Description: We introduce a novel perspective to determine conditions of "Climate Change Refugia" for Glaciers (CCR), a metaphor that simultaneously encapsulates glaciers’ resistance and resilience before predominant regional climate trends, and the hydrological consequences thereof. Glaciers are essential for the environment and thus their susceptibility to disturbances in rainfall and thermal regimes makes them one of systems most sensitive to climate variations. Meltwater is crucial to sustain streamflow during dry periods, allowing relatively continuous baseflow to sustain diverse activities. Despite fluctuations in temperature and precipitation are intrinsically linked to dynamics of mass loss and gain, there are several examples of mountain glaciers with similar size and elevation range, and located within broadly homogenous climatic regimes, that have shown a differential volumetric response. This suggests that glaciers’ climatic sensitivity is non-stationary, as glaciers may fluctuate from highly coupled to decoupled from climatic trends. CCR is defined as the combination of local geomorphometric and climatic conditions that decouple glaciers from regional warming and drying trends, thus maintaining a detectable influence on streamflow. While much less emphasized in the literature, for regions dependent on meltwater, understanding changes in glacier sensitivity, identification of conditions and locations of glacier survival, become as important as pinpointing areas of full withdraw. To evaluate CCR, we are combining moraine mapping and dating, glacier reconstruction, water isotope analysis, geomorphometry, remote sensing, and coupled hydroclimatic numerical modeling. We provide further details of our results to date, our geographical focus as well as what we foresee as further developments under this approach

Description: Knowledge of glacier volume is necessary to determine freshwater storage in glacierized regions. In particular, mountain glaciers provide important freshwater supply to communities and agriculture downstream, especially in scenarios of drought. Ice-thickness observations are needed to determine glacier volume, but measurements are usually rare, representing a key data gap to cryospheric research today. Numerical ice-flow models, as well as simpler glacier surface to volume relationships, are commonly used to estimate glacier volumes, despite the lack of observations. Chile has suffered a ‘mega drought’ in the last decade and such drier conditions are likely to persist in the future due to climate change. Hence, volume estimations for Chilean glaciers and knowledge on their accuracy are highly relevant.We investigate ice-volume estimates for Chilean glaciers on glacier and on watershed level obtained from different data sources, e.g. derived from global glacier models and from local inventories. The global models use glacier outlines of the Randolph Glacier Inventory and ice thickness observations from the Glacier Thickness Database. Unfortunately, we found that for Chile the first is not accurate and that, for the latter, observational ice-thickness data of more than 30 glaciers has not yet been made publically available. We compare the ice volumes derived from global models to volumes derived directly from the previously unavailable observational data. The comparison enables us to obtain a sense under which conditions current glacier models provide more accurate or rather poor ice-volume estimates, which may provide hints leading to an improved ice-volume estimation.

Description: We investigated the structural glaciology of the Nevados de Chillán Glacier, a small mountain glacier from the central-south of Chile, a glaciologic region considered as one of the most vulnerable mountain areas in the planet. We used satellite imagery to interpret several morphological descriptors. In the last decades the glacier has lost nearly 85% of its area in 1975, from 2.78km2 to 0.41 in 2022. This drastic retreat comes with important modification of the glacier morphology, first, in 1987 the glacier began to split in two tongues and, in 2018, it became disconnected from part of the accumulation area located on a crater. Currently, the glacier is fed by two small accumulation basins, with their respective ablation zones connected by an ice bridge almost completely covered by debris, also, in the middle of the main tongue there is bedrock emerging from the ice, insinuating a similar trajectory of the ridge that now divides the two glacier tongues. The clean ice surface shows a complex crevasse arrangement, with transverse crevasses on the upper reaches, intersecting both splaying and en echelon crevasses on the middle reaches, there is also a couple of icefalls generating complex crevasse zones. Analysis of preferred crevasse orientation along the glacier revealed recently exposed bedrock splitting the flow of the main tongue. These abrupt changes in glacier morphology and the shrinkage, have enhanced debris cover growth on this glacier, by exposing steep and unstable walls of volcanic sedimens.

Description: The intrusion of igneous sills into organic-rich sediments accompanies the emplacement of igneous provinces, continental rifting, and sedimented seafloor spreading. Heat from intruding sills in these settings alters sedimentary organic carbon, releasing methane and other gasses. Recent studies hypothesize that carbon released by this mechanism impacts global climate, particularly during large igneous province emplacements. However, the direct impacts of sill intrusion, including carbon release, remain insufficiently quantified. Here, we present results from International Ocean Discovery Program (IODP) Expedition 385 comparing drill-core and wireline measurements from correlative sedimentary strata at adjacent sites cored in Guaymas Basin, Gulf of California, one altered by a recently intruded sill and one unaffected. We estimate 3.30 Mt of carbon were released due to this sill intrusion, representing an order of magnitude less carbon than inferences from outcrops and modeling would predict. This attenuated carbon release can be attributed to shallow intrusion and the high heat capacity of young, high-porosity sediments. Shallow intrusion also impacts sub-seafloor carbon cycling by disrupting advective fluxes, and it compacts underlying sediments, increasing potential carbon release in response to subsequent intrusions.

Description: Here we present the first results of our study on the response of the mountain cryosphere to geoengineering. The Andes Mountains, traversing and modifying a large number of the Earth's climates, correspond to one of the most vulnerable mountain environments due to the generalized glacier retreat that is affecting water availability and is expected to continue under several climate projections. Therefore, this is a formidable case study for testing the regional impacts of solar geoengineering scenarios, as the response of the mountain cryosphere to geoengineering remains a significantly uncertaint. Therefore, the aim of our work is to compare and analyze the impact of solar geoengineering scenarios versus SSP245-585 scenarios using climate indices. In our research, we divided the Andes in 8 glaciological zones to study climatic indices analizing key variables that control glacier surface mass balance: precipitation, mean, minimum and maximum temperature at a daily frequency and spatial resolution of 100 and 250 km. Due to this low resolution, we applied a statistical downscaling and bias correction differentiated by glaciological zone. In the poster we show spatiotemporal trends of the indices along the Andes, discussing the implications of solar geoengineering scenarios relative to other climate scenarios, in particular to glacier mass balance.

Description: Worldwide mass removals are one of the most devastating geological events due to their destructive power and unpredictable nature. In this sense, landslide inventories are crucial to study the dynamics, associated risks, and effects of these geomorphological processes on the evolution of mountainous landscapes. The production of landslide maps is mainly based on manual visual interpretation of aerial and satellite images combined with field surveys. In Chile, for example, the SERNAGEOMIN (Chilean Geological Survey Service) created an inventory with 2,533 events in Northern Patagonia. However, only 11 events have known dates. Consequently, it is impossible to associate temporal triggers and mechanisms that control such events, resulting in a lack of understanding of the factors that enable these landslides. Recently, advances in machine learning methods have made it possible to explore landslide detection methodologies using different kinds of remotely sensed images. In Morales et al. (2022), the authors manually generated a dataset of 10,000 landslides for northern Chilean Patagonia (42-45°S). They trained a model based on Deep Learning to detect landslides in optical images of the Sentinel-2 constellation using a DeepLabv3+ architecture. Even though these methodologies allow to establish where the landsides occurred, they do not provide the time when they occurred. In this work, we propose an algorithm to determine, in an automatic way, the inter and intra-annual time windows when the landslides occurred. The results of this work will enable the creation of landslide inventories useful for studying hydroclimatic trigger factors. We acknowledge financial support by Centro CRHIAM Project ANID/FONDAP/15130015