5 research outputs found
Nova spoznanja o nastanku piroduktov Galapaškega otočja, Ekvador
There has been little research on the genesis and development of pyroducts (or lava tubes) originating from Gala´pagos volcanoes. Pyroducts are responsible for the lateral, post-eruptive transport of lava because they are highly effective as thermal insulators. After eruptions terminate, these conduits often become accessible as caves. In March 2014 the 16th International Symposium on Vulcanospeleology brought a large group of vulcanospeleological specialists to the Islands. During the meeting a number of pyroducts were visited and studied in context on the island of Santa Cruz and around Isabella’s Sierra Negra volcano in the western, most active, part of the Gala´pagos. The longest of the caves, Cueva del Cascajo, about 3 km in length, was partly surveyed and nine other caves were visited. Structural features such as thickness of roof, evidence of downcutting, presence of oxbows, secondary ceilings, lavafalls, collapses and pukas were particularly studied for evidence they reveal about developmental stages of pyroducts. The resulting data show that the pyroducts were formed by "inflation" with the primary roof consisting of uninterrupted paŻhoehoe sheets. No pyroducts were identified that developed by the crusting-over of channels. The studies strongly confirm inferences drawn from other hot-spot related islands, such as Hawai’i.Raziskav o nastanku in razvoju piroduktov ali lavinih cevi na galapaških vulkanih je malo. Pirodukti so pomembni za bočni transport lave po izbruhu in so toplotni ščit med tokom lave in zunanjim ozračjem. Po končanem izbruhu ti kanali ostanejo dostopni kot lavine cevi. Marca 2014 je na Galapaškem otočju potekal 16. mednarodni simpozij o vulkanospeleologiji. V okviru tega smo obiskali in proučevali številne pirodukte na otoku Santa Cruz in v okolici vulkana Isabella's Sierra Negra na zahodnem, najaktivnejšem delu Galapaškega otočja. Delno smo izmerili najdaljšo, 3 km dolgo jamo Cueva del Cascajo in obiskali še devet drugih jam. Pri tem smo bili pozorni na strukturne elemente, ki kažejo na razvojne faze piroduktov, kot so debelina stropa, vrezovanje, prisotnost obvodnih rovov (oxbow), ostankov lavinih slapov, sekundarnih stropov, odprtin na površje (puka) in vdorov. Podatki in opažanja kažejo, da so jame nastale z zaporednim napredovanjem in napihovanjem, na kar kaže tudi primarni strop iz neprekinjenih plasti pahoehoe lave.. Nobeden od piroduktov ni nastal zaradi strjevanja lave nad tokom. Podobne ugotovitve veljajo tudi jame na vulkanih drugih vročih točk, kot na primer na havajskih vulkanih
Observation of the Catfish Chaetostoma microps Climbing in a Cave in Tena, Ecuador
As part of a mapping and preliminary flora and fauna inventory of hypogean life in caves, developed in Cretaceous limestones in the sub-andean zone of Ecuador, we were able to observe a number of catfish climbing a steep flowstone waterfall in the dark zone of a cave. The waterfall was a minor infeeder to the small stream that flowed through the cave. On investigation the fish were determined to be Chaetostoma microps Günther, 1864 (Siluriformes Loricariidae), a detritivorous–herbivorous neotropical freshwater catfish, endemic to the upper reaches of the Amazon basin in Ecuador. We document the observation of this species exhibiting climbing behavior as well as the first observation of the family exhibiting climbing behavior in a cave. We also document the sympatry of this species and Astroblepus pholeter Collette, 1962 (Siluriformes Astroblepidae)
Observation of the Catfish Chaetostoma microps Climbing in a Cave in Tena, Ecuador
As part of a mapping and preliminary flora and fauna inventory of hypogean life in caves, developed in Cretaceous limestones in the sub-andean zone of Ecuador, we were able to observe a number of catfish climbing a steep flowstone waterfall in the dark zone of a cave. The waterfall was a minor infeeder to the small stream that flowed through the cave. On investigation the fish were determined to be Chaetostoma microps Günther, 1864 (Siluriformes Loricariidae), a detritivorous–herbivorous neotropical freshwater catfish, endemic to the upper reaches of the Amazon basin in Ecuador. We document the observation of this species exhibiting climbing behavior as well as the first observation of the family exhibiting climbing behavior in a cave. We also document the sympatry of this species and Astroblepus pholeter Collette, 1962 (Siluriformes Astroblepidae)
New records and new species of springtails (Collembola: Entomobryidae, Paronellidae) from lava tubes of the Galápagos Islands (Ecuador)
The Collembola fauna of the Galápagos Islands is relatively unexplored with only thirty-five reported species. Entomobryoidea, the most diverse superfamily of Collembola, is underrepresented, with only five species reported from the Galápagos. Here we present the findings of the first survey of Collembola from Galápagos lava tube caves, providing a significant update to the total number of entomobryoid Collembola species reported from the Galápagos Islands. Collections made during a March 2014 expedition to study lava tubes of the islands yielded new records for seven species of Entomobryoidea, including four genera not previously reported from the Galápagos Islands: Coecobrya, Entomobrya, Heteromurus, and Salina. As a result, three new species (Entomobrya darwini Katz, Soto-Adames & Taylor, sp. n., Pseudosinella vulcana Katz, Soto-Adames & Taylor, sp. n., and Pseudosinella stewartpecki Katz, Soto-Adames & Taylor, sp. n.) are described and new diagnoses are provided for Heteromurus (Heteromurtrella) nitens Yosii, 1964, Lepidocyrtus nigrosetosus Folsom, 1927 and Pseudosinella intermixta (Folsom, 1924). Lepidocyrtus leleupi Jacquemart, 1976 is synonymized with L. nigrosetosus. An updated checklist of all species within the superfamily Entomobryoidea reported from the Galápagos Islands is provided