The Puerto Princesa Underground River (Palawan, Philippines): some peculiar features of a tropical, high-energy coastal karst system

2018 ◽  
Vol 466 (1) ◽  
pp. 155-170 ◽  
Author(s):  
Giovanni Badino ◽  
Antonio De Vivo ◽  
Paolo Forti ◽  
Leonardo Piccini
2013 ◽  
Vol 7 ◽  
pp. 423-427 ◽  
Author(s):  
Mahmoud Khaska ◽  
Corinne Le Gal La Salle ◽  
Joël Lancelot ◽  
ASTER team
Keyword(s):  

2017 ◽  
Author(s):  
Victoria E. Frazier ◽  
◽  
James R. Garey

Author(s):  
Arnulf Schiller ◽  
Robert Supper ◽  
Ingrid Schattauer ◽  
Klaus Motschka ◽  
Gonzalo Merediz Alonso ◽  
...  

2015 ◽  
Vol 50 (2) ◽  
pp. 109-116
Author(s):  
MJ Alam ◽  
Y Daoxian ◽  
S Yachuan ◽  
YJ Jiang ◽  
ME Quayum ◽  
...  

Karst areas have much higher ecological vulnerability and are easy to be contaminated with hexachlorinated benzene (HCB) which is introduced as health risk pollutants. HCB concentrations were used to understand the transport of HCB conducted in the Nanshan karst system, China. Water, sediments from the underground river and water, sediments and soil from the surface systems were collected monthly in 2011 - 2012 and HCB were analyzed. The levels of HCB were 19.9 ng L-1 in underground waters and 11.6 ng g-1 in underground sediments while 99.1 ng L-1 in surface waters and 110.5 ng g-1 in surface sediments and 2.8 ng g-1 in soils. Seasonal variations were found in concentrations of HCB both in the waters and the sediments. HCB concentrations varied from 7.8 ng L-1 in winter to 86.9 ng L-1 in spring in the groundwaters and 0.3 ng g-1 in autumn to 36.7 ng g-1 in spring in the underground sediments. HCB concentrations varied from 38.6 ng L-1 in autumn to 1019.8 ng L-1 in spring in the surface waters, 0.7 ng g-1 in autumn to 133.4 ng g-1 in spring in the surface sediments and 2.5 ng g-1 in autumn to 17.4 ng g-1 in winter in soil. The substantial seasonal variation found between underground system and surface system which indicate that the surface systems play major role for the transport and contamination of HCB in the underground river systems due to karst features.Bangladesh J. Sci. Ind. Res. 50(2), 109-116, 2015


2021 ◽  
Author(s):  
Rosangela Addesso ◽  
Simona Cafaro ◽  
Filomena Papaleo ◽  
Rosanna Alaggio ◽  
Francescantonio D'Orilia ◽  
...  

<p>The Pertosa-Auletta cave is a complex karst system of southern Italy included in the “Cilento, Vallo di Diano and Alburni” UNESCO Global Geopark as a focal geosite for the important geological heritage, the experience in geoturism management and the cultural, didactic and recreational appeal. Representing one of the most important perennial springs of the Alburni massif, since the early 1900s, this cave has played a key role within the territory of the Alburni, Cilento and Vallo di Diano National Park, so the complex welcomes thousands of visitors from all over the world every year. The site is managed by the MIdA Foundation (Integrated Environmental Museum) with the goal of education on environmental and landscape value of the caves. Geological peculiarities, historical-cultural characteristics, as well as environmental protection of the geosite are the main subjects of MIdA actions targeted to the local community and geotouristis. Thanks to the cooperation with several national and international research institutes, the Foundation contributes to the production of new knowledge and to the dissemination of results through its organization. In addition to the cave, the MidA system includes two Museums: the Speleo-Archaeological Museum and the Soil Museums, where visitors are led on a journey into the underworld. Tours and practical activities focus on multidisciplinary information about carsism, genesis of the Pertosa-Auletta cave, archeological findings in the site. A special effort is devoted to soils, precious sources of underground treasures, and ecosystem processes regulating life on the planet. The tour starts from the rocks and their properties and continues through habitats for the growth of numerous lifeforms linked to their structure and chemical composition. The complex relationshis of below-ground environments with water and other earth features are presented. The Pertosa-Auletta cave offers a good example of how people can understand the importance of a complex karst system. Inside the cave the Negro, an underground river flows and it plays an important role in the karst complex. Water and sediments of the Negro have preserved an archeological settlement on piles dating back to the Bronze Age. The presence of piles inside a cave represents one of the most characteristic features of this karst complex and is an example of different uses of the cave through the ages. During the Bronze Age, the Pertosa-Auletta cave was used for both a cultural and a living purpose. In Classical and Medieval times, the complex became a shrine, dedicated first to pagan gods related to fertility and then to the Archangel Michael. Findings are shown in the MIdA Speleo-Archeological Museum along with multimedia displays and reconstructions of the Prehistoric pile. The Pertosa-Auletta cave is also a research site on karst phenomena, hydrology and speleo-biology with important findings on vermiculations, where the evidence of microbial activity supports the possible involvement of biogenic processes in vermiculation development in karst caves. </p>


1984 ◽  
Vol 75 ◽  
pp. 599-602
Author(s):  
T.V. Johnson ◽  
G.E. Morfill ◽  
E. Grun

A number of lines of evidence suggest that the particles making up the E-ring are small, on the order of a few microns or less in size (Terrile and Tokunaga, 1980, BAAS; Pang et al., 1982 Saturn meeting; Tucson, AZ). This suggests that a variety of electromagnetic and plasma affects may be important in considering the history of such particles. We have shown (Morfill et al., 1982, J. Geophys. Res., in press) that plasma drags forces from the corotating plasma will rapidly evolve E-ring particle orbits to increasing distance from Saturn until a point is reached where radiation drag forces acting to decrease orbital radius balance this outward acceleration. This occurs at approximately Rhea's orbit, although the exact value is subject to many uncertainties. The time scale for plasma drag to move particles from Enceladus' orbit to the outer E-ring is ~104yr. A variety of effects also act to remove particles, primarily sputtering by both high energy charged particles (Cheng et al., 1982, J. Geophys. Res., in press) and corotating plasma (Morfill et al., 1982). The time scale for sputtering away one micron particles is also short, 102 - 10 yrs. Thus the detailed particle density profile in the E-ring is set by a competition between orbit evolution and particle removal. The high density region near Enceladus' orbit may result from the sputtering yeild of corotating ions being less than unity at this radius (e.g. Eviatar et al., 1982, Saturn meeting). In any case, an active source of E-ring material is required if the feature is not very ephemeral - Enceladus itself, with its geologically recent surface, appears still to be the best candidate for the ultimate source of E-ring material.


Author(s):  
J. B. Warren

Electron diffraction intensity profiles have been used extensively in studies of polycrystalline and amorphous thin films. In previous work, diffraction intensity profiles were quantitized either by mechanically scanning the photographic emulsion with a densitometer or by using deflection coils to scan the diffraction pattern over a stationary detector. Such methods tend to be slow, and the intensities must still be converted from analog to digital form for quantitative analysis. The Instrumentation Division at Brookhaven has designed and constructed a electron diffractometer, based on a silicon photodiode array, that overcomes these disadvantages. The instrument is compact (Fig. 1), can be used with any unmodified electron microscope, and acquires the data in a form immediately accessible by microcomputer.Major components include a RETICON 1024 element photodiode array for the de tector, an Analog Devices MAS-1202 analog digital converter and a Digital Equipment LSI 11/2 microcomputer. The photodiode array cannot detect high energy electrons without damage so an f/1.4 lens is used to focus the phosphor screen image of the diffraction pattern on to the photodiode array.


Author(s):  
J. M. Oblak ◽  
W. H. Rand

The energy of an a/2 <110> shear antiphase. boundary in the Ll2 expected to be at a minimum on {100} cube planes because here strue ture is there is no violation of nearest-neighbor order. The latter however does involve the disruption of second nearest neighbors. It has been suggested that cross slip of paired a/2 <110> dislocations from octahedral onto cube planes is an important dislocation trapping mechanism in Ni3Al; furthermore, slip traces consistent with cube slip are observed above 920°K.Due to the high energy of the {111} antiphase boundary (> 200 mJ/m2), paired a/2 <110> dislocations are tightly constricted on the octahedral plane and cannot be individually resolved.


Author(s):  
E.D. Wolf

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.


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