Both California and the Philippines lie on plate boundaries and therefore both suffer from severe tectonic hazards. The Philippines lies on the subduction zone of a destructive boundary between the Eurasian and Philippines plate, and therefore is high-risk area for both earthquakes and volcanoes. The tectonics is very active in this area being a destructive boundary, evidence of which can be seen by the deep Manila Ocean Trench that lies on the west of the islands. There is a very high density of highly destructive composite volcanoes namely, Mt Pinotubo and Mt Taal. There are many active volcanoes in the Philippines including two of the worst in the world: Mt Pinotubo and Mt Taal. Mt Pinotubo erupted in June 1991 and was biggest the world had seen in years. It consisted of two eruptions causing huge lahars, and a 20km cloud of ash. Despite good organisation and evacuation there was a death and injury toll of 4300 people, mainly poorer farmers who could not afford to leave their crops. Economic losses were huge because of the 80,000 hectares of cropland that was destroyed and amounted to US$710 million. This wouldn’t be so much for California but this is a huge percentage of the Philippines GDP and would have had a profound affect on their economy and debts.
As with all plate boundaries, friction often builds up between the plates also causing regular earthquakes which can sometimes result in tsunamis as well. Ranked second in potential human losses due to earthquakes, the Philippines often finds that earthquakes have multiple impacts on the severity. This is partly to do with the physical geography of the land. Being a group of islands means that the epicentres of the earthquakes are often in the sea, which increases the likelihood of tsunamis and other freak waves. It is also very mountainous inland, and deforestation on the hillsides leaves many areas vulnerable to landslides. One earthquake in 2006 triggered landslides, a flood and a local tsunami 3 feet high. Another relatively minor earthquake was one of the causes of a catastrophic mudslide, killing1150 people.
California also suffers enormously from earthquakes but not so much from volcanoes as it lies on a conservative boundary between the Pacific and North American plate. The San Andreas fault runs all the way down the coastline of California where many cities namely San Francisco lie right on top. The Pacific plate moves the fastest so a lot of friction is created causing regular, high magnitude earthquakes. Populations on the Andreas fault have an average probability of 30 % of receiving a 6 to 7.5-magnitude earthquake and are ranked 6th in potential human losses due to earthquakes and 2nd in terms of potential economic losses because of all the expensive infrastructure that could be destroyed. Two high magnitude earthquakes struck California over 5 years. The second one, January 1994 in Los Angeles was of magnitude 6.7 on the Richter scale. There were also many aftershocks ranging from magnitude 4 to 5 which caused further damage. Because of the dense population in Los Angeles, human impacts were big considering the efficiency of the emergency services and aid available: 57 died, more than 1500 were seriously injured, 9000 homes were without electricity and 48,500 people had no access to clean water.
Although both California and Philippines are both susceptible to frequent tectonic events, Filipinos are clearly more at risk especially as they have the added risk of very high magnitude volcanic eruptions and tsunamis which are often secondary effects of earthquakes. On top of that there is much bigger population in the way.
Both California and the Philippines have coast on the Pacific Ocean. This means that much of their weather, specifically California’s, is dependant on the El Nino and La Nina oscillations. For California, the El Nino oscillation means wetter weather as it brings sub-tropical winds carrying heavy rain and consequently increased flooding, storms and landslides. La Nina oscillations means that California receives dry winds from the Arizona and Mexican deserts causing dry, hot weather often resulting in drought and increased wildfires. For the Philippines this is the other way round although, being in a tropical zone, wet monsoon seasons and dry seasons are experienced annually anyway. The Philippines is also within the Typhoon belt and so receives up to 20 typhoons every year, particularly in the north.
Most floods in California are riverine flooding in the Los Angeles and San Gabriel rivers where 390,000 people are exposed. Flooding is dependent on the EL Nino Oscillation so regular severe flooding only really occurs for a few years at a time. Economic losses can be huge. Many areas are also at risk to landslides after flooding, as deforestation and wildfires have made the hillsides vulnerable to soil erosion. Severe flooding has proven to undermine California’s investment in protection against hazards as the December-January floods of 1996/97, one of the wettest seasons on record, destroyed hundreds of levees causing severe flooding and landslides, killing 9 and displacing 230,000 people. $2 billion worth of flood management infrastructure was also damaged. However, a lot of money has gone into channelising rivers away from high-risk areas.
That was an example of flooding in California with failed protection yet the Philippines has suffered far worse because of their incapacity to deal with the magnitude. Regular monsoons and tropical storms mean that 788,572 people are exposed to frequent flooding. Typhoon Ketsana, with winds of 100mph, dumped 16.7 inches of rain in just 12 hrs in September 2009. 246 died and 2 million were affected in Manila where 80% of the city was submerged. The National Disaster Co-ordinating Council was overwhelmed and unable to provide sufficient aid for everyone, which accounts for the high death toll.
Despite the generally wet climate, the Philippines have suffered from drought 6 times from 1905 to 2007. Most of these cases will have been caused by the El Nino oscillation, which means flooding in California but, in the case of April 1998, means prolonged drought for the Philippines. This drought severely affected 2.5 million people as famine hit the southern island of Mindanao. Millions needed supplies of emergency food. Drought also curtailed the Philippines hydroelectric power which affected supplies to thousands of people. In total it has cost the government US$64,000 and affected 6 million people from 1905 to 2007.
However, drought is one of California’s most intense hazards and puts four times this amount at risk to drought and more precariously, wildfires. This makes it a much more dangerous hazard for California as the added threat of fire comes when the country is at its most vulnerable, both economically and socially. Drought almost always comes with wildfires in California because of the dense dry bush that covers much of the land. Wildfires grow frighteningly fast particularly during the dry Santa Ana wind periods. Los Angeles is most at risk as the city is expanding quickly and drawing closer to wildfire prone areas. On top of this the large population is putting a strain on the water supply and strict water restriction regulations often have to be put in place to avoid serious shortages. In September 2009 a wildfire intensified by the dense, dry bush in the area, came dangerously close to Los Angeles displacing over 100,000 residents and destroying over 20 houses. At the same time another fire further south destroyed 60 structures in Sacramento. As more and more immigrants settle on the poorer edges of the city, Los Angeles’ vulnerability will increase. If action isn’t taken the next wildfire might be in danger of sweeping through the whole of the city.
In conclusion, I found that, both The Philippines and California receive regular earthquakes, and both have a high risk of landslides due to the mountainous terrain and soil erosion caused by deforestation (and wildfires in California’s case). On top of that, the Philippines is part of the Ring of fire and has the rare but serious risk of eruptions from the 18 active volcanoes. The Philippines and California are also prone to flooding and drought. The Philippines receives around 10 Typhoons a year and experiences annual flooding as a result. El Nino intensifies the risk of drought in the Philippines but, although there are serious long-term effects on the peoples’ welfare, California also has the added threat of fire. I think this adds up to a pretty much equal magnitude of risk on both sides. However, it is evident that the Philippines is affected far more frequently and severely. It is clear that the Philippines has a higher vulnerability in terms of population, local attitude, and the fragility of their economy. They also have a far lower capacity, with a GDP 12 times smaller than California’s. If I go back to the risk equation, the fact that the Philippines has a higher vulnerability and lower capacity means it is definitely the most at risk.