Since much of Papua New Guinea lies close to the equator where the Coriolis effect is weak, the risk of tropical cyclones striking the island nation is relatively low, especially in its northern areas. Nevertheless, unusually warm sea surface temperatures and atmospheric conditions favorable to storm formation brought powerful Tropical Cyclone Maila dangerously close to the islands of Bougainville, New Britain, and New Ireland in April 2026, fueling intense rainfall.
The heavy rains saturated steep terrain in the Gazelle district of East New Britain, triggering landslides on and around April 9 that led to several deaths, according to news reports. The Landsat 9 satellite captured an image of the fresh landslide scars cutting through the dense tropical forests in the Baining Mountains on April 20, 2026. The Toriu River and other sediment-laden waterways are visible to the east of the landslides.
The landslides appear as light-brown swaths of exposed soil and debris extending north toward a nearby river valley, contrasting with the surrounding green vegetation and scattered white clouds. A second image from Landsat 9 shows the same area on September 24, 2025, before the landslides.
Maila was notable for its intensity—reaching Category 4 strength on Australia’s cyclone intensity scale (Category 3 on the Saffir-Simpson scale used for U.S. hurricanes)—and also for its slow movement near Papua New Guinea. Instead of passing quickly through the region, Maila lingered, allowing rainbands to repeatedly strike East New Britain. Satellite-based precipitation estimates from NASA’s Global Precipitation Measurement (GPM) mission indicate that hundreds of millimeters of rain likely fell across the region in less than a week.
NASA’s Landslide Hazard Assessment for Situational Awareness (LHASA) model uses precipitation estimates from GPM along with slope, soil, and land cover data to identify areas where rainfall i …