My case study is on the 1991 eruption of Mount Pinatubo in the Philippines. I decided to choose this event to focus on because it was the second largest eruption of the 20th century and having studied hazards for the past couple of years – I had never looked into this one and I was interested to do so.
Figure 1: Pyroclastic flows from Mount Pinatubo June 15 1991 https://mb.com.ph/2021/06/15/looking-back-at-mt-pinatubos-1991-eruption/
In June 1991, Mount Pinatubo, a once dormant stratovolcano for over 5 centuries became active once again following the Luzon 7.7 magnitude earthquake a year prior. Over the course of a few days before the eruption, magma reached the surface of Mount Pinatubo by which sulphur dioxide clouds had begun to erupt and a lava dome had formed due to a loss of the once contained gas. This activity of gas-charged magma indicated a cataclysmic eruption was imminent and by June 15th this is what occurred. More than a cubic mile of material and an ash cloud of 22 miles rose into the air and continued to do so until the following morning. As a result of the eruption, a typhoon (which blew the ash in all directions – in seven days it reached the Galapagos Islands), high speed pyroclastic flows (figure 1), lahars and ash flows were created and remained a hazardous threat to the people in the region for several years. For example, a sulphuric aerosol cloud remained in the atmosphere and circled the earth for several years – up to one year after the eruption the earth was in a period of climatic cooling by 2.3°C and resulted in a counterbalance of global warming (by 1994 most aerosols had gone). Moreover, lahars remained a great threat to the areas surrounding Mount Pinatubo for decades after because the ash deposits would remobilise during monsoon and typhoon weather and result in vast downwards debris flow.
Furthermore, in terms of preparation and mitigation strategies, given that the last time Mount Pinatubo erupted was around 600 years prior – the Philippine government reacted reasonably quickly and efficiently in terms of evacuation. Figure 2 shows the mapped-out danger zones where people are the most vulnerable which was around 40km away from Mount Pinatubo and everyone in these zones (~331,000 people) was transported to evacuation camps. 657 people died in 1991 and 184 were injured – the numbers increased with the years due to remobilisation of lahars – however half of these deaths were due to collapsing roof tops from wet tephra containing many people who refused to evacuate.
Figure 2: Map of the danger zones surrounding Mount Pinatubo: https://pubs.usgs.gov/pinatubo/tayag/
In terms of recovery, the Government responded quickly with rehabilitation and reconstruction plans which included foreign aid from countries such as the UK and USA alongside support from private sectors including NGOs such as the WHO and UNICEF. This included construction of a “megadike” to control and protect remobilising lahars in future monsoon seasons. 25 years on in 2016, there was a review on the area, and it proved that the mitigation post eruption has been successful and it is evident that the preparation in terms of evacuation before the eruption was effective and helped save hundreds of thousands of lives.
A snow blizzard has been disrupting areas in North Dakota for the last three days, and as of yesterday (04/14), schools, government offices and many businesses have had to shut down due to the extreme weather. Flights were cancelled, highways were shut and school learning switched to online. The city of Bismarck has experienced up to 1 foot of snow and Dickinson and Glenburn have had around 2 feet. Snow of this magnitude is not a common occurrence for this region to experience during April and so the Emergency Operations Centre has been activated. Moreover, the state has experienced drought in recent months so the precipitation will help with this prolonged dryness that North Dakota has been suffering with.
Last Monday (04/04), a British father and son (aged 9) died from falling rocks in a landslide in the Blue Mountains near Sydney and a woman and her son (14) were seriously injured. The woman’s teenage daughter witnessed the landslide and notified emergency services, she was subsequently treated for shock. The East Coast of Australia has been experiencing heavy spouts of rain over the past few weeks but the Wentworth Falls, where these families were hiking – was deemed safe. According to NSW National Parks and Wildlife Service, many areas around Wentworth Falls were closed off due to flood damage and ongoing rockfall risk. The area is now closed off to the public and the New South Wales Department of Environment and Heritage are looking into whether the area should have been open given the heavy rain.
There is now one other person who has died due to the damaging storms, high winds and tornadoes in and around the south – one dead in Georgia and the other in Texas. Another day of dangerous violent weather has been warned by authorities – yesterday (04/05) experienced hail among the other weather hazards previously mentioned.
The woman who died in Pembroke, Georgia was as a result of a tornado which also ripped off the roof of the Bryan County courthouse, destroyed the entrance to the local government building and damaged homes. Other people were also injured in Savannah, 30 miles west from Pembroke. Moreover, within 2 minutes of a citizen hearing the tornado sirens, the tornado was seen towering over the interstate in the distance where everyone on the highway then had to slam on their brakes.
There was also lightning damage in Wetumpka, Alabama as a result of the storm and Columbia, South Carolina had evacuation warnings for a tornado. Today (04/06) the damaging weather is moving further north, including Atlanta and Tennessee.
A winter storm hit San Francisco Bay yesterday afternoon (03/28) and has spread east and south overnight with records of rain reaching 2.5cm in Santa Rosa. Weather advisories were issued by the National Weather Service in Sierra Nevada where 6-8 inches of snowfall is expected to fall at elevations of 6,000 feet – this storm is said to bring in the biggest totals that the area has seen in some time. Moreover, Southern California is also expected to receive snow – up to 18 inches but at higher elevations (mountainous). Evacuations were ordered over fears of debris flows from hillsides in Orange County, however streets were then flooded but no major damage was done. Two people and a dog were trapped in the flow of the Los Angeles River in San Fernando Valley as the storm caused fast rushing waters through the inaccessible channel, but they were successfully rescued by the LA Fire Department.
Southern Oregon have persuaded the fifth Oregon county to declare a drought emergency due to the low water storage and current snowpack levels in the area. Jackson county made the declaration on Wednesday (03/23) but this follows four other counties which have made the same declaration. This year follows other years of drought along the Pacific Northwest, however this year is predicted to be worse than the last two years – the temperatures are higher than normal and the annual precipitation rates are lower than average. The emergency declarations made will allow for water rights to be overridden and allow for drought mitigation to take place – they are also then eligible for state and federal disaster relief funds.
As of midday today (03/08) hundreds of residents in the Florida Panhandle who have been forced to evacuate their homes after being threatened by the wildfires, have now been allowed to return to their homes even though three fires have grown to more than 29,000 acres. Only 10% of the biggest of the three wildfires has been contained (Bertha Swamp Road Fire) and has affected over 28,000 acres of land and as of this morning, the third fire (Star Avenue) has had 60% of the spread contained. Mandatory evacuations still do remain in place for hundreds of residents even though as of today around 600 people were allowed to return to their homes.
In the early hours of today (02/18) and currently continuing, Storm Eunice is said to have been one of the worst UK storms in three decades with parts of the UK experiencing 122mph winds. Most parts of the UK were issued a red warning for winds and institutions, flights and trains were closed/cancelled. At least two people have been injured and a man has died in Ireland from a falling tree. People are being urged to stay home and many infrastructures and homes are being damaged such as London’s O2 Arena which has had parts of its roof shredded.
Link to the BBC article as it updates throughout the day: https://www.bbc.com/news/live/uk-60421388
A 4.1 magnitude earthquake shook up inland San Diego County around quarter to ten in the morning on the 30th January. According to the US Geological Survey, the quake occurred about 65 miles northeast of downtown San Diego near Palomar Observatory but there were no reports of fatalities or injuries. The earthquake consisted of two main jolts with expressive shaking, however there were no reports of damage occurring due to such trembles but the shaking was felt by residents.
On January 3rd, a powerful winter storm attacked Washington D.C and surrounding areas of the Southeast killing 3 people, leaving half a million people without electricity and causing many to be stranded on the I95 for over 24 hours. In and around Washington D.C schools and Federal Government offices had to be closed due to the snow reaching up to 15 inches which additionally meant that hundreds of flights had to be cancelled. States of emergencies were issued due to the dangerous roads as a result of the storm, where over 650 crashes and 600 stranded vehicles on Interstate 95 were reported in Virginia and in Maryland 3 people died in a vehicle collision. Pictures of the storm on the I95 and other areas can be seen on the link below.