Geophysics and Seismology Commons^™

Warm Water Benthic Foraminifera Document The Pennsylvanian-Permian Warming And Cooling Events – The Record From The Western Pangea Tropical Shelves, Vladimir Davydov

Geosciences Faculty Publications and Presentations

Shallow warm water benthic foraminifera (SWWBF), including all larger fusulinids (symbiont-bearing benthic foraminifera), are among the best indicators of paleoclimate and paleogeography in the Carboniferous and Permian. The distribution of benthic foraminifera in space and time constrain important tectonic, paleogeographic and climatic events at a global scale. The North American shelves during Pennsylvanian and Permian time - though geographically within the tropical belt - are characterized by temperate environments with significantly lower foraminifera diversification and rare occurrences of warm water Tethyan forms, that are in general appear in the region as a migration entities. Such environments allow documentation of warming …

Comparing Near-Regional And Local Measurements Of Infrasound From Mount Erebus, Antarctica: Implications For Monitoring, A. L. Dabrowa, D. N. Green, J. B. Johnson, J. C. Phillips, A. C. Rust

Geosciences Faculty Publications and Presentations

Local (100s of meters from vent) monitoring of volcanic infrasound is a common tool at volcanoes characterized by frequent low-magnitude eruptions, but it is generally not safe or practical to have sensors so close to the vent during more intense eruptions. To investigate the potential and limitations of monitoring at near-regional ranges (10s of km) we studied infrasound detection and propagation at Mount Erebus, Antarctica. This site has both a good local monitoring network and an additional International Monitoring System infrasound array, IS55, located 25 km away. We compared data recorded at IS55 with a set of 117 known Strombolian …

Application Of The Monopole Source To Quantify Explosive Flux During Vulcanian Explosions At Sakurajima Volcano (Japan), Jeffrey B. Johnson, Alex J. C. Miller

Geosciences Faculty Publications and Presentations

A primary goal in volcano seismology is to characterize source motions internal to a volcano in terms of their representative forces. In a similar manner, much volcano infrasound research strives to recover eruptive force time histories corresponding to material accelerations occurring at Earth’s free surface. These motions may correspond to explosive emission of gas and pyroclasts (e.g., Banister, 1984), rapid ground distensions of a volcanic dome (e.g., Johnson and Lees, 2010), and/or gravity driven rock fall or pyroclastic flows (e.g., Yamasato, 1997). When free surface motion is unsteady it imposes stresses upon the surrounding atmosphere, which are propagated as acoustic …

Introduction To An Open Community Infrasound Dataset From The Actively Erupting Sakurajima Volcano, Japan, David Fee, Akihiko Yokoo, Jeffrey B. Johnson

Geosciences Faculty Publications and Presentations

Active volcanoes are significant sources of seismic and acoustic radiation. Extensive work has shown that infrasound is an effective tool to study and monitor active volcanoes. Infrasound is now a regular tool utilized by volcano observatories to aid in volcano monitoring and hazard mitigation. Infrasound‐based studies are able to provide important information on eruption dynamics and to develop quantitative models of volcanic eruptions. In addition, volcanoes provide excellent acoustic sources for atmospheric propagation studies and can be used to infer atmospheric dynamics and structure (see Johnson and Ripepe, 2011; Fee and Matoza, 2013 for recent reviews on volcano infrasound). The …

Eocene-Oligocene Latitudinal Climate Gradients In North America Inferred From Stable Isotope Ratios In Perissodactyl Tooth Enamel, Alessandro Zanazzi, Emily Judd, Andrew Fletcher, Harold Bryant, Matthew J. Kohn

Geosciences Faculty Publications and Presentations

The Eocene-Oligocene transition (~ 34 Ma) was one of the most pronounced episodes of climate change of the Cenozoic. In order to investigate this episode of global climate cooling in North America, we analyzed the carbon and oxygen stable isotope composition of the carbonate component of 19 perissodactyl (horse and rhino) tooth enamel samples from the Eocene-Oligocene rocks of the Cypress Hills Formation (southwestern Saskatchewan, Canada); we then compared the results with previously published data from the US Great Plains (Nebraska, South Dakota, and Wyoming).

Average (± 1σ) perissodactyl enamel δ¹³C values (vs. V-PDB) in the Eocene (-8.8 …

Explosive Dome Eruptions Modulated By Periodic Gas-Driven Inflation, Jeffrey B. Johnson, J. J. Lyons, B. J. Andrews, J. M. Lees

Geosciences Faculty Publications and Presentations

Volcan Santiaguito (Guatemala) “breathes” with extraordinary regularity as the edifice's conduit system accumulates free gas, which periodically vents to the atmosphere. Periodic pressurization controls explosion timing, which nearly always occurs at peak inflation, as detected with tiltmeters. Tilt cycles in January 2012 reveal regular 26 ± 6 min inflation/deflation cycles corresponding to at least ~10¹ kg/s of gas fluxing the system. Very long period (VLP) earthquakes presage explosions and occur during cycles when inflation rates are most rapid. VLPs locate ~300 m below the vent and indicate mobilization of volatiles, which ascend at ~50 m/s. Rapid gas ascent feeds …

Luminescence Dating Without Sand Lenses: An Application Of Osl To Coarse-Grained Alluvial Fan Deposits Of The Lost River Range, Idaho, Usa, M. K. Kenworthy, T. M. Rittenour, J. L. Pierce, N. A. Sutfin, W. D. Sharp

Geosciences Faculty Publications and Presentations

Optically stimulated luminescence (OSL) dating is increasingly used to estimate the age of fluvial deposits. A significant limitation, however, has been that conventional techniques of sampling and dose rate estimation are suitable only for thick (>60 cm) layers consisting of sand size or finer grains. Application of OSL dating to deposits lacking such layers remains a significant challenge. Alluvial fans along the western front of the Lost River Range in east-central Idaho, USA are one example. Deposits are typically pebble to cobble sheetflood gravels with a sandy matrix but thin to absent sand lenses. As a result, the majority …

The Spatial Cross-Correlation Method For Dispersive Surface Waves, Andrew P. Lamb, Kasper Van Wijk, Lee M. Liberty, T. Dylan Mikesell

Geosciences Faculty Publications and Presentations

Dispersive surface waves are routinely used to estimate the subsurface shear-wave velocity distribution, at all length scales. In the well-known Spatial Autocorrelation method, dispersion information is gained from the correlation of seismic noise signals recorded on the vertical (or radial) components. We demonstrate practical advantages of including the cross-correlation between radial and vertical components of the wavefield in a spatial cross-correlation method. The addition of cross-correlation information increases the resolution and robustness of the phase velocity dispersion information, as demonstrated in numerical simulations and a near-surface field study with active seismic sources, where our method confirms the presence of a …

Calculating The Velocity Of A Fast-Moving Snow Avalanche Using An Infrasound Array, Scott Havens, Hans-Peter Marshall, Jeffrey B. Johnson, Bill Nicholson

Geosciences Faculty Publications and Presentations

On 19 January 2012, a large D3 avalanche (approximately 10³ t) was recorded with an infrasound array ideally situated for observing the avalanche velocity. The avalanche crossed Highway 21 in Central Idaho during the largest avalanche cycle in the 15 years of recorded history and deposited approximately 8 m of snow on the roadway. Possible source locations along the avalanche path were estimated at 0.5 s intervals and were used to calculate the avalanche velocity during the 64 s event. Approximately 10 s prior to the main avalanche signal, a small infrasound signal originated from the direction of the …

Postglacial Early Permian (Late Sakmarian– Early Artinskian) Shallow-Marine Carbonate Deposition Along A 2000 Km Transect From Timor To West Australia, Vladimir I. Davydov

Geosciences Faculty Publications and Presentations

Late Sakmarian to early Artinskian (Early Permian) carbonate deposition was widespread in the marine intracratonic rift basins that extended into the interior of Eastern Gondwana from Timor in the north to the northern Perth Basin in the south. These basins spanned about 20° of paleolatitude (approximately 35°S to 55°S). This study describes the type section of the Maubisse Limestone in Timor-Leste, and compares this unit with carbonate sections in the Canning Basin (Nura Nura Member of the Poole Sandstone), the Southern Carnarvon Basin (Callytharra Formation) and the northern Perth Basin (Fossil Cliff Member of the Holmwood Shale). The carbonate units …

Discovery Of Shallow-Marine Biofacies Conodonts In A Bioherm Within The Carboniferous-Permian Transition In The Omalon Massif, Ne Russia Near The North Paleo-Pole: Correlation With A Warming Spike In The Southern Hemisphere, Vladimir I. Davydov, Alexander S. Biakov

Geosciences Faculty Publications and Presentations

The conodont genera Hindeodus and Streptognathodus are reported for the first time within the Carboniferous-Permian transition in the northern high latitudes of the Paren’ River, Omolon Massif, NE Russia. Several fossil groups, including brachiopods, bivalves, scaphopods and microgastropods were found to be prolific in the invertebrate-dominated bioherms. These bioherms occur within predominantly siliciclastic sequences with extremely poor fauna, whereas in the studied bioherms the diversity of the bivalves and brachiopods exceeded observed diversity elsewhere in coeval facies in NE Russia. The bioherms are biostratigraphically constrained as uppermost Pennsylvanian to lowermost Cisuralian based on ammonoids. The very unusual peak of bivalve …

Independent Evaluation Of The Snodas Snow Depth Product Using Regional Scale Lidar-Derived Measurements, A. R. Hedrick, H. P. Marshall, A. Winstral, K. Elder, S. Yueh, D. Cline

Geosciences Faculty Publications and Presentations

Repeated Light Detection and Ranging (LiDAR) surveys are quickly becoming the de facto method for measuring spatial variability of montane snowpacks at high resolution. This study examines the potential of a 750 km² LiDAR-derived dataset of snow depths, collected during the 2007 northern Colorado Cold Lands Processes Experiment (CLPX-2), as a validation source for an operational hydrologic snow model. The SNOw Data Assimilation System (SNODAS) model framework, operated by the US National Weather Service, combines a physically-based energy-and-mass-balance snow model with satellite, airborne and automated ground-based observations to provide daily estimates of snowpack properties at nominally 1 km resolution …

U-Pb Zircon Geochronology Of Roxbury Conglomerate, Boston Basin, Massachusetts: Tectono-Stratigraphic Implications For Avalonia In And Beyond Se New England, Margaret D. Thompson, Jahandar Ramezani, James L. Crowley

Geosciences Faculty Publications and Presentations

High-precision CA-TIMS ²⁰⁶Pb/²³⁸U zircon dates from sandstone and Brighton igneous rocks associated with Roxbury Conglomerate in the Boston Basin, eastern Massachusetts provide constraints on the age and tectonic significance of these deposits. Detrital zircon suites from Roxbury-related sandstones representing, in ascending order, the Franklin Park Member (proposed name), the Brookline Member and the Squantum Member establish closely comparable maximum depositional ages of 595.14 ± 0.90, 598.87 ± 0.71 and 596.39 ± 0.79 Ma, respectively. The youngest of these is the best maximum age estimate of the conglomerate. Brighton dacite near the base of the Brookline Member and …

Soil, Snow, Weather, And Sub-Surface Storage Data From A Mountain Catchment In The Rain–Snow Transition Zone, P. R. Kormos, D. Marks, C. J. Williams, H. P. Marshall, Pam Aishlin, D. G. Chandler, James P. Mcnamara

Geosciences Faculty Publications and Presentations

A comprehensive hydroclimatic data set is presented for the 2011 water year to improve understanding of hydrologic processes in the rain-snow transition zone. This type of dataset is extremely rare in scientific literature because of the quality and quantity of soil depth, soil texture, soil moisture, and soil temperature data. Standard meteorological and snow cover data for the entire 2011 water year are included, which include several rain-on-snow events. Surface soil textures and soil depths from 57 points are presented as well as soil texture profiles from 14 points. Meteorological data include continuous hourly shielded, unshielded, and wind corrected precipitation, …

A Combined Field And Numerical Approach To Understanding Dilute Pyroclastic Density Current Dynamics And Hazard Potential: Auckland Volcanic Field, New Zealand, Brittany D. Brand, Darren Gravley, Amanda Clarke, Jan Lindsay, Simon H. Boomberg, Javier Agustin-Flores, Károly Németh

Geosciences Faculty Publications and Presentations

The most dangerous and deadly hazards associated with phreatomagmatic eruption in the Auckland Volcanic Field (AVF; Auckland, New Zealand) are those related to volcanic base surges - dilute, ground-hugging, particle laden currents with dynamic pressures capable of severe to complete structural damage. We use the well-exposed base surge deposits of the Maungataketake tuff ring, (Manukau coast, Auckland) to reconstruct flow dynamics and destructive potential of base surges produced during the eruption. The initial base surge(s) snapped trees up to 0.5 m in diameter near their base as far as 0.7-0.9 km from the vent. Beyond this distance the trees were …

Dynamics Of Pyroclastic Density Currents: Conditions That Promote Substrate Erosion And Self-Channelization - Mount St Helens, Washington (Usa), Brittany D. Brand, Chelsea Mackaman-Lofland, Nicholas M. Pollock, Sylvana Bendaña, Blaine Dawson, Pamela Wichgers

Geosciences Faculty Publications and Presentations

The May 18th, 1980 eruption of Mount St. Helens (MSH) produced multiple pyroclastic density currents (PDCs), burying the area north of the volcano under 10s of meters of deposits. Detailed measurements of recently exposed strata from these PDCs provide substantial insight into the dynamics of concentrated currents including inferences on particle-particle interactions, current mobility due to sedimentation fluidization and internal pore pressure, particle support mechanisms, the influence of surface roughness and the conditions that promote substrate erosion and self-channelization. Four primary flow units are identified along the extensive drainage system north of the volcano. Each flow unit has intricate vertical …

Sequential Fragmentation / Transport Theory, Pyroclast Size-Density Relationships, And The Emplacement Dynamics Of Pyroclastic Density Currents – A Case Study On The Mt. St. Helens (Usa) 1980 Eruption, Chelsea Mackaman-Lofland, Brittany D. Brand, Jacopo Taddeucci, Kenneth Wohletz

Geosciences Faculty Publications and Presentations

Pyroclastic density currents (PDCs) are the most dangerous hazard associated with explosive volcanic eruptions. Despite recent advancements in the general understanding of PDC dynamics, limited direct observation and/or outcrop scarcity often hinder the interpretation of specific transport and depositional processes at many volcanoes. This study explores the potential of sequential fragmentation / transport theory (SFT; cf. Wohletz et al. 1989), a modeling method capable of predicting particle mass distributions based on the physical principles of fragmentation and transport, to retrieve the transport and depositional dynamics of well-characterized PDCs from the size and density distributions of individual components within the deposits. …

Lunar Cold Spots: Granular Flow Features And Extensive Insulating Materials Surrounding Young Craters, Joshua L. Bandfield, Eugenie Song, Paul O. Hayne, Brittany D. Brand, Rebecca R. Ghent, Ashwin R. Vasavada, David A. Paige

Geosciences Faculty Publications and Presentations

Systematic temperature mapping and high resolution images reveal a previously unrecognized class of small, fresh lunar craters. These craters are distinguished by near-crater deposits with evidence for lateral, ground-hugging transport. More distal, highly insulating surfaces surround these craters and do not show evidence of either significant deposition of new material or erosion of the substrate. The near-crater deposits can be explained by a laterally propagating granular flow created by impact in the lunar vacuum environment. Further from the source crater, at distances of ~10-100 crater radii, the upper few to 10s of centimeters of regolith appear to have been “fluffed-up” …

Analyst A: Alternatives In Analysis Of The Utexas1 Surface Wave Dataset, Paul Michaels

Geosciences Faculty Publications and Presentations

In February of 2011 an earthquake event caused significant damage and loss of life in Christchurch, New Zealand. Such an event serves as motivation for improved foundation design and characterization of the shallow subsurface. In January of 2013, University of Texas engineers acquired surface wave data which has been made available to the ASCE GeoInstitute Geophysical Engineering Committee for a benchmark project. Participants were invited to process and interpret the common data set. This paper reports the results designated as those of "Analyst A". The active vibroseis and sledgehammer data were combined to produce a composite Rayleigh wave dispersion curve. …

Climate- And Eustasy-Driven Cyclicity In Pennsylvanian Fusulinid Assemblages, Donets Basin (Ukraine), Rimma R. Khodjanyazova, Vladimir I. Davydov, Isabel P. Montañez, Mark D. Schmitz

Geosciences Faculty Publications and Presentations

A model of cyclic recurrence (~ 0.6–1.2 myr) of three fusulinid assemblages in the Middle Pennsylvanian siliciclastic–carbonate succession of the Donets Basin is proposed. Each cycle records progressive turnover of assemblages in shallow marine environments in response to sea-level and regional climate change. A Hemifusulina-assemblage (A), adapted to cooler and reduced salinity seawater records the onset of sea level rise accompanied by humid climatic conditions. Sea level high stand is captured by the Beedeina–Neostaffella–Ozawainella–Taitzehoella (or Beedeina-dominated) assemblage (B), characteristic of relatively deeper-water environments. The B assemblage is successively replaced by the most …

Application Of A Hillslope-Scale Soil Moisture Data Assimilation System To Military Trafficability Assessment, Alejandro N. Flores, Dara Entekhabi, Rafael L. Bras

Geosciences Faculty Publications and Presentations

Soil moisture is an important environmental variable that impacts military operations and weapons systems. Accurate and timely forecasts of soil moisture at appropriate spatial scales, therefore, are important for mission planning. We present an application of a soil moisture data assimilation system to military trafficability assessment. The data assimilation system combines hillslope-scale (e.g., 10s to 100s of m) estimates of soil moisture from a hydrologic model with synthetic L-band microwave radar observations broadly consistent with the planned NASA Soil Moisture Active–Passive (SMAP) mission. Soil moisture outputs from the data assimilation system are input to a simple index-based model for vehicle …

Assessing Ability To Forecast Geomorphic System Responses To Climate And Land-Use Changes, Jon D. Pelletier, A. Brad Murray, Jennifer L. Pierce

Geosciences Faculty Publications and Presentations

As the global community faces the effects of ongoing and future climate and land-use changes (C&LUC), geoscientists are called to action to assess the risks associated with such changes, assist with forecasts of future Earth states, quantify hazards to life, and suggest reasonable adaptation strategies. Earth surface scientists have developed conceptual and mathematical models for how geomorphic systems, including those associated with natural hazards that put trillions of dollars in infrastructure and tens of millions of lives at risk, will respond to and give feedback on C&LUC.

U-Pb Zircon Age Of The Krásné Loučky Tuffite: The Dating Of Visean Flysch In The Moravo-Silesian Paleozoic Basin (Rhenohercynian Zone, Czech Republic), Jakub Jirásek, Jiří Wlosok, Martin Sivek, Dalibor Matýsek, Mark Schmitz, Ivana Sýkorová, Zdeněk Vašíček

Geosciences Faculty Publications and Presentations

The only previous U-Pb zircon date for the the Early Carboniferous flysch sequence of the Moravian-Silesian Paleozoic Basin was published in 1987 from tuffogenic material from Kobylí Quarry at Krásné Loučky near the town of Krnov (Silesia, Czech Republic). The measured age of 319 Ma did not agree with its stratigraphic position, and was used as the basis for a hypothesized block of Late Carboniferous paralic molasse incorporated during a later tectonic event. During a survey of the still-active quarry in 2010, volcaniclastic horizons were identified and sampled. Direct correspondence of the tuff units to those sampled in 1987 cannot …

Geothermal Systems Of Northern Thailand And Their Association With Faults Active During The Quaternary, Spencer H. Wood, Fongsaward Suvagondha Singharajwarapan

Geosciences Faculty Publications and Presentations

Many of northern Thailand hot springs systems are associated with regions of active faulting. An arcuate pattern of wells with high-fluoride water occurs in the Chiang Mai basin. The pattern is parallel to the Mae Tha fault which cuts Paleozoic and Mesozoic rocks 10 km east of the basin. The San Kamphaeng geothermal system is within parallel faults in Paleozoic rocks. The Mae Tha fault is believed to be active in the Quaternary. A conceptual diagram shows deep groundwater circulation driven by ~300 to 800 meters of relief in the hills east of the basin. The Mae Chan geothermal system …

Continuous Snowpack Monitoring Using Upward-Looking Ground-Penetrating Radar Technology, Lino Schmid, Achim Heilig, Christoph Mitterer, Jürg Schweizer, Hansruedi Maurer, Robert Okorn, Olaf Eisen

Geosciences Faculty Publications and Presentations

Snow stratigraphy and water percolation are key contributing factors to avalanche formation. So far, only destructive methods can provide this kind of information. Radar technology allows continuous, non-destructive scanning of the snowpack so that the temporal evolution of internal properties can be followed. We installed an upward-looking ground-penetrating radar system (upGPR) at the Weissfluhjoch study site (Davos, Switzerland). During two winter seasons (2010/11 and 2011/12) we recorded data with the aim of quantitatively determining snowpack properties and their temporal evolution. We automatically derived the snow height with an accuracy of about ±5 cm, tracked the settlement of internal layers (±7 …

Teaching Geophysics With A Vertical-Component Seismometer, Kasper Van Wijk, Ted Channel, Karen Viskupic, Martin L. Smith

Geosciences Faculty Publications and Presentations

Earthquakes are some of the more dramatic expressions of the dynamics of our planet. The sudden release of stress built up slowly by tectonic or volcanic processes often has far-reaching consequences, and can be measured (in classrooms) around the world. This is one reason why designing and building seismometers has been a popular activity,^1,2 and why different versions of “Seismometer in Schools” projects thrive in the United States, Australia, and Europe. We present a cheap, robust, and easy-to-build seismometer—called the TC1 —to measure seismic displacements in the vertical direction. Its components are easy to obtain and assemble, yet the …

Single And Multi-Date Landsat Classifications Of Basalt To Support Soil Survey Efforts, Jessica J. Mitchell, Rupesh Shrestha, Carol A. Moore-Ellison, Nancy F. Glenn

Geosciences Faculty Publications and Presentations

Basalt outcrops are significant features in the Western United States and consistently present challenges to Natural Resources Conservation Service (NRCS) soil mapping efforts. Current soil survey methods to estimate basalt outcrops involve field transects and are impractical for mapping regionally extensive areas. The purpose of this research was to investigate remote sensing methods to effectively determine the presence of basalt rock outcrops. Five Landsat 5 TM scenes (path 39, row 29) over the year 2007 growing season were processed and analyzed to detect and quantify basalt outcrops across the Clark Area Soil Survey, ID, USA (4,570 km²). The …

Holocene Fire Occurrence And Alluvial Responses At The Leading Edge Of Pinyon–Juniper Migration In The Northern Great Basin, Usa, Kerrie N. Weppner, Jennifer L. Pierce, Julio L. Betancourt

Geosciences Faculty Publications and Presentations

Fire and vegetation records at the City of Rocks National Reserve (CIRO), south-central Idaho, display the interaction of changing climate, fire and vegetation along the migrating front of single-leaf pinyon (Pinus monophylla) and Utah juniper (Juniperus osteosperma). Radiocarbon dating of alluvial charcoal reconstructed local fire occurrence and geomorphic response, and fossil woodrat (Neotoma) middens revealed pinyon and juniper arrivals. Fire peaks occurred ~10,700–9500, 7200–6700, 2400–2000, 850–700, and 550–400 cal yr BP, whereas ~9500–7200, 6700–4700 and ~1500–1000 cal yr BP are fire-free. Wetter climates and denser vegetation fueled episodic fires and debris flows during the …

High-Resolution Δ13CCarb Chemostratigraphy From Latest Guadalupian Through Earliest Triassic In South China And Iran, Vladimir Davydov

Geosciences Faculty Publications and Presentations

Large carbon cycle perturbations are associated with the end-Permian mass extinction and subsequent recovery, but Late Permian (Lopingian) carbon cycle dynamics prior to the mass extinction event remain poorly documented. Here we present a high-resolution δ¹³C_carb chemostratigraphic framework from latest Guadalupian to earliest Triassic time, calibrated with high-resolution conodont biostratigraphy and high-precision geochronology. We observe two large negative excursions in δ¹³C_carb, the first in uppermost Guadalupian strata and the second at the end of the Changhsingian stage, and between these events distinctive excursions from the middle Wuchiapingian to the early Changhsingian. The end-Changhsingian …

Anticipating Stream Ecosystem Responses To Climate Change: Toward Predictions That Incorporate Effects Via Land–Water Linkages, J. M. Davis, C. V. Baxter, E. J. Rosi-Marshall, J. L. Pierce, B. T. Crosby

Geosciences Faculty Publications and Presentations

Climate change (CC) is projected to increase the frequency and severity of natural disturbances (wildfires, insect outbreaks, and debris flows) and shift distributions of terrestrial ecosystems on a global basis. Although such terrestrial changes may affect stream ecosystems, they have not been incorporated into predictions of stream responses to CC. Here, we introduce a conceptual framework to evaluate to what extent responses of streams to CC will be driven by not only changes in thermal and hydrologic regimes, but also alterations of terrestrial processes. We focused on forested water-sheds of western North America because this region is projected to experience …