Seismicity

Iran is one of the most seismically active countries in the world due to ninety percent of the country crossing over several major fault lines. It is positioned in a 1000- km- wide zone of compression between the colliding Eurasian and Arabian continents. From 1918- 2004, more than 2000 earthquakes were recorded in Iran. Most earthquakes in the continental lithosphere take place in the upper crust. Continental collision creates a shortening in the crust, resulting in thickening and distributed deformation. In the Zagros Mountains, nearly all earthquakes have a depth less than 20 kilometers (km) since they take place in the upper crust; this is where earthquakes occur the most frequent. On the other hand, in Southeastern Iran, where the Arabian seafloor is subducted beneath the Makran coast, low- level earthquakes occur from the upper crust to depths of at least 150 kilometers. Close to the Oman line, between Zagros and Makrain, seismicity reaches to depths of 30 to 45 km in the crust. In North- Central Iran, along the Aborz mountain belt, there is seismic activity in both the upper and lower crust, although mostly upper. The band across central Caspian consists of earthquakes with depths of 30 to 100 kilometers that deepen northwards. From the early 1900's to the late 1990's, there has been many earthquakes with a magnitude higher than 7. For example, in 1978 quake Tabas consisted of a 7. 7 magnitude which is highly destructive. Luckily, the Zagro's region has not faced any in the 20th century with a magnitude higher than 7.0. But earthquakes with magnitudes over 7.0 have shocked Central and Eastern Iran. Unfortunately, these earthquakes have been catastrophic and lead to the loss of human life and wide spread damage. 
 Due to the devastating earhtquake, Bam, the U.S. offered assistance in return the state promised to comply with the International Atomic Energy Agency. Iran agreed with the U.S. and focused on rebuilding their country. Testing, analyzing, and other methods were used by scientists, as well, to monitor activity. For example, the seismic hazard assessment of Iran was created by the International Institute of Earthquake Engineering and Seismology so that it could indicate the earthquakes hazard of Iran.

Works Cited:
Geofisica, Annali. "Seismic Hazard Assessment of Iran." International Institution of Earthquake  Engineering and Seismology. Vol 42, N. 6. 6 December, 1999. Web. 18 Feb 2016.

"Relocation and Assessment of Seismicity in the Iran Region." Geophys. J. Int. 4 April. 2006. Web. 18 Feb 2016.

Blog 2- Plate boundaries

Plate tectonics are known as a large- scale geographic process that deform Earth's lithosphere resulting in land forms such as ocean basins, continents, and mountains. Plate boundaries are defined as the relative movement of the plates on either side of the boundary. Iran has a micro plate called the Iranian Plate. A micro plate is grouped with an adjacent major group and contains an area less than 1 million square kilometers. The Iranian Plate surrounds Iran and Afghanistan and even parts of Pakistan and Iraq. It is pressed between the Arabian Plate to the south and the Eurasian Plate to the north. Its boundaries are continental- continental. Subduction of ocean lithosphere ultimately leads to convergence of continents. Because continents are too buoyant to subduct, high mountains develop as the continents are forced upwards in the collision zone. This compression causes a great of mountains in its terrain such as the Zagros Mountains, that are continuing to get higher and higher. Unfortunately it creates earthquakes, a life threatening hazard. A subduction zone quake was the strongest earthquake to hit Iran in 50 years. The Khash earthquake ranged 51 miles, where the Arabian plate dives under the massive Eurasian plate. Dozens of people were known to be killed due to the collision of business. Since it is a convergent (collision) flooding and mass wasting can occur.

Hazards, Disasters, and Catastrophes

Many dangerous circumstances can occur in the world. They are mostly categorized as either hazards, disasters, or catastrophes. Hazards are defined as a danger or risk. A disaster is a sudden event, such as an accident or a natural catastrophe, that causes great damage or loss of life. Catastrophes, on the other hand, are even more severe. I found a few definitions for catastrophe. One, it could be the final event of the dramatic action especially of a tragedy. Second, a momentous tragic event ranging from extreme misfortune to ruin. Third, a violent and sudden change in a feature of the earth or destructive natural event. A hazard is known as a threat to anything living on the earth. Global warming for example is a well known hazard. There are a few different kinds of hazards known as physical, chemical, biological. Disasters are known to have a greater affect on human population. Natural disasters can cause very drastic problems. Some examples of a natural disaster are floods, earthquakes, tsunamis, tornadoes, and fires. These are incidents that have a direct impact on the earth. Natural catastrophes and disasters can be very similar except catastrophes have a much greater impact and result.