The country of Indonesia has been seriously hit with natural disasters within the past couple of years. In December 2004, a 9.1-9.3 magnitude earthquake struck off the Indonesian coast of Sumatra which caused a destructive tsunami to occur.
The estimated death toll for the people killed or missing and presumed dead is over 225,000 between a dozen countries. It caused over 10 billion dollars in material losses in the Indian Ocean region. Indonesia had experienced one of the craziest natural disasters on record.
On August 5th, a 6.9 magnitude earthquake struck the resort island of Lombok in Indonesia. It killed at least 430 people and injured over 1,300. The aftershock that took place on August 9th was a 5.9 magnitude earthquake that caused more trauma that the actual earthquake. But, the Aug. 5 quake was so powerful that island Bali, more than 100 miles east, felt it.
Soon after, on September 28th, a 7.5 earthquake hit the island of Sulawesi which triggered a tsunami. The tsunami hit the city of Palu with waves over 3 meters high. More than 1,400 people have been killed and the death toll is likely to rise.
The damage caused by the tsunami wasn’t all just from the water rushing in. It was soil liquefaction that caused lots of damage. Soil liquefaction is when loose sand is saturated with water that can behave like a liquid when shaken by an earthquake.
One thing that went wrong was the tsunami warning system. They meant to replace the entire system after the 2004 tsunami but it cost too much so they couldn’t completely do it. Indonesia’s warning system consists of seismographic sensors, buoys, tidal gauges, and GPS. But, none of the measures were able to predict the scale of the recent tsunami that hit.
In this case, the seismographic sensors (designed to record an earthquake and determine its strength and location) registered it by 6:03 p.m and the first waves struck 6:18 p.m. The Indonesia President sent out a tsunami warning of 1.6 to 9.8 feet waves and to evacuate immediately. The 22 open water Indonesian buoys (used to record changes in the sea level in deep water to confirm the existence of a tsunami) didn’t collect any data because they had been vandalized or there was a lack of maintenance.
The tidal gauges (used to measure sea level every 15 minutes and then send to the national meteorological agency) didn’t have time to register the tsunami because tsunamis tend to rush in directly after a large earthquake. There also wasn’t data observation equipment close enough to Palu Bay to measure tidal changes. When the tsunami hit, the nearest tidal gauge recorded a 2.3-inch rise in water levels. The shortfalls of the tsunami warning system may have contributed to the tsunami’s death toll due to their not being enough notice to evacuate.
A volcano erupted Wednesday, October 3rd, on the same island the earthquake struck, just days after the tsunami. Authorities on the island have warned that possible ash clouds and lava flows could impact air travel. The eruption has spewed ash over 19,000 feet into the sky.
If you can donate or send your condolences to everyone affected by the disaster, it would be highly appreciated!