Eruptive history Kīlauea

1 eruptive history

1.1 prehistoric eruptions
1.2 1790 1934
1.3 1952 1982
1.4 1983 – present
1.5 volcanic explosivity index

eruptive history
prehistoric eruptions

rainbow , volcanic ash sulfur dioxide emissions halemaʻumaʻu crater

geologists have dated , documented dozens of major eruptions on volcano s long history, bridging long gap between kīlauea s oldest known rock , extremely recent written records , historical observation. historical lava flows volcano recovered scientists in 1 of 3 ways. oldest flows, dating 275,000 225,000 years, have been recovered kīlauea s submerged southern slope ship-towed remotely operated vehicles. these lavas exhibit forms characteristic of early, submerged preshield-stage eruptive episodes, when volcano still rising seamount had not yet breached ocean surface, , surface exposure unusual, in other volcanoes such lavas have since been buried more recent flows.

the second method of recovering older rock through drilling of deep core samples; however, cores have proved difficult date, , several samples depths of around 1,700 m (5,600 ft) suggested dates old 450,000 years have since been found erroneous. more reliable paleomagnetic dating, limited rocks dating after kīlauea s emergence sea, has suggested ages of around 50,000 years. exposed flows above sea level have proved far younger. of oldest reliably dated rock, 43,000 years old, comes charcoal sandwiched beneath ash layer on fault scarp known hilina pali; however, sampled dated higher scarp indicate ash deposition @ average rate of 6 m (20 ft) per thousand years, indicating oldest exposed flows, base of feature, date far 70,000 years. date similar of oldest dated extant lava flow, southwestern rift zone flow uncorrected radiocarbon dating of approximately 4650 bc.

the oldest well-studied eruptive product kīlauea uwēkahuna ash member, product of explosive eruptions between 2,800 , 2,100 years ago. although has since been largely buried younger flows, remains exposed in places, , has been traced more 20 km (12 mi) volcano s caldera, evidence of powerful eruptions. evidence suggests existence of active eruptive center @ time, termed powers caldera, 2 km (1 mi) away modern one. @ least 1,200 years ago, lava powers caldera overtopped rim , solidified structure; followed period of voluminous tube-fed pāhoehoe flows summit. following cessation of activity around 400 years ago, eruptions re-centered on eastern part of kīlauea s summit, , concurrently activity increased @ northern end of eastern rift zone.

1790 1934

1891 eruption picture

the earliest reliable written records of historical activity date 1820, , first well-documented eruption occurred in 1823, when volcano first put under observation; although native hawaiians thought have first settled on island around 1,500 years ago, oral records predating european arrival on island few , difficult interpret. 1 pre-contact eruption in particular, phreatomagmatic event in 1790, responsible death of party of warriors, part of army of keōua kuahuʻula, last island chief resist kamehameha s rule; death evidenced set of footprints preserved within hawai‘i volcanoes national park listed on national register of historic places. kīlauea has been site of 61 separate eruptions since 1823, making 1 of active volcanoes on earth.

during observed history, volume of lava erupted kīlauea has varied widely. in 1823 kīlauea s summit caldera far deeper today, in process of filling under continuous summit eruption, 3 km (1 cu mi) of lava erupted there alone 1840. period between 1840 , 1920 saw approximately half in eruptive volume, , in thirty years between , 1950, volcano unusually quiet , exhibited little activity; kīlauea s eruptive volume has increased steadily since then, present activity comparable of 1800s.

the length , origin these eruptions has varied. events last anywhere between days , years, , occur @ number of different sites. half of eruptions occur @ or near kīlauea s summit caldera. activity there continuous of 19th century, , after reprieve between 1894 , 1907, continued onwards until 1924. there have been 5 historical eruptions @ volcano s relatively southwestern rift zone, , 24 along more active eastern rift zone, along upper section.

the volcano s observed history has been 1 of effusive eruptions; however, relatively recent occurrence. prior arrival of first europeans on island, kīlauea site of regular explosive activity, evidenced tribal chants referencing volcano s fickle nature, , today geological records of explosively active mode of past activity. although explosive activity still occurs @ volcano, not intense once was, , volcano become more dangerous general public if returned old phase of activity once more.

kīlauea erupted in 1823 , 1832, first major eruption since 1790 event occurred in 1840, when eastern rift zone became site large, effusive hawaiian eruption on 35 km (22 mi) of length, unusually long rift eruption. eruption lasted 26 days , produced estimated 205 265 million cubic meters of lava; light created event intense 1 reportedly read newspaper in hilo @ night, 30 km (19 mi) away.

the volcano active again in 1868, 1877, 1884, 1885, 1894, , 1918, before next major eruption in 1918–1919. halemaʻumaʻu, small upwelling in caldera floor, topped lava lake drained, before refilling again, forming enormous lava lake , reaching top edge of caldera before draining once more. activity gave way construction of mauna iki, building large lava shield within caldera on period of 8 months. eruption featured concurrent rift activity , large amount of lava fountaining.

activity in 1921–1923 followed. next major eruption occurred in 1924. halemaʻumaʻu crater, formed pit crater after 1919 event , site of sizable lava lake, first drained, began sinking ground, deepening 210 m (689 ft) beneath thick cloud of volcanic ash. explosive activity began on may 10 of year, blowing rock chunks weighing as 45 kg (99 lb) 60 m (197 ft) out, , smaller fragments weighing 9 kg (20 lb) out far 270 m (886 ft), and, after brief reprieve, intensified through major blast on may 18, when enormous explosive event caused eruption s fatality. eruption continued , formed numerous eruption columns , beyond 9 km (6 mi) in height, before petering down , ending may 28. volcanic activity confined summit, , ceased after 1934.

1952 1982

pu u pua i, cinder cone on rim of kīlauea iki crater formed lava fountaining event of 1959

after halemaʻumaʻu event, kīlauea remained relatively quiet, and, time, silent, activity confined summit. came alive again in 1952 enormous lava fountain 245 m (804 ft) high @ halemaʻumaʻu crater. multiple continuous lava fountains between 15 , 30 m (49 , 98 ft) persisted, , eruption lasted 136 days. eruptions occurred after in 1954, 1955, , 1959, capped large event in 1960, when fissure-based phreatic eruption , earthquake activity gave way massive a flow overran multiple evacuated communities , resorts; resulting summit deflation caused ever-active halemaʻumaʻu collapse further.

following event, eruptive events yearly , continuous, state of activity remains today. 1967–1968 saw particularly large, 80-million-cubic-meter, 251-day event halemaʻumaʻu crater. event superseded next year marathon mauna ulu eruption, large effusive eruption lasted may 24, 1969 july 24, 1974 , added 230 acres (93 ha) of new land island. after eruptive activity had died down, there magnitude 7.2 earthquake caused partial summit collapse, after activity did not resume @ kīlauea until 1977.

the mauna ulu eruption of kīlauea began on may 24, 1969, , ended on july 22, 1974. @ time, mauna ulu longest flank eruption of hawaiian volcano in recorded history. eruption created new vent, covered large area of land lava, , added new land island. eruption started fissure between 2 pit craters, ʻĀloʻi , ʻalae, mauna ulu shield form. both pāhoehoe , ʻaʻā lava erupted volcano. on, fountains of lava burst out as 540 meters (1772 ft) high. in 1973, earthquake occurred caused kīlauea briefly stop erupting near original mauna ulu site , instead erupt near craters pauahi , hiʻiaka.

1983 – present

puʻu ʻŌʻō @ dusk, june 1983

the recent major eruption @ kīlauea has proved far eruption of longest-known duration. current kīlauea eruption began on january 3, 1983, along eastern rift zone. vent produced vigorous lava fountains built puʻu ʻŌʻō cone, sending lava flows down volcano s slope. in 1986, activity shifted down rift new vent, named kūpaʻianahā, took on more effusive character. kūpaʻianahā built low, broad volcanic shield, , lava tubes fed flows extending 11 12 km (about 7 mi) sea. between 1986 , 1991, chain of craters road cut, , community of kapa’ahu, village of kalapana, , subdivisions of kālapana gardens , royal gardens lost lava. black sand beach @ kaimu engulfed. in 1992, eruption moved puʻu ʻŌʻō, continued in same manner, covering of 1983–86 lava flows , large areas of coastline. of december 2012, eruption had produced 4 km (1 cu mi) of lava, covered 125 km (48 sq mi) of land, added 202 ha (499 acres) of land island, destroyed 214 structures, , buried 14.3 km (9 mi) of highway under lava thick 35 m (115 ft).

in december 2014, june 27 flow ongoing eruption threatened enter town of pahoa, , cut highway 130, route , out of lower puna. result, work begun reopen chain of craters road, one-lane gravelled surface, , make railroad avenue , government beach road usable emergency routes. flow stopped short of entering pahoa, , march 2015, threat town reduced.

volcanic explosivity index

the global volcanism program has assigned volcanic explosivity index (vei) except 5 of kīlauea s ninety-five known eruptions of last 11,700 years. eruption of 1790 has vei of 4. eruptions of 1820, 1924, 1959 , 1960 have vei of 2. eruptions of 680, 1050, 1490, 1500, 1610, 1868, 4 eruptions in 1961 , current eruption since 1983 have vei of 1. other seventy-four eruptions have vei of 0.