PHYSICAL WORLD ESCI 243  -  NICHOLS COLLEGE ONLINE COURSE

Professor Mauri S. Pelto, 508-213-2168 peltoms@nichols.edu   

Earthquakes

Home Page Plate Tectonic Setting Earthquakes Volcanic Hazards Glaciers-Sea Level Rise Coastal Management  
Water Resources Groundwater Management Global Warming Fossil Fuel Resources Alternative Energy Sources River Types-Flooding

 Bam Earthquake satellite image note destruction across the region.

BAM, Iran, Dec 30 (From AFP) - The official death toll from the earthquake in southeast Iran rose to 28,000. State radio quoted local officials as saying that 28,000 bodies had been recovered from the rubble in Bam and surrounding villages and buried, but predicting that the final toll could top 30,000.  Earlier Iran's supreme leader Ayatollah Ali Khamenei also pledged that Bam, which was constructed largely of mud brick, would be rebuilt but more solidly. Seventy percent of Bam was destroyed in the quake which measured 6.7 on the Richter scale. According to public radio, the Iranian central bank has decided to suspend for a year the repayment of debts owed by residents in the quake-hit region. The oil-rich Gulf states late Monday earmarked 400 million dollars of aid for victims of the earthquake, hours after the United Nations appealed for more money as it began assessing the damage. 


 

 Answers to your questions are posted on the page linked above, Your questions.  The best question of the week is in the right table cell on this page.  The huge debris slides shaken from the mountains on the left and spilling across the glacier in the valley were caused by a 7.9 magnitude earthquake on the Denali Fault in November of 2002. 

Reading: 70-93  Each of the  assignment block will require reading the appropriate chapter and web assigned material and answering the  key concept questions. I also expect two questions to be submitted from each chapter from each student on material that was either unclear or led you to further thinking.  I will answer these for the entire class to see on the web page or in an email. 

Concept Questions:

1.Using the Richter Scale explain what magnitude earthquake is required to inflict significant damage?

2. Rank the tectonic settings according to earthquake hazard.

3.  What has been the principal source of damage in recent earthquakes at Kobe, Japan; Izmit, Turkey and Gujarat, India.  Why the difference?

Assignment: Contrast the earthquake activity in one eastern and one western state (State Earthqauke Maps).  Identify the tectonic setting of each state and the likely maximum earthquake.  Also the number and location of the majority of the quakes in the state map.  The tectonic setting is not noted on the map or at this site.  But just as you did in the first assignment look at page 48 and note the pattern of earthquakes. 

 

 

Earthquakes result from the sudden release of energy caused by the slippage of rock along a fault.  This energy is built up from the long terms difference in movement of the earth materials across a fault.  The energy is released as seismic waves which travel through the earth.  The waves are amplified by weak and moist sediments.   Earthquakes do not exhibit consistent precursors and have a chaotic behavior.  Thus, predicting their timing accurately  is not possible.  We can only rate the relative likelihood along specific fault segments given historic behavior.