What is Earthquake Magnitude? Understanding the Scale of a Disaster Reporter Zulkifli Ramadhani September 16, 2025 | 03:33 pm Earthquake seismograph. ANTARA/Shutterstock/pri TEMPO.CO, Jakarta – The Meteorology, Climatology, and Geophysics Agency (BMKG) recorded a tectonic earthquake with a magnitude of 4.4 shaking the southern region of West Java from Sukabumi to Garut on Friday, August 15, 2025, at 00:35 a.m. local time. Based on BMKG’s analysis, the earthquake originated at coordinates 7.7 degrees South Latitude and 106.91 degrees East Longitude.”The offshore quake occurred 87 kilometers away from the center of Sukabumi City,” said the Head of BMKG Region II Tangerang, Hartanto. Based on citizen reports, the tremor was felt in the Tegalbuleud and Cidolog areas with a III MMI intensity scale—the shaking was akin to a passing truck. Meanwhile, in Pelabuhan Ratu, Cianjur, Garut Regency, Cililin, West Bandung Regency, Cibadak, Jampang Kulon, Pabuaran, Kadupandak, and Cisurupan, the earthquake was felt by residents with varying II-III MMI intensity scales, causing light hanging objects to swing and the tremors to be felt inside homes. A similar-intensity earthquake occurred on Thursday afternoon, August 14, 2025 at 4:13 p.m. local time, with a magnitude of 1.8, shaking the villages of Pasir Langu and Jambudipa in the Cisarua District, West Bandung Regency, from a depth of 19 kilometers.”The tremor was a shallow crustal earthquake caused by the activity of the Lembang Fault Segment, Cimeta,” said the Director of Earthquakes and Tsunamis at BMKG, Daryono.What is an earthquake magnitude?Earthquake magnitude, citing the United States Geological Survey (USGS), is a scale for measuring earthquakes—the larger the earthquake, the higher its magnitude. The magnitude is determined based on the maximum signal amplitude recorded on the seismograph, an earthquake-measuring instrument that records ground vibrations from earthquakes directly beneath it.The modern system for measuring earthquakes has strengthened, and they precisely amplify and record ground motion at periods of between 0.1 and 100 seconds as a function of time. The resulting vibrations have varying values from one place to another based on distance, surface material type, and other factors.The scales of earthquake magnitudesMagnitude, according to the Swiss Seismological Service website, has four commonly used scales:Local magnitudeSurface-wave magnitudeBody-wave magnitudeMoment magnitudeMagnitude scales are expressed in whole numbers and decimal fractions. Citing Michigan Technological University, earthquakes with a magnitude of less than 2.5 are usually not felt, but are still recorded by seismographs. Here are other magnitude scales:Magnitude 2.5 to 5.4 causes minor damageMagnitude 5.5 to 6.0 results in slight damage in buildings and other infrastructureMagnitude 6.1 to 6.9 causes significant damage in densely populated areasMagnitude 7.0 to 7.9 is considered a major earthquake, causing serious damageMagnitude 8.0 or higher is considered a great earthquakes and can totally destroy communities near the epicenterEarthquake magnitude scales and extent of damageThe earthquake magnitude scale and its corresponding damage categories do not always align. On May 23, 2025, in Bengkulu, a 6.0 magnitude earthquake caused damage to at least 140 housing units and several public facilities. The extent of the damage led the Director of Earthquakes and Tsunamis at BMKG, Daryono, to describe the earthquake that occurred then as an intraslab earthquake.”Intraslab earthquakes indeed have stronger shaking characteristics compared to earthquakes of the same strength from other sources,” he said when contacted on Friday afternoon, May 23, 2025.Earthquake expert from the Bandung Institute of Technology (ITB), Irwan Meilano, considers intraslab earthquakes as dangerous because the earthquake epicenter is closer to land and has the potential to cause greater damage.Anwar Siswadi, Tempo.Co, and Zacharias Wuragil contributed to this article.Editor’s Choice: Why the BMKG is Concerned About Megathrust Earthquake Threat in IndonesiaClick here to get the latest news updates from Tempo on Google News What is Earthquake Magnitude? Understanding the Scale of a Disaster Reporter Zulkifli Ramadhani September 16, 2025 | 03:33 pm Earthquake seismograph. ANTARA/Shutterstock/pri TEMPO.CO, Jakarta – The Meteorology, Climatology, and Geophysics Agency (BMKG) recorded a tectonic earthquake with a magnitude of 4.4 shaking the southern region of West Java from Sukabumi to Garut on Friday, August 15, 2025, at 00:35 a.m. local time. Based on BMKG’s analysis, the earthquake originated at coordinates 7.7 degrees South Latitude and 106.91 degrees East Longitude.”The offshore quake occurred 87 kilometers away from the center of Sukabumi City,” said the Head of BMKG Region II Tangerang, Hartanto. What is Earthquake Magnitude? Understanding the Scale of a Disaster Reporter Zulkifli Ramadhani September 16, 2025 | 03:33 pm Earthquake seismograph. ANTARA/Shutterstock/pri TEMPO.CO, Jakarta – The Meteorology, Climatology, and Geophysics Agency (BMKG) recorded a tectonic earthquake with a magnitude of 4.4 shaking the southern region of West Java from Sukabumi to Garut on Friday, August 15, 2025, at 00:35 a.m. local time. Based on BMKG’s analysis, the earthquake originated at coordinates 7.7 degrees South Latitude and 106.91 degrees East Longitude.”The offshore quake occurred 87 kilometers away from the center of Sukabumi City,” said the Head of BMKG Region II Tangerang, Hartanto. What is Earthquake Magnitude? Understanding the Scale of a Disaster Reporter Zulkifli Ramadhani September 16, 2025 | 03:33 pm Earthquake seismograph. ANTARA/Shutterstock/pri TEMPO.CO, Jakarta – The Meteorology, Climatology, and Geophysics Agency (BMKG) recorded a tectonic earthquake with a magnitude of 4.4 shaking the southern region of West Java from Sukabumi to Garut on Friday, August 15, 2025, at 00:35 a.m. local time. Based on BMKG’s analysis, the earthquake originated at coordinates 7.7 degrees South Latitude and 106.91 degrees East Longitude.”The offshore quake occurred 87 kilometers away from the center of Sukabumi City,” said the Head of BMKG Region II Tangerang, Hartanto. What is Earthquake Magnitude? Understanding the Scale of a Disaster Reporter Zulkifli Ramadhani September 16, 2025 | 03:33 pm Earthquake seismograph. ANTARA/Shutterstock/pri TEMPO.CO, Jakarta – The Meteorology, Climatology, and Geophysics Agency (BMKG) recorded a tectonic earthquake with a magnitude of 4.4 shaking the southern region of West Java from Sukabumi to Garut on Friday, August 15, 2025, at 00:35 a.m. local time. Based on BMKG’s analysis, the earthquake originated at coordinates 7.7 degrees South Latitude and 106.91 degrees East Longitude.”The offshore quake occurred 87 kilometers away from the center of Sukabumi City,” said the Head of BMKG Region II Tangerang, Hartanto.
Source: en.tempo.co
