Kīlauea Iki - lava and life

The hike across the floor of Kīlauea Iki offers impressive views of a once molten lava lake (check out this video for some amazing footage of the fire fountain during the 1959 eruption).

The floor of Kīlauea Iki - note polygonal cracks, and the well-tread trail

There are plenty of exciting geologic details - olivine phenocrysts, polygonal cracking (visible in the photo above, here's a paper on their formation), active steam vents - but there is also a surprising amount of life. Most striking are the blossoms of the ōhiʻa lehua, lonely frontrunners in the inexorable march of vegetative reclamation, splashing the landscape with red. The contrast is a reminder that eruptions not only destroy, but resurface and rejuvenate. The newborn rock hosts species endemic to Hawaii, adapted to live on freshly cooled flows.

 

 

 

ōhiʻa lehua (metrosideros polymorpha)

Waimea Canyon

Waimea Canyon: layers of solidified lava on the island of Kauai, HI

Waimea Canyon on the island of Kauai in Hawai'i is impressive. Beyond the surreal beauty of standing on the edge of a 3000 ft (900 m) cliff, there are a some fascinating details in the rock.

First off, these aren't layers of sedimentary rock, but igneous basalt! They formed by the solidification of lava flow upon lava flow upon lava flow over several million years! That's pretty darn unusual - every other layered canyon I know of cuts through layers of sediment.

Secondly, the layers are remarkably horizontal and undisturbed. What's so special about that? Well when lava flows down the side of a volcano and solidifies, the solidified rock layer dips with the slope of the volcano (you can't see it in the photo, but the west side of the canyon actually has layers that slope gently).  Horizontal layering of lava only happens when lava is fills in a hole; the lava flows down, settles and solidifies. So what happened here? It turns out that about 4 million years ago, the volcano collapsed, leaving a huge depression and then over the next several million years lava flowed in and filled the depression.

Gneiss Views: Introduction

Much of my time is spent outdoors hiking, rock climbing, walking and sitting. Being a geologist of sorts, the landscapes I journey over often provoke more than simple appreciation of nature - the scene we see is the culmination of a process, not just a static beauty. In this blog I'll share some photos and stories of places I've visited, showing the world from the perspective of a theoretical geophysicist on vacation in the field.

The next few posts will contain photos and accounts from a recent trip to Hawai'i.