Mokuaweoweo is the summit crater ( caldera) of Mauna Loa, the largest active volcano formed by the Hawaii hotspot, located on the Island of Hawaii. Although a trail was developed in ancient times, it proved a difficult goal for the first outsiders who underestimated the difficulty of the journey. An American visit in 1840 turned into a trip of almost a month. Historically very active, Mokuaweoweo has been quiet since 1984.

Description

The name of the summit crater comes from moku a weo weo in the Hawaiian language meaning roughly "burning red area". ^[1] Another potential meaning is moku 'āweoweo after the Hawaiian red big-eyed fish, Priacanthus meeki. ^[2] The main oval depression is about 3 miles (4,800 m) long and 1.5 miles (2,400 m) wide. A smaller crater called "south pit" located to the south, with summit elevation 13,249 feet (4,038 m) and floor 13,040 feet (3,970 m), has the Hawaiian name Pohakuohanalei. ^[3] Southwest of the summit caldera are two small pit craters, Lua Hou (New Pit) and Lua Hohonu (Deep Pit). ^[4]

Earliest visitors

John Ledyard led a team to attempt an ascent on the third voyage of Captain James Cook in January 1779. They struggled to go directly up from Kealakekua Bay, but turned back after an estimated 24 miles, thinking they had about 11 miles more to go. ^[5] The summit was actually only a total of 20 miles from the coast. ^[6]

Archibald Menzies led a party from the Vancouver Expedition in the first successful ascent to Mokuaweoweo with a written record. He also first tried a direct route from the west and turned back in February 1793. After arriving again the next year, he was able to climb to the summit of Hualalai, near the western coast of the island. He then tried to cross the interior plateau to Mauna Loa, but again had to turn back. He consulted King Kamehameha I and was astonished to learn he could take canoes to the south and follow a route established by Ancient Hawaiians. ^[6]

They guided him to the village of Kapapala where the Ainapo Trail rises over 11,200 feet (3,400 m) in about 35 miles (56 km). Although the more active and acessable Kīlauea caldera was the traditional site to honor the fire goddess Pele, offerings and prayers were also made on Mokuaweoweo during extended trips up the trail with many porters. Several established camps along the way supplied water and food. ^[7]

On February 16, Menzies used a barometer to estimate the height as 13,634 feet (4,156 m) compared to its currently known height of 13,679 feet (4,169 m). ^[8] He was surprised to find heavy snow and morning temperatures of 26 °F (−3 °C). They again underestimated the length of the climb and exhausted their food rations, arriving with only three coconuts left for the summit party. The sheer mass of Mauna Loa is deceptive. Slopes are generally not very steep (always less than 12° ^[4]) which makes it very hard to judge progress on the trail. It would be 40 years before another European, David Douglas, would reach the summit on January 29, 1834 (also using Ainapo Trail). ^[8] It is sometimes reported that missionary Joseph Goodrich reached the summit around this time, but he never claimed this himself. He did climb Mauna Kea, and described the sight of Mokuaweoweo from that summit through a telescope. Isidor Löwenstern made a successful climb in February 1839, only the third in 60 years. ^[6]

Wilkes expedition

Wilkes Campsite
U.S. National Register of Historic Places
Sketch by ship's artist Alfred Thomas Agate
Nearest city	Hilo, Hawaii
Coordinates	19°27′59″N 155°34′54″W / 19.46639°N 155.58167°W / 19.46639; -155.58167
Area	4 acres
Built	1840
Architect	Charles Wilkes
Architectural style	Stone shelter
NRHP reference  No.	74000295 [9]
Added to NRHP	July 24, 1974

The United States Exploring Expedition led by Lieutenant Charles Wilkes was tasked with a vast survey of the Pacific Ocean starting in 1838. ^[10] In September 1840 they arrived in Honolulu, where repairs to the ships took longer than expected. He decided to spend the winter in Hawaii, and take the opportunity to explore its volcanoes while waiting for better weather to continue the expedition. King Kamehameha III assigned American medical missionary Dr. Gerrit P. Judd to the expedition as translator. ^[5]

He sailed to Hilo on the island of Hawaiʻi, and decided to climb Mauna Loa first, since it looked easier than Mauna Kea. On December 14 he hired about 200 porters, but after he left he realized only about half the equipment was taken, so had to hire even more Hawaiians at higher pay. When they reached Kīlauea after two days, their guide Puhano headed off to the Ainapo Trail. Wilkes did not want to head back downhill to the established trail; he blazed his own way through dense forest directed by a compass. The Hawaiians were offended by the waste of sacred trees, which did not help morale. At about 6,000 feet (1,800 m) elevation they established a camp called "Sunday Station" at the edge of the forest.

Two guides joined them at Sunday Station: Keaweehu they called "the bird-catcher" and another whose Hawaiian name is not recorded, they called "ragsdale". Although Wilkes thought he was almost to the summit, the guides knew they were less than half way up. Since there was no water at Sunday Station, porters had to be sent back ten miles to a lava tube on Ainapo Tail which had a known supply. After an entire day replenishing stocks, they continued up to a second camp they called "Recruiting Station" at about 9,000 feet (2,700 m) elevation. After another full day's hike they established "Flag Station" on December 22, and by this time were on the Ainapo Trail. Most of the porters were sent back down to get another load.

At the Flag Station Wilkes and his eight remaining men built a circular wall of lava rocks and covered the shelter with a canvas tent. A snowstorm was in progress and several suffered from altitude sickness. That night (December 23), the snow on the canvas roof caused it to collapse. At daylight some of the group went down the trail to retrieve firewood and the gear abandoned on the trail the day before. After another day's climb, nine men reached the rim of Mokuaweoweo. They could not find a way down its steep sides so chose a smooth place on the rim for the camp site, at coordinates 19°27′59″N 155°34′54″W / 19.46639°N 155.58167°W / 19.46639; -155.58167. Their tent was pitched within 60 feet of the crater's edge, secured by lava blocks. ^[11]

The next morning they were unable to start a fire using friction due to the thin air of that altitude, and sent for matches. By this time, they naval officers and Hawaiians could not agree on terms to continue hiring porters, so sailors and marines were ordered from the ships. Dr. Judd traveled between the summit and the Recruiting Station to tend the many who suffered from altitude sickness or worn out their shoes on the rough rock. Christmas Day was spent building rock walls around the camp to give some protection from the high winds and blowing snow. It took another week to bring all the intended equipment to the summit, including a pendulum designed for measuring slight variations in gravity. ^[11]

On December 31, 1840 the pre-fabricated pendulum house was assembled. Axes and chisels cut away the rock surface for the pendulum's base. It took another three days to adjust the clock to the point where the experiments could begin. However, the high winds made so much noise that the ticks could often not be heard, and varied the temperature to make measurements inaccurate. Grass had to be painstakingly brought from the lowest elevations for insulation to get accurate measurements.

On Monday, January 11, Wilkes hiked around the summit crater. Using an optical method, he estimated Mauna Kea was only 193 feet (59 m) higher (modern measurements are 104 feet (32 m) feet). On January 13, 1841, he had "Pendulum Peak, January 1841 U.S. Ex, Ex." cut into a rock at the site. The tents were dismantled and Hawaiians carried the gear down over the next three days, while Wilkes enjoyed a lomilomi Hawaiian massage. He continued his measurements at lower elevations and left the island on March 5. For all the effort he did not obtain any significant results, attributing gravity discrepancies to "the tides". ^[5]

The camp site ruins are the only known physical evidence in the Pacific of the U. S. Exploring Expedition. ^[11] The summit was listed on the National Register of Historic Places July 24, 1974 as site 74000295, ^[9] and is state historic site 10-52-5507. ^[12]

More recent history

Mokuaweoweo erupted in 1849, 1851, and 1863, followed by a nearly continuous active period from 1870 to 1876. ^[4] The use of pack mules on the Ainapo Trail starting in 1870 made the trip much easier. Professor W. T. Brightman recorded observations of the summit in 1864 and 1880. ^[13] A series of short eruptions filled the time from 1880 to 1914. In 1916 Mokuaweoweo was included in the Hawaii Volcanoes National Park, and a new trail was built directly from park headquarters at Kīlauea, an even more direct route than the one taken by Wilkes. ^[7]

Mokuaweoweo erupted again in 1933, 1940, 1949 and 1950. ^[4] The 1950 eruption produced lava flows along a 20 kilometres (12 mi) fissure from Lua Hou to the southwest which reached the ocean in some places. ^[14]

A summit shelter was built with some of the stones from Wilkes' camp site and mortar in 1934. An unusually quiet period lasted from 1950 to a short eruption in 1975, and then to March 25, 1984 when a small summit eruption was followed by a larger flank lava flow that threatened Hilo. ^[15] This was followed by another period of inactivity of at least 25 years.

After falling into disuse, the historic Ainapo trail was reopened in the 1990s. Mokuaweoweo is now part of the Hawaii Volcanoes Wilderness area, in the U.S. National Wilderness Preservation System. ^[16] A third route to the summit is from the Saddle Road, up to the Mauna Loa Observatory which is located at the elevation of 11,135 feet (3,394 m) a few miles north of Mokuaweoweo, and the North Pit trail. ^[17] The Hawaiian Volcano Observatory maintains seismic sensors and a web cam on Mokuaweoweo. ^[18]

References

Category:National Register of Historic Places in Hawaii