Tim R. Orr
Physical volcanology and eruption dynamics of basaltic volcanoes, principally Kīlauea volcano, Hawaii, and the Bering Sea Basalt Province, Alaska. Eruptive histories and hazards of Hawaiian and Alaska volcanoes.
My position as a Research Geologist at the Alaska Volcano Observatory focuses on fundamental research on eruption and flow field processes to understand hazards better and improve forecasts, first in Hawaiʻi and now in Alaska. My work entails observing and measuring eruptive activity as part of operational monitoring and through directed field studies to analyze the data collected to gain fundamental insights into eruptive phenomena in Hawaiʻi, Alaska, and worldwide.
In addition, a fundamental part of my position is the monitoring of, and response to, volcanic unrest and eruptions. I serve as a 24/7 on-call duty scientist and duty remote sensor at AVO periodically throughout the year, and more often as needed during eruption crises, with primary responsibility for assessing volcanic activity daily and issuing hazard alerts. Because of my previous experience at the Hawaiian Volcano Observatory, I am also called upon to help with eruption response efforts in Hawaiʻi, when needed.
Professional Experience
Research Geologist, USGS Alaska Volcano Observatory, June 2017–Present
Research Geologist, USGS Hawaiian Volcano Observatory, May 2016–June 2017
Operational Geologist, USGS Hawaiian Volcano Observatory, June 2005–May 2016
Physical Science Technician, University of Hawaiʻi at Hilo, November 2002–June 2005
Education and Certifications
University of Hawaii at Manoa, PH.D. (2015) – Geology and Geophysics
Northern Arizona University, M.S. (1997) – Geology
University of Montana, B.A. (1995) – Geology
University of Montana, B.A. (1993) – Geography
Affiliations and Memberships*
American Geophysical Union
Geological Society of America
International Association of Volcanology and Chemistry of the Earth’s Interior
Science and Products
Filter Total Items: 84
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Filter Total Items: 82
Pushing the Volcanic Explosivity Index to its limit and beyond: Constraints from exceptionally weak explosive eruptions at Kīlauea in 2008 Pushing the Volcanic Explosivity Index to its limit and beyond: Constraints from exceptionally weak explosive eruptions at Kīlauea in 2008
Estimating the mass, volume, and dispersal of the deposits of very small and/or extremely weak explosive eruptions is difficult, unless they can be sampled on eruption. During explosive eruptions of Halema‘uma‘u Crater (Kīlauea, Hawaii) in 2008, we constrained for the first time deposits of bulk volumes as small as 9–300 m3 (1 × 104 to 8 × 105 kg) and can demonstrate that they show...
Authors
Bruce Houghton, Don Swanson, J. Rausch, R.J. Carey, S.A. Fagents, Tim Orr
Time-lapse camera observations of gas piston activity at Pu‘u ‘Ō‘ō, Kīlauea volcano, Hawai‘i Time-lapse camera observations of gas piston activity at Pu‘u ‘Ō‘ō, Kīlauea volcano, Hawai‘i
Gas pistoning is a type of eruptive behavior described first at Kīlauea volcano and characterized by the (commonly) cyclic rise and fall of the lava surface within a volcanic vent or lava lake. Though recognized for decades, its cause continues to be debated, and determining why and when it occurs has important implications for understanding vesiculation and outgassing processes at...
Authors
Tim R. Orr, James Rea
Externally triggered renewed bubble nucleation in basaltic magma: the 12 October 2008 eruption at Halema‘uma‘u Overlook vent, Kīlauea, Hawai‘i, USA Externally triggered renewed bubble nucleation in basaltic magma: the 12 October 2008 eruption at Halema‘uma‘u Overlook vent, Kīlauea, Hawai‘i, USA
From October 2008 until present, dozens of small impulsive explosive eruptions occurred from the Overlook vent on the southeast side of Halema‘uma‘u Crater, at Kīlauea volcano, USA. These eruptions were triggered by rockfalls from the walls of the volcanic vent and conduit onto the top of the lava column. Here we use microtextural observations and data from clasts erupted during the well...
Authors
Rebecca Carey, Michael Manga, Wim Degruyter, Donald Swanson, Bruce Houghton, Tim R. Orr, Matthew Patrick
Inflation rates, rifts, and bands in a pāhoehoe sheet flow Inflation rates, rifts, and bands in a pāhoehoe sheet flow
The margins of sheet flows—pāhoehoe lavas emplaced on surfaces sloping
Authors
Richard P. Hoblitt, Tim Orr, Christina Heliker, Roger Denlinger, Ken Hon, Peter Cervelli
Inflation rates, rifts, and bands in a pāhoehoe sheet flow Inflation rates, rifts, and bands in a pāhoehoe sheet flow
The margins of sheet flows—pāhoehoe lavas emplaced on surfaces sloping
Authors
Richard Hoblitt, Tim R. Orr, Christina Heliker, Roger Denlinger, Ken Hon, Peter Cervelli
Explosive eruptions triggered by rockfalls at Kīlauea volcano, Hawaii Explosive eruptions triggered by rockfalls at Kīlauea volcano, Hawaii
Ongoing eruptive activity at Kīlauea volcano’s (Hawai‘i) summit has been controlled in part by the evolution of its vent from a 35-m-diameter opening into a collapse crater 150 m across. Geologic observations, in particular from a network of webcams, have provided an unprecedented look at collapse crater development, lava lake dynamics, and shallow outgassing processes. These...
Authors
Tim R. Orr, Weston Thelen, Matthew Patrick, Donald A. Swanson, David C. Wilson
Rootless shield and perched lava pond collapses at Kīlauea Volcano, Hawai'i Rootless shield and perched lava pond collapses at Kīlauea Volcano, Hawai'i
Effusion rate is a primary measurement used to judge the expected advance rate, length, and hazard potential of lava flows. At basaltic volcanoes, the rapid draining of lava stored in rootless shields and perched ponds can produce lava flows with much higher local effusion rates and advance velocities than would be expected based on the effusion rate at the vent. For several months in...
Authors
Matthew Patrick, Tim R. Orr
Selected time-lapse movies of the east rift zone eruption of KĪlauea Volcano, 2004–2008 Selected time-lapse movies of the east rift zone eruption of KĪlauea Volcano, 2004–2008
Since 2004, the U.S. Geological Survey's Hawaiian Volcano Observatory has used mass-market digital time-lapse cameras and network-enabled Webcams for visual monitoring and research. The 26 time-lapse movies in this report were selected from the vast collection of images acquired by these camera systems during 2004–2008. Chosen for their content and broad aesthetic appeal, these image...
Authors
Tim R. Orr
Small explosion from new vent at Kilauea’s summit Small explosion from new vent at Kilauea’s summit
At 0258 Hawaii‐Aleutian Standard Time (HST) on 19 March 2008, a small explosion scattered altered and fresh lithic debris across a 40‐hectare area at the summit of Kilauea volcano. This explosion, the first recorded there since 1924, issued from a vent about 35 meters wide along the east wall of Halema'uma'u Crater. Ballistic fragments—the largest measuring nearly 1 meter across—were...
Authors
David Wilson, Tamar Elias, Tim R. Orr, Matthew Patrick, Jeff Sutton, Don Swanson
Shallow degassing events as a trigger for very-long-period seismicity at Kilauea Volcano, Hawaii Shallow degassing events as a trigger for very-long-period seismicity at Kilauea Volcano, Hawaii
The first eruptive activity at Kīlauea Volcano’s summit in 25 years began in March 2008 with the opening of a 35-m-wide vent in Halema‘uma‘u crater. The new activity has produced prominent very-long-period (VLP) signals corresponding with two new behaviors: episodic tremor bursts and small explosive events, both of which represent degassing events from the top of the lava column...
Authors
Matthew Patrick, David C. Wilson, David Fee, Tim Orr, Don Swanson
Cyclic spattering, seismic tremor, and surface fluctuation within a perched lava channel, Kilauea Volcano Cyclic spattering, seismic tremor, and surface fluctuation within a perched lava channel, Kilauea Volcano
In late 2007, a perched lava channel, built up to 45 m above the preexisting surface, developed during the ongoing eruption near Pu‘u ‘Ō‘ō cone on Kīlauea Volcano’s east rift zone. The lava channel was segmented into four pools extending over a total of 1.4 km. From late October to mid-December, a cyclic behavior, consisting of steady lava level rise terminated by vigorous spattering and...
Authors
Matthew Patrick, Tim Orr, David Wilson, David Dow, R. Freeman
Infrasound from the 2007 fissure eruptions of Kīlauea Volcano, Hawai'i Infrasound from the 2007 fissure eruptions of Kīlauea Volcano, Hawai'i
Varied acoustic signals were recorded at Kīlauea Volcano in mid-2007, coincident with dramatic changes in the volcano's activity. Prior to this time period, Pu'u 'Ō'ō crater produced near-continuous infrasonic tremor and was the primary source of degassing and lava effusion at Kīlauea. Collapse and draining of Pu'u 'Ō'ō crater in mid-June produced impulsive infrasonic signals and...
Authors
D. Fee, M. Garces, Tim R. Orr, Michael Poland
Science and Products
Filter Total Items: 84
No results found.
Filter Total Items: 82
Pushing the Volcanic Explosivity Index to its limit and beyond: Constraints from exceptionally weak explosive eruptions at Kīlauea in 2008 Pushing the Volcanic Explosivity Index to its limit and beyond: Constraints from exceptionally weak explosive eruptions at Kīlauea in 2008
Estimating the mass, volume, and dispersal of the deposits of very small and/or extremely weak explosive eruptions is difficult, unless they can be sampled on eruption. During explosive eruptions of Halema‘uma‘u Crater (Kīlauea, Hawaii) in 2008, we constrained for the first time deposits of bulk volumes as small as 9–300 m3 (1 × 104 to 8 × 105 kg) and can demonstrate that they show...
Authors
Bruce Houghton, Don Swanson, J. Rausch, R.J. Carey, S.A. Fagents, Tim Orr
Time-lapse camera observations of gas piston activity at Pu‘u ‘Ō‘ō, Kīlauea volcano, Hawai‘i Time-lapse camera observations of gas piston activity at Pu‘u ‘Ō‘ō, Kīlauea volcano, Hawai‘i
Gas pistoning is a type of eruptive behavior described first at Kīlauea volcano and characterized by the (commonly) cyclic rise and fall of the lava surface within a volcanic vent or lava lake. Though recognized for decades, its cause continues to be debated, and determining why and when it occurs has important implications for understanding vesiculation and outgassing processes at...
Authors
Tim R. Orr, James Rea
Externally triggered renewed bubble nucleation in basaltic magma: the 12 October 2008 eruption at Halema‘uma‘u Overlook vent, Kīlauea, Hawai‘i, USA Externally triggered renewed bubble nucleation in basaltic magma: the 12 October 2008 eruption at Halema‘uma‘u Overlook vent, Kīlauea, Hawai‘i, USA
From October 2008 until present, dozens of small impulsive explosive eruptions occurred from the Overlook vent on the southeast side of Halema‘uma‘u Crater, at Kīlauea volcano, USA. These eruptions were triggered by rockfalls from the walls of the volcanic vent and conduit onto the top of the lava column. Here we use microtextural observations and data from clasts erupted during the well...
Authors
Rebecca Carey, Michael Manga, Wim Degruyter, Donald Swanson, Bruce Houghton, Tim R. Orr, Matthew Patrick
Inflation rates, rifts, and bands in a pāhoehoe sheet flow Inflation rates, rifts, and bands in a pāhoehoe sheet flow
The margins of sheet flows—pāhoehoe lavas emplaced on surfaces sloping
Authors
Richard P. Hoblitt, Tim Orr, Christina Heliker, Roger Denlinger, Ken Hon, Peter Cervelli
Inflation rates, rifts, and bands in a pāhoehoe sheet flow Inflation rates, rifts, and bands in a pāhoehoe sheet flow
The margins of sheet flows—pāhoehoe lavas emplaced on surfaces sloping
Authors
Richard Hoblitt, Tim R. Orr, Christina Heliker, Roger Denlinger, Ken Hon, Peter Cervelli
Explosive eruptions triggered by rockfalls at Kīlauea volcano, Hawaii Explosive eruptions triggered by rockfalls at Kīlauea volcano, Hawaii
Ongoing eruptive activity at Kīlauea volcano’s (Hawai‘i) summit has been controlled in part by the evolution of its vent from a 35-m-diameter opening into a collapse crater 150 m across. Geologic observations, in particular from a network of webcams, have provided an unprecedented look at collapse crater development, lava lake dynamics, and shallow outgassing processes. These...
Authors
Tim R. Orr, Weston Thelen, Matthew Patrick, Donald A. Swanson, David C. Wilson
Rootless shield and perched lava pond collapses at Kīlauea Volcano, Hawai'i Rootless shield and perched lava pond collapses at Kīlauea Volcano, Hawai'i
Effusion rate is a primary measurement used to judge the expected advance rate, length, and hazard potential of lava flows. At basaltic volcanoes, the rapid draining of lava stored in rootless shields and perched ponds can produce lava flows with much higher local effusion rates and advance velocities than would be expected based on the effusion rate at the vent. For several months in...
Authors
Matthew Patrick, Tim R. Orr
Selected time-lapse movies of the east rift zone eruption of KĪlauea Volcano, 2004–2008 Selected time-lapse movies of the east rift zone eruption of KĪlauea Volcano, 2004–2008
Since 2004, the U.S. Geological Survey's Hawaiian Volcano Observatory has used mass-market digital time-lapse cameras and network-enabled Webcams for visual monitoring and research. The 26 time-lapse movies in this report were selected from the vast collection of images acquired by these camera systems during 2004–2008. Chosen for their content and broad aesthetic appeal, these image...
Authors
Tim R. Orr
Small explosion from new vent at Kilauea’s summit Small explosion from new vent at Kilauea’s summit
At 0258 Hawaii‐Aleutian Standard Time (HST) on 19 March 2008, a small explosion scattered altered and fresh lithic debris across a 40‐hectare area at the summit of Kilauea volcano. This explosion, the first recorded there since 1924, issued from a vent about 35 meters wide along the east wall of Halema'uma'u Crater. Ballistic fragments—the largest measuring nearly 1 meter across—were...
Authors
David Wilson, Tamar Elias, Tim R. Orr, Matthew Patrick, Jeff Sutton, Don Swanson
Shallow degassing events as a trigger for very-long-period seismicity at Kilauea Volcano, Hawaii Shallow degassing events as a trigger for very-long-period seismicity at Kilauea Volcano, Hawaii
The first eruptive activity at Kīlauea Volcano’s summit in 25 years began in March 2008 with the opening of a 35-m-wide vent in Halema‘uma‘u crater. The new activity has produced prominent very-long-period (VLP) signals corresponding with two new behaviors: episodic tremor bursts and small explosive events, both of which represent degassing events from the top of the lava column...
Authors
Matthew Patrick, David C. Wilson, David Fee, Tim Orr, Don Swanson
Cyclic spattering, seismic tremor, and surface fluctuation within a perched lava channel, Kilauea Volcano Cyclic spattering, seismic tremor, and surface fluctuation within a perched lava channel, Kilauea Volcano
In late 2007, a perched lava channel, built up to 45 m above the preexisting surface, developed during the ongoing eruption near Pu‘u ‘Ō‘ō cone on Kīlauea Volcano’s east rift zone. The lava channel was segmented into four pools extending over a total of 1.4 km. From late October to mid-December, a cyclic behavior, consisting of steady lava level rise terminated by vigorous spattering and...
Authors
Matthew Patrick, Tim Orr, David Wilson, David Dow, R. Freeman
Infrasound from the 2007 fissure eruptions of Kīlauea Volcano, Hawai'i Infrasound from the 2007 fissure eruptions of Kīlauea Volcano, Hawai'i
Varied acoustic signals were recorded at Kīlauea Volcano in mid-2007, coincident with dramatic changes in the volcano's activity. Prior to this time period, Pu'u 'Ō'ō crater produced near-continuous infrasonic tremor and was the primary source of degassing and lava effusion at Kīlauea. Collapse and draining of Pu'u 'Ō'ō crater in mid-June produced impulsive infrasonic signals and...
Authors
D. Fee, M. Garces, Tim R. Orr, Michael Poland
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government