R. Greg Vaughan

United States Geological Survey | USGS · Astrogeology Science Center, Flagstaff AZ

In the past century, most eruptions of Steamboat Geyser in Yellowstone National Park's Norris Geyser Basin were mainly clustered in three episodes: 1961–1969, 1982–1984, and ongoing since 2018. These eruptive episodes resulted in extensive disturbance to surrounding trees. To characterize tree response over time as an indicator of geyser activity a...

An important aspect of volcanic hazard assessment is determination of the level and character of background activity at a volcano so that deviations from background (called unrest) can be identified. Here, we compile the instrumentally recorded eruptive and noneruptive activity for 161 US volcanoes between 1978 and 2020. We combine monitoring data...

Plain Language Summary The Yellowstone Plateau Volcanic Field has had three cataclysmic volcanic eruptions over the past ~2.1 million years. The youngest of these eruptions at 0.631 Ma resulted in the formation of the Yellowstone Caldera and was followed by several smaller eruptive episodes of large volume rhyolite flows up to ~70,000 years ago. Th...

Yellowstone is a large restless caldera that contains many dynamic thermal areas that are the surface expression of the deeper magmatic system. In 2018, using a Landsat 8 nighttime thermal infrared image, we discovered the emergence of a new thermal area located near Tern Lake on the northeast margin of the Sour Creek dome. A high-spatial-resolutio...

After 53 years of quiescence, Mount Agung awoke in August 2017, with intense seismicity, measurable ground deformation, and thermal anomalies in the summit crater. Although the seismic unrest peaked in late September and early October, the volcano did not start erupting until 21 November. The most intense explosive eruptions with accompanying rapid...

This volume, prepared as part of the Geological Society of America Annual Meeting in Phoenix, includes field guides covering aspects of the spectacular geology of southwestern North America. Field guides tackle the geology of the southern Colorado Plateau, from paleoenvironments of Petrified Forest National Park, to Jurassic sand dunes of southern...

In October 2016, an airborne thermal infrared (TIR) survey was conducted over the area surrounding the Casa Diablo geothermal power plant, near Mammoth Lakes, CA. This data collection campaign was part of an ongoing monitoring program to assess the potential impacts of geothermal energy production on the natural surface expression of the geothermal...

This paper explores for the first time the possibilities to use two land surface temperature (LST) time series of different origins (geostationary Meteosat Second Generation satellite data and Noah land surface modelling, LSM), to detect geothermal anomalies and extract the geothermal component of LST, the LSTgt. We hypothesize that in geothermal a...

We quantified gas and heat emissions in an acid-sulfate, vapor-dominated area (0.04-km²) of Norris Geyser Basin, located just north of the 0.63Ma Yellowstone Caldera and near an area of anomalous uplift. From 14 May to 3 October 2016, an eddy covariance system measured half-hourly CO2, H2O and sensible (H) and latent (LE) heat fluxes and a Multi-GA...

Every two years, scientists, natural resource managers, outreach specialists, and a variety of other interested parties get together for the biennial meeting of the Yellowstone Volcano Observatory (YVO). Each time, the theme varies. In past years, we have focused the meeting around topics including monitoring plans, emergency response, geodesy, and...

Maps that define the current distribution of geothermally heated ground are useful toward setting a baseline for thermal activity to better detect and understand future anomalous hydrothermal and (or) volcanic activity. Monitoring changes in the dynamic thermal areas also supports decisions regarding the development of Yellowstone National Park inf...

A combination of satellite and airborne high-resolution visible and thermal infrared (TIR) image data detected and measured changes at Redoubt Volcano during the 2008-2009 unrest and eruption. The TIR sensors detected persistent elevated temperatures at summit ice-melt holes as seismicity and gas emissions increased in late 2008 to March 2009. A ph...

Remote sensing observations of thermal features associated with (and often preceding) volcanic activity have been used for decades to detect and monitor volcanism. However, anomalous thermal precursors to volcanic eruptions are usually only recognized retrospectively. One of the reasons for this is that precursor thermal activity is often too subtl...

The overarching aim of this study was to use satellite thermal infrared (TIR) remote sensing to monitor geothermal activity within the Yellowstone geothermal area to meet the missions of both the U.S. Geological Survey and the Yellowstone National Park Geology Program. Specific goals were to: 1) address the challenges of monitoring the surface ther...

The purpose of this work was to use satellite-based thermal infrared (TIR) remote sensing data to measure, map, and monitor geothermal activity within the Yellowstone geothermal area to help meet the missions of both the U.S. Geological Survey Yellowstone Volcano Observatory and the Yellowstone National Park Geology Program. Specifically, the goals...

The aim of this study was to use satellite thermal infrared (TIR) remote sensing to monitor geothermal activity within Yellowstone geothermal area (YGA) to meet the missions of both the U.S. Geological Survey and the National Park Service. Specific goals were to 1) address the challenges of monitoring the surface thermal characteristics of the >10,...

On March 17, 2009, a surtseyan eruption occurred around Hunga Ha'apai Island, Tonga. A series of observations from the high-spatial resolution Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), and the high-temporal resolution Moderate Resolution Imaging Spectroradiometer (MODIS), was used to estimate the magnitude, location, s...

On September 4, 2007, after 25years of effusive natrocarbonatite eruptions, the eruptive activity of Oldoinyo Lengai (OL), N Tanzania, changed abruptly to episodic explosive eruptions. This transition was preceded by a voluminous lava eruption in March 2006, a year of quiescence, resumption of natrocarbonatite eruptions in June 2007, and a volcano-...

Understanding the characteristics of volcanic thermal emissions and how they change with time is important for forecasting and monitoring volcanic activity and potential hazards. Satellite instruments view volcanic thermal features across the globe at various temporal and spatial resolutions. Thermal features that may be a precursor to a major erup...

The Yellowstone National Park (YNP) geothermal system is one of the largest in the world, with thousands of individual thermal features ranging in size from a few centimeters to tens of meters across, (e.g., fumaroles, geysers, mud pots and hot spring pools). Together, large concentrations of these thermal features make up dozens of distinct therma...

Oldoinyo Lengai (OL) is the only active volcano in the world that produces natrocarbonatite lava. These carbonate-rich lavas are unique in that they have relatively low temperatures (495–590 °C) and very low viscosity. OL has been erupting intermittently since 1983, mostly with small lava flows, pools and spatter cones (hornitos) confined to the su...

The stable, persistent, active lava lake at Erebus volcano (Ross Island, Antarctica) provides an excellent thermal target for analysis of spacecraft observations, and for testing new technology. In the austral summer of 2005 visible and infrared observations of the Erebus lava lake were obtained with sensors on three space vehicles Terra (ASTER, MO...

Oldoinyo Lengai (OL) is the only active volcano in the world that produces natro-carbonatite lava. These carbonate-rich lavas are unique in that they have relatively low temperatures (500-600 C) compared with typical silicate lavas (600-1100 C), and they have a low viscosity, behaving more like a mud flow than a lava flow. OL has been erupting on a...

In December 1999, the first Moderate Resolution Imaging Spectroradiometer (MODIS) instrument and an Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument were launched into polar orbit on the Terra spacecraft. Both instruments measure surface radiance, which requires that they are calibrated and validated in flight. In-f...

A rising volcanic plume from an unknown source was observed on 9-11 August 2006 in the Vava'u Island group in the northernmost islands of Tonga [Matangi News Online, 2006]. On 12 August, the crew on board the yacht Maiken, sailing west from Vava'u to Fiji, encountered ``a vast, many miles wide, belt of densely packed pumice'' floating on the water...

Thermal Infrared (TIR) remote sensing measurements of high-temperature volcanic features improve our understanding of volcanic processes and our ability to identify renewed volcanic activity, forecast eruptions, and assess hazards. We will present a time-series analysis of ASTER TIR data acquired over 3 different volcanoes that span a range of temp...

ASTER thermal infrared data over Mt. St Helens were used to characterize its thermal behavior from Jun 2000 to Feb 2006. Prior to the Oct 2004 eruption, the average crater temperature varied seasonally between -12 and 6 C. After the eruption, maximum single-pixel temperature increased from 10 C (Oct 2004) to 96 C (Aug 2005), then showed a decrease...

Since the beginning of renewed eruptive activity at Mount St. Helens numerous thermal infrared (TIR) remote sensing data sets have been acquired to monitor changes in temperature and thermal flux from the new dome. High-resolution (5 m) TIR data from the MODIS-ASTER airborne simulator (MASTER) were acquired during the first 20 days of activity alon...

The purpose of this study was to evaluate the use of airborne multispectral and hyperspectral thermal infrared (TIR) image data for mapping surface minerals characteristic of active geothermal systems. TIR image data from the MASTER multispectral spectrometer and the SEBASS hyperspectral spectrometer were acquired over Steamboat Springs, Nevada, US...

radiative cooling rate of � 714 J/m2/s over the new dome, corresponding to a radiant power of � 24 MW. MASTER data indicated the new dome was dacitic in composition, and digital elevation data derived from LIDAR acquired concurrently with MASTER showed that the dome growth correlated with the areas of elevated temperatures. Low SO2 concentrations i...

Recent significant improvements in the wavelength coverage, spectral resolution and quality of remote sensing imagery have lead to the extensive application of these data sets in exploration and site characterization. Traditional techniques in spectral and spatial analysis of imagery, coupled with new, high signal to noise data, allow their direct...

The Comstock mining district, around Virginia City, Nevada, consists of mostly Miocene volcanic rocks that have been subjected to multiple episodes of hydrothermal alteration, extensional faulting, and mineralization. The distribution of alteration zones is related to the occurrence of precious metal deposits. Also, as a result of past mining activ...

The purpose of this study was to use a combination of high spatial resolution airborne visible, near infrared, short wave infrared (VNIR/SWIR) and thermal infrared (TIR) image data to remotely identify and map exposed alteration minerals around both active and ancient hydrothermal systems, and the mineral by-products of weathered mine tailings. Thr...

This study focuses on mapping surface minerals using a new hyperspectral thermal infrared (TIR) sensor: the spatially enhanced broadband array spectrograph system (SEBASS). SEBASS measures radiance in 128 contiguous spectral channels in the 7.5- to 13.5-μm region with a ground spatial resolution of 2 m. In September 1999, three SEBASS flight lines...

This study focuses on corroboration of remotely derived surface mineral maps based on thermal infrared (TIR = 7-14 microns) radiance measurements of field samples from Steamboat Springs, Nevada. Steamboat Springs is an active geothermal area with recent siliceous sinter deposits and a variety of exposed alteration minerals, including kaolinite, alu...

Airborne thermal infrared multi- and hyperspectral data sets are used to map sulfate alteration of basaltic andesites near Reno, NV. Alteration includes quartz-alunite, jarosite and a number of clay minerals such as kaolinite and montmorillonite. Additional information is contained in the original extended abstract.

Remote sensing imagery has been widely used as an exploration and site characterization tool for both mineral and petroleum economic development as well as environmental assessment. Well-established techniques in multispectral and hyperspectral analysis, coupled with new, state-of-the-art imagery from spaceborne and airborne sensor systems, allows...

The surface alteration properties of Mars pose significant unsolved problems such as the presence of high levels of Si, S, and Cl in martian soils and the lack of definitive identification of specific minerals to assign to these elemental contents. Recent results from both Pathfinder and the Thermal Emission Spectrometer (TES) show a substantial po...

Recent observations show that much of the martian surface is andesitic in nature. Examination of acid sulfate alteration on basaltic-andesite volcanics near Reno, NV can provide clues to the weathering of the martian northern lowlands.

The region near Reno, Nevada, provides a unique opportunity to compare acid rock weathering from a natural source with exposures that occur primarily from anthropogenic activities. The initial phase of the study focuses on mapping the presence and abundance of sulfate minerals using a new hyperspectral thermal infrared airborne sensor SEBASS (Spati...

Conventional and laser microprobe measurements of S isotope ratios were made on a suite of eight natural sulfide samples to develop a well-characterized, isotopically homo-geneous set of standards for in situ laser microprobe analysis. All the samples are from massive sulfide deposits in either high-grade metamorphic terranes or igneous systems. Th...