Sunday, September 25, 2022

Week 5: Volcanoes

 In the Philippines around 400 volcanoes, 25 of which are active. 


Here is a map of 25 active volcanoes and as you can see many of the volcanoes are spread out among different islands. On January 12th, 2020 the volcano, Taal, created hazards such as "volcanic lightning, lava fountains... and fissures that cut through the ground" in specific areas of the Philippines. This was rated a 4 out of 5 hazard level by PHIVOLCS.  

This is only one example of how hazardous volcanoes can be to the Philippines. In many situations, the volcanoes act as a domino effect and cause more disasters such as earthquakes. 



It is also important to note that there is an active underwater volcano named Didicas. Didicas is a submarine volcano first recorded in 1773. Although there are very few cases of death related to the activity from Didicas, it has been recorded. 

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) is in charge of keeping people safe and creating warnings in the event of volcanic activity. 

They are in charge of creating safety plans for people to follow, having a reliable warning system in place, and also monitoring the probability and occurrence of volcanic activity. 

https://www.discoverthephilippines.com/25-active-volcanoes-in-the-philippines/

https://sea.mashable.com/science/7008/the-largest-known-volcano-in-the-world-has-been-discovered-in-the-philippine-sea

https://www.vulkaner.no/v/volcan/mayon/didicas.html

https://temblor.net/earthquake-insights/philippine-volcano-taal-erupts-with-a-fury-of-earthquakes-and-ash-10371/

https://www.phivolcs.dost.gov.ph/index.php/about-us/about-phivolcs


Friday, September 9, 2022

Week 3: Earthquakes

 


The Philippines has an abundant history of earthquakes but while there have been catastrophic earthquakes, the majority have a magnitude of 4-5. There are on average 982 earthquakes a year in the Philippines, but many cannot be felt. 

According to the Iris monitoring website, the most recent earthquake in the Philippines was on September 4th, 2022 with a magnitude of 4.5. The image below is the waveform from the September 4th earthquake taken by the Global Seismograph Network from Po Shan, Hong Kong.

The P wave formation in the reading tells us that the P waves travel faster and the station can therefore pick up the waves faster. What the reading mostly picked up is the surface waves. It is likely that these surface waves were picked up in the form of ocean waves. The particles of the median in this graph move up and down. When I listened to the waveform graph I could hear the up and down shaking movement, which is verified by the graph. 

Like many earthquakes, scientists can hypothesize that it comes from a fault of some sort. After studies of the faults around the Philippines, it was determined that the fault most related to the earthquakes is the "Central Philippine Fault Zone consisting of the Guinayangan, Masbate, and Central Leyte faults". The Philippine Fault is a strike-slip fault which tells us its movement is horizontal. This type of fault is dangerous because it can cause buildings to fall apart, and roads to break due to shearing stress. 



The Philippines have put together what they call a more "reactive" approach rather than a proactive approach. They do not spend as much time trying to prevent earthquakes as they do dealing with the damage after it happens. This has caused many financial burdens among the citizens and government in the Philippines. 

A few proactive disaster precautions the Philippines has taken is having disaster management centers that provide aid, rescue, and information. As part of this program, they conduct research and help teach people what to do in case of an emergency disaster such as an earthquake. 


References:

https://www.adrc.asia/management/PHL/Philippines_Disaster_Plans.html#:~:text=The%20Philippine%20disaster%20management%20program,information%2C%20and%20research%20and%20development.

https://openknowledge.worldbank.org/handle/10986/8748#:~:text=The%20Philippine%20institutional%20arrangements%20and,avoid%20the%20creation%20of%20disaster

https://www.independent.co.uk/news/world/asia/philippines-earthquake-today-masbate-cataingan-death-toll-a9675236.html

https://www.forbes.com/sites/trevornace/2019/04/22/earthquake-shakes-philippines-leaving-five-dead-north-of-manila/?sh=4aedf82861f1

http://ds.iris.edu/ds/nodes/dmc/tools/event/11594811

https://en.wikipedia.org/wiki/Philippine_Fault_System#:~:text=and%203.8%20Ma.-,Earthquakes,islands%20of%20Bondoc%20to%20Leyte.

https://www.phivolcs.dost.gov.ph/index.php/2-uncategorised/635-philippine-fault-zone-maps#:~:text=The%201%2C200%2Dkm%2Dlong%20Philippine,northwestern%20Luzon%20to%20southeastern%20Mindanao.


Friday, September 2, 2022

Tectonic Plates

Based on the NOAA map of tectonic plates we can see that the Philippines is in close proximity to multiple plate boundaries. These plates are the Philippine Sea Plate, Indo-Australian Plate, and the Eurasian Plate.

The plate tectonic movement near the Philippines is what creates such a high chance for disaster. Since the Philippines is located in the Southeast Asia part of the Pacific Ring of Fire. Where the plates meet and the volcanoes surround the Philippines there is an overlap of convergent boundaries. This overlap of convergent boundaries is called a subduction zone. Specifically significant to the Philippines is the Philippine Sea Plate because it is moving towards the Eurasian Plate at a rate of  "6-8 cm/year". The subduction causes earthquakes, volcanic activity, and more. 

It is interesting as to why the Eurasian Plate is being subducted under the Philippine Sea Plate since it is mostly continental crust. This also explains why there is the philippine fault. If the fault slips it will cause a devastating disaster.


 
Overall the chance for disaster in the Philippines is very high due to the mass movement of tectonic plates and the convergence of multiple plate boundaries. 

SOURCES:

https://tectonicsofasia.weebly.com/philippine-sea-plate.html

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016JB012923

https://www.nationsonline.org/oneworld/map/philippines-political-map.htm#:~:text=The%20archipelago%20is%20situated%20within,intense%20volcanic%20and%20seismic%20activities.&text=Along%20the%20eastern%20side%20of,floor%20of%20the%20Philippine%20Sea.

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016JB012923

Final Blog Post

  Main natural hazards The two most important hazards in the Philippines to address are coastal hazards and mass wasting (landslides). The w...