Stratovolcano stability assessment methods and results from Citlalt petl, Mexico

ثبت نشده
چکیده

Citlalt petl volcano is the easternmost stratovolcano in the Trans-Mexican Volcanic Belt. Situated within 110 km of Veracruz, it has experienced two major collapse events and, subsequent to its last collapse, rebuilt a massive, symmetrical summit cone. To enhance hazard mitigation efforts we assess the stability of Citlalt petl’s summit cone, the area thought most likely to fail during a potential massive collapse event. Through geologic mapping, alteration mineralogy, geotechnical studies, and stability modeling we provide important constraints on the likelihood, location, and size of a potential collapse event. The volcano’s summit cone is young, highly fractured, and hydrothermally altered. Fractures are most abundant within 5–20-m wide zones defined by multiple parallel to subparallel fractures. Alteration is most pervasive within the fracture systems and includes acid sulfate, advanced argillic, argillic, and silicification ranks. Fractured and altered rocks both have significantly reduced rock strengths, representing likely bounding surfaces for future collapse events. The fracture systems and altered rock masses occur non-uniformly, as an orthogonal set with N–S and E–W trends. Because these surfaces occur non-uniformly, hazards associated with collapse are unevenly distributed about the volcano. Depending on uncertainties in bounding surfaces, but constrained by detailed field studies, potential failure volumes are estimated to range between 0.04–0.5 km3. Stability modeling was used to assess potential edifice failure events. Modeled failure of the outer portion of the cone initially occurs as an “intact block” bounded by steeply dipping joints and outwardly dipping flow contacts. As collapse progresses, more of the inner cone fails and the outer “intact” block transforms into a collection of smaller blocks. Eventually, a steep face develops in the uppermost and central portion of the cone. This modeled failure morphology mimics collapse amphitheaters present at many of the world’s stratovolcanoes that have experienced massive failure events.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Antiradical, Antibacterial and Oxidative Stability of Cinnamon Leaf Oil Encapsulated in β-cyclodextrin

Safety and quality of food have become a challenge for the food industry looking to replace synthetic preservatives with natural agents. In this context, cinnamon leaf essential oil (CLO) showed to be potent antioxidant and antimicrobial agent; however, its active compounds are highly reactive volatiles and grant strong odors and flavors when used as food additive. With this in mind, the object...

متن کامل

THE EFFECTS OF ANTERIOR DISCECTOMY AND INTERPOSITION AL IMPLANT UPON LUMBAR MOTION SEGMENT STABILITY

The cadaver spine motion segment behavior under torsional load was evaluated with the disc intact, with partial anterior discectomy and with spacer insertion. The results of this study explain how anterior lumbar discectomy and interbody fusion (ALIF) affects the torsional stability of the motion segment. The pseudarthrosis rate of the anterior lumbar discectomy and interbody fusion (ALIF)...

متن کامل

Health Risk Assessment of Heavy Metals: Cu, Cd, Pb, Ni and Hg, in Catfish Ariopsis Felis in Southern Mexico

Background: Metal pollution is a problem in many parts of the world. These metals can be harmful when they exceed the recommended limits. By analyzing metal concentrations in living organisms, it is possible to deduce the bioavailability and the level of environmental contamination for specific metals in an ecosystem. The aim of this study was to determine the heavy metals copper, cadmium, lead...

متن کامل

Chimeric fusions of subunit IV and PetL in the b6f complex of Chlamydomonas reinhardtii: structural implications and consequences on state transitions.

The cytochrome b(6)f complex of Chlamydomonas reinhardtii contains four large subunits and at least three small ones, PetG, PetL, and PetM, whose role and location are unknown. Chimeric proteins have been constructed, in which the C terminus of subunit IV is fused to either one or the other of the two putative N termini of PetL. Biochemical and functional analysis of the chimeras together with ...

متن کامل

A human reproductive approach to the study of infertility in chimpanzees: An experience at Leon’s Zoological Park, Mexico

Great apes are mammals close to humans in their genetic, behavioral, social and evolutionary characteristics and new genomic information is revolutionizing our understanding of evolution in primates. However, all these species are endangered. While there are many global programs to protect these species, the International Union for Conservation of Nature (IUCN) projects that in a near future th...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2003