Plate Tectonics Blog Post
The link below is related to the article Duarte, Joao & Schellart, Wouter. (2016). Introduction to Plate Boundaries and Natural Hazards. 10.1002/9781119054146.ch1.:
This link is the AGU book where the article is found. It can be accessed as an ebook:
This is the link to an informative video from Sci Show: https://www.youtube.com/watch?v=XOCxNVDiOnE
I found this article, which aggregates the two topics of plate tectonics and geological hazards neatly. I also found this video from my favorite YouTube channel called SciShow, which I found it relevant to share. This channel has other informative and straightforward videos from other science courses too.
First, I learned that the association of tsunamis with earthquakes was brought by the Greek philosopher Thucydides, but it was forgotten time by time. It was after the great Lisbon earthquake in 1755 that many philosophers started to suspect the distinguishable relationship of natural causes and God’s punishment to humanity. The magnitude (Mw) of this earthquake was estimated to be around 8.5 to 9, which also produced a tsunami. I found it interested that the Portuguese authorities at that time ordered a survey to the population, and centuries later it was important to the birth of seismology. However, according to the article, it was after 200 years of this event that the plate tectonics theory emerged. Also, I learned that initially, it was believed that there would be twelve lithospheric plates instead of seven.
Second, I learned that plate boundary has an essential relationship with the magnitude of causing natural hazards like earthquakes, volcanic eruptions, and tsunamis. Divergent plate boundaries are characterized by two plate tectonics moving apart and by regions where lithospheric material is created. Convergent place boundaries are more likely to occur high magnitude of earthquakes, thrust faults, and volcanism due to the collision of continental plates or when the oceanic plate is subducted below another plate. A great example is the 2004 Sumatra Earthquake. Transform plate boundaries happen when two plate boundaries slip against each other horizontally. This can produce small to large earthquakes, for example, the 8.4 magnitude earthquake in 1941 in Azores-Gibraltar. Also, megathrust earthquakes like the 1964 Alaska earthquake are the most powerful, and it occurs at subduction zones. This earthquake had a magnitude of 9.2 and produced gigantic tsunamis. I also learned that tsunamis are more correlate with subduction zones where the convergence of two plates happens, and a vertical uplift of the seafloor can cause water displacement. Importantly, as shown in the video, “plate boundaries are just one type of fault or fracture in the crust, and earthquakes can occur far from plate margins.”
Third, I learned that geological hazards are divided into two categories — geophysical hazards, which include earthquakes, tsunamis, hurricanes, floods, and fires. A second category is biological hazards where usually happen after a geophysical event and comprises pandemic spreading of viruses or the contamination of watercourses. A good example is the spreading of diseases after a tsunami.
A final consideration of these resources is the number of geological hazards events that I did not know before reading the article. A good example is the 1755 great Lisbon earthquake, the megathrust magnitude 9.5 Valdivia earthquake in Chile, and the eruption of the Lake Toba supervolcano Indonesia!