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At least 37 records · Page 2Linked to original sources
USGS2021

Exploring basin-scale relations and unsupervised classification to quantify and automate the definition of assessment units in USGS continuous oil and gas resource assessments

The U.S. Geological Survey (USGS) assesses potential for undiscovered, technically recoverable oil and gas resources in priority geologic provinces and quantifies resource volume estimates within subdivisions called assessment units (AUs). AU boundaries are defined by USGS geologists using quantitative and qualitative geologic information. Variables contained in IHS Markit’s well and production databases can quantify and/or function as proxies for many of the qualitative, boundary-defining variables. This research explores a new approach to determine AU boundaries and the potential to automate their definition, using data analytics and machine learning algorithms on key, qualitative variables within the IHS Markit databases. Well and production data from the U.S. onshore Gulf Coast region for the Upper Cretaceous Eagle Ford Group and Austin Chalk are used in this analysis because each is relatively geologically uniform in Texas and both have recently been assessed by the USGS. The Eagle Ford is an example of an in situ continuous oil and gas accumulation, and the overlying Austin Chalk is an example of a combined conventional and continuous resource, sourced from the underlying Eagle Ford. Wellspecific values were extracted or calculated from data in IHS Markit’s well and production databases for depth to top and base of the formations, formation thickness, bottom-hole temperature, temperature gradient, temperature at base of formation, cumulative oil and gas production values, barrels of oil equivalent, oil and gas gravities, mud weights from initial well test, depth pressure ratio, and excess pressure. A raster for each variable was interpolated using the natural neighbor technique from the spatial analyst toolbox in ArcGIS. Rasters were then transformed using minimum-maximum scaling, which rescales the distribution to the range of 0–1. Clustering was completed using the iso cluster unsupervised classification tool on the normalized rasters. Raster cell groupings from two to ten were explored, with initial results demonstrating that four to six classes return the most differentiable groups, with depth to formation, oil gravity, pressure, and temperature variables containing the greatest between-group differences. Modeled clusters have spatial similarities to the geologically defined AUs, with indication that temperature and pressure are the most fundamental to AU definition. Input from geologists will remain crucial for further dividing clusters and defining final AUs, since AUs are defined by both qualitative and quantitative information; however, this research documents promising cluster modeling results for the automation of initial AU definitions.

Louisiana, Mississippi, Texas↗
USGS2019

#EarthquakeAdvisory: Exploring discourse between government officials, news media and social media during the Bombay Beach 2016 Swarm

Communicating probabilities of natural hazards to varied audiences is a notoriously difficult task. Many of these challenges were encountered during the 2016 Bombay Beach, California, swarm of ~100 2≤M≤4.3 earthquakes, which began on 26 September 2016 and lasted for several days. The swarm’s proximity to the southern end of the San Andreas fault caused concern that a larger earthquake could be triggered. Within 1–2 days, different forecast models were used to evaluate the likelihood of a larger event with two agencies (the U.S. Geological Survey [USGS] and the California Governor’s Office of Emergency Services) releasing probabilities and forecasts for larger earthquakes. Our research explores communication and news media efforts, as well as how people on a microblogging social media site (Twitter) responded to these forecasts. Our findings suggest that news media used a combination of information sources, basing their articles on what they learned from social media, as well as using information provided by government agencies. As the swarm slowed down, there is evidence of the continued interplay between news media and social media, with the USGS issuing revised probability reports and scientists from the USGS and other institutions participating in media interviews. In reporting on the swarm, news media often used language more generally than the scientists; terms such as probability, likelihood, chance, and possibility were used interchangeably. Knowledge of how news media used scientific information from the 2016 Bombay Beach forecasts can assist local, state, and federal agencies in developing effective communication strategies to respond to future earthquakes.

California↗
USGS2021

Long-term ecosystem and biogeochemical research in Loch Vale watershed, Rocky Mountain National Park, Colorado

Loch Vale watershed was instrumented in 1983 with initial support from the National Acid Precipitation Assessment Program to ask whether ecosystems of Rocky Mountain National Park (RMNP) were affected by acidic atmospheric deposition. Research and monitoring activities were expanded in 1991 by the U.S. Geological Survey Water, Energy, and Biogeochemical Budgets program to understand the processes, and their interactions, controlling water, energy, and biogeochemical fluxes. With help from many collaborators we have characterized trends and patterns in atmospheric deposition, climate, and hydrology, including glaciers and other ice features. Instead of acidic deposition, we documented high atmospheric inputs of reactive nitrogen (Nr), and have studied the ecological consequences in soils, surface water, and vegetation. Using paleolimnology, we documented the onset of human-caused change to lake primary producers ca. 1950 in response to increased Nr deposition and warming. Our results provided the basis for the Colorado Nitrogen Deposition Reduction Plan, a state policy that aims to reduce Nr emissions to protect resources in RMNP by 2032. Carbon cycle research revealed mountain wetlands now release more carbon than they store, and respiration and methane flux occurs even during winter through deep snow packs. Trend analyses found export of Nr to be closely tied to atmospheric inputs, but can lag in response to drought. Current research explores consequences of the combination of warming, changes in precipitation dynamics, and atmospheric deposition of Nr and dust on stream and lake CO 2 dynamics, lake biology and trophic state, and soil carbon composition. Dramatic increases in park visitors have prompted studies on the effects of recreational use on water quality. New tools such as remote sensing and high frequency instream water quality sensors are being applied to lake and stream studies. Monitoring, combined with experiments, models, and spatial comparisons is an essential foundation for science-based resource management.

Colorado↗
USGS1994

The applicability of terrestrial visitor impact management strategies to the protection of coral reefs

A dramatic expansion in nature-based tourism to tropical coastal destinations has occurred in the past 20 years. Tourism development, combined with intense recreational pressures, has irreversibly transformed and degraded many popular scenic natural environments. This paper examines the management of recreational impacts to coral reefs using Virgin Islands National Park as a case study. A review of terrestrial recreational ecology research explores the implications and potential applicability of some principal findings to the protection of coral reefs. Visitor impact management recommendations for the protection of coral reefs are offered. Managers can minimize coral reef recreational impacts by (1) restricting high-impact uses, (2) containing rather than dispersing recreational use, (3) encouraging the use of resistant environments, (4) teaching low-impact recreational practices, and (5) enforcing park rules and regulations.

Ocean and Coastal Management↗
USGS2002

Mexican native trouts: A review of their history and current systematic and conservation status

While biologists have been aware of the existence of native Mexican trouts for over a century, they have received little study. The few early studies that did much more than mention their existence began in the 1930s and continued into the early 1960s, focusing primarily on distributional surveys and taxonomic analyses. Starting in the 1980s the Baja California rainbow trout became the subject of more detailed studies, but very little remains known of mainland trouts of the Sierra Madre Occidental. We review earlier studies and report on our own collections and observations made between 1975 and 2000. We present newly discovered historical evidence that leads us to conclude that a "lost" cutthroat trout, a lineage not previously known from Mexico, was collected more than a century ago from headwaters of the Ri??o Conchos (a major tributary of the Rio Grande (= Ri??o Bravo)), a basin not previously considered to harbor a native trout. We review the last century of regional natural resource management and discuss our own observations of trout habitats. Impacts of logging, road building and overgrazing are widespread and expanding. Many streams suffer from heavy erosion, siltation and contamination, and though long-term hydrologic data are generally not available, there is evidence of decreased discharge in many streams. These problems appear related to region-wide land management practices as well as recent regional drought. Trout culture operations using exotic rainbow trout have rapidly proliferated throughout the region, threatening genetic introgression and/or competition with native forms and predation on them. Knowledge of distribution, abundance, relationships and taxonomy, not to mention ecology and population biology, of native trouts of the Sierra Madre Occidental remains inadequate. Vast areas of most mainland drainages are still unexplored by fish collectors, and even rudimentary information regarding basic biology, ecology and population structure of stocks remains lacking. Concentrated exploration, research and management of this long overlooked and undervalued resource are all urgently needed. The history of natural resources exploitation that placed so many native trouts of the western United States on threatened and endangered species lists is repeating itself in the Sierra Madre Occidental. Without concentrated action and development of region-wide socio-economic solutions for current, largely non-sustainable resource management practices, native Mexican trout gene pools will soon be in grave danger of extinction.

Reviews in Fish Biology and Fisheries↗
USGS2010

Performance of spread spectrum Global Positioning System collars on grizzly and black bears

Global Positioning System (GPS) telemetry is a prevalent tool now used in the study of large mammals. Global Positioning Systems either store the data on board the collar or contain a remote-transfer system that allows for data recovery at more frequent intervals. Spread spectrum (S–S) technology is a new mode of data transfer designed to overcome interference problems associated with narrow-band very high frequency and ultra high frequency data-transfer systems. We evaluated performance of S–S GPS radiocollars deployed on grizzly ( Ursus arctos ) and black bears ( U. americanus ). We also evaluated variables that influenced GPS fix success rates, with particular focus on animal activity, time of year, and temperature. The S–S GPS collars performed to our expectations and met study objectives; we did not experience any major problems with the data-transfer system. We observed varying rates of fix success that were directly related to recorded activity counts. Using logistic regression, we verified that activity counts were a reasonable measure of resting or feeding–traveling in both bear species. Our results showed that 73% and 79% of missed fixes, respectively, occurred when we predicted black and grizzly bears to be resting. Temperatures measured in the canister of the collar were not correlated with air temperature, suggesting posture and activity influenced canister temperature. Both measures of temperature were predictive of fix success. We did not find that fix success was related to body morphology (i.e., neck circumference, mass, and chest girth), fix interval, position of the GPS antenna relative to the sky, or sex of the bear. We conclude that fix success for both species is strongly related to activity patterns and time of year. Activity counters appear to be a reasonable measure of this behavior, and we recommend researchers consider including an activity-count system when deploying GPS collars. We also recommend researchers explore building separate models of habitat selection based upon categories of activity to account for bias in fix success associated with bear behavior.

Wyoming↗
USGS1969

Sample submittal manual

Instructions for submitting samples to the Branch of Analytical Laboratories and laboratories of the Field Services Section of the Branch of Exploration Research.

Report↗
USGS1979

Geochemical data for Cohutta Wilderness, Georgia-Tennessee

Trace-element data obtained from stream-sediment, soil, and rock-chip samples by semiquantitative spectrographic and atomic absorption analyses. Geochemical data are grouped alphabetically by letter prefix and arranged in numerical order within the lettered groups. The listed data were obtained from samples collected in 1977 and 1978 by Jacob E. Gair and John F. Slack, assisted by Andrew Grosz, Richard Ketelle, Donald Henry, Thomas Hanley, Ann Stevens, and Gregory R. Morley. The spectrographic and atomic absorption analyses were done in laboratories of the Branch of Exploration Research, U.S. Geological Survey, Denver. The spectrographic analyses were done by David F. Siems and Elwin L. Mosier; the atomic absorption analyses, by Allen L. Meier. Data retrieval from the computerized storage file of the U.S. Geological Survey was made by Nancy A. Wright.

Georgia, Tennessee↗
USGS2022

Fighting misinformation in seismology: Expert opinion on earthquake facts vs fiction

Misinformation carries the potential for immense damage to public understanding of science and for evidence-based decision making at an individual and policy level. Our research explores the following questions within seismology: which claims can be considered misinformation, which are supported by a consensus, and which are still under scientific debate? Consensus and debate are important to quantify, because where levels of scientific consensus on an issue are high, communication of this fact may itself serve as a useful tool in combating misinformation. This is a challenge for earthquake science, where certain theories and facts in seismology are still being established. The present study collates a list of common public statements about earthquakes and provides–to the best of our knowledge–the first elicitation of the opinions of 164 earth scientists on the degree of verity of these statements. The results provide important insights for the state of knowledge in the field, helping identify those areas where consensus messaging may aid in the fight against earthquake related misinformation and areas where there is currently lack of consensus opinion. We highlight the necessity of using clear, accessible, jargon-free statements with specified parameters and precise wording when communicating with the public about earthquakes, as well as of transparency about the uncertainties around some issues in seismology.

Frontiers in Earth Science↗
USGS2022

Simulation of heat flow in a synthetic watershed: Lags and dampening across multiple pathways under a climate-forcing scenario

Although there is widespread agreement that future climates tend toward warming, the response of aquatic ecosystems to that warming is not well understood. This work, a continuation of companion research, explores the role of distinct watershed pathways in lagging and dampening climate-change signals. It subjects a synthetic flow and transport model to a 30-year warming signal based on climate projections, quantifying the heat breakthrough on a monthly time step along connected pathways. The system corresponds to a temperate watershed roughly 27 km on a side and consists of (a) land-surface processes of overland flow, (b) infiltration through an unsaturated zone (UZ) above an unconfined sandy aquifer overlying impermeable bedrock, and (c) groundwater flow along shallow and deep pathlines that converge as discharge to a surface-water network. Numerical simulations show that about 40% of the warming applied to watershed infiltration arrives at the water table and that the UZ stores a large fraction of the upward-trending heat signal. Additionally, once groundwater reaches the surface-water network after traveling through the saturated zone, only about 10% of the original warm-up signal is returned to streams by discharge. However, increases in the simulated streamflow temperatures are of similar magnitude to increases at the water table, due to the addition of heat by storm runoff, which bypasses UZ and groundwater storage and counteracts subsurface dampening. The synthetic modeling method and tentative findings reported here provide a potential workflow for real-world applications of climate-change modeling at the full watershed scale.

Water↗
USGS2021

A roadmap for planetary caves science and exploration

While researchers have pondered the possibility of extraterrestrial caves for more than 50 years, we have now entered the incipient phase of planetary caves exploration. Our knowledge of planetary caves varies from body to body. Earth represents the most advanced level of exploration, but many unanswered questions remain. Beyond Earth, identification of possible caves is most advanced for the Moon and Mars , with hundreds of documented candidate cave entrances and several proposed cave mission concepts. To date, the community has catalogued 2,660 SAPs on eight planetary bodies (excluding Earth) across our Solar System. Planetary caves science has the potential to significantly expand over the next decade. A potential roadmap for planetary cave research and exploration is discussed.

Nature Astronomy↗
USGS2018

Chapter 5: Impact of sedimentary-exhalative hydrothermal systems on marine chemistry and mass extinctions: Applications for ore genesis research and mineral exploration

Times of metal-rich brine discharge into ancient ocean basins, associated with the formation of sedimentary-exhalative (sedex) Zn-Pb-Ba ore deposits, coincided with short-duration positive excursions (“spikes”) in the global marine Sr isotope record. While these spikes are unexplained by conventional oceanic models, chronostratigraphic correlations, combined with mass balance evidence and oceanographic modeling, suggest that the flux of radiogenic Sr from sedex brines during ore formation is sufficient to explain these previously enigmatic 87 Sr/ 86 Sr spikes. We review existing 87 Sr/ 86 Sr data and present new data as verification of these global 87 Sr/ 86 Sr spikes and their correlations with the formation of giant sedex ore deposits. Major events include an 1 ×10 −4 (~0.7078–~0.7079) excursion contemporaneous with formation of the Rammelsberg deposit at ~389 Ma; spikes on the order of 1 to 3 × 10 −4 , coeval with formation of the Meggen deposit at ~381 Ma, several ore deposits in the Macmillan Pass district at ~379 to 375 Ma, and the Silvermines deposits at ~352 Ma; and two >6 × 10 −4 spikes coincident with formation of the giant Navan deposit at ~346 Ma and Red Dog deposits at ~337 Ma. Moreover, the timing of peak 87 Sr/ 86 Sr spikes correlates with global δ 13 C and δ 18 O spikes, deposition of metal-rich black shales and ironstones, metal-induced malformation (teratology) of marine organisms, and mass extinctions. The relationships among these features were poorly understood, but our new model explains how the flux of key biolimiting nutrients and metals contained in sedex brines, demonstrably equivalent to or exceeding that of the total modern riverine flux to the ocean, spurred ocean eutrophication, which, ultimately, through a series of positive feedback mechanisms, may have triggered global chemical and biological events. If, as we hypothesize, sedex hydrothermal systems are recorded in the global marine isotopic, geologic, and biological records, our findings define a new approach to the study of and exploration for sedex deposits. We demonstrate that fluid inclusion solute chemistry and isotopic and stratigraphic studies of sedex deposits, coupled with chronostratigraphic correlation and high-resolution 87 Sr/ 86 Sr isotope chemostratigraphy, can be used to answer long-standing questions about geologic processes responsible for formation of these extraordinary deposits. This approach provides evidence for the age, duration, and fluxes of fluids and metals vented into the ocean by these giant hydrothermal systems. Accordingly, the marine 87 Sr/ 86 Sr curve constitutes a global exploration tool that could be applied to assess the mineral potential of sedimentary basins. To illustrate the potential of this tool to identify favorable stratigraphic ages and basins with potential for undiscovered giant sedex deposits, we highlight several spikes, on par with those characteristic of the Red Dog and Navan deposits, which have not been correlated with known metal deposits. Given these strong temporal correlations, mass balance estimates, and results of ocean chemistry modeling, our study suggests that further work is warranted to determine the extent to which periodic venting of hydrothermal basinal brines into the ocean has influenced the evolution of marine chemistry. Ultimately, these global signatures can be applied to the study of and exploration for sedex deposits.

Book chapter↗
USGS2023

Detrending Great Basin elevation to identify structural patterns for identifying geothermal favorability

Topography provides information about the structural controls of the Great Basin and therefore information that may be used to identify favorable structural settings for geothermal systems. The Nevada Machine Learning Project (NVML) tested the use of a digital elevation map (DEM) of topography as an input feature to predict geothermal system favorability. A recent study re-examines the NVML data, identifying the DEM as the most important feature, showing a broad uniform pattern of high-favorability in the lower-elevation west and low-favorability in the higher elevation east of their study area in north-central Nevada. This regional elevation trend conflicts with the geologic notion that local relative topography should be used to identify geologic structures associated with favorable structural settings for hydrothermal upflow. Specifically, local relative topography gives information about position in the mountains, in the valleys, or at the transitions between, aiding in identification of faults and fault intersections. As part of U.S. Geological Survey efforts to engineer features that are useful for predicting geothermal resources, we construct a detrended elevation map that emphasizes local relative topography and highlights features that geologists use for identifying geothermal systems (i.e., providing machine learning algorithms with features that may improve predictive skill by emphasizing the information used by geologists). Herein, we describe the removal of the regional trend in elevation to emphasize the basin-and-range scale structural features, creating detrended elevation maps. Regional elevation trends were estimated using a local linear regression and subtracted from the actual elevation using a 30-m DEM. In an effort to optimize the detrended surface, alternate versions were produced with different rates of smoothness resulting in three detrended elevation maps. The resulting elevation trend surfaces (a proxy for crustal thickness) are compared with conductive heat flow maps, and a general pattern was observed of a negative correlation between heat flow and regional elevation in many areas, indicating that thinner crust may be causing elevated heat flow in some areas and thicker crust may cause the observed heat flow lows. Because these detrended elevation maps emphasize geologic structure and relative displacement, these products may also be useful for other geologic research including mineral exploration, hydrologic research, and defining geologic provinces.

Geothermal Resources Council Transactions↗
USGS1972

Bartin-Amasra earthquake, Turkey, September 3, 1968

A brief examination of the Bartin-were whether earthquake area was made on September 23 and September 24,1968, by the authors to determine whether or not geologic effects had been produced that were significant enough to warrant further detailed study by the Mineral Research and Exploration Institute of Turkey or by the National Center for Earthquake Research of the U.S. Geological Survey. In particular, the questions to be answered were whether this "natural experiment" had produced unique or unusual results that would cast light on means of controlling damage by geologic conditions, and whether or not surface faults or other tectonic deformation, h.ad developed which might help define the geologic control of earthquakes in northern Turkey. The brief field examination was made jointly by personnel of the U.S. Geological Survey and Mineral Research and Exploration Institute of Turkey, because of the interest of both agencies in the earthquake hazard problem. Both agencies had participated in the Conference on Earthquake Hazard Minimization sponsored by the Central Treaty Organization held in Ankara in July 1968. The brief examination was, in part, prompted by the recommendations of the Conference group to take advantage of each significant earthquake to learn "how to live with earthquakes in greater safety." No additional study of this earthquake by either organization seems warranted at this time, and our observations made during the brief investigation are reported here.

Amasra, Bartin↗
USGS2023

Cold-water corals of the world: Gulf of Mexico

The Gulf of Mexico is a semi-enclosed sea that borders the USA and Mexico and covers approximately 1.5 million square kilometers. The northern Gulf is topographically complex and is a rich source of oil and gas deposits, which has led to a great deal of research on benthic ecosystems from the coastal zone to the deep sea. While not fully explored, the distribution of cold seeps and deep corals in the northern Gulf is reasonably well described. The eastern Gulf has a moratorium on energy industry development and consequently less exploration and research has been conducted in this region; however, recent explorations have revealed deep scleractinian reefs on the west Florida slope and extensive octocoral gardens on the deep escarpment. The Gulf is a productive sea with lucrative fisheries in addition to oil and gas. Exploitation of natural resources and potential climate change impacts threaten vulnerable ecosystems in the Gulf, including those in the deep sea. This chapter describes the oceanography and geology of the Gulf of Mexico, presents the current state of the knowledge of cold-water coral distribution, physiology and ecology, and provides an assessment of the threats to these vulnerable ecosystems.

Book chapter↗
USGS2020

Planetary cave exploration progresses

Planetary caves have been identified on the Moon and on Mars, and are likely to occur across the Solar System. They present a new frontier for planetary science, subsurface astrobiology, geology and human exploration. The fourth in a series of scientific meetings focusing on the science and exploration of planetary caves brought together 55 terrestrial and planetary scientists, robotics and instrumentation engineers, and students (16 including 1 undergraduate). Conference participants discussed the state of the art of relevant sciences and current engineering capabilities as applied to planetary cave exploration and research. Specifically, they considered cave formation mechanisms, preserved geological records, cave micro-climate and astrobiological potential, engineering challenges of subsurface exploration, and potential robotic mission concepts to explore the subsurface of other worlds, especially the Moon and Mars.

Eos, Earth and Space Science News↗
USGS2025

Prospectivity mapping for geologic hydrogen

Geologic, or naturally occurring, hydrogen has the potential to become a new, low-carbon, primary energy resource. Often referred to as “white” or “gold” hydrogen, this gas occurs naturally in the Earth’s subsurface, similar to petroleum resources. However, unlike petroleum, which releases carbon dioxide when burned, burning hydrogen only produces water as a byproduct. Exploration for geologic hydrogen remains in an early stage and discoveries of high concentrations of subsurface hydrogen are still relatively rare. To facilitate research and exploration for this potential resource, this report presents the first publicly available prospectivity map of geologic hydrogen accumulations in the conterminous United States. Prospective regions are those regions in which all major components necessary for a hydrogen accumulation likely are present—a source of sufficient hydrogen generation, porous reservoirs for storage, and seals to prevent leakage. The midcontinent region of the United States and the central California coast are revealed as having high prospectivity. This analysis also identifies previously unrecognized prospective regions that may be favorable due to long distance lateral migration of subsurface hydrogen, such as the offshore eastern seaboard of the United States, and can provide a linkage between surface observations of hydrogen degassing and far-field source regions. The methodology developed to create this map is expandable and flexible and may be adapted to incorporate new concepts in the hydrogen system and for application to other regions of the world.

conterminous United States↗
USGS2015

Exploring drought controls on spring phenology

The timing of spring phenology can be influenced by several drivers. Many studies have shown the effect of temperature on spring vegetation growth, but the role of moisture is complex and not as well researched. We explored drivers for aspen spring phenology in the mountains of the western U.S. While temperature exerted control over the timing of aspen green-up in the spring, snow moisture as measured by April 1 snow water equivalent (SWE), played a significant role especially in southern locations bordering the Colorado Plateau. Maximum spring temperatures (March-May) were significantly (p<0.01) correlated with the start of the growing season across the entire Wasatch and Uinta Mountains and most of the western and northern Southern Rocky Mountains. Spring SWE was significantly (p<0.01) correlated with the growing season start across all of the Wasatch and Uinta Mountains and more than half of the Southern Rockies. The locations that experienced a larger snow influence, given by linear regression and R2 values, were located adjacent to the drier Colorado Plateau and south of 40oN latitude. Historical spatial patterns of regional snow accumulations and anomalies in the western U.S. have been chiefly explained by decadal antiphasing patterns across a north-south dipole. Anomalously low SWE co-occurs with a Pacific/North American teleconnection winter circulation associated with strong high pressure over the Pacific Northwest. The pattern shown in aspen phenology in this study, where the timing of spring green-up in the southern half of the intermountain West (south of a zone from 40oN - 42oN and mainly west of the continental divide in Colorado) showed higher sensitivity to winter snow moisture, and this spatial pattern was supported by other studies. Although winter moisture was not as consistent a factor as temperature in driving the start of the season, this study shows evidence that possible future winter drought could shift the growing season earlier than temperature increases alone.

Book chapter↗