This video is a live-streamed conversation from the E/V Nautilus research vessel about the science and challenges of modern seafloor mapping. The discussion features Marley Parker (Communications Lead), Lynette Davis (Mapping Coordinator), and special guest Laura Trethewey, an ocean journalist and author of the book "The Deepest Map."
The conversation explores the complexities of 24/7 mapping operations, including the use of multibeam sonar and the significant impact of weather conditions, which can degrade data quality. Laura Trethewey shares her experience sailing on the Nautilus and discusses how the famous cliché, "we know more about the surface of Mars than our own seafloor," inspired her to write a book about the global effort to map the ocean. A central focus is the Seabed 2030 initiative, a large-scale international project aiming to create a complete, publicly available map of the entire seafloor by 2030. The participants also discuss the critical role of autonomous vehicles and crowdsourcing to achieve this ambitious goal, the process of discovering unexpected geological features, and how this foundational data is essential for conservation efforts and the establishment of marine protected areas.
Mapping the Final Frontier: A Conversation on Seafloor Exploration
0:00:53 Introduction from E/V Nautilus: The live stream is broadcast from the research vessel E/V Nautilus during its Mid-Pacific Mapping Southbound Expedition (NA152). The hosts are joined by author Laura Trethewey to discuss seafloor mapping.
0:02:24 24/7 Mapping Operations: Mapping Coordinator Lynette Davis explains that mapping is a continuous, 24/7 operation. The team monitors multibeam sonar, the ship's position and attitude, and regularly measures the speed of sound in the water to ensure data accuracy.
0:05:13 The Challenge of Weather: Rough seas can significantly hinder mapping by creating "bubble wash down" under the ship's hull. These bubbles interfere with the sonar's acoustic signals, preventing them from reaching the seafloor and resulting in poor or unusable data.
0:09:46 Inspiration for "The Deepest Map": Author Laura Trethewey explains her book was inspired by the well-known cliché that we know more about other planets than our own ocean. This gap in knowledge is primarily about the lack of a complete, high-resolution map of the seafloor.
0:15:37 The Seabed 2030 Initiative: This is a major global initiative launched in 2017 with the ambitious goal of mapping 100% of the world's seafloor by 2030 and making the data publicly available. The E/V Nautilus is a key contributor to this project.
0:21:07 The Future is Autonomous: The panel discusses how autonomous vehicles (drones, AUVs) are seen as a "force multiplier" and are likely essential to meeting the Seabed 2030 deadline. While they are more cost-effective and efficient, there's a nostalgic feeling about potentially replacing human explorers at sea.
0:31:31 Tools of the Trade: The speakers explain the use of a Sound Velocity Probe (XBT), which is deployed from the ship to measure temperature and pressure, allowing for corrections to the sonar data to create more accurate maps.
0:33:34 Low vs. High-Resolution Mapping: While a low-resolution map of the global seafloor exists from satellite altimetry, it can only resolve features on a kilometer scale. Ship-based multibeam sonar provides much higher resolution (e.g., 100 meters), revealing features that are otherwise invisible.
0:40:28 Mapping Priorities: Mapping efforts prioritize coastal areas, ports, and harbors for navigational safety, as well as a country's Exclusive Economic Zone (EEZ). In the deep, international waters, transits are often planned to investigate potential unmapped features identified by satellite data.
0:45:08 Mapping for Conservation: Mapping is described as the critical first step in ocean exploration. By identifying and characterizing seafloor habitats and biodiversity, this data can inform policy and support the creation and expansion of Marine Protected Areas.