INCOGNITA PATAGONIA Exploring the Last Unknown Patagonian Icefield 2016 Expedition Report by Eñaut Izagirre Evan Miles Ibai Rico EXPEDITION REPORT INCOGNITA PATAGONIA: Exploring the Last Unknown Patagonian Icefield An exploratory and glaciological research expedition to the Cloue Icefield of Hoste Island, Tierra del Fuego, Chile in March-April 2016. Eñaut Izagirre* Evan Miles Ibai Rico *Correspondence to: [email protected] Dirección de Programas Antárticos y Subantárticos Universidad de Magallanes 2016 This unpublished report contains initial observations and preliminary conclusions. It is not to be cited without the written permission of the team members. Incognita Patagonia returns from Tierra del Fuego with an improved understanding of the region's glacial history and an appreciation for adventure in terra incognita, having traversed the Cloue Icefield and ascended two previously unclimbed peaks. EXECUTIVE SUMMARY INCOGNITA PATAGONIA sought to explore and document the Cloue Icefield on Hoste Island, Tierra del Fuego, Chile, with a focus on observing the icefield's glaciers to develop a chronology of glacier change and associated landforms (Figure 1). We were able to achieve all of our primary observational and exploratory objectives in spite of significant logistical challenges due to the fickle Patagonian weather. Our team first completed a West-East traverse of the icefield in very difficult conditions. We later returned to the glacial plateau with better weather and completed a survey of the major mountains of the plateau, validating two peaks' summit elevations. At the glaciers' margins, we mapped a series of moraines of various ages, including very fresh moraines from recent glacial advances. One glacier showed a well-preserved set of landforms indicating a recent glacial lake outburst flood (GLOF), and we surveyed and dated these features. We explored three undocumented fjords, conducting extensive bathymetric surveys to determine historical glacier areas by determining submarine moraine positions. We maintained several automated weather stations (AWS) established by the late Charlie Porter, the only meteorological records for the region. Finally, our presence in the area greatly improved the documentation of historical explorations, and enabled collection of local place-names. Figure 1 Geographical map of the Cloue Icefield and its surroundings with major landmarks, expedition’s tracks and glacier area change between 1945 and 2016. Background in hillshade DEM built with a SRTM 3. Expedition Report, Incognita Patagonia 2016 5 Table of Contents I EXECUTIVE SUMMARY 5 Table of Contents 6 1. INTRODUCTION 8 1.1. Tierra del Fuego and the Cloue Icefield 8 1.1.1. Regional glaciological context 9 1.1.2. Climate regime and some possible explanations of the regional glacier retreat 13 1.2. History and Exploration 14 1.3. Objectives 20 2. EXPEDITION TEAM 22 2.1. Participants 22 2.2. Sailboat crew 23 3. RESEARCH: GLACIER INVENTORY 24 3.1. Background 24 3.2. Methods 24 3.3. Results 25 3.4. Discussion and Conclusions 28 4. RESEARCH: GLACIAL GEOMORPHOLOGY 30 4.1. Background 30 4.2. Methods 30 4.2.1. Imagery 31 4.2.2. Geomorphological mapping 31 4.2.3. Bathymetric survey 34 4.2.4. Dendrochronology 34 4.3. Results 34 4.4. Discussion and Conclusions 36 5. RESEARCH: METEOROLOGICAL DATA 38 5.1. Background 38 5.2. Methods 39 5.3. Results 40 5.3.1. AWS Cloue 40 5.3.2. AWS Pia 40 5.3.3. AWS Diablo 41 5.4. Discussion and Conclusions 42 6. CARTOGRAPHY AND HISTORY 43 6.1. Local Information 43 6.2. Expedition History 43 Expedition Report, Incognita Patagonia 2016 6 Table of Contents II 7. ADVENTUROUS ACTIVITIES 45 7.1. Traverse of the Cloue Icefield 45 7.2. First Ascents at Cloue Icefield 46 7.3. Exploration in Pia Este, Cordillera Darwin 48 8. TRIP LOGISTICS 49 8.1. Route Planning and Late Adjustments 49 8.2. Permits and Access Restrictions 49 8.3. Risk Assessment, Insurance and Medical Support 50 8.4. Air Travel and Equipment Freight 50 8.5. Communications 51 8.6. Northanger Sailboat Support 51 8.7. Environmental and Social Impact 52 8.8. Budget 53 8.9. Key Challenges and Lessons Learned 54 8.10. Appealing Future Objectives 54 9. TRIP LOG 55 9.1. Summary 55 9.2. Daily Log of Events 56 10. SUMMARY OF MAJOR ACCOMPLISHMENTS 59 11. OBSERVED FLORA AND FAUNA 62 11.1. Flora 62 11.2. Notable fauna 64 11.3. Beavers and anthropic effects 66 12. ACKNOWLEDGMENTS 69 12.1. Trip Donors, Sponsors and Collaborators 69 12.2. Personal Support 70 13. BIBLIOGRAPHY 71 13.1. Scientific Articles 71 13.2. Expedition Reports and Books 74 13.3. Reference Maps and Nautical Charts 75 14. PUBLIC MEDIA COVERAGE 76 14.1. Television 76 14.2. Radio 76 14.3. Mountain and Science Outreach Magazines 76 15. MAP AND REPORT DISSEMINATION 77 Expedition Report, Incognita Patagonia 2016 7 1. INTRODUCTION 1.1 Tierra del Fuego and the Cloue Icefield In geographical terms, Tierra del Fuego refers to all the land and sea territory that is located to the South and East of the Strait of Magellan, thus separating the continental Patagonia from the characteristic isolation that possess the “fuegian” lands, geopolitically divided between the countries of Chile and Argentina. This glaciated and glacierized terrain forms the southern tip of the Andean Cordillera as it plunges into the Southern Ocean (Figure 2). Figure 2 Geographical context of the Cloue Icefield: It is located in the southernmost end of South America where the belt of Southern Hemisphere Westerlies dominates the main winds in the area (A) and it is affected by the precipitation fronts that enter the area from the Pacific Ocean (B). The archipelago of Tierra del Fuego, as delimited by the illustrious Alberto de Agostini, has a surface area of 72,000 km2 and is located between the parallels of 52º30’ and 56º S and longitudes 63º45’ and 74º45’ W. The Atlantic and Pacific Oceans, with the Strait of Magellan to the North, laterally bound the archipelago. Its southern boundary includes Cape Horn, Cape San Juan at the eastern end of Staten Island, and Cape Desire at the western end of Desolation Island (Agostini, 1956). This archipelago of seemingly-infinite islands divided by intricate fjords and channels can be divided in three large groups: 1) the main island of Tierra del Fuego, which with 48,100 km2 is the largest land surface of the archipelago and lies between the Strait of Magellan and the Beagle Channel; 2) the islands south and southeast of the Beagle Channel which continue down to Cape Horn, the largest being Hoste Island (4,117 km2), Navarino Island (2,473 km2) and Staten Island (534 km2); 3) the islands of the northwest, to the west of Cockburn and Magdalena Channels but still to the southwest of the Strait of Magellan, including the islands of Santa Ines (3,688 km2), Capitan Aracena (1,164 km2), Clarence (1,111 km2) and numerous other small land-masses (Figure 3). Expedition Report, Incognita Patagonia 2016 8 Figure 3 Panoramic Views of the diVerse geography of Tierra del Fuego: A) Main Island of Tierra del Fuego, from the top of Cerro Pietro Grande (425 m) facing the foothills of the main mountain range; B) NaVarino Island in the foreground, with the Dientes de NaVarino mountains and Robalo Lake, to the Beagle Channel and the Argentine part of the Main Island of Tierra del Fuego; C) Wild and windy landscape of the western part of Hermite Island (55º50’ S), in the background is possible to sight the group of Wollaston Islands; D) High peaks of the Cordillera Darwin from the Beagle Channel, to the right is Gordon Island. Photo credit: Eñaut Izagirre. 1.1.1 Regional glaciological context The Andean cordillera, oriented North-South for thousands of kilometres, is slightly diverted in the area of the Strait of Magellan due to a major active tectonic fault, known as the Magallanes-Almirantazgo- Fagnano failure-system (Klepeis, 1994). This creates an important altitude difference between the mountains to the north of the Strait of Magellan, known as the Patagonian Andes, where peaks higher than 3,000 meters above sea level (masl onwards) are partly covered by the extensive Northern and Southern Patagonia Icefields, with 4,200 km2 and 13,000 km2 respectively (Rivera et al, 2007; Aniya, 1996). However, the southern mountains, known as Austral Andes, and oriented NW-SE, have elevations that just break above 2,000 masl. These mountain complexes are splattered by many mountain glaciers and smaller icefields, which according to the latest measurements with satellite images, encompass a total of 3,290 km2 spread over 1,681 glacier basins in Chilean territory (Figure 4; Bown et al., 2014). Expedition Report, Incognita Patagonia 2016 9 Figure 4 Relief of the central part of Tierra del Fuego: It shows the location of the major glaciated areas: Santa Ines Icefield (SI), glaciers around Monte Sarmiento (MS), Cordillera Darwin Icefield and adjacent glaciers (CD) and Peninsula Cloue Icefield and adjacent glaciers (PC). The terrestrial relief is based on a Digital EleVation Model (90 m x 90 m) deriVed from SRTM3 images. The bathymetry is based on General Bathymetric Chart of the Oceans (GEBCO, 2003) with bathymetric curVes of 100 meters. The extent of glaciers and ice masses was obtained from the Chilean National Inventory of Glaciers (DGA, 2012) and Randolph Glacier InVentory (Pfeffer et al., 2014). The glaciers and icefields are mainly found in the Cordillera Darwin Icefield (54º30’ S), which is a continuous mountain axis above 2,000 masl and accounts for 71% of the glaciers in the region. Other major glacier zones include: Santa Ines Island (53º45’ S) with an icefield of around 274 km2 and maximum altitude of 1,370 masl; Monte Sarmiento (54º27’ S), which is an isolated section of the Cordillera Darwin, but still comprises a half-dozen glaciers in separate basins surrounding its two almost identical summits that culminate at 2,207 masl (personal communication from Camilo Rada, 2013); and the area of Hoste Island (55º S), covering 409.5 km2, with the majority concentrated on the Cloue peninsula to form the southernmost icefield of the entire Andes range.