Smoke from multiple wildfires hung over the Malaysian Peninsula and the Indonesian island of Sumatra on July 16, 2021. The Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a true-color image of the scene on that same day.
The fire season in Indonesia normally begins in mid-August and lasts for 13 weeks. Despite the smoke in the air, data published by Global Forest Watch show that the period from July 20, 2020 and July 12, 2021 was normal compared to previous years.
Near the center of the image is Lake Toba, the largest lake in Southeast Asia and the one of the deepest lakes in the world. Located in the northern portion of the island of Sumatra, the lake fills the caldera of a supervolcano. About 70,000 years ago, the earth was rocked by the largest volcanic eruption to have occurred in the past 2 million years. Over what was probably a two-week span, thousands of cubic kilometers of debris poured from this caldera. Ash from the Toba eruption reached India, leaving layers up to 6 meters (20 feet) thick. The central island, Samosir, is a resurgent volcanic dome—a mount of rock uplifted by pressure from un-erupted magma in the chamber beneath the volcano.