諏訪湖の御神渡り：2023年2月5日（日）

昨日4日は立春。この時期，長野県の諏訪湖では御神渡り（おみわたり）という現象が起きることで有名である。平安時代の堀河院御時百首和歌に次のような歌がある。

　諏訪の海の氷の上のかよひちは

　神のわたりてとくるなりけり　（源朝臣顕仲）

諏訪湖が全面結氷することにより，湖の氷が競り上がってできるもので，春の訪れを象徴する現象の一つとされ，古来行われてきた諏訪市の御神渡り神事は無形民俗文化財であるという。しかし，近年では2018年を最後に御神渡りは観察されておらず，今年も5季連続で観察が難しいようだ。これも地球温暖化の影響によるものであろうか。

Omiwatari on Lake Suwa：February 5th(Sunday)

Yesterday, February 4th, was the beginning of spring according to the Japanese calendar. During this time, Lake Suwa in Nagano Prefecture is famous for a phenomenon called "Omiwatari," where the frozen surface of the lake splits open, creating a unique pattern. There is a poem in the Hyakunin Isshu, a collection of one hundred poems by one hundred poets from the Heian period, that goes like this:

"Suwa no umi no kori no kayoichiwa kami no watarite tokurunarikeri" (Written by Minamoto no Akinaka)

The Omiwatari ritual, which has been held since ancient times in Suwa City, symbolizes the arrival of spring, and is considered an intangible cultural asset. However, the Omiwatari has not been observed since 2018, and this year marks the fifth consecutive season without it being observed. This may be due to the effects of global warming.