In April 2026, Tropical Cyclone Maila brought unprecedented rainfall to Papua New Guinea, setting off a series of devastating landslides in the Gazelle district of East New Britain. This Q&A explores the key aspects of this event, from the storm's unusual behavior to the satellite imagery that captured the aftermath.
What caused the landslides in Papua New Guinea in April 2026?
The landslides were primarily caused by intense and prolonged rainfall from Tropical Cyclone Maila. Although Papua New Guinea is near the equator where the Coriolis effect is weak—typically reducing cyclone risks—unusually warm sea surface temperatures and favorable atmospheric conditions allowed Maila to form and strengthen. The storm stalled near the islands of Bougainville, New Britain, and New Ireland, allowing its rainbands to repeatedly soak the steep terrain of the Gazelle district in East New Britain. This saturation destabilized hillslopes, triggering multiple landslides on and around April 9, 2026. According to news reports, several people lost their lives as a result.
Why was Cyclone Maila considered unusual for this region?
Cyclone Maila was unusual for several reasons. First, tropical cyclones rarely strike the northern areas of Papua New Guinea because the Coriolis effect is too weak near the equator to spin up storms. However, in April 2026, sea surface temperatures were abnormally high, providing the energy needed for Maila to intensify. Second, the storm moved very slowly—instead of passing quickly, it lingered near the islands, dumping heavy rain over the same areas for days. Third, Maila reached Category 4 status on Australia’s cyclone scale (equivalent to Category 3 on the Saffir-Simpson scale), making it one of the stronger cyclones to threaten the region. Its combination of intensity and slow movement was a rare and dangerous event.
What did satellite images reveal about the landslides?
NASA’s Landsat 9 satellite captured two key images of the Gazelle district, allowing scientists to compare conditions before and after the landslides. The image from September 24, 2025 shows dense green tropical forests with no visible disturbances. The image from April 20, 2026—taken during a break in the clouds—reveals fresh landslide scars as light-brown swaths of exposed soil and debris. These scars cut through the forested Baining Mountains and extend northward toward the Toriu River, which appears sediment-laden. The contrast between the lush green vegetation and the bright brown slides highlights the scale of erosion. Landsat 9’s OLI (Operational Land Imager) provided high-resolution data that helped scientists assess the extent and impact of the landslides.
How strong was Cyclone Maila and what damage did it cause?
Cyclone Maila reached Category 4 intensity on Australia’s cyclone scale, which corresponds to Category 3 on the U.S. Saffir-Simpson hurricane wind scale. This means sustained winds of around 120–150 mph (193–241 km/h). However, its greatest threat was not wind but rainfall. The storm’s slow movement allowed rainbands to repeatedly hit East New Britain, delivering extreme precipitation. Satellite-based estimates from NASA’s Global Precipitation Measurement (GPM) mission show that huge amounts of rain fell in a short period. The heavy rains saturated the steep, mountainous terrain, causing landslides that destroyed forests and infrastructure. News reports confirm several deaths and likely damage to roads and villages in the Gazelle district.
Where exactly did the landslides occur?
The landslides struck the Gazelle district of East New Britain, a province in Papua New Guinea. Specifically, satellite images show the scars in the Baining Mountains, a heavily forested and sparsely populated area. The debris flows extended northward toward the Toriu River valley. Two images from Landsat 9—one from September 24, 2025, and one from April 20, 2026—clearly delineate the affected region. The area is notoriously prone to landslides due to its steep slopes, and the added weight of rainwater from Cyclone Maila proved critical. Nearby islands such as Bougainville and New Ireland also experienced heavy rain, though the most severe landslides were reported in East New Britain.
What role did NASA's GPM mission play in monitoring the storm?
NASA’s Global Precipitation Measurement (GPM) mission provided satellite-based precipitation estimates that were crucial for understanding Cyclone Maila’s rainfall intensity. GPM uses a constellation of satellites to measure rain and snow globally every three hours. During Maila, GPM data showed the storm’s rainbands repeatedly drenching East New Britain. This information helped scientists link the heavy rainfall to the landslides. By comparing GPM rainfall totals with the landslide locations seen in Landsat 9 imagery, researchers can better predict where similar events might occur in the future. GPM’s high-resolution estimates are especially valuable in remote areas like Papua New Guinea, where ground-based rain gauges are scarce.