A new study suggests that earthquake early warning systems, which aim to provide people with seconds of warning time before an earthquake strikes, could be improved for large magnitude earthquakes. The research team, led by scientists from the Japan Agency for Marine-Earth Science and Technology, used physics-based computer simulations to investigate how different factors, such as the earthquake's magnitude and location, affect the performance of early warning systems. They found that for magnitude-9 earthquakes, the current system could underestimate shaking intensity and arrival times in certain areas compared to actual observations. By considering these insights, the team proposed modifications to the early warning algorithms to improve the accuracy of the warnings for such large events.