Global tephra studies: role and importance of the international tephra research group “Commission on Tephrochronology” in its first 60 years
Authors: Lowe David J. , Abbott Peter M. , Suzuki Takehiko , Jensen Britta J. L. 
Published: July 2022

Abstract. Tephrochronology is a correlational and age-equivalent dating
method whereby practitioners characterize, map, and date tephra (or volcanic
ash) layers and use them stratigraphically as connecting and dating tools in
the geosciences (including volcanology) and in studies of past environments
and archaeology. Modern tephra studies per se began around 100 years ago (in the
1920s), but the first collective of tephrochronologists with a common purpose
and nascent global outlook was not formed until 7 September 1961 in
Warsaw, Poland. On that date, the inaugural “Commission on Tephrochronology”
(COT) was ratified under the aegis of the International Union for Quaternary
Research (INQUA). The formation of COT is attributable largely to the leadership
of Kunio Kobayashi of Japan, the commission's president for its first 12 years. We were motivated to record and evaluate the function and importance of COT because tephrochronology continues to grow globally and its heritage needs
to be understood, appreciated, and preserved. In addition, studies on
cryptotephras, which are fine-grained glass-shard and/or crystal
concentrations preserved in sediments or soils but insufficiently numerous
to be visible as a layer to the naked eye, have also expanded dramatically
in recent times. Therefore, in this article, we review the role and impacts
of COT under the umbrella of INQUA for 53 of the last 60 years or under
IAVCEI (International Association of Volcanology and Chemistry of the
Earth's Interior) for 7 of the last 60 years, including since 2019. The
commission also functioned under other names (abbreviated as COTS, CEV,
ICCT, COTAV, SCOTAV, and INTAV; see Table 2 for definitions). As well as identifying key persons of
influence, we describe the development of the commission, its leaders, and
its activities, which include organizing nine specialist tephra field meetings
in seven different countries. Members of the commission have participated in
numerous other conferences (including specialist tephra sessions) or
workshops of regional to international scale, and they have played leading roles in
international projects such as INTIMATE (INTegrating Ice-core, MArine and TErrestrial records) and SMART (Synchronising
Marine And ice-core Records using Tephrochronology). As well as strongly
supporting early-career researchers including graduate students, the
commission has generated 10 tephra-themed journal volumes and two books. It
has published numerous other articles including field guidebooks, reports,
and specialist internet documents/sites. Although its fortunes have ebbed as
well as flowed, the commission began to prosper after 1987 when key changes
in leadership occurred. COT has blossomed further, especially in the past
decade or so, as an entire new cohort of specialists, including many engaged
in cryptotephra studies, has emerged alongside new geoanalytical and dating
techniques or protocols to become a vibrant global group today. We name 29
elected officers who have been involved with COT since 1961 as well as 15
honorary life members. After reviewing the aims of the commission, we
conclude by evaluating its legacies and by documenting current and future
work.