Search USGS⌕ Search

Geology topics

Christina Heliker

Publications and source records attributed to Christina Heliker.

11 recordsLinked to original sources
USGS2024

Using ground crack and very low frequency measurements to map the location of the June 2007 Father’s Day dike, Kīlauea Volcano

An intrusion into Kīlauea’s upper East Rift Zone during June 17–19, 2007, during the 1983–2018 Pu‘u‘ō‘ō eruption, led to widespread ground cracking and a small (approximately 1,525 cubic meters) eruption on the northeast flank of Kānenuiohamo, a cone about 6 kilometers upslope from Pu‘u‘ō‘ō. Transmitted and induced very low frequency (VLF) magnetic fields were measured with a handheld VLF receiver along transects spanning the dike trace, and zones of ground cracking related to the intrusion were mapped. The locations of crack zones and the VLF receiver measurements suggest that the Father’s Day dike splayed as it approached the surface, dividing into four segments—one between Pauahi Crater and Pu‘uhuluhulu and three en echelon segments near Kānenuiohamo. The dike did not extend appreciably northeastward beyond the eruption site.

Hawaii↗
USGS2018

The Puʻu ʻŌʻō eruption of Kīlauea Volcano, Hawai‘i—Episode 21 through early episode 48, June 1984–April 1987

The Pu‘u ‘Ō‘ō eruption from the middle East Rift Zone of Kīlauea Volcano began in January 1983 with intermittent activity along several fissures. By June 1983, the eruption had localized at the Pu‘u ‘Ō‘ō vent and the activity settled into an increasingly regular pattern of brief eruptive episodes characterized by high lava fountains. The first 18 months of the eruption (episodes 1–20) are chronicled in previous publications. In the two years following episode 20, Pu‘u ‘Ō‘ō produced another 27 high-fountaining episodes. Episodes 21–47 lasted an average of 12.9 hours and were separated by inter-episode periods averaging 26.5 days. The lava fountains, which reached as high as 510 meters (m), fed lava flows (mostly channelized ʻaʻā) that brought the total area covered by the eruption to 40 square kilometers (km 2 ) by the end of episode 47. Flow thickness measurements obtained for episodes 21–40 averaged 3.4 m; lava volumes for episodes 21–47 averaged 8.0×10 6 m 3 per episode (including the 16-day fissure outbreak of episode 35). The Pu‘u ‘Ō‘ō cone—a composite of pyroclastic material and lava flows—reached its maximum height of 255 m above the pre-eruption surface during episode 43 and maintained that height through episode 47. Short-lived eruptive fissures and vents at or near the base of the Pu‘u ‘Ō‘ō cone accompanied episodes 21, 25, 29, 35, 39, and 44. Episode 35 was unusual in that a fissure on the uprift flank of the cone erupted early in the episode, and then reactivated and extended 2.5 km uprift after the high fountaining was over and erupted for the next 16 days. The volcano was primed for the 48th episode of high fountaining on July 18, 1986, when the conduit beneath Pu‘u ‘Ō‘ō ruptured again and magma erupted through new fissures at the base of the cone on both its uprift and downrift sides. These fissures were active for only 21 hours, but a third fissure, which opened 3 km downrift from Pu‘u ‘Ō‘ō on July 20, persisted and evolved into a single vent, later named Kupaianaha. Kupaianaha erupted almost continuously for the next 5.5 years (the main part of episode 48). The onset of episode 48 marked the end of episodic high fountaining and the transition to nearly continuous effusion. A lava lake developed over the Kupaianaha vent, and overflows from the lake built a broad, low shield that reached a relatively stable height of 45 m by November 1986. After weeks of continuous eruption, the main lava channel leading from the lake gradually roofed over, forming a lava tube. By November 1986, the tube had extended from the lake to the ocean, 12 km southeast, closing the coastal highway. Tube-fed flows overran 28 houses in the coastal communities of Kapa‘ahu and Kalapana over the next month.

Hawai'i↗
USGS2015

Petrologic testament to changes in shallow magma storage and transport during 30+ years of recharge and eruption at Kīlauea Volcano, Hawai‘i

Petrologic monitoring of Kīlauea Volcano from January 1983 to October 2013 has yielded an extensive record of glass, phenocryst, melt inclusion, and bulk-lava chemistry from well-quenched lava. When correlated with 30+ years of geophysical and geologic monitoring, petrologic details testify to physical maturation of summit-to-rift magma plumbing associated with sporadic intrusion and prolonged magmatic overpressurization. Changes through time in bulk-lava major- and trace-element compositions, along with glass thermometry, record shifts in the dynamic balance of fractionation, mixing, and assimilation processes inherent to magma storage and transport during near-continuous recharge and eruption. Phenocryst composition, morphology, and texture, along with the sulfur content of melt inclusions, constrain coupled changes in eruption behavior and geochemistry to processes occurring in the shallow magmatic system. For the first 17 years of eruption, magma was steadily tapped from a summit reservoir at 1–4 km depth and circulating between 1180 and 1200°C. Furthermore, magma cooled another 30°C while flowing through the 18 km long rift conduit, before erupting olivine-spinel-phyric lava at temperatures of 1150–1170°C in a pattern linked with edifice deformation, vent formation, eruptive vigor, and presumably the flux of magma into and out of the summit reservoir. During 2000–2001, a fundamental change in steady state eruption petrology to that of relatively low-temperature, low-MgO, olivine(-spinel)-clinopyroxene-plagioclase-phryic lava points to a physical transformation of the shallow volcano plumbing uprift of the vent. Preeruptive comagmatic mixing between hotter and cooler magma is documented by resorption, overgrowth, and compositional zonation in a mixed population of phenocrysts grown at higher and lower temperatures. Large variations of sulfur (50 to >1000 ppm) in melt inclusions within individual phenocrysts and among phenocrysts in most samples provide an unequivocal glimpse of rapid crystal growth amid sulfur degassing at <30 MPa in a turbulent preeruptive environment. We speculate that, during the last decade, one or more shallow open-system reservoirs developed along the conduit between the summit and Pu‘u ‘Ō‘ō and now serve to buffer the magmatic throughput associated with ongoing recharge and eruption. Lava with identical trace-element signatures erupted simultaneously at the summit and at Pu‘u ‘Ō‘ō from 2008 to 2013 confirms magmatic continuity between the vents. Complementary changes in compositions of matrix glasses, phenocrysts, and melt inclusions of summit tephra are mirrored by similar changes in contemporaneous rift lava at eruption temperatures 20–35°C lower than those at the summit. Petrologic parameters measured at opposite ends of the shallow magmatic plumbing system are both correlated with summit deformation, demonstrating that effects of summit magma chamber pressurization are translated throughout interconnected magma pathways in the shallow edifice.

Hawaii↗
USGS2013

The ongoing Puʻu ʻŌʻō eruption of Kīlauea Volcano, Hawaiʻi: 30 Years of eruptive activity

The Puʻu ʻŌʻō eruption of Kīlauea 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 Hawaiʻi. 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 Hawaiʻi Volcanoes National Park. U.S. Geological Survey (USGS) scientists closely monitor and evaluate hazards at Hawaiʻi’s volcanoes and also work with park rangers to help ensure safe lava viewing for visitors.

Hawai'i↗
USGS2012

Inflation rates, rifts, and bands in a pāhoehoe sheet flow

The margins of sheet flows—pāhoehoe lavas emplaced on surfaces sloping <2°—are typically delineated by structures that form to accommodate vertical flow inflation. We refer to these structures as inflation rifts. The surfaces of inflation rifts almost always exhibit bands of varying color and texture. Various explanations for the bands have been proposed, but active band formation has never been documented. In order to test our hypothesis that banding is caused by changes in the inflation rate, we collected time-lapse photographs of the margin of an actively inflating flow and simultaneously measured the height of the flow with an extensometer. Data collected over a period of ∼1 d indicate that the height of the flow margin changed in a stepwise manner and that rate changes correlate with band formation. This confirms our hypothesis. Inflation and rift-band formation is probably cyclic, because the pattern we observed suggests episodic or crude cyclic behavior. Furthermore, some inflation rifts contain numerous bands whose spacing and general appearances are remarkably similar. We propose a conceptual model wherein the inferred cyclicity is due to the competition between the fluid pressure in the flow's liquid core and the tensile strength of the viscoelastic layer where it is weakest—in inflation rifts. The viscoelastic layer consists of lava that has cooled to temperatures between 800 and 1070 °C. This layer is the key parameter in our model because, in its absence, rift banding and stepwise changes in the flow height would not occur.

Hawaii↗
USGS2003

A compilation of whole-rock and glass major-element geochemistry of Kilauea Volcano, Hawai'i, near-vent eruptive products: January 1983 through September 2001

This report presents major-element geochemical data from 652 glasses (~6,520 analyses) and 795 whole-rock aliquots from 1,002 fresh samples of olivine-tholeiitic lava collected throughout the near-continuous eruption of Kïlauea Volcano, Hawai'i, from January 1983 through September 2001. The data presented herein provide a unique temporal compilation of lava geochemistry that best reflects variations of pre-eruptive magma compositions during prolonged rift-zone eruption. This document serves as a repository for geochemical data referred to in U.S. Geological Survey Professional Paper 1676 (Heliker, Swanson, and Takahashi, eds., 2003) which includes multidisciplinary research papers pertaining to the first twenty years of Puu Oo-Kupaianaha eruption activity. Details of eruption characteristics and nomenclature are provided in the introductory chapter of that volume (Heliker and Mattox, 2003). Geochemical relations among all or portions of this data set are depicted and interpreted by Thornber (2003), Thornber and others (2003) and Thornber (2001). Trace element compositions and Nd, Sr and Pb isotopic analyses of representative samples of this select eruption suite will be provided in a separate and complimentary open file report. From 1983 to October 2001, approximately 2,500 eruption samples were collected and archived by the U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO). Geochemical data for 1,002 of these samples are included here. Previous reports present bulk-lava major- element chemistry for eruption samples collected from 1983 to 1986 and from 1990 to 1994 (Neal and others, 1988 and Mangan and others, 1995, respectively). Major element glass chemistry and thermometry data for samples collected from 1983 to 1994 is reported by Helz and Hearn (1998) and whole-rock and glass chemistry for samples collected from September 1994 to October 2001 is provided by Thornber and others (2002). This report is a compilation of previously published data along with unpublished whole-rock data for the 1986–1990 eruptive interval (episode 48, see Heliker and Mattox, 2003). The geochemical data in this report is mostly limited to well-quenched samples collected at or near their respective vents. The samples include tephra and spatter, in addition to lava dipped from lava lakes, lava tubes, and surface lava flows. The details of sample collection techniques as described by Thornber and others (2002) are generally applicable for this entire sampling interval. Specifically excluded from this database are samples of distal surface flows, many of which were collected for topical studies of emplacement dynamics (for example, Cashman and others, 1999). Samples of sluggish or crystal-laden tube flows collected during eruptive pauses were also excluded, because they bear visual, petrographic and geochemical evidence for crystal accumulation during surface-flow stagnation. In addition, the pre-1992 whole-rock major element data reported here has been corrected to compensate for minor analytical discrepancies between pre- and post-1991 XRF analyses. These discrepancies resulted from a change in instrumentation at the USGS Denver analytical laboratories. This select suite of time-constrained geochemical data is suitable for constructing petrologic models of pre-eruptive magmatic processes associated with prolong rift zone eruption of Hawaiian shield volcanoes.

Hawai'i↗
USGS2001

Maps showing the development of the Pu‘u ‘Ö‘ö-Küpaianaha flow field, June 1984-February 1987, Kïlauea Volcano, Hawaii

The Pu'u 'O'o - Kupaianaha eruption on the middle east rift zone of Kilauea began in January 1983 with intermittent activity along several fissures. By June 1983, the eruption had localized at the Pu'u 'O'o vent, and the activity settled into an increasingly regular pattern of brief eruptive episodes characterized by high lava fountains. The first 18 months of this eruption are chronicled in Wolfe and others (1988), which includes maps of the flows erupted in episodes 1-20. The maps presented here extend this series through the beginning of episode 48.

Hawaii↗
USGS1997

Living on active volcanoes - The Island of Hawai'i

People on the Island of Hawai'i face many hazards that come with living on or near active volcanoes. These include lava flows, explosive eruptions, volcanic smog, damaging earthquakes, and tsunamis (giant seawaves). As the population of the island grows, the task of reducing the risk from volcano hazards becomes increasingly difficult. To help protect lives and property, U.S. Geological Survey (USGS) scientists at the Hawaiian Volcano Observatory closely monitor and study Hawai'i's volcanoes and issue timely warnings of hazardous activity.

Hawaii↗
USGS1992

Map showing lava-flow hazard zones, Island of Hawaii

This map shows lava-flow hazard zones for the five volcanoes on the Island of Hawaii. Volcano boundaries are shown as heavy, dark bands, reflecting the overlapping of lava flows from adjacent volcanoes along their common boundary. Hazard-zone boundaries are drawn as double lines because of the geologic uncertainty in their placement. Most boundaries are gradational, and the change In the degree of hazard can be found over a distance of a mile or more. The general principles used to place hazard-zone boundaries are discussed by Mullineaux and others (1987) and Heliker (1990). The differences between the boundaries presented here and in Heliker (1990) reflect new data used in the compilation of a geologic map for the Island of Hawaii (E.W. Wolfe and Jean Morris, unpub. data, 1989). The primary source of information for volcano boundaries and generalized ages of lava flows for all five volcanoes on the Island of Hawaii is the geologic map of Hawaii (E.W. Wolfe and Jean Morris, unpub. data, 1989). More detailed information is available for the three active volcanoes. For Hualalai, see Moore and others (1987) and Moore and Clague (1991); for Mauna Loa, see Lockwood and Lipman (1987); and for Kilauea, see Holcomb (1987) and Moore and Trusdell (1991).

Hawai'i↗