Subterranean Tunnels Research Articles

Light sensitivity of the circadian system in the social Highveld mole-rat Cryptomys hottentotus pretoriae.

Highveld mole-rats (Cryptomys hottentotus pretoriae) are social rodents that inhabit networks of subterranean tunnels. In their natural environment, they are rarely exposed to light, and consequently their visual systems have regressed over evolutionary time. However, in the laboratory they display nocturnal activity, suggesting that they are sensitive to changes in ambient illumination. We examined the robustness of the Highveld mole-rat circadian system by assessing its locomotor activity under decreasing light intensities. Mole-rats were subjected to seven consecutive light cycles commencing with a control cycle (overhead fluorescent lighting at 150lx), followed by decreasing LED lighting (500, 300, 100, 10 and 1lx) on a 12h light:12h dark (L:D) photoperiod and finally a constant darkness (DD) cycle. Mole-rats displayed nocturnal activity under the whole range of experimental lighting conditions, with a distinct spike in activity at the end of the dark phase in all cycles. The mole-rats were least active during the control cycle under fluorescent light, locomotor activity increased steadily with decreasing LED light intensities, and the highest activity was exhibited when the light was completely removed. In constant darkness, mole-rats displayed free-running rhythms with periods (τ) ranging from 23.77 to 24.38 h, but was overall very close to 24 h at 24.07 h. Our findings confirm that the Highveld mole-rat has a higher threshold for light compared with aboveground dwelling rodents, which is congruent with previous neurological findings, and has implications for behavioural rhythms.

A mmWave Radar SLAM Method in Subterranean Tunnel for Low Visibility and Degradation

A mmWave Radar SLAM Method in Subterranean Tunnel for Low Visibility and Degradation

Evolution of water extraction technology (spring tunnels) in the Southern Levant during the last three millennia

AbstractA spring tunnel is an ancient water installation used to artificially increase the water yield of a spring through a subterranean tunnel. We have developed a database of 216 spring tunnels documented in the central region of the Southern Levant (present‐day Israel), constructed between Iron Age II and the modern era. The study focuses on the evolution of this water installation over a period of 2500 years, examining these constructions from technological, typological, spatial, and cultural perspectives. Within the larger database, 132 spring tunnels have been mapped, from which we present 36 examples selected to outline the typology and chronology of this type of water installation. The findings of the study indicate a diachronic correlation between the distribution of settlement in the mountain region and the number and geographical distribution of spring tunnels. Ethnic and religious changes, and the complexity of the mountain region's population, are also reflected in the use of these water installations. The comprehensive water structure database presented in this article, from a peripheral, yet strategically located region in relation both to the Far East and to West Mediterranean Empires, is used for initial consideration of local initiatives versus the knowledge‐transfer process.

Pressurized lunar lava tubes for habitation

Lava tubes are subterranean tunnels that form as a result of lava flows and appear to extend for long distances beneath the surface of a planet. They are a naturally occurring feature of the Moon. For decades these cave systems have piqued the interest of researchers, not just for their geological complexity, but also for their potential as a habitation site when humans return to the Moon. The internal environment of a lunar lava tube promises to be a benign alternative to the harsh lunar surface; it can provide natural protection from radiation, micrometeoroids, and extreme temperature fluctuations. This paper furthers the study of lunar lava tubes by presenting the possibility of pressurizing them with breathable air. Using a 2D ANSYS simulation model, a range of lava tube sizes are subjected to varied magnitudes of internal pressurization. It is ultimately concluded that it is possible to pressurize a small lava tube while maintaining its structural integrity.

Parallel evolution of semicircular canal form and sensitivity in subterranean mammals.

The vertebrate vestibular system is crucial for balance and navigation, and the evolution of its form and function in relation to species' lifestyle and mode of locomotion has been the focus of considerable recent study. Most research, however, has concentrated on aboveground mammals, with much less published on subterranean fauna. Here, we explored variation in anatomy and sensitivity of the semicircular canals among 91 mammal species, including both subterranean and non-subterranean representatives. Quantitative phylogenetically informed analyses showed significant widening of the canals relative to radius of curvature in subterranean species. A relative canal width above 0.166 indicates with 95% certainty that a species is subterranean. Fluid-structure interaction modelling predicted that canal widening leads to a substantial increase in canal sensitivity; a reasonably good estimation of the absolute sensitivity is possible based on the absolute internal canal width alone. In addition, phylogenetic comparative modelling and functional landscape exploration revealed repeated independent evolution of increased relative canal width and anterior canal sensitivity associated with the transition to a subterranean lifestyle, providing evidence of parallel adaptation. Our results suggest that living in dark, subterranean tunnels requires good balance and/or navigation skills which may be facilitated by more sensitive semicircular canals.

Unsupervised Online Learning for Robotic Interestingness With Visual Memory

Autonomous robots frequently need to detect "interesting" scenes to decide on further exploration, or to decide which data to share for cooperation. These scenarios often require fast deployment with little or no training data. Prior work considers "interestingness" based on data from the same distribution. Instead, we propose to develop a method that automatically adapts online to the environment to report interesting scenes quickly. To address this problem, we develop a novel translation-invariant visual memory and design a three-stage architecture for long-term, short-term, and online learning, which enables the system to learn human-like experience, environmental knowledge, and online adaption, respectively. With this system, we achieve an average of 20% higher accuracy than the state-of-the-art unsupervised methods in a subterranean tunnel environment. We show comparable performance to supervised methods for robot exploration scenarios showing the efficacy of our approach. We expect that the presented method will play an important role in the robotic interestingness recognition exploration tasks.

Image Recognition about Stability of Soft Surrounding Rock in Tunnel Based on ILBP Algorithm

With China’s fast expansion of urban traffic and railway engineering, a great number of subway and railway lines have been erected in subterranean tunnels in recent years. When the tunnel is in the process of construction, it will encounter the weak fracture zone, and the surrounding rock of this part of the tunnel is often poor stability and deformation is difficult to control, which will lead to the smooth progress of the project, delay and other problems. Therefore, to facilitate the timely treatment of tunnel soft surrounding rock, the study of image recognition of its stability is particularly important. Based on this, an improved local binary mode algorithm (ILBP) is proposed in this paper. By adjusting the weight of binary polynomial in local binary mode (LBP) operator, the target of ILBP is to extract the characteristics of weak surrounding rock of tunnel at a specific location, hoping to provide reference for the follow-up study of tunnel engineering.

Multimodality robotic systems: Integrated combined legged-aerial mobility for subterranean search-and-rescue

This work presents a field-hardened autonomous multimodal legged-aerial robotic system for subterranean exploration, extending a legged robot to be the carrier of an aerial platform capable of a rapid deployment in search-and-rescue scenarios. The driving force for developing such robotic configurations are the requirements for large-scale and long-term missions, where the payload capacity and long battery life of the legged robot is combined and integrated with the agile motion of the aerial agent. The multimodal robot is structured around the quadruped Boston Dynamics Spot, enhanced with a custom configured autonomy sensor payload as well as a UAV carrier platform, while the aerial agent is a custom built quadcopter. This work presents the novel design and hardware implementation as well as the onboard sensor suites. Moreover it establishes the overall autonomy architecture in a unified supervision approach while respecting each locomotion modality, including guidance, navigation, perception, state estimation, and control capabilities with a focus on rapid deployment and efficient exploration. The robotic system complete architecture is evaluated in real subterranean tunnel areas, in multiple fully autonomous search-and-rescue missions with the goal of identifying and locating objects of interest within the subterranean environment.

Towards Autonomous Aerial Scouting Using Multi-Rotors in Subterranean Tunnel Navigation

Towards Autonomous Aerial Scouting Using Multi-Rotors in Subterranean Tunnel Navigation

Animal architecture

Many animals shape and modify their physical environment, thereby creating a diversity of structures, from underground burrows to constructed nests to towering above-ground edifices, all of which are referred to as 'animal architecture'. Examples of animal architecture are found everywhere on Earth: beneath the sea and on land, below and above ground, and hanging into the air off trees and precipices. Fossils suggest that animals have been acting as architects by constructing shelters and other built structures for hundreds of millions of years. Animal architects are widespread taxonomically, spanning invertebrates (Figure 1) and vertebrates (Figure 2). Their architectural creations are diverse, including: the fortress-like mounds of termites, the housing markets of architecturally remodeled shells of social hermit crabs, the subterranean tunnel systems of naked mole rats, the intricately decorated bowers of bowerbirds or the engineered dams of beavers. Even the tallest of human architecture is rivaled by animal architecture: termite mounds exceed skyscrapers in their size relative to that of the architects. Animal architecture raises many fascinating questions at the interface of behavior, ecology and evolution: How is this architecture built? What instinctive 'blueprints' or cognitive mechanisms underlie its creation? What functions does the architecture serve? And why did it evolve? Notably, because architecture changes the world, it may have far-reaching impacts on collective behavior and social life, interactions among communities of species and whole ecosystems. Architecture may even have altered the very course of evolution.

A history of tunnels and using active seismic methods to find them

The modern use of clandestine tunnels has antagonized military and law enforcement agencies alike over the past 50 years, not only in their simplicity and effectiveness, but also in the challenges of defending against them. Likewise, geophysicists have been confounded, finding what should be a straightforward target on paper — detecting an anomaly with often vastly different physical properties than its surroundings — a much more difficult task than models would suggest. We have evaluated half a century of applied seismic investigation, gaining a history of the use of active seismic methods to detect subterranean tunnels in war zones, along borders, and around facility perimeters. Previously published studies using a variety of seismic methods such as reflection, refraction, surface waves, diffraction, resonance, and full-waveform inversion were aggregated to serve as a reference for void and tunnel detection-related research and to show the progression of the methods used over time.

Correction to “Towards Autonomous Aerial Scouting Using Multi-Rotors in Subterranean Tunnel Navigation”

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Towards Autonomous Aerial Scouting Using Multi-Rotors in Subterranean Tunnel Navigation

This work establishes a robocentric framework around a non-linear Model Predictive Control (NMPC) for autonomous navigation of quadrotors in tunnel-like environments. The proposed framework enables obstacle free navigation capabilities for resource constraint platforms in areas with critical challenges including darkness, textureless surfaces as well as areas with self-similar geometries, without any prior knowledge. The core contribution of the proposed framework stems from the merging of perception dynamics in a model-based optimization approach, aligning the vehicles heading to the tunnels’ open space expressed in the $x$ axis coordinate in the image frame of the most distant area. Moreover, the aerial vehicle is considered as a free-flying object that plans its actions using egocentric onboard sensors. The proposed method can be deployed in both fully illuminated indoor corridors or featureless dark tunnels, leveraging visual processing from either RGB-D or monocular sensors for generating direction commands to keep flying in the proper direction. Multiple experimental field trials demonstrate the effectiveness of the proposed method in challenging environments.

Painful Subjects

Painful Subjects

Insects as zoogeomorphic agents: an extended review

AbstractInsects are the largest and most diverse group of living organisms on Earth, playing a critical but underestimated role as agents of geomorphic change. Burrowing insects create micro‐scale landforms such as subterranean tunnels and surface mounds and, by this way, exert an influence on hydrology, soil erosion and sediment transfer at a wider landscape scale. However, social insects represented by ants and termites were the main taxa studied as geomorphic agents and ecosystem engineers. This article proposes an extended and critical literature review of insects as zoogeomorphic agents, with reference to various taxonomic orders and families of insects having a burrowing behaviour. It provides a large overview of their primary and secondary impacts on Earth surface systems, both supported by naturalistic evidence and available quantitative data. Some evolutionary insights are discussed based on fossil evidence of geomorphic work by insects and, at finer temporal scale, on recent advances in radiometric and luminescence dating of insect mounds. Finally, this article explores the fruitful links between geomorphology and entomology, and suggests several research perspectives in order to develop an integrated understanding of the importance of insects in Earth surface processes and landforms. © 2020 John Wiley &amp; Sons, Ltd.

A preliminary investigation of the effect of mole cricket (Gryllotalpa unispina Saussure; Orthoptera: Gryllotalpidae) activity on soil evaporation in semiarid Loess Plateau of northwest China

Many insect species, especially soil-inhabiting ones, greatly affect the physical and chemical properties of soil. The widespread soil-inhabiting mole cricket on the northern Loess Plateau creates subterranean tunnels, damages topsoil structures, and likely alters soil infiltration, erosion, and evaporation. In this study, we assessed the effect of adult and immature mole crickets (Gryllotalpa unispina Saussure; Orthoptera: Gryllotalpidae) on soil water evaporation in loam soil. A series of simulation experiments was conducted in iron buckets (20 cm in diameter and 20 cm high) filled with disturbed soil at the Shenmu Erosion and Environment Research Station. The soil was saturated and drained until the water content approached the field moisture capacity (25.3%), and then the soil was subjected to evaporation for 58 days. Evaporation was found to occur in two stages. In the first 18 days, daily evaporation in soil with adult and immature mole crickets was significantly (P < 0.05) lower than that in soil without mole cricket. Compared with bare soil treatment, the cumulative evaporation of soil treated with adult and immature mole crickets decreased by 24.6% and 13.9%, respectively. In the second stage, daily evaporation in soil treated with mole cricket was greater than that in bare soil due to the higher soil moisture in treatments with mole cricket in the first stage. Under the condition of continuous drought, mole cricket activity had a lag effect on soil water evaporation. The effects of mole cricket activity on soil evaporation depended on the soil-surface disturbance area, i.e., a larger disturbance area corresponded to more greatly reduced soil-evaporation function. These results can help elucidate the effects of soil-inhabiting insects on water movement in semiarid areas.

Qanat and territorial cooperation in Iran

In the central plateau of Iran, the climatic and geographical conditions promoted the technology of qanat which on its turn underlay the production systems in this region. A qanat consists of a series of shaft wells interconnected by a subterranean tunnel into a hill slope that drains out the groundwater seepage and conveys it onto the earth surface. This paper takes up the qanat of Hassan Abad and its peculiarities from which a model of common benefit has been abstracted. This model explains how several territories with similar economic structure could have developed a cooperative water management system that ensures sustainable water equality. The Hasan Abad qanat originates from Ebrahim Abad valley near the town of Mehriz and travels 40 km to Yazd. The water of this qanat is shared between the town of Mehriz and the villages of Dehno and Hasan Abad. One of the most important properties of this qanat is its territorial cooperation which relates to the qanat’s dynamics. The paper argues that dormant territorial behavior can pave the way for a high sense of cooperation and social capital, which are all associated with the peculiarities of qanat.

First Report of a Population of the Freshwater Caridean Shrimp Macrobrachium carcinus from an Anchialine Cave on Grand Cayman

Macrobrachium carcinus is reported for the first time from the Cayman Islands. Specimens were collected on multiple occasions from an unusual habitat for this species – an anchialine cave. It is likely the cave was colonized by M. carcinus larvae via movement through subterranean karst tunnels from the sea inland to the cave entrance. Because only juveniles were collected, it is uncertain whether reproduction is occurring in this cave. However, it is possible M. carcinus may continue to colonize this and other similar caves, and sustained populations may eventually become established on Grand Cayman.

Staying in a fallout shelter: exploring ostalgia through post-socialist heterotopia

This article details our attempts at making sense of an ostalgic heterotopic space. We relay here our analysis of staying in and exploring a disused air raid shelter built during WWII, converted into a fallout shelter at the beginning of the Cold War and recently repurposed in an anti-communist museum/tourist hotel/ostalgic canteen called 10Z Bunker. As we enter the subterranean tunnels packed with memorabilia from an indistinct ‘past’, we strive to shed some light on the dim heterotopic space we found. We explore the intersection of material objects and partly refurbished underground spaces and employ the concept of heterotopia to understand how ostalgia is enmeshed with anti-communism in this commodified history display. We argue that the heterotopic (and heterochronic) nature of the display allows for stripping ostalgia of its disruptive potential to challenge the prevailing narratives of Western domination and using it to further the anti-communist meaning promulgated by the 10Z Bunker.

Late Holocene hydrology of Lake Maharlou, southwest Iran, inferred from high-resolution sedimentological and geochemical analyses

Sedimentological (dry density, micro-fa-cies analysis on thin-slides, X-ray diffraction, layer counting) and elemental analyses (X-ray fluorescence) of a 3.5-m-long sediment core (MAH-B) from saline Lake Maharlou (SW Iran) were used to infer hydrological changes over the last * 3800 years. The sediment consists of thin, alternating beds of evapor-ites (halite, gypsum), carbonates (calcite, aragonite) and detrital minerals (quartz, muscovite, chlorite). We interpret the data with respect to three main hydrologic conditions: (1) nearly complete desiccation of the lake, marked by frequent halite layers, (2) hypersaline conditions marked by gypsum abundance, (3) wet conditions, characterized by high river-borne terrige-nous sediment input with high potassium content. Distinct flood layers indicate fluvial activity. From about 3800-2000 cal year BP, terrigenous sediment supply was high, with peaks at 3700-3650, 3500-3450, and 3400-3250 cal year BP. Evaporative conditions were not common. From ca. 2000 cal year BP to present, detrital minerals are less abundant, and the increase in gypsum abundance suggests drier climate with enhanced evaporation. Frequent desiccation events occurred from 1100 to 700 cal year BP. The late Holocene hydrology of Lake Maharlou corresponds well with records of dune formation and phases of river alluviation in Iran and the Arabian Peninsula, and with regional speleothem records. In addition to the influence of climate change on the lake hydrology, ancient humans modified water drainage in the catchment. Periods of subterranean tunnel (qanats) use correspond to dramatic shrinkage of the water body. We propose that climate changes drove long-term water shortages that were enhanced by anthro-pogenic activities, leading to more frequent desiccation of the lake during the last millennium.