Nate’s Adventures: Summer Solstice from Makapuʻu Sea Cave

by Nate Yuen | Reading time: 1.5 minutes

I stumbled on a beam of sunlight emanating from a sea cave aligned with the sunrise on the summer solstice.

The summer solstice is an astronomical event caused by Earth’s tilt on its axis and by its orbital motion around the sun. In 2022, the summer solstice was on June 20.

The spot on the horizon where the sun rises changes each day. The summer and winter solstices mark their furthest positions on the horizon. The northern-most position is the summer solstice and the southern-most position is the winter solstice.

Around the summer and winter solstice, the sun's position on the horizon appears to pause briefly before reversing direction for the next six months.  As a result, the cave is aligned with the sunrise for a period of several weeks.

When the tide is low and the waves small you can crawl into the lava tube sea cave. When the full strength of the sun penetrates the cave at sunrise, the light is blinding.

When clouds dim the light level, the sea cave is illuminated and is a sight to see.

The offshore islets of Mānana and Kāohikaipu are visible through the lava tube at sunrise.

Hawaiians have two names for the summer and winter solstices.

SUMMER SOLSTICE - June 20-22

Ka māuikiʻikiʻi o ke kauwela

Ke Alanui Polohiwa a Ka̅ne

WINTER SOLSTICE - December 20-22

Ka māuikiʻikiʻi o ke hoʻoilo

Ke Alanui Polohiwa a Ka̅naloa

Polynesians observed the movement of the heavens and aligned sites with astronomical events. Hāpaiali’i Heiau on Hawaiʻi Island is a solar calendar. The heiau’s top platform allows the viewer to accurately mark the passing of the seasons by aligning it with other various points on the heiau. The winter and summer solstices are accurately marked by noting where the sun sets relative to the structure.