PROGRAMME

Eastern Snow Conference

AN INTERNATIONAL ORGANIZATION

IN

EASTERN CANADA AND THE NORTHEASTERN UNITED STATES

CONCERNED WITH THE

ORIGIN, PRECIPITATION, ACCUMULATION, CHARACTER, MELT, AND RUNOFF OF SNOW

&

CANADIAN GEOPHYSICAL UNION
HYDROLOGY SECTION

Welcome you to the Joint Meeting of the 58^th Annual ESC and CGU:

‘Snow and Ice:
Principles, Processes, Management and Use’.

Cosponsored by the Canadian Snow Committee, the International Glaciological Society and the International Commission on Snow and Ice Working Group on Snow Vegetation Interactions.

Corporate Sponsors:
Geonor and New Brunswick Environment

Executive for the 58th Eastern Snow Conference (Ottawa, ONT):

Past President: Dorothy Hall (NASA Goddard Space Flight Center)

President: Mary Albert (CRREL)

Vice-President (Program Chair): John Pomeroy (Univ. of Wales, Aberystwyth)

Secretary-Treasurer (Canada): Miles Ecclestone (Trent University)

Secretary-Treasurer (U.S.A.): Austin Hogan

Editor: Janet Hardy (CRREL)

Co-Editor: John Pomeroy (Univ. of Wales, Aberystwyth)

Steering Committee:

Austin Hogan (Chair)

Ken Rancourt

John Pomeroy

Research Committee:

Andrew Klein (Chair) (Texas A & M University)

Dave Milburn (Indian and Northern Affairs Canada)

Jim Cragin

Webmaster: Ross Brown (Meteorological Service of Canada)

Local Arrangements Committee – Eastern Snow Conference

Ross Brown, Montreal

Mike Demuth, Ottawa

Miles Ecclestone, Peterborough

Susanne Hanson, Aberystwyth

John Pomeroy, Aberystwyth

Executive for Canadian Geophysical Union Hydrology Section:

Past President: Phil Marsh (NWRI, Saskatoon)

President: Hok Woo (McMaster University, Hamilton)

Vice-President: Dan Moore (University of British Columbia, Vancouver)

Secretary-Treasurer: Al Pietroniro (NWRI, Saskatoon)

Member at Large: Denis Gratton (Université du Québec a Trois Rivières)

Member at Large: John Pomeroy (Univ. of Wales, Aberystwyth)

Special Thanks to: the CGU Executive and Organising Committee

TUESDAY MORNING , 15 MAY

ESC/HS/CRIPE Room: Montpetit Bldg 202

TIME		AUTHORS		TITLE
		Chair: R Bourdages	ESC/HS/CRIPE - Cold Season Hydrology: from Freezeup to Breakup
	8:30	Ferrick, M.G.	Simple wave and monoclinal wave models of unsteady river flow surges
	8:50	Kuchment, L.S. and Gelfan, A.N.	Dynamic-stochastic model of snowmelt runoff generation and application for estimating extreme floods
	9:10	Hamilton, S., Hutchinson, D.G. and Moore, R.D.	Application of a conceptual hydrological model for estimating discharge under ice
	9:30	Andres, D.	Calibration of ice growth models for bare and snow covered conditions: A summary of experimental data from a small prairie pond
	9:50	Duguay, C.R., Flato, G.M., Jefferies, M. O., Menard, P. and Morris, K.	Simulation of ice phenology on shallow lakes using a 1-D thermodynamic model
10:10		COFFEE BREAK AND POSTER VIEWING **
		Chair: M Ferrick	ESC/HS/CRIPE - Cold Season Hydrology: from Freezeup to Breakup
	10:30	Bonsal, B.R. and Prowse, T.D.	Trends and variability in the 0 deg C isotherm and relationships to lake and river ice cover characteristics over northern Canada
	10:50	Yang, D., Kane, D.L. and Hinzman, L.D.	Major Siberian river streamflow regime and recent change
	11:10	Zufelt, J.E.	Modelling snowmelt runoff and the effects of climate change in Central New York State
	11:30	Weber, F. and Nixon, D.	Identification of river ice types on the peace river using RADARSAT-1 SAR imagery
	11:50	Liu, L., Tuthill, A. and Shen, H.T.	Dynamics simulation of ice condition in the vicinity of Lock and Dams
12:10		LUNCH

* Student Paper Poster Room:

** A list of poster titles appears at the end of this section of the program booklet

TUESDAY AFTERNOON, 15 MAY

ESC/HS Room: Monpetit 202

TIME		AUTHORS		TITLE
		Chair: P Marsh	Snow & Ice Hydrology
	13:30	Collins, D. A.	Climatic variation and runoff from partially-glacierised Alpine basin
	13:50	Lafreniere, M.J. and Sharp, M.J.*	Seasonal change in snowpack, soil water and stream water DOC concentrations in glacial and snowmelt fed catchments in the Alberta Rocky Mountains
	14:10	Hopkinson, C., Lowe, A. and English, M.	Using tracers to evaluate and optimise flow components generated by the UBC watershed in a glacierised mountain basin
	14:30	Mitchell, A, Brown, G.H. and Fuge, R.*	Minor and trace element export from a glacierised alpine headwater catchment - implications for downstream water quality
	14:50	Taylor, S., Feng, X. and Williams, M.	Estimating snowmelt's isotopic composition for hydrograph separation from field, laboratory and modelling work
15:10		COFFEE BREAK AND POSTER VIEWING **
		Chair: M Albert	Snow & Ice Hydrometeorology
	15:30	Brown, R., Brasnett, B. and Robinson, D.	Development of a gridded north American daily snow depth and snow water equivalent dataset for GCM validation
	15:50	Brubaker, K.L.	A technique to estimate snow depletion curves from time-series data using the beta distribution
	16:10	Daly, S.F., Davis, R.E., Ochs, E., Hardy, J., Bryant, E. and Pangburn, T.	A preliminary study on the feasibility for monitoring prairie snow cover for operational runoff assessment
	16:30	Dye, D. G.	Variation in the Northern Hemisphere annual snow-free period and its significance for ecosystem processes
	16:50	Pomeroy, J.W. , Hanson, S. and D. Faria	Small-scale Variation in Snowmelt Energy: An Additional Factor Controlling Snowcover Depletion

* Student Paper Poster Room:

** A list of poster titles appears at the end of this section of the program booklet

CGU/ESC BARBEQUE, UNIVERSITY OF OTTAWA 18:30

WEDNESDAY MORNING , 16 MAY

ESC/HS Room: Monpetit 203

TIME		AUTHORS		TITLE
		Chair: C. Burn	Frozen Ground
	8:30	Riseborough, D.W.*	An analytical model of the ground surface temperature under snowcover with soil freezing
	8:50	Janowicz, J.R., Gray, D.M. & Pomeroy, J.W.*	Characterisation of snowmelt infiltration scaling parameters within a mountainous sub-arctic watershed
	9:10	Lacelle, D., Bjornson, J., Clark, I.D. and Lauriol, B.*	Isotopic variations in retrogressive thaw slumps, Richardson Mountains, N.W.T., Canada
	9:30	Lewkowicz, A.G. and Kokelj, S.V.	Slope erosion by overland flow, Canadian Arctic Archipelago
	9:50	Marsh, P. and Neumann, N.N.	Rapid drainage of a permafrost-dammed lake in north-western Canada
10:10		COFFEE BREAK AND POSTER VIEWING **
		Chair: A. Lewkowicz	Frozen Ground/Snow & Ice Hydrology
	10:30	Burn, C.R.	Tundra lakes and permafrost, Richards Island, western Arctic coast, Canada
	10:50	Turcotte, D.S., English, M.C., Holmes, A. and B. Reid	Active layer development and radiation balance in a low arctic tundra basin, Coppermine River, NWT
	11:10	Jones, H.G. and Pomeroy, J.W.	Snowmelt in a small boreal forest basin in eastern Canada: influence of concrete frost on the hydrology and chemical composition of the surface waters
	11:30	Daanen, R.P. and Nieber, J.L.	Coupled moisture, heat and solute transport in a snowpack
	11:50	Fassnacht, S.R., Dressler, K. A. and Bales, R.C.*	Physiographic parameters as indicators of snowpack state for the Colorado River basin
12:10		LUNCH

* Student Paper Poster Room:

** A list of poster titles appears at the end of this section of the program booklet

WEDNESDAY MORNING , 16 MAY

ESC Author’s Breakfast

0630-0800h ‘Le Rendez-vous’, 1^st Floor University Centre, Univ of Ottawa

Eastern Snow Conference Room: Monpetit 202

TIME		AUTHORS		TITLE
		Chair: D Hall	Cryosphere
	8:30	Barber, D. G, Yackel, J. and Iacozza, J.	On the estimate of SWE over first-year sea ice using Radarsat-1
	8:50	Papapkyriakou, T., Barber, D., Hanesiak, J. and Yackel, J.	Application of an analytical model of periodic heat flow through layred snow to examine relationships between the surface heat budget and microwave scattering from RADARSAT-1 over snow-covered sea ice.
	9:10	Riggs, G. Hall, D. K. and Key, J.R.	Initial evaluation of MODIS sea ice observations
	9:30	Harouche, I. and Barber, D.G.	Seasonal characterization of microwave emissions over snow-covered first-year sea ice
	9:50	Klein, A.G.	Validation of a MODIS snow albedo algorithm
10:10		COFFEE BREAK AND POSTER VIEWING **
		Chair: D Barber	Cryosphere
	10:30	Ramsay, B.H. and Robinson, D.A.	Comparison of the NESDIS weekly and daily Northern hemisphere snowcover products
	10:50	Hall, D.K., Salomonson, V.V. and Riggs, G. A.	Snow cover variability in North America in the 2000-2001 winter as determined from MODIS snow products
	11:10	Romanov, P., Tarpley, D. and Csiszar, I.	Mapping and monitoring snow cover over North America using automated satellite data based systems
	11:30	Fortin, R. and Fortier, R.*	Tomographic imaging of a snow pack
	11:50	Haehnel, R., Liston, G., Sturm, M. and Lever, J.	GIS based three dimensional snow drift computer model
12:10		LUNCH

* Student Paper Poster Room:

** A list of poster titles appears at the end of this section of the program booklet

WEDNESDAY AFTERNOON, 16 MAY

Eastern Snow Conference Room: Monpetit 202

TIME		AUTHORS		TITLE
		Chair: J. Dowdeswell	Arctic Glaciers Workshop
	13:30	Dowdeswell, J	Arctic ice masses: past and present form and flow ESC Invited Paper
	14:10	Bingham, R. G., Nienow, P. W., Sharp, M. J., Boon, S. and Heppenstall, K. E.	Dye-tracer studies of the hydrology of a High-Arctic polythermal valley glacier: implications for glacier motion
	14:30	Boon, S. and Sharp, M.*	Impact of high latitude chinook events on Arctic glacier hydrology
	14:50	Cogley, J. G. and Ecclestone, M.A.	Spatial variation of melting on glaciers measured by orbiting radar
15:10		COFFEE BREAK AND POSTER VIEWING **
		Chair: J. Dowdeswell	Arctic Glaciers Workshop
	15:30	Copland, L., Burgess, D. and Sharp, M.*	The GLIMS (Global Land Ice Measurements from Space) project at the University of Alberta: initial results for the Canadian Arctic Islands
	15:50	Mumford, P.N., Hodson, A.J. and Tranter, M.*	Nutrient transport by glacial meltwaters on Svalbard
	16:10	Wohlleben, T.M.H., Sharp, M.J. and Bush, A.B.G.	3D internal temperature distribution of a High Arctic polythermal glacier: implications for glacier flow and evolution
	16:30	Dowdeswell, J., Adams, P., Cogley, J.G. and others	Discussion on Arctic Glaciers & Research
	16:50

* Student Paper Poster Room:

** A list of poster titles appears at the end of this section of the program booklet

ESC General Meeting, 5:10 p.m., Place: Monpetit 202

ESC-HS Social Evening – Dunvegan Pub, 7:00 p.m.,

THURSDAY MORNING, 17 MAY

Eastern Snow Conference/HS Room: Monpetit 203

TIME		AUTHORS		TITLE
		Chair: K Brubaker	Snow & Ice Hydrometeorology
	8:30	Hellström R. A.	Meteorological Forcing of the abrupt springtime temperature rise at the Greenland crest
	8:50	Helfrich, S.R. and Robinson, D.A.	Snowfall regionality over eastern North America
	9:10	Li, L., Cline, D., Fall, G., Rost, A. and Nilsson	Performance and suitability of a single-layer and a multiple-layer snow model for operational, moderate-resolution, CONUS snow data assimilation
	9:30	Marchand, W-D. and Killingtveit*	Analyses of the relation between spatial snow distribution and terrain characteristics
	9:50	Menoes, M.C. and Brubaker, K.L.*	How similar are snow depletion curves from year to year? Case study in the Upper Rio Grande watershed
10:10		COFFEE BREAK AND POSTER VIEWING **
		Chair: R Brown	Snow & Ice Hydrometeorology
	10:30	Martin, C., Jacobs, J.D. and Banfield, C.E.*	Historical variability of snowcover on the Big Level Plateau, Gros Morne National Park (Newfoundland)
	10:50	Pelto, M.S. and Riedel, J.	Temporal and spatial variation in regional annual mass balance observed on glaciers in the North Cascades of Washington 1984-2000
	11:10	Munro, D.S. and Lowe, A.T.	Late summer patterns of surface short-waver reflectivity on Peyto Glacier in 1990, 1994 and 1998
	11:30	Pohl, S. and Marsh, P.*	Small scale variability of snowmelt energy balance components in an arctic catchment
	11:50	Goodison, B, Yang, D. and Louie, P.	Bias correction of gauge-measured precipitation data: A review of WMO intercomparison results and applications
12:10		LUNCH

* Student Paper Poster Room:

** A list of poster titles appears at the end of this section of the program booklet

THURSDAY AFTERNOON, 17 MAY

Eastern Snow Conference/HS Room: Monpetit 203

TIME		AUTHORS		TITLE
		Chair: J Hardy	Snow & Ice Processes
	13:30	Albert, M.R. and Perron, Jr.,F. E.	Evolution of ice layer and surface crust permeability in a seasonal snow pack
	13:50	Cathles IV, L.M. and Albert, M.R.*	Diffusion of an inert gas in seasonal snow
	14:10	Tavakoli, C., Fofana, I. and Farzaneh, M.*	Dynamic modelling of flashover process on ice-covered insulator surface
	14:30	English, M.C., Turcotte, D.S., Holmes, A., Reid, B., and Milburn, D.	Snow column in an arctic tundra snowpack, Coppermine River basin, N.W.T.
	14:50	van Bochove, E., Theriault, G., Jones, H.G. and Pomeroy, J.W.	Greenhouse gas exchange between snow-covered soils and the atmosphere in eastern Canada
15:10		COFFEE BREAK AND POSTER VIEWING **
		Chair: S Munro	Snow & Ice Processes
	15:30	Fischer, U.H., Porter, P.R. and Schuler, T.	Excess pore-water pressures in sub-glacial sediments: implications for basal motion
	15:50	Hubbard, B.	Direct measurement of basal sliding at a hard-bedded, temperate glacier: Glacier de Tsanfleuron, Switzerland
	16:10	Schuster, C.J.*	Weathering crust processes on melting glacier ice
	16:30	Volat, C. , Farzaneh, M. and Gakwaya, A.*	3-D modelling of potential and electric field distributions around an ice-covered insulator
	16:50	Karev, A.R. and Farzaneh, M.	Freezing of flowing supercooled water film on an icing surface

* Student Paper Poster Room:

** A list of poster titles appears at the end of this section of the program booklet

THURSDAY AFTERNOON, 17 MAY

Eastern Snow Conference Room: Monpetit 202

TIME		AUTHORS		TITLE
		Chair: J. Pomeroy	Snow Vegetation Interactions
	15:30	Winkler, R.	Snow science and forest planning in British Columbia
	15:50	Derksen, C., LeDrew, E., Walker, A. and Goodison, B.	Evaluation of the Meteorological Service of Canada Boreal Forest Snow water Equivalent Algorithm
	16:10	Hopkinson, C., Sitar, M., Agro, D., Enter, R., Foster, J., Heels, N., Hoffman, C., Nilsson, J. and St. Pierre, R.*	Mapping the spatial distribution of snow pack depth beneath a variable forest canopy using airborne laser altimetry
	16:30	Corner, B., Rubinstein, I. Whitley, H. Bryant, C.*	Applications of in situ, ancillary and multi-sensor satellite information for monitoring of snowpack conditions for a forested watershed in Northern Ontario
	16:50	Singh, P.R. and Gan, T.Y.*	A semi-distributed snowmelt model (SDSM) using energy balance method

ESC/CGU AWARDS BANQUET

17:30h ROOM 200, WEST BLOCK, PARLIAMENT HILL

List of Poster Presentations

Note that ‘W’ denotes a Wednesday poster and ‘T’ denotes a Thursday poster – posters may be up from 0800-1700h on the designated day only.

Barber, D. G and Iacozza, J.	The utilization of microwave radiometry to estimate snow water equivalent (SWE) over First-Year sea ice	W
Brown-Mitic, C., MacPherson, I. Schuepp, P. and Bales, R.*	Surface-atmosphere exchange during and after snowmelt for different Arctic environments during MAGS	T
Brown, G., H., Hubbard, B. and Seagren, A.G.	Kinetics of suspended sediment weathering in dilute solutions at low temperature	T
Bryant, C., Whiteley, H. Rubinstein, I. And Corner, B.*	Comparison of satellite-based snow water equivalent data with snowcourse data and with modelled snowpack content for a forested watershed in northern Ontario	W
Chasmer, L. and Hopkinson, C.*	Using airborne LIDAR, Landsat TM & ArcINFO GIS to assess scale induced radiation loading errors in a glacierised Basin	T
Chasmer, L. and LeDrew, E.*	Interactions between the Odden sea ice peninsula and the North Atlantic oscillation	W
Copland, L., Sharp, M. and Nienow, P.	Relationships between short-term velocity variations and the subglacial hydrology of a high Arctic polythermal glacier	W
Green, J.R., Cecil, L.D., Naftz, D.L., Schuster, P., Delwiche, M. and Roberto, F.F.	Ecosystem impacts of heavy-metal and radionuclide loading in alpine areas of the Northern Hemisphere	T
Hall, D.K., Bayr, K.J., Bindschadler, R.A., Lieb, G.K. and Shoener, W.	Changes in the Pasterze Glacier, Austria (1976-2000), as measured from space.	W
Hardy, J.P., McDonald, K., Davis, R.E., Melloh, R.A. and McKenzie, C.	Distributed mapping of SNTHERM-modelled snow properties for monitoring seasonal freeze/thaw dynamics	W
Hedstrom, N.R., Granger, R.J., Pomeroy, J.W., Gray, D.M., Brown, T., and Little, J.L.	Enhanced indicators of land use change and climate variability impacts on prairie hydrology using the Cold Regions Hydrological Model	T
Heppenstall, K. and Sharp, M.*	The chemical composition of meltwater draining a High Arctic glacier	W
Hopkinson, C. and English, M.*	Spatio-temporal variations of delta-18 O isotope signatures of hydrological components within a glacierised mountainous basin	T
Hugenholtz, C.H. and Lewkowicz, A.*	Alpine snow cover, BTS and thaw layer depths, Kluane Lake, Yukon Territory, Canada	W
Iacozza, J. and Barber, D.G.	Seasonal evolution of snow cover to melt pond over first-year sea ice	W
Jacobs, J.D., Banfield, C.E. and Wadleigh, M.A.	Hydroclimatology and hydrochemistry of seasonally snow-covered watersheds in Newfoundland	T
Jones, D. R. M. and Young, K. L.*	Monitoring snowmelt in the Canadian High Arctic using a DEM and remote sensing	W
Klein, A.G.	Historical snow cover changes in the Southern Portion of Ross Island, Antarctica	T
Kuchment, L.S. and Gelfan, A.N.	Statistical self-similarity of spatial variations of snow cover: verification of the hypothesis and application for runoff modelling	T
Lee, S., Klein, A. and Over, T.	Effects of the El Nino/ Southern Oscillation on temperature, snow water equivalent and resulting streamflow in the Upper Rio Grande River	T
Melloh, R. A., Hardy, J.P. and Robinson, P.	Snow surface albedo in the Northern Hardwood Forest	W
Moore, R.D. and Demuth, M.N.	Mass balance and streamflow variability, Place Glacier, Canada	T
Murray C.D. and Buttle, J.M.	Impacts of clearcutting on snow accumulation and melt in a northern hardwood forest	W
Papapkyriakou, T., Barber, D., Hanesiak, J. and Yackel, J.	Application of an analytical model of periodic heat flow through layred snow to examine relationships between the surface heat budget and microwave scattering from RADARSAT-1 over snow-covered sea ice.	W
Pivot, F., Duguay, C.R. and Kergomard, C.	Snow cover monitoring at treeline using satellite synthetic aperture radar and ground penetration radar	W
Pomeroy, J.W. , Hanson, S. and D. Faria	Small-scale Variation in Snowmelt Energy: An Additional Factor Controlling Snowcover Depletion	W
Richard, C. and Gratton, D.	The importance of the air temperature variable for the snow-melt runoff modelling using the SRM model	T
Risk, D., Beltrami and Kellman*	Cold-season CO2 production in four soil profiles	W
Robinson, P.B., Melloh, R.A. and Hardy, J.P.	Comparison of winter litterfall in the two forest communities in northern Vermont	W
Schuler, T., Fischer, U.H. and Gudmundsson, G.H.	Changing subglacial flow conditions as revealed by dye tracer studies	T
Singh, P.R. and Gan, T.Y.*	A semi-distributed snowmelt model (SDSM) using modified temperature index method	W
Takeuchi, N.	The altitudinal distribution of snow algae on an Alaska glacier	T
Toupin, J.	Urban and rural perception of winter along the St. Lawrence Valley. A case study on Trois-Rivieres and Champlain, Quebec	W

The following page contains an abstract that is not found in the main conference booklet.
Ecosystem impacts of heavy-metal and radionuclide loading in alpine areas of the Northern Hemisphere

Jaromy R. Green¹, L. DeWayne Cecil¹, David L. Naftz², Paul Schuster³, Mark Delwiche⁴, and Francisco F. Roberto⁴

¹ U.S. Geological Survey, 900 N. Skyline Dr. Suite C, Idaho Falls, Idaho, U.S.A., 83402;

Phone: 208-528-2611; Fax: 208-528-2605; Email: ldcecil@usgs.gov

² U.S. Geological Survey, Salt Lake City, Utah, U.S.A.

³ U.S. Geological Survey, Boulder, CO., U.S.A.

⁴Idaho National Engineering and Environmental Laboratory, Idaho Falls, Idaho, U.S.A.

Abstract

The U.S. Geological Survey (USGS) is conducting a collaborative research program in mid-latitude glacial environments in the Northern Hemisphere to study the effects of increased loading of anthropogenic heavy metals and radionuclides on alpine ecosystems. The heavy metals of interest are mercury, arsenic, and lead; the radionuclides of interest include plutonium isotopes, chlorine-36 (³⁶Cl), and iodine-129 (¹²⁹I). Mid-latitude glacial sites are being studied in China, Kazakhstan, Kyrghyzstan, Nepal, Russia, and the United States.

Mercury has been measured in the ice cores collected from the Upper Fremont Glacier (UFG) in the Wind River Mountain Range, Wyoming, U.S.A. Local, regional, and global events (natural and anthropogenic) produced the mercury concentrations in the cores. Large, naturally spiked concentrations of mercury coincided mostly with singular volcanic events. Evidence of anthropogenic events such as the gold rush in western North America (1854-80) and World War II manufacturing in the United States (1940-45), was also visible in the ice. A 100-meter ice core collected in the summer of 2000 from the Inilchek Glacier, located in the Tien Shan Mountains on the borders of Kyrghyzstan, Kazakhstan, and China, also will be analyzed for mercury. The mercury profile from this ice core should show local and regional trends of mercury input.

Advances in accelerator mass spectrometry allow detection of small concentrations of radionuclides archived in ice cores. The ice core from the UFG may show measurable isotopic plutonium input from the Nevada Test Site and the U.S. Department of Energy’s Hanford Reservation, U.S.A., as well as a global weapons-tests plutonium signature. The ice core collected from the Inilchek Glacier in 2000 and an ice core collected in Nepal in 1998 show local and regional ³⁶Cl and ¹²⁹I signatures and should show plutonium signals as well.

Imaging of the glacial samples from the UFG with EPI-fluorescence microscopy (after staining with nonspecific DNA dyes) revealed that significant numbers of viable microorganisms are present within the ice. Preliminary results of these studies indicate the presence of microbial populations adapted to low-temperature, nutrient-poor conditions. Changes in the diversity of these microbiological communities, in correlation with isotopic and geochemical signatures in the ice, will help to establish the ecosystem impacts caused by the heavy metal and radionuclide loading that result from global and regional volcanic events, industrialization, agriculture, and atmospheric nuclear weapons tests.