Every measurement relies on a “standard measure.” For geologists examining periods 50,000 years into the past, “varves”—thin geological layers deposited at the bottom of Lake Suigetsu—serve as a global standard measure. Researchers worldwide had reached a limit in improving the quality of this measure, but this project has surpassed that limit using new technology, dramatically enhancing both the precision and ease of use. This technology can also be applied to reconstructing past climate changes, enabling us to depict the climate history over the past 50,000 years.

Establishing measurement standards has profound ripple effects. For example, the introduction of the international prototype metre revolutionised both civilisation and industry. Similarly, modern, precise measurement technologies have expanded the boundaries of physics and enhanced our understanding of space. The same potential exists for geologic time. Accurate measurements of geologic time can transform the fields of geology and archeology, and reshape our understanding of the Earth and humanity. I would be delighted to contribute to such impactful research.

Since this work aims to establish a “standard measure,” any compromises could have widespread impacts across geology and archaeology (similar to the issues that would arise from an inaccurate international prototype metre). Conversely, data that are meticulously and uncompromisingly developed can not only be used with confidence by the community, but also provides a profound sense of achievement for those who generated them. My goal is to create such data, leaving behind a legacy that brings me joy when I reflect on my work.

Varves from Lake Suigetsu have already been collected through excavation; I will therefore process these samples to extract the pollen fossils. The extracted pollen fossils will then be analysed using an accelerator at the University of Tokyo and a mass spectrometer that will be introduced for this project. I anticipate that the next revision of the “standard measure for time” will be around 2026, so I aim to report the organised data by then.

This research has the potential to impact various fields related to the past 50,000 years, including geology, archeology, and anthropology. Moreover, by pinpointing the precise timing of past climate changes, we can better understand the mechanisms behind climate change and potentially improve future climate predictions. I anticipate that this will significantly deepen our understanding of how humans activities have shaped the world and the environments in which these processes occurred.

Partnerships:

The varves of Lake Suigetsu offer the world’s most accurate time scale for Geology. I am eager to collaborate with researchers who will use this resource for further analyses. Currently, for instance, I am advancing research on reconstructing the timing and dimension of volcanic eruptions by examining volcanic ash within the varves, and on reconstructing precipitation amounts by analysing specific types of organic matter, in collaboration with international partners. I also warmly welcome proposals for analyses that we have not yet envisioned.

Research collaborations:

I value partners who find meaning in taking their time to produce ‘ultimate’ data. While theories often have fleeting relevance, thoroughly and comprehensively collected data has enduring significance. Truly groundbreaking discoveries often emerge unexpectedly as by-products of meticulous data collection. I believe that I will be able to form ongoing partnerships with people who share this sense of value.