters” of earthquakes that were occurring in groups that were “closely timed” and zeroed in on (Oskin, 2014, para. 4). These earthquakes have been tracked since March of 2013 and are occurring below Mauna Loa. The earthquakes were reported to have occurred on the following dates, “March 2013, Sept.-Oct. 2013, April 2014 and May 2014” (Oskin, 2014, para. 4).

These earthquakes occurred northwest of the summit crater and were reported to be between 2.5 and 9 miles deep. These deeper tremors were reported to be followed by shallower, less significant, but still vital, earthquakes anywhere from a few days to a month after the initial tremors (Oskin, 2014, para. 5). The Hawaii Volcano Observatory observed that none of these shallower earthquakes were more than 2.2 in magnitude (excluding one that was measured at 3.5 magnitude occurring on May 9^th). These were termed as “rumbles” and were much smaller in magnitude than the ones that preceded Mauna Loa’s eruption in 1984 (Oskin, 2014, para. 6).

These earthquakes are important, as the Hawaii Volcano Observatory reports that prior to the 1984 eruption of the Mauna Loa “the volcano’s fiery inner chambers and its flanks trembled with earthquakes for three years” (Oskin, 2014, para. 8). The Hawaii Volcano Observatory also noted that more than earthquakes precede Mauna Loa eruptions. Scientists also observed a swelling of the earth around the surface of the volcano (e.g. ground deformation) and gas leaks around fissures and cracks. These early signs indicated a flow of magma below the earth’s surface (Oskin, 2014, para. 9).

The Hawaii Volcano Observatory notes that there are no “significant ground deformation[s]” (Oskin, 2014, para. 10) at least in the past year of their observing the earthquake swarms. These deformations were, however, noted in both 2004 as well as in 2006. This means that there is a significant amount of time between swelling and eruptions, as well as a calibration between the amount of swelling and time between the physical notation of the swelling and the eruption.

The Hawaii Volcano Observatory also notes the difference between “earthquakes that signal magma pushing toward the surface” (Oskin, 2014, para. 11) and “earthquakes that strike at faults” (Oskin, 2014, para. 11). In fact, scientists make use of these rumbles in order to inform what is happening below the surface of Mauna Loa: “The recent quake swarm signals that magma is squeezing into Mauna Loa’s magma storage chambers in the same spots below where the 1984 eruption occurred, the observatory said” (Oskin, 2014, para. 12).

The data shown proves that although there are limited earthquake indicators as precursors to Mauna Loa eruptions, such seismic activity can still be confirmed to be a small percentage of quantifiable proof of impending volcanic identity. The observation of “ground swelling” years prior to eruption may also be a clue as to impending eruption, as well as the emission of gas from fissures around the volcano. Although not one single indicator is a precursor for eruption, observing such tactile signs may prove to be beneficial for potential eruptions. Paying attention to seismic activity from large to small-scale earthquakes may prove to be beneficial as well in seizing up Mauna Loa’s eruption cycle.

References

Klemetti, E. “25 years since Mauna Loa’s last eruption.” (2009). Wired Science. Retrieved from http://www.wired.com/2009/03/25-years-since-mauna-loas-last-eruption/

MacDonald, G. A. (1960). “Prediction of eruption of Hawaiian volcanoes.” The Smithsonian 23(1), pp. 211-211. “Mauna Loa: a cyclical eruption model is proposed.” (2006). USGS: Hawaiian Volcano Observatory. Retrieved from http://hvo.wr.usgs.gov/maunaloa/history/model.html

“Mauna Loa: Eruption History.” (2006). USGS: Hawaiian Volcano Observatory. Retrieved from http://hvo.wr.usgs.gov/maunaloa/history/main.html

“Mauna Loa volcanic emissions 1958-present.” (n.d.). Earth System Research  Laboratory. Retrieved from http://www.esrl.noaa.gov/gmd/obop/mlo/programs/esrl/volcanicco2/volc anicco2.html

“Mauna Loa Volcano.” (2014). Hawaii Center for Volcanology. Retrieved from http://www.soest.hawaii.edu/GG/HCV/maunaloa.html

Oskin, B. (2014). “Largest active volcano on earth rumbles back to life.” Scientific American. Retrieved from http://www.scientificamerican.com/article/largest-active-volcano-on-earth-rumbles-back-to-life/

Ryan, S. (2010). “How do scientists know that Mauna Loa’s volcanic emissions don’t effect the carbon dioxide data collected there?” Earth Observatory. Retrieved from http://earthobservatory.nasa.gov/blogs/climateqa/mauna-loa-co2-record/

Seach, J. “Mauna Loa Volcano.” (n.d.). Volcano Live. Retrieved from http://www.volcanolive.com/maunaloa.html

Swan & Sandiland. (1995). “Introduction to Geological Data.” Blackwell Science. Retrieved from http://maps.unomaha.edu/maher/GEOL2300/week13/timeanal.html