Icy Environments Research Articles

Impact of environmental conditions on organic matter in astrophysical ice analogues

ABSTRACT The existence of organic matter presenting a high molecular diversity in extraterrestrial environments is well documented. To understand the origin of this organic diversity, laboratory experiments were developed and showed that irradiation and thermal alteration of simple molecules such as methanol, water, and ammonia in conditions mimicking astrophysical ice environments. Ices containing water, methanol, and ammonia (H2O: MeOH: NH3) photolyzed and monitored by infrared spectroscopy, while the organic matter formed at room temperature was analyzed in situ with infrared spectroscopy and ex situ with high-resolution mass spectrometry. Those ices irradiated at 77 K and 10−8 mbar shows a significant organic molecular diversity: residual organic compounds contain up to 78 C, 188 H, 123 N, and 37 O. Most of them contains all four CHNO atoms (76–86 per cent), followed by CHO (11–17 per cent), and CHN compounds (5–6 per cent). CHNO and CHO compounds are more aliphatic (34–53 per cent), while CHN compounds are mostly condensed aromatics (83–90 per cent). In this work, our objective is to investigate impacts of environment on this organic molecular diversity by focusing on three parameters: photon dose, pressure, and heating rate during the warming process. Analyses of the residue formed showed that the heating rate and pressure weakly alter the abundance of the final organic material, while the irradiation rate reduced its abundance at high photon doses by a factor of 8. These results give insights on the impact of icy environment conditions in the evolution of astrophysical organic matter.

A systematic mid-infrared spectroscopic study of thermally processed H2S ices

The positive identification of the molecular components of interstellar icy grain mantles is critically reliant upon the availability of laboratory-generated mid-infrared absorption spectra which can be compared against data acquired by ground- and space-borne telescopes. However, one molecule which remains thus far undetected in interstellar ices is H2S, despite its important roles in astrochemical and geophysical processes. Such a lack of a detection is surprising, particularly in light of its relative abundance in cometary ices which are believed to be the most pristine remnants of pre-solar interstellar ices available for study. In this paper, we present the results of an extensive and quantitative mid-infrared spectroscopic characterisation of H2S ices deposited at 20, 40, and 70 K and thermally processed to sublimation in an ultrahigh-vacuum system. We anticipate our results to be useful in confirming the detection of interstellar H2S ice using high-resolution and high-sensitivity instruments such as the James Webb Space Telescope, as well as in the identification of solid H2S in icy environments in the outer Solar System, such as comets and moons.

EELS: Autonomous snake-like robot with task and motion planning capabilities for ice world exploration.

Ice worlds are at the forefront of astrobiological interest because of the evidence of subsurface oceans. Enceladus in particular is unique among the icy moons because there are known vent systems that are likely connected to a subsurface ocean, through which the ocean water is ejected to space. An existing study has shown that sending small robots into the vents and directly sampling the ocean water is likely possible. To enable such a mission, NASA's Jet Propulsion Laboratory is developing a snake-like robot called Exobiology Extant Life Surveyor (EELS) that can navigate Enceladus' extreme surface and descend an erupting vent to capture unaltered liquid samples and potentially reach the ocean. However, navigating to and through Enceladus' environment is challenging: Because of the limitations of existing orbital reconnaissance, there is substantial uncertainty with respect to its geometry and the physical properties of the surface/vents; communication is limited, which requires highly autonomous robots to execute the mission with limited human supervision. Here, we provide an overview of the EELS project and its development effort to create a risk-aware autonomous robot to navigate these extreme ice terrains/environments. We describe the robot's architecture and the technical challenges to navigate and sense the icy environment safely and effectively. We focus on the challenges related to surface mobility, task and motion planning under uncertainty, and risk quantification. We provide initial results on mobility and risk-aware task and motion planning from field tests and simulated scenarios.

Laptop-Induced Erythema ab igne: A Case Report and Review of the Literature

Erythema ab Igne (EAI) or “toasted skin syndrome”, is a skin reaction manifested by a reticulate hypermelanosis on body areas submitted to prolonged exposure to infrared radiation (IRR) in the form of moderate heat insufficient to produce a skin burn. This reaction is probably as old as civilization and accompanies the use of fire for heating icy environments or the body directly. Currently, several cases due to bodily contact with laptops have been reported and makings EAI an old condition new again.
 Here, we present a case of a male patient with continuous use of a laptop computer placed on the abdominal area in a reclining position and the consequent formation of EAI on the exposed site.

Structure freezing in the ice

Freezing into ice is a complex phenomenon that presents challenges and risks in both individual and construction contexts. Work provides a concise overview of the key aspects surrounding freezing in ice. It highlights the dangers. For construction, the risks lie in compromised structural integrity, limited stability, and access difficulties. Calculating freezing in ice involves considering temperature, material properties, freezing time, ice formation, and expert consultation. Different types of freezing into ice are identified, and the freezing process is shown to be influenced by the type of ice, such as freshwater ice or sea ice. Dealing with freezing in ice requires strategic approaches, including following established procedures, utilizing proper equipment, seeking professional assistance, and adapting to changing conditions. Engineering construction aspects encompass planning, design, ground preparation, foundation design, construction techniques, material selection and monitoring. Understanding and managing freezing in ice is crucial for ensuring safety and successful construction projects in icy environments.

Ice collars around freezing in the ice hydrotechnical structures

Arctic engineering projects pose unique challenges due to severe cold conditions and the presence of ice. Among the critical factors affecting offshore constructions in these regions, ice loads stand out as a primary concern. Accurate estimation of ice loads is essential to ensure safe and cost-effective operation of marine structures in icy environments. One specific ice formation that significantly influences the total design load on marine structures is the ice collar. Ice collars are thicker thermodeveloped ice formations that occur around marine structures with high thermal conductivity when level ice stops moving. The presence of ice collars can considerably alter the total load on the structure, demanding careful consideration during the design process. Various methods to manage ice collars’ impact on marine structures exist, including mechanical removal, specialized cover layers, heating systems, and design adaptations. Numerical modeling proves valuable in predicting ice collar growth and its influence on load distribution. Implementing appropriate mitigation strategies ensures the continuous operability and structural integrity of marine installations in ice-prone regions.

Spatial and temporal distribution of sinuous ridges in southeastern Terra Sabaea and the northern region of Hellas Planitia, Mars☆

Sinuous ridges are an important yet understudied component of Mars' hydrologic history. We have produced a map of sinuous ridges, valleys and channels, and tectonic ridges across southeastern Terra Sabaea and into northern Hellas Planitia (10°-45° S, 35°-80° E) using a CTX mosaic. Although we mapped different types of ridges and negative relief features, the focus of this paper are the sinuous ridges. We present here a new dataset of sinuous ridges that includes basic morphometry (e.g., length, width, sinuosity), morphology, and the types of terrains they are located on. We chose our region of interest because it includes surface ages spanning Mars' geologic history, with emphasis on Noachian and Hesperian terrains. The shift from either a warm and wet or a cold and icy environment to our modern cold and dry climate occurred towards the end of the Noachian and into the Hesperian, a critical temporal window to characterize fluvial landforms.Our CTX-based mapping significantly improved the documentation of fluvial landforms within the study region, with over an order of magnitude increase in the number of valley networks and channels, and nearly 1700 sinuous ridges. Sinuous ridges are found in concentrated settings, with the majority (∼80%) located within impact craters and relatively few (∼20%) on the intercrater plains. Fluvial features are prevalent on Early and Middle Noachian-aged terrain but are relatively rare in the Late Noachian, signifying a shift in fluvial activity that likely led to a decrease in channel incision and subsequent inversion of relief. A subset of sinuous ridges—radial ridges in high-elevation, degraded craters— are possible records of ancient proglacial lakes. The youngest sinuous ridges are associated with intracrater alluvial fans in a narrow zone (∼12°S to 30°S and ∼ 62°E to 77°E). These formed in the Late Hesperian into the Amazonian, reflecting a later epoch of punctuated fluvial events driven by pre-existing topography and solar insolation.

Organic matter distribution in the icy environments of Taylor Valley, Antarctica

Glaciers can accumulate and release organic matter affecting the structure and function of associated terrestrial and aquatic ecosystems. We analyzed 18 ice cores collected from six locations in Taylor Valley (McMurdo Dry Valleys), Antarctica to determine the spatial abundance and quality of organic matter, and the spatial distribution of bacterial density and community structure from the terminus of the Taylor Glacier to the coast (McMurdo Sound). Our results showed that dissolved and particulate organic carbon (DOC and POC) concentrations in the ice core samples increased from the Taylor Glacier to McMurdo Sound, a pattern also shown by bacterial cell density. Fluorescence Excitation Emission Matrices Spectroscopy (EEMs) and multivariate parallel factor (PARAFAC) modeling identified one humic-like (C1) and one protein-like (C2) component in ice cores whose fluorescent intensities all increased from the Polar Plateau to the coast. The fluorescence index showed that the bioavailability of dissolved organic matter (DOM) also decreased from the Polar Plateau to the coast. Partial least squares path modeling analysis revealed that bacterial abundance was the main positive biotic factor influencing both the quantity and quality of organic matter. Marine aerosol influenced the spatial distribution of DOC more than katabatic winds in the ice cores. Certain bacterial taxa showed significant correlations with DOC and POC concentrations. Collectively, our results show the tight connectivity among organic matter spatial distribution, bacterial abundance and meteorology in the McMurdo Dry Valley ecosystem.

The Macrobiotus ariekammensis species complex provides evidence for parallel evolution of claw elongation in macrobiotid tardigrades

Abstract The recent integrative revision of the family Macrobiotidae demonstrated monophyly of the genus Macrobiotus and its complex, mosaic morphological evolution. Here, we analyse three Macrobiotus populations that exhibit extraordinary claw morphology characterized by elongated primary branches. Two of these populations, from the Arctic, were initially classified as Macrobiotus ariekammensis, but detailed integrative analyses resulted in splitting them into two subspecies: Macrobiotus ariekammensis ariekammensis and Macrobiotus ariekammensis groenlandicus subsp. nov.. The third population was Macrobiotus kirghizicus from Kyrgyzstan. Given the unusual phenotype of the above-mentioned taxa, we tested whether they constitute a distinct lineage in the family Macrobiotidae and could be delineated as a new genus. Although the phylogenetic investigation showed that the three taxa form a monophyletic group, the clade is nested in the genus Macrobiotus. Therefore, despite their morphological distinctiveness, a new genus cannot be established and we group these taxa in the Macrobiotus ariekammensis species complex instead. The complex includes the three above-mentioned taxa and Macrobiotus ramoli, which is included based on morphological characters. Moreover, our results provide evidence for rapid parallel evolution of long claws in macrobiotid tardigrades inhabiting cold and icy environments. Finally, we discuss the validity of the recent suppression of the genus Xerobiotus, which gathers macrobiotids with reduced claws.

Color Catalogue of Life in Ice: Surface Biosignatures on Icy Worlds.

With thousands of discovered planets orbiting other stars and new missions that will explore our solar system, the search for life in the universe has entered a new era. However, a reference database to enable our search for life on the surface of icy exoplanets and exomoons by using records from Earth's icy biota is missing. Therefore, we developed a spectra catalogue of life in ice to facilitate the search for extraterrestrial signs of life. We measured the reflection spectra of 80 microorganisms-with a wide range of pigments-isolated from ice and water. We show that carotenoid signatures are wide-ranged and intriguing signs of life. Our measurements allow for the identification of such surface life on icy extraterrestrial environments in preparation for observations with the upcoming ground- and space-based telescopes. Dried samples reveal even higher reflectance, which suggests that signatures of surface biota could be more intense on exoplanets and moons that are drier than Earth or on environments like Titan where potential life-forms may use a different solvent. Our spectra library covers the visible to near-infrared and is available online. It provides a guide for the search for surface life on icy worlds based on biota from Earth's icy environments.

Cryogenian Origin and Subsequent Diversification of the Plant Cell-Wall Enzyme XTH Family.

All land plants encode large multigene families of xyloglucan endotransglucosylase/hydrolases (XTHs), plant-specific enzymes that cleave and reconnect plant cell-wall polysaccharides. Despite the ubiquity of these enzymes, considerable uncertainty remains regarding the evolutionary history of the XTH family. Phylogenomic and comparative analyses in this study traced the non-plant origins of the XTH family to Alphaproteobacteria ExoKs, bacterial enzymes involved in loosening biofilms, rather than Firmicutes licheninases, plant biomass digesting enzymes, as previously supposed. The relevant horizontal gene transfer (HGT) event was mapped to the divergence of non-swimming charophycean algae in the Cryogenian geological period. This HGT event was the likely origin of charophycean EG16-2s, which are putative intermediates between ExoKs and XTHs. Another HGT event in the Cryogenian may have led from EG16-2s or ExoKs to fungal Congo Red Hypersensitive proteins (CRHs) to fungal CRHs, enzymes that cleave and reconnect chitin and glucans in fungal cell walls. This successive transfer of enzyme-encoding genes may have supported the adaptation of plants and fungi to the ancient icy environment by facilitating their sessile lifestyles. Furthermore, several protein evolutionary steps, including coevolution of substrate-interacting residues and putative intra-family gene fusion, occurred in the land plant lineage and drove diversification of the XTH family. At least some of those events correlated with the evolutionary gain of broader substrate specificities, which may have underpinned the expansion of the XTH family by enhancing duplicated gene survival. Together, this study highlights the Precambrian evolution of life and the mode of multigene family expansion in the evolutionary history of the XTH family.

Constraining Floating Ice Shelf Structures by Spectral Response of Teleseismic P‐Wave Coda: Ross Ice Shelf, Antarctica

AbstractThe recent deployment of a broadband seismic array on the floating ice shelf in the Antarctica's Ross sea presents a great opportunity to study the shelf structure using broadband seismic data. In this study, we develop a further improvement of the P‐wave coda autocorrelation method, which proved capable of characterizing grounded ice‐cap structures. Ice shelves are floating ice sheets connected to a landmass, and in order to decipher their structures, a water layer has to be added to the problem. We construct the power spectrum stacks of P‐wave coda data, waveform records that immediately follow P arrivals, in the spectral domain, which are equivalent, via a Fourier transform, to widely used autocorrelograms in the time domain. At half of temporary seismic stations under consideration, we report prominent resonant peaks in the spectral autocorrelograms, associated with the ice‐water configuration of the ice shelf. The lack of clear resonant pattern for the rest of the stations is suspected due to a high noise level in the icy environment and significant lateral heterogeneity at the local scale. Subsequently, we develop a formalism to explain the observed resonance and devise a grid‐search scheme to estimate ice‐ and water‐thicknesses underneath the stations. Our water‐thickness estimates agree well with the previously documented measurements, but there is a discrepancy in the ice thickness results. Therefore, the method has a great potential to complement the existing ice‐shelf model, to be used in future monitoring applications of ice shelves, or near‐future space exploration to icy planets.

Living (with) Ice

The main tenet of this article is to show how the ice, so visually dominant in the High Arctic, is also a prominent life force. The ice is never still and as it moves, melts or freeze, it deeply affects human and animal life in the region; conversely the diverse life-forms affect the icy environment in their own way and tempo. This interplay exposes the geo-social relations at the centre of this article, taking off from the gradual retraction of the ice after the last Ice Age, opening up for human movement and settlement in High Arctic America and eventually in Thule (Avanersuaq), in Northwest Greenland. Today some 750 people live there as hunters in the unsurpassable old hunting style, yet also as modern as anybody when it comes to outlook. Through brief discussions of particular periods, from the “discovery” of the Inughuit in 1819 and until the present, it is shown how deeply their life is implicated in the living ice, for better and for worse. The ice emerges as a refrain that holds the landscape together. The argument is based both in historical research and in regular anthropological fieldwork in the region over ten years 2007–2017.

A Comparative View of Glacial and Periglacial Landforms on Earth and Mars

This paper emphasizes the importance of using terrestrial analogues to improve our understanding of the role of ice on Mars through its associated landforms. We discuss terrestrial regions and techniques that can help understand Martian icy environments, and highlight the necessity to explore the Martian cryosphere as the next natural step.

Understanding Permafrost Responses to Climate Change

It is not just the polar ice caps that are melting. On our warming planet, the ice buried within the layers of ground around the Arctic Circle is thawing, irreversibly changing these spectacular landscapes and posing risks to the communities that call these areas home. Understanding the dynamics of ‘permafrost’ is vital for predicting its future responses to climate change. The long-term research of permafrost expert Dr Christopher Burn, from the Department of Geography and Environmental Studies at Carleton University, Canada, is integral to shaping our collective knowledge of these icy environments.

Microsensors in Icy Environments to Detect Microbial Activities

Electrochemical techniques such as impedance spectroscopy offer a non-invasive approach to monitor microorganisms in natural and engineered environments. Here, we present data on the use of microfabricated impedance spectroscopy sensors for the detection of microbes in icy environments. Under controlled laboratory settings, the effects of different cell concentrations of the Antarctic isolate Flavobacterium sp. ANT 11 on impedance spectroscopy was investigated at ambient temperature (22°C) and -10°C. Results show that varying cell concentrations of the bacterial isolate generate unique spectral responses that vary with temperature. Subsequent tests on the performance of microfabricated impedance sensors on natural microbial communities in icy environments in the Beartooth Mountains, WY, USA, confirmed laboratory findings. Different environmental samples at varying microbial concentrations in liquid, semi-frozen (slushy), or frozen states generated discrete impedance spectra. While caution is advised to generalize these results due to the potential contribution of unknown environmental variables, our data provide fertile territory for research in cryo-microbiology, as information on the applicability of impedance spectroscopy under frozen conditions is limited. [2020-0150]

Cultivation With Powdered Meteorite (NWA 1172) as the Substrate Enhances Low-Temperature Preservation of the Extreme Thermoacidophile Metallosphaera sedula

Recent studies have uncovered a vast number of thermophilic species in icy environments, permanently cold ocean sediments, cold sea waters, and cool soils. The survival of thermophiles in psychrobiotic habitats requires thorough investigation of the physiological and molecular mechanisms behind their natural cryopreservation. Such investigations are mainly impeded due to a restricted cultivation of thermophiles at low temperatures under the laboratory conditions. Artificial culture media used under the laboratory conditions usually fail to support cultivation of thermophiles at low-temperature range. In this study we cultivated the extreme thermoacidophilic archaeon Metallosphaera sedula with the preliminary powdered and sterilized multimetallic extraterrestrial mineral material (the meteorite NWA 1172) under a low temperature regime in laboratory conditions. Our data indicate that M. sedula withstands cold stress and can be maintained at low temperatures, when supplemented with the meteorite NWA 1172 as the sole energy source. Cultivation with the meteorite NWA 1172 opens up new, previously unknown psychrotolerant characteristics of M. sedula, emphasizing that culture conditions (i.e., the nutritional environment) may affect the microbial survival potential in stress related situations. These observations facilitate further investigation of strategies and underlying molecular mechanisms of the survival of thermophilic species in permanently cold habitats.

Modelling of short synthetic antifreeze peptides: Insights into ice-pinning mechanism

Organisms living in icy environments produce antifreeze proteins to control ice growth and recrystallization. It has been proposed that these molecules pin the surface of ice crystals, thus inducing the formation of a curved surface that arrests crystal growth. Such proteins are very appealing for many potential applications in food industry, material science and cryoconservation of organs and tissues. Unfortunately, their structural complexity has seriously hampered their practical use, while efficient and accessible synthetic analogues are highly desirable. In this paper, we used molecular dynamics based techniques to model the interaction of three short antifreeze synthetic peptides with an ice surface. The employed protocols succeeded in reproducing the ice pinning action of antifreeze peptides and the consequent ice growth arrest, as well as in distinguishing between antifreeze and control peptides, for which no such effect was observed. Principal components analysis of peptides trajectories in different simulation settings permitted to highlight the main structural features associated to antifreeze activity. Modeling results are highly correlated with experimentally measured properties, and insights on ice-peptide interactions and on conformational patterns favoring antifreeze activity will prompt the design of new and improved antifreeze peptides.

4D printing composite with electrically controlled local deformation

4D printing holds the important potential for various applications in military, robotics, and healthcare. Among the numerous 4D printed materials, the thermally induced shape memory polymer has been the most used one, which is traditional driven by thermal environments like hot water bath or hot stage. In such way, the whole structure deforms at the same time to transform the shape. However, the environment independent local deformation is required for many applications. In this work, the silver nanowires (Ag-NWs) were employed combining with polylactic acid (PLA) to create a novel electrically driven 4D printing composite. Ag-NWs networks ensured the excellent electric conductivity after repeated tensile and bending deformations. As a result, Ag-NWs could be the excellent “heater” to stimulate the local deformation of PLA under an applied voltage. The theoretical constitutive equations were given, which allowed quantitatively design the structure for desired deformation and property. A biomimetic flower with five petals were demonstrated, that each petal could be controlled independently. An application of the 4D printed structure as a gripper grabbing the cargo in the cold icy environment was realized. Our study has great significance for the future application of shape memory composite materials for multi-functionality in different environments.

Icephery and Icy Score - concepts for multi sensory approach

Introduction For years during the darkest moment of the year, I have photographed the reflections of light in the cracks of ice on a remote frozen lake in Eastern Finland. At first glance it may seem that there is only ice, snow and some light. And this is the case in some point of view, but the more detailed focusing widens the view. This exposition describes how by carefully multisensory reading the environment – here by reading the auditive and thermoception information - is organized and is in continuous moving process. My key concepts are Icephery and The Icy Score which I have created by analyzing what kind of information my thermoception and auditive orientations will give about the ice and the icy environment. In this presentation the other senses are less attentive. Those I have opened in my previous investigations (see Timonen 2014, 2019). By concentrating the multisensory close-reading the place gets new meanings and layers. The place that while ago was peripheral, remote and silence are now near with full of meanings and sounds. The understanding created by the sensory attention pushes the borders of periphery of the place in a constant float. The article proceeds by presenting the theoretical starting points of the research, then describing the concrete workplace on ice from the point of view of the place and materiality and then presenting the concepts the Icephery and the Icy score as a result of carefully multi sensory close-reading. The Icy Score is a visual outcome of the auditive layers of the ice.