Science topics: Geological Hazards
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Geological Hazards - Science topic

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Questions related to Geological Hazards
  • asked a question related to Geological Hazards
8 answers
Dear Esteemed Experts. 
Your comments are highly appreciated regarding our bachelor program in field of Engineering Geology and Hydrogeology).
We are working on updating of the study program (Curriculum) to Engineering Geology and Hydrogeology department. The below competences and outcomes are designed for bachelor program (Engineering Geology and Hydrogeology Department). We kindly as you to write your comments and feedbacks.
Graduated students are able to:
Subject Competences:
· Ability to identify and classify different rocks and soils
· Ability to collect Data and interpret them
· Making and using engineering geological and Hydro maps
· Ability to determine geological hazards and analyze them
· Ability to plan and conduct geotechnical and Hydro investigations
· Site selection of wells and analysis aquifer parameter’s
· Ability to perform field test and logging of wells
· Analyze water quality tests
· Ability to prepare Hydrogeological and geotechnical reports
· To be familiar with geology of Afghanistan
· Ability to manage and run engineering projects
· Basic knowledge in High Mathematics, physics, chemistry, plan geometry
· Identity, explain and apply basic knowledge
Learning Outcomes of program:
· Identify and classify different rocks and soils
· Collect, interpret and synthesize the data to solve the geotechnical and hydrogeological problem
· Produce the engineering geological and hydrogeological maps and extract information from the maps
· Identify the geological hazards and characterize them
· Plan, conduct, and organize the geotechnical and hydrogeological investigations
· Select well site, development of wells and analyze aquifer parameters
· Perform and interpret field test and logging of wells
· Conduct and analyze water quality test
· Prepare hydrogeological and geotechnical reports
· Describe and interpret the geology of Afghanistan
· Organize and implement geo-engineering projects
· Achieve awareness of the work safety guidelines
· Read and comprehend the relevant literature, hold technical communication with people from the field and from outside the field and write technical reports in their native and international language
· Apply and transform acquired knowledge into practice
· Work in a team, under pressure and in different areas and situations
· Use new technology, equipment, and software
· Plan and manage time
· Take over social responsibilities
Relevant answer
You should firs consider basic details pertaining to all three basic types of rocks i.e. Igneous, Metamorphic and Sedimentary Rocks.
Subsequently, basics about site selection/ geological investigation studies for various civil structures, esp. Hydro Power Projects (Dams/ Reservoirs etc.), Underground Excavations (Tunnels, Caverns etc.), Bridges etc.
Rock Mass Characterization including various empirical approaches like Rock Mass Rating (RMR), Q-Syste, Geological Strength Index (GSI) etc. preferably with some case studies.
Basic aspects of Structural Geology including dip strike calculations, plans and sections preparations etc.
Engineering Geological Properties of Rocks and Soils, with procedures/ codes for their determination with in laboratory as well as in field.
Basic/ Advanced Hydrological Properties/ Tests/ Investigation Procedures with examples/ case studies.
Best Wishes
  • asked a question related to Geological Hazards
10 answers
Hello everyone,
I asked a previous question as to whether dense ash aggregates (or "acc-laps") have ever been made in any wind tunnel lab thus far in their fully formed sub-spherical or ellipsoïdal shape ?
The answer has been: "not yet", even though this would allow to more closely simulate mixed phase aggregation under more realistic in situ ashcloud conditions.
I am wondering if any accretionary lapilli greater than about 10mm across or so have ever been collected immediately upon reaching the ground and studied immediately, or preserved in a cold box (to prevent them from any melting) and studied in the lab (eg. on a cryogenic SEM stage, or to measure their in situ temperature, and recover inner fluids from the intergranular space....) ?
The reason is that there is the hypothesis that they form like hailstones by riming, once they grow above a size characteristic of the drop break-up limit (5-6mm across). If this "volcanogenic hailstone" hypothesis is correct, then my expectation is that a proportion of accretionary lapilli larger than about 6mm diameter should still be frozen upon reaching the ground (especially if above-ground températures are close to 0°C; if not partial melting takes place), so that somewhat larger ones (say 10mm diameter ones) may still be frozen (despite partial melting) and still contain inner ice upon landing on the ground.
Has anyone checked for this ?
Assuming for a moment that larger sub-concentric acclaps can be sampled immediately, preserved and analysed for oxygen isotopes of any trapped ice water, then this could provide valuable data as to the temperature environments through which the acc-laps have been recycled again and again in the volcanic cloud before ultimately falling out.
Analogous oxygen isotope ratio studies  of the subconcentric layers of hailstones from severe thunderstorms have provided such information in that case.
I am looking forward to hearing back.
Best wishes and kind regards,
Relevant answer
Hello Gerald, Ulli, Volker,
There quite a few nice examples I'm aware of where accretionary lapilli were sampled soon after fallout. One is the 2002 study by Bonadonna et al. on the 1995-1999 eruption at Montserrat (Geol. Soc. London Memoirs). Another is the 2009 eruption of Redoubt, Alaska, described by Kristi Wallace et al. in JVGR, 2013. The latter samples provided the basis of my study of 'volcanic hail' using radar observations and plume modeling with ATHAM in Nature Communications. As suggested by Gerald, these samples were indeed frozen upon landing, though that's not too surprising for an Alaskan eruption. It is clear from lab experiments that neither ice nor salt precipitates are required to grow aggregates >1cm diameter. I do not think aggregates need to undergo freezing, however, it does seem to be very common and does affect their growth rates and internal structure. 
There are also some gorgeous, layered accretionary lapilli from the 18 May 1980 eruption of Mount St. Helens, which have been archived for the past 35 years. I've recently thin-sectioned these samples and am currently working on comparing their internal structures to the eruptive stratigraphy and photographic record of the eruption dynamics. Hopefully I'll be presenting this work at the Cities on Volcanoes meeting in Chile this year. Ulli and I were talking about organizing a workshop on ash aggregation there if there's enough interest. 
All the best
  • asked a question related to Geological Hazards
8 answers
I prepared physical and social vulnerability maps of Seoul and Busan megacities. But I could not find the methods to validate those maps.
Relevant answer
I do not work with social modelling, but I would use old data and analyse them against the predictor variables (environmental and others). And based on this statistic I would create a predictive models and then used a second old dataset to validate, or rather evaluate, the predictive model. But that requires that the data used for happening is within the range of the data used for creating the model, if not you can not trust the predictive model if you  do not fully trust the interpolation that is made.
  • asked a question related to Geological Hazards
5 answers
How to incorporate rainfall probability and landslide susceptibility to make future landslide hazard map
Relevant answer
Dear Ananta,
There are many ways to assess rainfall induced landslides susceptibility. In general the available techniques are divided in physical and probabilistic approaches. Both need morphological data (DEM) and a database of past events to be calibrated for a specific region considered geologically and morphologically homogeneous. In particular physical models need IDF curves and a certain amount of geotechnical parameters of soils that are in some cases difficult to obtain. But their major advantage is that they can easily include the return period without having information on timing and rainfall amount that have triggered the landslide, which are hardly available in remote areas (i.e. mountainous areas). While statistical models can avoid the use of geotechnical parameters, but they need an extended database with information on time and rainfall of previous events (not easily available) to build, for instance, rainfall thresholds.
The reference given by Hamid is really interesting. Many authors, including my research group, have been investigating on these topics. I leave you some more references hoping that will be of your interest.
Fell R, Corominas J, Bonnard C, Cascini L, Leroi E, Savage WZ (2008) Guidelines for landslide susceptibility, hazard and risk zoning for land use planning. Eng Geol 102:85–98
J. Corominas and J. Moya, “A review of assessing landslide frequency for hazard zoning purposes,” Engineering Geology, vol. 102, no. 3-4, pp. 193–213, 2008
Chevalier G, Medina V, Hürlimann M, Bateman A (2013) Debris-flow susceptibility analysis using fluvio-morphological parameters and data mining: application to the Central-Eastern Pyrenees. Natural Hazards. Springer, Netherlands, pp 1–26
Bregoli, F., Medina, V., Chevalier, G., Hürlimann, M., & Bateman, A. (2014). Debris-flow susceptibility assessment at regional scale: Validation on an alpine environment. Landslides, 1-18.
Good luck,
  • asked a question related to Geological Hazards
6 answers
I’m interested in teaching several introductory labs about the ocean for geology and physics students. I am particularly interested in doing hands on activities about waves and tsunamis. Does anyone have suggestions of activities, demonstrations, or case studies that are low cost/free to set up that you like to use with your classes?
Thanks in advance for your helpful hints!
Relevant answer
Demonstrations of different wave phenomena at five stations.Students work with the five hand-on demos in small groups
  • asked a question related to Geological Hazards
3 answers
Need to analysize landslide hazard ratings.
Relevant answer
Dear Sandip,
The relevant part of the distribution in natural hazard analysis is the tail, especially in distributions with hard tails (ie, with extreme values). Mean values are not so relevant. We quantify natural hazard using the concept of Average Recurrence Interval (ARI) which can be calculated by fitting an Extreme Value Distribution to the tail of your data. This ARI gives you the magnitude of extreme values of an event and their recurrence, it is more commonly known as 'Return Period'.