A well-made loaf has a certain magic to it.
Break through the outer crust and there is a momentary crack; crisp, brittle and audible. Beneath lies something entirely different: a softer interior, full of air pockets and hidden structure. What appears solid from the outside reveals a more complex story within.
A recent visit to Rangitoto, the volcanic island that rises from the waters of the Hauraki Gulf, prompted a similar reflection. Its distinctive silhouette feels permanent and settled, yet the island itself is relatively young. On first glance, the landscape appears freshly ploughed, ready for planting. We have since learned, this is ‘Aʻā lava’. As molten lava cools, its surface hardens into a brittle crust while the liquid rock beneath continues to flow, tearing and buckling the crust into jagged ridges. The result is a terrain that resembles cultivated soil, shaped not by a tractor, but by fire.
Formed around 600 years ago, Rangitoto is the largest and youngest volcano within the Auckland Volcanic Field, a monogenetic volcanic landscape comprising more than 53 volcanic centres that have emerged over the last 200,000 years.
What appears dormant still carries traces of its fiery origins.
Researchers from the University of Auckland recently discovered evidence that the solidified magma beneath Rangitoto remains warm enough to drive a weak hydrothermal system six centuries after its eruption. The volcano is not considered active, nor is it preparing to erupt again, but the finding offers a reminder that geological processes often continue long after visible activity has ceased.
It is easy to forget this. We walk across ridgelines, through glens, alongside cliffs and over mountain passes with little thought for the forces that shaped them. Landscapes become scenery rather than processes. Their stories are flattened into views.
Yet beneath every footstep lies a deeper history. Consider Yr Wyddfa, whose rocks were formed through volcanic activity hundreds of millions of years ago. Or Glen Coe, a dramatic remnant of an ancient volcanic collapse structure shaped further by ice, water and time. Slemish, Slieve Mish, rises from the landscape of County Antrim as the hardened core of a long-eroded volcano, its resistant rock outlasting the softer material around it. Each stands as a marker of geological change rather than permanence.
Elsewhere, volcanoes such as Mount Etna and Stromboli continue to remind us that the Earth's surface remains dynamic. They reveal, more visibly than most landscapes, the energy and movement that exist far below our field of view.
The ground beneath us is not fixed. Continents drift. Plates move. Magma circulates. Heat dissipates. Landscapes evolve.
Most of these processes unfold at timescales beyond human perception, which perhaps explains why we rarely think about them. The surface feels stable enough to convince us otherwise.
And yet, every summit, valley, island and coastline tells a story of pressure, fracture, eruption, erosion and renewal.
Like the crust of a loaf, the surface is only part of the story. What lies beneath is often where things become most interesting.