Fusa Miyake is a

cosmic ray Cosmic rays or astroparticles are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the ...

physicist at

Nagoya University , abbreviated to or NU, is a Japanese national research university located in Chikusa-ku, Nagoya. It was established in 1939 as the last of the nine Imperial Universities in the then Empire of Japan, and is now a Designated National Universit ...

, Japan, whose work measuring isotope abundances led to recognition of so-called

Miyake event A Miyake event is an observed sharp enhancement of the production of Cosmogenic nuclide, cosmogenic isotopes by cosmic rays. It can be marked by a spike in the concentration of radioactive carbon isotope Carbon-14, in tree rings, as well as Beryl ...

s. These have resulted in reconciling differences between dates from documents and materials such as ice-cores and tree rings.

Scientific career

Fusa Miyake gained her doctorate from

in 2013 and was then appointed as an assistant professor. In 2017 she was promoted to associate professor in the Division for Cosmic Ray Research within the Space-Earth Environmental Research Division. Her doctoral research identified events in the wood of long-lived Japanese cedar trees, now called

s, where there are sudden increases in

cosmogenic isotopes Cosmogenic nuclides (or cosmogenic isotopes) are rare nuclides (isotopes) created when a high-energy cosmic ray interacts with the nucleus of an ''in situ'' Solar System atom, causing nucleons (protons and neutrons) to be expelled from the atom (s ...

such as radioactive

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

isotope Isotopes are distinct nuclear species (or ''nuclides'') of the same chemical element. They have the same atomic number (number of protons in their Atomic nucleus, nuclei) and position in the periodic table (and hence belong to the same chemica ...

, and produced by

s originating from the Sun when large solar flares or eruptions occur. Although the event was initially proposed to be a signature of an unidentified supernova, it was soon independently confirmed and proven to be the discovery of an extreme solar particle event. The measurements utilised the polymer cellulose extracted from tree-rings formed in individual years that could be measured using

accelerator mass spectrometry Accelerator mass spectrometry (AMS) is a form of mass spectrometry that accelerates ions to extraordinarily high kinetic energies before mass analysis. The special strength of AMS among the different methods of mass spectrometry is its ability t ...

. Detection of these isotopes in materials such as tree-rings and

ice core An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier ...

s. Measuring these isotopes in materials that have been independently dated allow the events to be dated with precision. This gives information about the Sun's long-term activity. She identified an event in 775 during her doctoral work, and along with colleagues, has subsequently identified events centred on 993-4 and also 660 and 5480 BCE. By 2023, 6 Miyake events had been identified. Her subsequent research with worldwide collaborators, and that of other researchers, has suggested that the source of the radiation causing Miyake events is more complicated than from single solar events. Some may be from multiple solar flares, influenced by tree physiology or by interactions of high energy particles with the Earth's magnetic field.

Publications

Miyake is the author or coauthor of over 50 scientific publications and books. These include: *

Ilya G. Usoskin Ilya G. Usoskin is a Finnish astrophysicist who is a professor at University of Oulu and head of Cosmic Ray Station at Sodankylä Geophysical Observatory. He is a Vice President of the International Astronomical Union since 2021. Education In 1 ...

, Fusa Miyake, Mélanie Baroni and 17 others (2023
Extreme Solar Events: Setting up a Paradigm.
''Space Science Reviews'' 219 pp73 * P.J. Reimer, W.E.N, E. Bard ... F. Miyake ... and 38 others (2020
The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0–55 cal kBP).
''Radiocarbon'' 62 pp 725–757 * A. Scifo, M. Kuitems, A. Neocleous ... F. Miyake and 6 others (2019
Radiocarbon Production Events and their Potential Relationship with the Schwabe Cycle.
''Scientific Reports'' 9 17056 * Fusa Miyake, Ilya Usoskin and Stepan Poluianov (2019) ''Extreme Solar Particle Storms: The hostile Sun'' Institute of Physics Publishing, pp 447. ISBN 9780750322300 * Fusa Miyake, A.J. Timothy Jull, Irina P. Panyushkina and 7 others (2017
Large 14C excursion in 5480 BC indicates an abnormal sun in the mid-Holocene.
''Proceedings of the National Academy of Sciences (U.S.A.) 114 pp 881–884 * F. Miyake, K. Nagaya, K. Masuda and T. Nakamura (2012
A signature of cosmic-ray increase in AD 774–775 from tree rings in Japan.
''Nature'' 486 pp 240 –242

Awards

In 2017 Miyake received an Commendation Award for Young Scientists from the Japanese Minister of Education, Culture, Sports, Science and Technology. In 2022 she received the José A. Boninsegna Frontiers in Dendrochronology Award from the Tree-Ring Society.

References

{{DEFAULTSORT:Miyake, Fusa Living people Japanese physicists Japanese women scientists Nagoya University alumni Year of birth missing (living people)