BEKASI, WEST JAVA – Nunung, a Grade V teacher at SDN Hegarmukti I, explained that, having learned about natural phenomena and disasters in Indonesia last week, the students would now learn to create an earthquake detection device using simple materials. "The topic is related to the basic competence of understanding natural phenomena that occur in Indonesia and neighboring countries," said Nunung.
The equipment and materials used were wood and boards to make a frame and base, raffia string, 600ml mineral water bottles filled with gravel or sand, small felt tip marker pens, needles, paper, and a knife. The seismograph was made using the following steps: 1) create a frame and base using the wood and boards; 2) make a hole in the lid of the bottle so that a marker pen can be inserted; 3) make a hole in the bottom of the bottle and insert the raffia; 4) fill the bottle with gravel or sand, then close it again; 5) suspend the bottles with the marker pen pointing down right above the blank paper.
The way the seismograph worked was simple. When there are shocks or an earthquake, the tremors cause the bottle containing the gravel to swing. The tip of the bottle, which has been fitted with a marker pen, will swing back and forth drawing lines. The greater the vibration caused by the shock, the longer the lines produced. The pattern created by the marker pen will reflect the scale of the seismic event. Using this seismograph, students can learn in a concrete way about earthquakes. (Smd)