JAKARTA — A devastating 7.4-to-7.7-magnitude earthquake struck eastern Indonesia’s Flores region in East Nusa Tenggara province early Saturday, killing at least 40 people, injuring dozens more, and triggering localized tsunami waves and landslides across coastal villages.
Hours later, a second major tremor—measuring 6.9 magnitude—hit North Sumatra province on the western island of Sumatra near Pematangsiantar, striking at a deep 183 kilometers beneath the earth’s surface.
INDONESIA SEISMIC IMPACT
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├── Primary Quake: M7.7 | Depth: ~10-15 km | Location: Flores Sea / East Nusa Tenggara
│ ├── Fatalities: 40+ confirmed | Landslides & structural collapses
│ └── Secondary Impact: Localized tsunami waves (up to 1.6 meters)
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└── Secondary Quake: M6.9 | Depth: ~183 km | Location: Near Pematangsiantar, North Sumatra
└── Impact: Deep-focus tremor; minimal structural damage reported
Shallow Quake Causes Widespread Destruction in Flores
The initial 7.7-magnitude earthquake struck at 5:58 a.m. local time at a shallow depth of roughly 10 kilometers (6 miles), approximately 68 kilometers north-northwest of the city of Ende.Because the epicenter was shallow, violent shaking caused severe structural collapses across the Sikka, West Manggarai, and East Manggarai regencies.
The main shock was followed by over 200 aftershocks.Indonesia’s Meteorology, Climatology, and Geophysics Agency (BMKG) initially issued a regional tsunami warning, which was lifted after sea-level monitoring confirmed the primary surge had passed.
- Tsunami Inundation:Localized tsunami waves reaching up to 1.6 meters (5.3 feet) hit coastal communities, including the village of Riung in Ngada regency, leaving homes blanketed in mud and sediment and grounding fishing vessels.
- Landslides:Rain-soaked hillsides collapsed under the force of the shaking, with rescue teams recovering multiple bodies buried beneath landslides in the village of Reok.
- Infrastructure Failure:Widespread power outages and disrupted telecommunications networks hindered early search and rescue efforts across affected districts.
| Seismic Event | Magnitude | Depth | Epicenter Location | Primary Impact Status |
| Flores Sea Quake | 7.7 | ~10–15 km | 68 km NNW of Ende, East Nusa Tenggara | 40+ dead, localized tsunami, building collapses |
| Sumatra Quake | 6.9 | ~183 km | Near Pematangsiantar, North Sumatra | Deep-focus tremor; no major damage reported |
Deep-Focus Sumatra Tremor
In the afternoon following the primary disaster in eastern Indonesia, a separate 6.9-magnitude earthquake struck North Sumatra, centered inland near Pematangsiantar.
Despite the high magnitude, disaster management officials reported minimal surface impact. Because the earthquake originated at a intermediate depth of nearly 183 kilometers beneath the earth’s surface, the seismic energy dissipated through the mantle before reaching the surface, preventing significant structural damage or casualties in western Indonesia.
Search and Rescue Underway
Emergency personnel, including the National Search and Rescue Agency (Basarnas) and military units, have deployed across East Nusa Tenggara to locate survivors trapped under collapsed residential structures and landslide debris.Authorities warn that the death toll will likely rise as communications are restored to remote coastal settlements.
