U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2012–3127

January 2013

The Ongoing Pu‘u ‘Ö‘ö Eruption of Kïlauea Volcano, 

Hawai‘i—30 Years of Eruptive Activity

U.S. GEOLOGICAL SURVEY and the NATIONAL PARK SERVICE—OUR VOLCANIC PUBLIC LANDS

The Pu‘u ‘Ö‘ö eruption of Kïlauea Volcano is its longest rift-zone 

eruption in more than 500 years. Since 

the eruption began in 1983, lava flows 

have buried 48 square miles (125 square 

kilometers) of land and added about 500 

acres (200 hectares) of new land to the 

Island of Hawai‘i. The eruption not only 

challenges local communities, which 

must adapt to an ever-changing and 

sometimes-destructive environment, 

but has also drawn millions of visitors 

to Hawai‘i Volcanoes National Park. U.S. 

Geological Survey (USGS) scientists 

closely monitor and evaluate hazards at 

Hawai‘i’s volcanoes and also work with 

park rangers to help ensure safe lava 

viewing for visitors.

Just after midnight on January 2, 1983, 

residents of Hawai‘i Volcanoes National 

Park and the nearby community of Volcano 

were awakened by rattling dishes and doors. 

Hundreds of small earthquakes indicated 

that magma (underground molten rock) 

was on the move again, forcing its way 

from Kīlauea’s summit into the volcano’s 

East Rift Zone, splitting it like a wedge. 

Scientists with the U.S. Geological Survey 

(USGS) Hawaiian Volcano Observatory 

(HVO) tracked the magma’s progress 

underground by the locations of these 

earthquakes. At 12:31 a.m. on January 

3, almost exactly 24 hours later, lava 

broke the surface and began erupting near 

Nāpau Crater. Thus began the Pu‘u ‘Ō‘ō 

eruption—an eruption that is still going 

after 30 years of nearly continuous activity.

Kīlauea is the Island of Hawai‘i’s 

youngest volcano and one of the world’s 

most active. More than 90 percent of the 

volcano’s surface has been covered by lava 

flows in the past 1,000 years. Kīlauea erupts 

either at its summit or along its East or 

Southwest Rift Zones. From the early 1800s 

through 1954, Kīlauea erupted mainly in the 

volcanic depression (caldera) at its summit. 

Since 1955, however, most eruptions have 

occurred along the East Rift Zone. The 

Pu‘u ‘Ō‘ō eruption, which has produced 

more than half the volume of lava erupted 

by Kīlauea in the past 190 years, is by far 

the largest of these eruptions.

1983–1986: The Rise of Pu‘u ‘Ö‘ö

During the opening days of the 

eruption, fissures extended nearly 5 miles 

(8 kilometers) along Kīlauea’s East Rift 

Zone, but activity soon became localized 

along a shorter section of the fissure 

system that stretched between the forested 

volcanic cones of Pu‘u Kamoamoa 

and Pu‘u Kahauale‘a. Lava erupted 

intermittently in this area over the next 

5 months, building Pu‘u Halulu—the first 

substantial vent structure of the eruption.

In mid-June 1983, the eruption finally 

focused at one vent, now known as Pu‘u 

‘Ō‘ō, which straddled the national park 

boundary about 12 miles (19 kilometers) 

from Kīlauea’s summit caldera. From then 

until mid-1986, Pu‘u ‘Ō‘ō was the site of 

Lava slowly engulfs rainforest on March 6, 2011, during the Kamoamoa fissure eruption—a 

brief interlude during Kïlauea Volcano’s long-lived Puÿu ÿÖÿö eruption (USGS photo by Tim Orr).

spectacular lava fountains—44 episodes 

in total—that were visible and audible for 

miles around. Towering as high as 1,500 

feet (460 meters), the fallout from these 

fountains built the Pu‘u ‘Ō‘ō cone, which 

reached a height of 835 feet (255 meters). 

The fountains, occurring every 3 to 4 

weeks and lasting about a day, fed thick 

‘a‘ā flows—the less fluid of the two types 

of Hawaiian lava flows—that blanketed 

the surrounding landscape. Some of these 

flows reached the sparsely populated 

Royal Gardens subdivision, and several 

houses were destroyed.

1986–1992: Eruption Shifts to 

Kupaianaha

In July 1986, the magma conduit 

beneath Pu‘u ‘Ō‘ō ruptured, and new 

fissures opened and extended 2 miles (3 

kilometers) downrift from the base of the 

cone. The easternmost fissure evolved into 

a single vent, later named Kupaianaha. 

This event marked the beginning of 51⁄2 

years of nearly continuous, quiet effusion 

Departme nt

of the Interio r
of lava. A tadpole-shaped lava lake 460 

feet (140 meters) across formed over 

the vent, and frequent overflows built a 

broad, low shield 185 feet (56 meters) 

high in less than a year. During this period, 

the top of the Pu‘u ‘Ō‘ō cone collapsed 

progressively, forming a crater that often 

contained a small lava lake.

Pāhoehoe flows (the more fluid of the 

two types of Hawaiian lava flows) from 

Kupaianaha spread slowly downslope, 

constructing lava tubes as they advanced. 

On November 28, 1986, these flows 

reached the Pacific Ocean, 7.5 miles (12 

kilometers) away, after cutting a swath 

through the community of Kapa‘ahu and 

closing the coastal highway. Over the 

next 5 years, lava flows overran houses 

on both sides of the ever-widening flow 

field. The village of Kalapana was almost 

completely buried, and its famous black 

sand beach was destroyed as nearby 

Kaimū Bay was filled by lava.

flows advanced slowly downslope, 

reaching the ocean in November 1992. 

From the end of 1992 through January 

1997, tubes fed lava to the ocean almost 

continuously and widened the existing 

flow field, which was mostly contained 

within Hawai‘i Volcanoes National Park. 

The growing lava shield on the side of 

Pu‘u ‘Ō‘ō became pockmarked with 

collapse pits as lava tubes eroded down 

into the thick deposits of buried tephra 

(fragments of volcanic material) on the 

cone’s flank.

On January 29, 1997, a swarm of 

earthquakes struck Kīlauea’s East Rift 

Zone as the conduit leading to Pu‘u 

‘Ō‘ō ruptured, cutting off the supply of 

magma to the ongoing eruption. The lava 

lake in Pu‘u ‘Ō‘ō drained, and residents 

10 miles (16 kilometers) away heard a 

low, rumbling roar as the crater floor 

dropped 500 feet (150 meters) and 

the west wall of the Pu‘u ‘Ō‘ō cone 

collapsed. A few hours later, magma 

found a new path to the surface in nearby 

Nāpau Crater, and lava fountains lit up 

the night sky.

The eruption in Nāpau Crater lasted 

less than a day, and was followed by a 

24-day hiatus, during which there was 

no eruptive activity on Kīlauea. Lava 

reappeared in the crater of Pu‘u ‘Ō‘ō in 

late February 1997 and erupted outside 

the cone a month later. Several new flank 

vents opened over the following few 

months, and tube-fed pāhoehoe flows 

began to advance downslope again, 

reaching the ocean within the national 

park in July. During these months, Pu‘u 

‘Ō‘ō filled with lava and overflowed for 

the first time in 11 years.

From early 1998 through 2001, lava 

flowed almost continuously to the ocean, 

and eruptive activity within Pu‘u ‘Ō‘ō 

dropped to its lowest level since 1990. 

In early 2002, activity within Pu‘u ‘Ō‘ō 

increased briefly, with multiple vents 

erupting lava flows that filled the crater 

to within 33 feet (10 meters) of its east 

rim. On May 12, 2002, lava burst through 

the shield on the western flank of Pu‘u 

‘Ō‘ō and advanced downslope along the 

western margin of the flow field. Flows 

began to enter the ocean near the end of 

Chain of Craters Road in the national park 

in mid-July, drawing as many as 4,000 

visitors per day.

Activity at Pu‘u ‘Ō‘ō picked up 

again in late 2003, and lava filled the 

crater to overflowing by January 2004. 

The first 31⁄2 years of the Pu‘u ‘Öÿö eruption of 

Kïlauea Volcano (January 1983–June 1986) 

were dominated by episodic lava fountains 

that constructed the Pu‘u ‘Öÿö cone and fed 

‘a‘ä flows (the less fluid of the two types of 

Hawaiian lava flows) (USGS photo by J.D. 

Griggs, June 1984). The map shows lava flows 

erupted from Kïlauea Volcano in the 19th and 

20th centuries (gray). These flows originated 

from the summit caldera, the East Rift Zone, 

or the Southwest Rift Zone (not shown). Flows 

erupted during the first 31⁄2 years of the Pu‘u 

‘Öÿö eruption are shown in red. The Island of 

Hawai‘i (see inset map) is composed of five 

volcanoes—Kohala, Mauna Kea, Hualälai, 

Mauna Loa, and Kïlauea.

The First Years of Pu‘u ‘Öÿö (January 1983–June 1986)

By 1991, lava output from 

Kupaianaha was in steady decline, while 

activity at Pu‘u ‘Ō‘ō began to increase 

proportionately. Magma pressure 

increased uprift of Kupaianaha, and for 

3 weeks in November 1991, new fissures 

erupted between Kupaianaha and Pu‘u 

‘Ō‘ō. The rate of lava erupted from 

Kupaianaha continued to wane afterwards 

and, on February 7, 1992, finally stopped.

1992–2007: Activity Returns to 

Pu‘u ‘Ö‘ö

Ten days later, on February 17, 

1992, eruptive activity returned to 

Pu‘u ‘Ō‘ō. Low lava fountains erupted 

from a fissure on the west flank of the 

massive cone. This was the first in a 

series of flank vents that gradually built 

a lava shield 425 feet (130 meters) high, 

banked against the southwestern slope of 

Pu‘u ‘Ō‘ō. As at Kupaianaha, pāhoehoe 

155°15' 155°10' 155°05' 155°00'

19°25'

19°20' P A C I F I C O C E A N

Kīlauea

Caldera

Hawai‘i Volcanoes National Park

EAST RIFT ZONE

EAST RIFT ZONE

Chain of Craters Road

0 1 2 3 4 MILES

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130

11

Pu‘u ‘Ō‘ō

Island of

Hawai‘i

Map area

Kohala

Mauna Loa

Mauna Kea

Kīlauea

Hualālai

Kalapana

2
155°15' 155°10'

19°25'

19°20'

Kilauea

Caldera

Hawai‘i Volcanoes National Park

EAST RIFT ZONE

Chain of Craters Road

11

155°05' 155°00'

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P A C I F I C O CEA N

Pu‘u ‘Ō‘ō

Kupaianaha

Island of

Hawai‘i

Map area

Kohala

Mauna Loa

Mauna Kea

Kīlauea

Hualālai

Kalapana

In 1986, the Pu‘u ‘Öÿö eruption shifted to the 

Kupaianaha vent. This photo shows lava flows erupted 

from Kupaianaha entering the community of Kalapana 

on the Island of Hawai‘i’s southeast coast in May 

1990 (USGS photo by J.D. Griggs). Over the following 

months, Kalapana was almost completely destroyed, 

and lava filled beautiful nearby Kaimü Bay. The map 

shows lava flows erupted from Kupaianaha and 

nearby fissures during 1986–1992 in red. Older flows 

from the Pu‘u ‘Öÿö eruption are shown in orange.

Kupaianaha Vent (July 1986–February1992)

Lava flows erupt from new vents on the south flank of 

the Pu‘u ‘Öÿö cone (right side of photo) that opened 

after Pu‘u ‘Öÿö Crater filled to overflowing in early 

2004 (USGS photo by Richard Hoblitt, January 2004). 

Collapse of the southwest side of the cone formed a 

scallop-shaped scar, revealing red layers of welded 

spatter (deposited as clots of molten lava) that underlie loose tan-colored pyroclastic deposits (hot debris 

ejected during an eruption). The map shows flows 

erupted from Pu‘u ‘Öÿö and from fissures in Näpau 

Crater during 1992–2007 in red. Older flows from the 

Pu‘u ‘Öÿö eruption are shown in orange.

Pu‘u ‘Öÿö and Näpau Craters (February 1992–June 2007)

155°15' 155°10' 155°05' 155°00'

19°25'

19°20'

130

11

Kīlauea

Caldera EAST RIFT ZONE

EAST RIFT ZONE

Chain of Craters Road

P A C I F I C O CEA N

Hawai‘i Volcanoes National Park

Kupaianaha

Näpau

Crater NäpauCrater

Pu‘u ‘Ō‘ō

0 1 2 3 4 MILES

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Island of

Hawai‘i

Map area

Kohala

Mauna Loa

Mauna Kea

Kīlauea

Hualālai

Kalapana

cracked open, relieving the pressure 

that had been building and producing a 

This was followed on March 20 by a 

major breakout from the shield on the 

which remained active for the next 3 

years, sending lava to the ocean in the 

national park until 2007.

2007–2011: A New Fissure 

Takes Over

On June 17, 2007, magma from 

Kīlauea’s summit began to intrude into 

the volcano’s upper East Rift Zone. 

Magma was also withdrawn from the 

reservoir beneath Pu‘u ‘Ō‘ō, severing 

deep. The intrusion culminated on June 

19 with a brief eruption on the east 

from Pu‘u ‘Ō‘ō. Kīlauea then entered 

a hiatus, during which there was no 

eruptive activity at the surface.

After 2 weeks of quiet, the eruption 

resumed at Pu‘u ‘Ō‘ō on July 1, when 

21, after reaching within 100 feet (30 

meters) of the eastern rim of the crater, 

‘Ō‘ō cone and extended downrift to the 

base of Kupaianaha. Activity focused 

designated as Fissure D, and produced 

a series of short-lived channelized ‘a‘ā

(6 kilometers) to the northeast.

In late August, the open lava 

the progressive development of a 

“perched” lava channel elevated above 

the surrounding terrain. This perched 

channel eventually stood 150 feet (45 

meters) above the older lava surface on 

through the end of 2007. Its dominance 

ended on November 21, when a new 

breakout from the Fissure D vent 

diverted most lava to the southeast. 

The perched lava channel was 

abandoned for good in early 2008, as 

3

1992)
A lava channel, elevated as much as 150 feet (45 meters) above the adjacent terrain, transports 

lava away from the Fissure D vent, which opened in July 2007 (USGS photo by James Kauahikaua, 

October 2007). The “perched” (elevated) lava channel was the main path for lava until November 

2007, when lava was diverted from the vent to the southeast. Pu‘u ‘Öÿö is at upper right. The map 

shows lava flows erupted in Pu‘u ‘Öÿö and from the Fissure D vent between Pu‘u ‘Öÿö and Kupaianaha during 2007–2011 in red. Older flows from the Pu‘u ‘Öÿö eruption are shown in orange. 

155°15' 155°10' 155°05' 155°00'

19°25'

19°20'

130

11

Kīlauea

Caldera

EAST RIFT ZONE

EAST RIFT ZONE

Chain of Craters Road

P A C I F I C O C E A N

Hawai‘i Volcanoes National Park

Kupaianaha

Fissure

D vent Pu‘u ‘Ō‘ō

0 1 2 3 4 MILES

0 1 2 3 4 KILOMETERS

Island of

Hawai‘i

Map area

Kohala

Mauna Loa

Mauna Kea

Kīlauea

Hualālai

Kalapana

Pu‘u ‘Öÿö and the Fissure D Vent 

(July 2007–March 2011)

the southeastward-advancing flows swept 

down Kīlauea’s south flank, reaching the 

Pacific Ocean on March 5. Flow activity 

was relatively stable for the next 2 years, 

even with the opening of a new eruptive 

vent within Halema‘uma‘u Crater at 

Kīlauea’s summit in mid-March 2008. 

In January 2010, however, the tube 

system broke down, and surface flows 

began moving toward the east, encroaching 

on the Kalapana area once again. Three 

more houses were destroyed between July 

2010 and March 2011, when the surface 

flows faltered.

2011–2013: History Repeats 

Itself

Pu‘u ‘Ō‘ō began to refill slowly 

during 2010, and by early March 2011, 

the crater floor was within 65 feet (20 

meters) of the crater’s east rim. On March 

5, 2011, following rapid summit deflation 

and increased seismicity, the crater floor of 

Pu‘u ‘Ō‘ō collapsed. Within a few hours, 

it had dropped 380 feet (115 meters). 

Shortly thereafter, lava broke to the surface 

between Pu‘u ‘Ō‘ō and Nāpau Crater, 

marking the start of the Kamoamoa fissure 

eruption, which was active through 

March 9. Reminiscent of Kīlauea’s 1997 

and 2007 East Rift Zone fissure eruptions, 

the Kamoamoa eruption cut the lava supply 

to the active tube, causing activity on the flow 

field to die.

After 2 weeks of quiet, lava reappeared 

in Pu‘u ‘Ō‘ō on March 26, and a perched 

lava lake developed as the crater refilled. In 

late June, wholesale uplift of the crater floor 

raised the entire lava lake until its surface 

was higher than the eastern and western 

crater rims. Leaks from the “ring” fault 

bounding the uplifted area resulted in lava 

overflowing the crater for the first time since 

2004, sending flows down the southwestern 

flank of Pu‘u ‘Ō‘ō.

On August 3, 2011, the crater floor of 

Pu‘u ‘Ō‘ō collapsed again when lava burst 

through Pu‘u ‘Ō‘ō’s west flank, burying the 

western base of the cone in a massive flood 

of lava. The floor of the crater dropped 260 

feet (80 meters), accompanied by the collapse 

of large slabs of rock from the crater walls 

into the resulting pit. The flow on the west 

side of Pu‘u ‘Ō‘ō diminished greatly after the 

first several hours but remained active until 

August 15.

As in March, lava returned to Pu‘u ‘Ō‘ō 

within days of the August outbreak, but this 

time the crater filled quickly. By September 

10, lava had begun to overflow the crater 

again, with flows spilling toward the 

northeast and southwest. This activity ended 

on September 21, when the northeastern 

flank of the cone fractured and lava began 

pouring out.

Confined to a shallow valley between 

older Pu‘u ‘Ō‘ō flow fields, lava turned 

again toward the volcano’s southern coast. 

In March 2012, lava flows destroyed another 

house—the 214th since 1983—within the 

now-abandoned Royal Gardens subdivision.

Unlike past years, however, eruptive 

activity throughout 2012 was relatively 

weak. Lava flows were almost always 

active on the coastal flow field but failed 

to make significant forward progress. 

4

Eruption Statistics 1983 to 2013

Lava Flows

• Area covered: 48.4 square miles

 (125.5 square kilometers)

• New land: 500 acres (202 hectares)

• Volume erupted: ~1 cubic mile

 (~4 cubic kilometers)

• Thickness along coast: 33 to 115 feet 

 (10 to 35 meters)

• Coastal highway covered: 8.9 miles 

 (14.3 kilometers)

• Structures destroyed: 214

Pu‘u ‘Öÿö Facts

• Maximum height in 1987: 835 feet (255 meters)

• Height in 2012: 560 feet (171 meters)

• Crater size: 985 × 1,475 feet 

 (300 × 450 meters)
0 1 2 3 4 MILES

0 1 2 3 4 KILOMETERS

155°15' 155°10' 155°05' 155°00'

19°25'

19°20'

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11

Kīlauea

Caldera

EAST RIFT ZONE

EAST RIFT ZONE

Chain of Craters Road

Hawai‘i Volcanoes National Park

P A C I F I C O C E A N

Kupaianaha

Fissure

D vent

Pu‘u ‘Ō‘ō

Island of

Hawai‘i

Map area

Kohala

Mauna Loa

Mauna Kea

Kīlauea

Hualālai

Kalapana

Näpau Crater

In March 2011, lava broke to the surface 

between Pu‘u ‘Öÿö and Näpau Crater 

marking the start of the Kamoamoa fissure 

eruption. In this photo lava erupts from the 

fissure shortly after the beginning of the 

eruption and pours into a deep, older crack 

(USGS photo by Tim Orr). The map shows 

flows erupted during the Kamoamoa 

eruption and from Pu‘u ‘Öÿö during 

2011–2012 in red. The Kamoamoa flows 

are to the left, flows from the August 2011 

Pu‘u ‘Öÿö flank breakout are at center, flows 

from a fissure high on Pu‘u ‘Öÿö’s northeast 

flank are to the right. Older flows from the 

Pu‘u ‘Öÿö eruption are shown in orange.

Pu‘u ‘Öÿö and the Kamoamoa 

Eruption (March 2011–January 2013)

Finally, in late November, lava reached 

the coastline for the first time in nearly 

11 months, forming a small and sporadic 

ocean entry. This marked the end to the 

longest period without an ocean entry 

since lava first reached the water in 1986.

As the eruption enters its 31st year in 

2013, it is showing no signs of stopping, 

despite the recent slow down in activity. 

What Kīlauea Volcano has in store next 

remains to be seen. Although recent 

patterns suggest continued activity on the 

East Rift Zone, this could change abruptly. 

Even a return to Kīlauea’s more explosive 

past is possible (see USGS Fact Sheet 

2011–3064, Kīlauea—an Explosive Volcano 

in Hawai‘i, available at http://pubs.usgs.

gov/fs/2011/3064/). What is certain is that 

Kīlauea will remain an active volcano for 

millennia to come. 

Pähoehoe Lava Flows Dominate

The high lava fountains at Pu‘u ‘Ō‘ō 

from 1983 to 1986 produced mainly ‘a‘ā 

flows that were typically 10 to 15 feet 

(3 to 5 meters) thick. Because of the short 

duration of each fountaining episode, none 

of these flows reached the ocean.

When the eruptive activity changed 

from episodic high lava fountains to 

nearly continuous effusion of lava flows 

in 1986, pāhoehoe, which is less viscous 

than ‘a‘ā, became the dominant type of 

lava erupted on Kīlauea’s East Rift Zone. 

The main lava channels exiting the active 

vents since 1986 have often crusted over 

to form lava tubes that eventually reach 

the ocean. Tubes insulate lava from 

heat loss, allowing it to remain hot and 

fluid and able to travel long distances 

without cooling. Tube-fed pāhoehoe 

flows erupted since 1986 have formed a 

barren plain of lava as much as 115 feet 

(35 meters) thick and spanning a distance 

of about 9.5 miles (15 kilometers) along 

the coast.

Building New Land

In the period since late 1986, lava 

from Pu‘u ‘Ō‘ō has poured into the 

Pacific Ocean about 70 percent of the 

time, by far the longest such interval in 

at least 2,000 years. New land is created 

as lava deltas build seaward over steep 

submarine slopes of lava rubble, black 

sand, and pillow lava (the submarine 

form of pāhoehoe). Such steep slopes are 

unstable and prone to slumping, which 

removes support for the active, leading 

edge of the delta. Delta collapses can 

happen suddenly and without warning, 

with several acres of land sliding into 

the ocean in less than a minute. They 

sometimes consist of a series of collapses, 

which occur episodically over a period 

of several minutes or hours. Large 

collapses are extremely dangerous and 

frequently cause violent steam explosions 

and scalding waves. Four people who 

ventured too close have died near 

Kīlauea’s active lava deltas.

Impact on People

The current eruption ranks as 

Kīlauea’s most destructive event since 

a tragic explosive eruption in 1790 that 

killed more than 80 Hawaiians. Between 

1983 and 1991, lava flows repeatedly 

invaded communities on Kīlauea’s 

southern coast, burying 184 structures that 

included homes, a church, and a national 

park visitor center. The destruction of 

Kalapana in 1990 by lava flows from 

Kupaianaha led to a Federal disaster 

declaration for coastal communities 

directly impacted by the eruption. Sadly, 

the destruction continued into the 21st 

century, with the loss of 30 more houses 

between 2000 and 2012.

The Pu‘u ‘Ō‘ō eruption has also been 

constructive, creating about 500 acres (200 

hectares) of new land. Stunningly beautiful 

lava flows in Hawai‘i Volcanoes National 

Park have drawn millions of visitors 

seeking to experience and enjoy volcanic 

activity up close.

Kīlauea’s nearly continuous emission 

of sulfur dioxide (SO2) gas each day results 

in volcanic air pollution downwind of the 

volcano. The SO2 in eruption plumes reacts 

with oxygen, water, and particles in the 

air to form the sulfuric acid droplets and 

solid sulfate particles that produce vog, 

or volcanic smog, and corrosive acid rain. 

Vog damages crops and can aggravate 

preexisting respiratory ailments.

From 1992 to 2007, lava flows 

remained mostly within the national 

park, reducing the immediate threat to 

5
6

residential areas. However, with the 

shift in vent location to the east side of 

Pu‘u ‘Ō‘ō in 2007, the threat returned 

as lava flows again encroached on the 

Kalapana area. With the establishment 

of a new vent high on Pu‘u ‘Ō‘ō’s east 

flank in 2011, the threat remains as the 

eruption surpasses 30 years. To counter 

such threats, USGS Hawaiian Volcano 

Observatory scientists continuously 

monitor Hawai‘i’s volcanoes to provide 

reliable and timely warnings of new and 

ongoing volcanic activity.

Tim R. Orr, Christina Heliker,

and Matthew R. Patrick

Edited by James W. Hendley II

Graphic design by Jeanne S. DiLeo

COOPERATING ORGANIZATIONS

Hawaiÿi County Civil Defense 

Hawaiÿi Volcanoes National Park

University of Hawaiÿi at Hilo

During the early years of the Pu‘u ‘Öÿö eruption 

(January 1983–June 1986), fallout from 

lava fountains at Pu‘u ‘Öÿö built a pyroclastic 

(volcanic fragments) cone 835 feet (255 meters) 

high, more than twice as high as any other 

cone on Kïlauea’s East Rift Zone. Cone growth 

ceased after the activity shifted to Kupaianaha 

in mid-1986. When the eruption returned to 

Pu‘u ‘Öÿö in 1992, lava flows from flank vents 

built a “shield” against the west flank of the 

cone (top). In 1993, collapse pits appeared 

on the west flank of Pu‘u ‘Öÿö as subsidence 

over the flank vents undermined the cone. 

When the crater floor dropped in January 

1997, the weakened flank also failed, leaving 

the prominent “west gap” (middle). Continued 

shield growth after 1997, along with additional 

cone collapse and accumulation from crater 

overflows, has removed much of Pu‘u ‘Öÿö’s 

prominence as a landmark (bottom). (USGS 

photos by Tari Mattox, Christina Heliker, and 

Tim Orr.)

Pu‘u ‘Öÿö Cone Through the Years

1992

Pu‘u ‘Ō‘ō

1999

West gap

2012

Lava shield

For more information contact:

U.S. Geological Survey

Hawaiian Volcano Observatory

P. O. Box 51

Hawaii National Park, HI 96718

http://hvo.wr.usgs.gov/

See also other USGS Hawaiian Volcano Fact 

Sheets at http://volcanoes.usgs.gov/publications/

index.php or

USGS Volcano Hazards Program

http://volcanoes.usgs.gov/

This Fact Sheet and any updates to it

are available online at

http://pubs.usgs.gov/fs/2012/3127/