O vjerojatnosti prethodnih potresa u Hrvatskoj i susjednim područjima

master's thesis

• Title (english): About foreshock probability in Croatia and nearby areas
• Author: Lada Dvornik
• Mentor: Marijan Herak (mentor)
• Committee member: Marijan Herak (predsjednik povjerenstva)
• Committee member: Iva Dasović (član povjerenstva)
• Committee member: Ivana Herceg Bulić (član povjerenstva)
• Committee member: Josip Stipčević (član povjerenstva)
• Committee member: Branko Grisogono (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Geophysics); Zagreb
• Defense date and country: 2022-09-29, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Geophysics; Seismology and Physics of the Earth's Interior

Abstract

Koliko je vjerojatno da je potres koji je upravo nastupio samo prethodni te da nakon njega slijedi još i jači, glavni potres je često postavljeno pitanje netom nakon što se potres dogodi. Odgovor na to pitanje leži u dosadašnjoj seizmičnosti područja od interesa: potrebno je provesti analizu kataloga potresa, što je upravo i tema ovog rada. Nakon što su potresi označeni kao prethodni, glavni ili naknadni, iz analize se izbacuju oni naknadni te se računa koji je postotak potresa neke magnitude M bio prethodni. Taj postotak ujedno predstavlja i traženu vjerojatnost za promatranu magnitudu. Ispituje se i kako odabir parametara za definiciju prethodnih i naknadnih potresa utječe na vjerojatnosti za različite magnitude te se računaju otežane vjerojatnosti kako bi se dobio što vjerodostojniji rezultat. Takva je analiza, osim za cijelo područje Hrvatske i okolice, provedena zasebno i za šire područje panonske Hrvatske te za područje Dinarida. Dobiveno je da u prosjeku ta vjerojatnost, za ukupno područje i za sve promatrane magnitude, iznosi 10.5%. Pritom najveću vjerojatnost da budu prethodni imaju potresi magnituda između 3.4 i 4.0 s vjerojatnošću oko 12%. Slični se rezultati dobivaju i kada se promatra područje Dinarida, s vjerojatnostima većima za oko 0.5%, dok su za šire područje panonske Hrvatske vjerojatnosti nešto manje (oko 8% za sve magnitude) s maksimumom za klasu magnituda od 4.5 do 5.0 koji iznosi oko 12%.

Abstract (english)

A frequently asked question shortly after an earthquake occurs is "What is the probability of that earthquake being a foreshock of a stronger one?". The answer lies in the past seismicity of the area of interest, so it is necessary to analyze the earthquake catalogue. This in particular is the topic of this thesis. After the earthquakes are determined to be foreshocks, mainshocks or aftershocks, the aftershocks are disregarded in future analysis. Then, the percentage of foreshocks among earthquakes of magnitude M is calculated. This percentage represents the probability we are trying to determine for the earthquake of interest. This thesis also studies the impact of the choice of parameters which define foreshocks and aftershocks on the probability for different magnitudes, and calculates weighted probabilities to get the most relevant results. In addition to the one for the whole of Croatia and nearby areas, a separate analysis was performed for the wider area of Pannonian Croatia and the Dinarides. Calculations show that, in general, for the whole area and for all the magnitudes, the probability is 10.5%. Earthquakes of magnitudes from 3.4 to 4.0 have the largest probability - approximately 12% - of being foreshocks. Results for the Dinarides are similar with probabilities that are around 0.5% larger, while they are somewhat lower when it comes to Pannonian Croatia - for all the magnitudes, the probabilities are around 8%, while the maximum probability of 12% occurs for the magnitudes from 4.5 to 5.0.

• Keywords: katalog potresa; prethodni potres; glavni potres; otežana vjerojatnost
• Keywords (english): earthquake catalogue; foreshock; mainshock; weighted probability
• Language: croatian
• URN:NBN: urn:nbn:hr:217:067866
• Study programme: Title: Graduate university study pf Physics - Geophysics; specializations in: Seismology and Physics of the Earth's Interior, Meteorology and Physical Oceanography; Course: Seismology and Physics of the Earth's Interior; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra fizike – geofizike (magistar/magistra fizike – geofizike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-09-30 09:07:52