Ninth International Conference on Permafrost ... - IARC Research

More documents

Recommendations

Info

Application of DC Resistivity Tomography in the Alpine Area of the SouthernCarpathians (Romania)Petru Urdea, Florina Ardelean, Alexandru Opaca, Mircea Ardelean, Marcel Törok-OanceWest University of Timişoara, Department of Geography, B-dul. V. Parvan, Nr. 4, 300223, Timişoara, RomaniaIntroductionDuring the last decade, the use of geophysical techniqueshas become increasingly important in geomorphologicalstudy and for many geomorphologists, new and excitingtools (Schrott & Sass 2008).The acquisition of a complex geophysical system,PASI 16GS24, opens new possibilities for performanceinvestigations of some landforms and deposits of the alpinearea of the Southern Carpathians—for first time in Romaniangeomorphology—and, accordingly, the aim of this paper isto present some results of the application of DC resistivitytomography in alpine area of the Southern Carpathians(Romania). By application of geophysical techniques ondifferent geomorphic deposits, we have the possibility togain insight into their overall thickness and inner structures,as well as the aspect of the contact surfaces with bedrock(Milmson 1996).Study areaThe Southern Carpathians, or Transylvanian Alps, arethe most massive and the highest part of the RomanianCarpathians, having 11 peaks above 2500 m and a maximumelevation of 2544 m in Moldoveanu Peak (FăgăraşMountains). In the high area of the Southern Carpathians,the geomorphological landscape is dominated by glaciallandforms, the detailed characteristics being due to periglacialforms, like rock glaciers, talus cones, and scree slopes,block fields, rock streams, cryoplanation terraces, patternedground, solifluction forms, etc. (Urdea et al. 2004).Geophysical investigations were carried out in numerousstudy areas of the Southern Carpathians in the Făgăraş,Retezat, and Şureanu Mountains (Fig. 1), representative unitsfor the main geomorphological landscapes of RomanianCarpathians. Our investigation focused on rock glaciers,scree slope deposits, late glacial stadial moraines, postglacialin-filled glacial depressions, solifluction lobes, andfossil patterned grounds (Table 1).MethodologyThe PASI system consisted of 32 electrodes with astandard spacing of 5 m. In function of deposits andlandforms dipole-dipole, Wenner and Wenner-Schlumbergerarrays was used, with a maximum penetration depth of 30 m.The longitudinal profiles were carried, and for rock glacierswere carried also longitudinal and transversal profiles. DueTable 1. Location of DC resisitivity investigations.Area & date Altitude Latitude Longitude(m)Scree slopesBâlea Lake (FăgăraşMts.) 03.07.2007 208845°36′06″ N24°37′10″ EVăiuga(Făgăraş Mts.) 227045°35′17″ N24°37′22″ E11.09.2007Stadial morainesDoamnei Valley(Făgăraş Mts.) 190345°36′19″ N24°35′51″ E04.07.2007Rock glaciersAna(Retezat Mts.) 198945°21′13″ N22°52′04″ E22.08.2007Pietrele(Retezat Mts.) 204345°22′13″ N22°52′16″ E23.08.2007Capra(Făgăraş Mts.) 192845°35′20″ N24°37′19″ E10.09.2007Postglacial in-filled glacial depressionValea Doamnei(Făgăraş Mts.)04.07.20071879 m45°36′21″ N24°35′49″ ECăldarea Berbecilor(Făgăraş Mts. 190703.07.2007Şureanu (ŞureanuMts.) 26.08.2007 176945°36′33″ N24°37′07″ E45°34′51″ N23°30′33″ EFigure 1. Location of the investigated areas.Solifluction lobesPaltinu (Făgăraş Mts.)06.07.2007 2372Patterned grounds (fossil)Paltinu – PiscuNegru (Făgăraş Mts.) 233806.07.200745°35′52″ N24°36′25″ E45°35′48″ N24°36′26″ E323
Ni n t h In t e r n at i o n a l Co n f e r e n c e o n Pe r m a f r o s tAcknowledgmentsThe authors are grateful to numerous students from WestUniversity of Timişoara for their committed help in carryingand installing the heavy equipment in the field. Financialexpenses was supported by National Council for UniversityResearch (grant CEEX 738/2006).Figure 2. 2-D resistivity longitudinal section at Pietrele rockglaciers.to the special characteristics, in the case of solifluction lobeand fossil patterned ground, the electrodes were arranged ina different configuration, on equal distance of 1 m, whichpermits a differentiation of distinct layers of 40–50 cm. Twodimensionalmodel interpretation was undertaken using thesoftware package RES2DINV (Loke 1999). This softwarepackage produces a two-dimensional subsurface model fromthe apparent resistivity pseudosection.Results and InterpretationApplication of 2-D electrical resistivity tomographybegan with measurements in Făgăraş, Retezat, and ŞureanuMountains on different geomorphic landforms, such as rockglaciers, scree slopes, solifluction lobes, fossil patternedground, and glacial overdeepening depression filled withpostglacial sediments. In all cases the results show varyingresistivity. Starting with this design, we can know and interpretthe structure of different deposits and, importantly, the depthand configuration of the surface contact with bedrock. Inthe case of scree deposits is the evidence of the presenceof quasi-layered structure and some different bodies of rockblocks and/or fines—made by downwash and debris flowprocesses—with contrasting resistivity (more than 10 kΩ/mand, respectively, less than 2 kΩ/m). For fossil-patternedgrounds are revealed undulating layers and elipsoidal bodiesof fines, more humid and with low resistivity (500–800Ω/m). In the case of Ana and Pietrele rock glaciers, electricaltomography reveals typical structures, and, important forpermafrost scientists, the presence of ice-rich bodies in theAna rock glaciers or ice-rich layer on Pietrele rock glaciers,revealed by high resistivities, on the order of more than 900k Ω/m (Fig. 2).We must mention that the presence of permafrost in thereported area was indicated by BTS measurements and bythe low temperatures (
Page 1:
NICOP 2008 Ninth <
Page 6 and 7:
ContentsPreface ...................
Page 8 and 9:
Mapping and Modeling the Distributi
Page 10 and 11:
Satellite Observations of Frozen Gr
Page 13 and 14:
xiiIce Wedge Thermal Regime in Nort
Page 15 and 16:
xivPermafrost Response to Dynamics
Page 17 and 18:
xvi
Page 19 and 20:
NICOP SponsorsUniversitiesUniversit
Page 22 and 23:
Deep Permafrost Studies at the Lupi
Page 24 and 25:
Effect of Fire on Pond Dynamics in
Page 26 and 27:
Cryological Status of Russian Soils
Page 28 and 29:
Acoustical Surveys of Methane Plume
Page 30 and 31:
Permafrost Delineation Near Fairban
Page 32 and 33:
Preparatory Work for a Permanent Ge
Page 34 and 35:
A Provisional Soil Map of the Trans
Page 36 and 37:
Martian Permafrost Depths from Orbi
Page 38 and 39:
Time Series Analyses of Active Micr
Page 40 and 41:
Impact of Permafrost Degradation on
Page 42 and 43:
DC Resistivity Soundings Across a P
Page 44 and 45:
Modeling Thermal and Moisture Regim
Page 46 and 47:
A Provisional Permafrost Map of the
Page 48 and 49:
Alpine Permafrost Distribution at M
Page 50 and 51:
Cryogenic Formations of the Caucasu
Page 52 and 53:
Modeling Potential Climatic Change
Page 54 and 55:
A Hypothesis: A Condition of Growth
Page 56 and 57:
Modeled Continual Surface Water Sto
Page 58 and 59:
Freeze/Thaw Properties of Tundra So
Page 60 and 61:
Discontinuous Permafrost Distributi
Page 62 and 63:
Thermal Regime Within an Arctic Was
Page 64 and 65:
Seasonal and Interannual Variabilit
Page 66 and 67:
Twelve-Year Thaw Progression Data f
Page 68 and 69:
Continued Permafrost Warming in Nor
Page 70 and 71:
Landsliding Following Forest Fire o
Page 72 and 73:
A Permafrost Model Incorporating Dy
Page 74 and 75:
Seasonal Sources of Soil Respiratio
Page 76 and 77:
Greenland Permafrost Temperature Si
Page 78 and 79:
The Importance of Snow Cover Evolut
Page 80 and 81:
The Account of Long-Term Air Temper
Page 82 and 83:
The Combined Isotopic Analysis of L
Page 84 and 85:
Adaptating and Managing Nunavik’s
Page 86 and 87:
Human Experience of Cryospheric Cha
Page 88 and 89:
HiRISE Observations of Fractured Mo
Page 90 and 91:
A Soil Freeze-Thaw Model Through th
Page 92 and 93:
Mapping and Modeling the Distributi
Page 94 and 95:
First Results of Ground Surface Tem
Page 96 and 97:
Historical Changes in the Seasonall
Page 98 and 99:
Rock Glaciers in the Kåfjord Area,
Page 100 and 101:
Snowpack Evolution on Permafrost, N
Page 102 and 103:
Climate Change in Permafrost Region
Page 104 and 105:
Maximizing Construction Season in a
Page 106 and 107:
Pleistocene Sand-Wedge, Composite-W
Page 109 and 110:
Ni n t h In t e r n at i o n a l Co
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Ni N t h iN t e r N at i o N a l Co
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
Page 209 and 210:
Page 211 and 212:
Page 213 and 214:
Page 215 and 216:
Page 217 and 218:
Ni N t h iN t e r N at i o N a l Co
Page 219 and 220:
Page 221 and 222:
Page 223 and 224:
Page 225 and 226:
Page 227 and 228:
Page 229 and 230:
Page 231 and 232:
Page 233 and 234:
Page 235 and 236:
Page 237 and 238:
Page 239 and 240:
Page 241 and 242:
Page 243 and 244:
Page 245 and 246:
Page 247 and 248:
Page 249 and 250:
Page 251 and 252:
Page 253:
Page 257 and 258:
Page 259 and 260:
Page 261 and 262:
Page 263 and 264:
Page 265 and 266:
Page 267 and 268:
Page 269 and 270:
Page 271 and 272:
Page 273 and 274:
Page 275 and 276:
Page 277 and 278:
Page 279 and 280:
Page 281 and 282:
Page 283 and 284:
Page 285 and 286:
Page 287 and 288:
Page 289 and 290:
Page 291 and 292:
Page 293 and 294: Ni n t h In t e r n at i o n a l Co
Page 343: Ni n t h In t e r n at i o n a l Co
Page 391 and 392: 370Huang, B. 339Hugelius, G. 105, 1
Page 393: 372
show all

Ninth International Conference on Permafrost ... - IARC Research

Create successful ePaper yourself

Delete template?

Save as template?