The Call of the Pacific

What brought us here? Nothing but the truth! Or at least an attempt to find it. This question – why did we come here – has multiple answers, such as: to find the broken part of a stalagmite that was lost for unknown reasons, to explore new study sites, to collect interesting samples, to deploy a monitoring device –  even the advice of a wise elephant and his buddy the lucky cat could count as a valid reason to come here.

50 years ago Dr. Chris Hendy one of the pioneers of the speleothem science, collected a stalagmite from a legendary cave. This stalagmite was kept in the archives of his collection until the visionaries Dr. Sebastian Breitenbach and Dr. Adam Hartland decided that this would be the object of study for my doctoral project. That’s how stalagmite C132 reappeared from a laboratory drawer, and with it came incredible adventures.


Last summer, members of the team QUEST undertook an expedition to a tiny island situated right in the middle of the Pacific Ocean. The team is formed by Dr. Sebastian Breitenbach, Dr. Adam Hartland, Dr. Ola Kwiecien and Dr. Maximilan Hansen and myself, along with the very skilled and experienced field technical officer Warrick Powrie, and an the enthusiastic PhD student Sebastian Hoepker both from the University of Waikato. The name of this tropical paradise is Niue.

Everyone is ready to explore Niue caves
From right to left: Max, Dayren, Seb B. and Adam working  intensively on drilling a stalagmite core
Ola closely examining snails on the cave sediment.  Photo by Adam Hartland 

But don’t assume that just because Niue is small and in the middle of nowhere that means it’s not interesting. In fact, it’s just the opposite. Niue island is situated right where the one of the switches that activate the dynamics of the climate on Earth turns on and off. Yeah, where the magic happens! Niue is witness to the warming of the ocean surface waters. This heat, which comes from the sun, is stored and transported towards the west by the ocean currents, which in turn are driven by the trade winds. Part of this warm water is evaporated and forms thousands of towering clouds that discharge this water as rain in the south-west of Asia and Australia. Another part is distributed to higher latitudes.


And if this were not enough, the Niue bedrock is full of caves. Incredible caves of many kinds: some very deep, some very hot and humid, others not so much, some that intrigue, even some that open their doors and joyfully receive the Pacific Ocean with, listen attentively to its secrets and jealously guard them in their stalagmites.

“The cave that invites”
“The intriguing Cave” coated by a black sediment
Niue cave residents having deep conversations with the visitors

But what does the Pacific Ocean have to say? The Pacific Ocean? Yes yes the big guy, yeees the biggest ocean on earth. That one! The Pacific Ocean was named by the Portuguese explorer Ferdinand Magellan in 1521, and as its name implies it means “the peaceful sea”. But to tell the truth, there’s very little that’s peaceful about it. It’s calm in some places and at some times, but it is also true that it is highly dynamic, powerful, sometimes violent and destructive.

I like to say that the Pacific Ocean is everything! Because it contains everything – waters of thousands of colours, a wide range of temperatures, soft sounds that relax and resounding sounds that shake – because it produces much of the oxygen that a great number of beings on Earth breathe, sustains marine life, disappears when its waters evaporate and some time later comes back to itself, and because every time I see it inundates my life with infinite inspiration and completeness.

The Pacific Ocean helps me to understand that everything is connected and it fascinates me to think that every time I inhale air I am breathing the one who is everything.

“The cave with the turquoise pool”  Photo by Adam Hartland

After two years of intense lab work the geochemical analysis of the stalagmite C132 is starting to reveal interesting climate dynamics. But that’s another story, one that’s cooking in the laboratories of Earth Sciences of RUB University in Germany, The University of Waikato in New Zealand and the Geological Institute, ETH in Switzerland.

Rain water sample

In the end the expedition was successful and we returned to the university with many samples. We did not find the missing part of the stalagmite – and that’s fine, too. No one said it would be easy to find a puzzle piece that contains the history of the last 5000 years of climate in the Tropical Pacific. Without doubt it was the best expedition of the year. What incredible luck to have answered the call of the Pacific and experienced for a week the same conditions in which the stalagmite C132 grew happily in a remote past.

Are you ready to jump in?



Starting time

To debut The Cave Journey, this first story is enriching because it is about the fieldwork experiences during this last summer in Waipuna Cave, a charming place beneath the Waitomo region landscapes in northwest New Zealand.

The appointment:  7:30 am at Gate 9 of the University.  The scientific team is ready. Dr. Adam Hartland, researcher from University of Waikato New Zealand, Inken Heidke, Ph.D. student from Johannes Gutenberg-Universität, in Mainz, Germany and myself.  Helmets, boots, gear and work equipment is organized in the vehicle. The first stop is at the famous road bakery where coffee and a delicious cake will provide the necessary energy to start the day’s adventure.


A beautiful open landscape illuminated by the sunny morning awaits us to begin the journey to Waipuna cave. Here we organize the material, put on this funny getup and start hiking up the hills and enter the forest where the sunlight is being trapped by the lush vegetation where the forest star is The Silver Fern (Cyathea dealbata) “Ponga” in Māori language, this fern is native to New Zealand and is now a symbol of national identity.


Moving onward we take a detour to the meteorological station to download the data of temperature and rainfall that the devices record every day. We then continue on this passage full of discoveries, obstacles, and expectations that take us into the Earth’s depths.



The descent is quite an experience that challenges your physical and mental limits, forcing you to focus all your attention on the steps that you are making, because to go downwards you have to use your four extremities very efficiently + balance your body’s gravity centre + analyze the possible pathways + summon up courage+ decide which step to take next+ trust your grip on the rocks (that by the way are covered with slippery mud) and sometimes use unknown strength that helps you not to fall.


Once the fright is over it’s possible to enjoy the release of adrenaline during the descend, this accompanied by a discrete feeling of happiness which is increasing after the first steps made underground and is leading into an interesting maze of stalactites where ducking, turning or squeezing a little bit is required. However, the reward is amazing an ornate palace with whimsical shapes of calcic formations.



We made it!  Waipuna’s heart is the source of information that we have been looking for all this time. So now the work begins by organizing to take water samples from the different drip points.

Photo author Inken Heidke

This water will later be analyzed in the laboratory to determine its elemental content as well as the oxygen and carbon isotopic composition. We also measure the drip rate to which these drops fall as well as the temperature, pH, and electrical conductivity, another important parameter is the C02 concentration in the cave air.


Photo author Inken Heidke

The characterization of these geochemical parameters helps us understand the environmental conditions that led to this drop of water from the beginning of its path, the chemical transformation through the soil layer and the limestone bedrock until finally get to the dripping point, that under delicate equilibrium conditions in the cave atmosphere and after some thousands of years will build speleothems (stalactites and stalagmites among others).  Isn’t this amazing? Super exciting!  Think about it, if just one drop of water or a very small amount of calcium carbonate coming from a stalactite has information about the environmental conditions that occurred in the past… Can you imagine what else? Or what other kinds of information the entire cave has?  I know, it’s mind-blowing!


Going some meters further into the cave the team looks for a place to set the passive sampling of aerosols (tiny particles suspended in the air). Because it is an area of research is beginning to develop we applied a type of experiment called “No target experiment” because there is no question or objective to pursue, just put filters in the Petri dishes, wait for a while and come back the following week to take the samples to the lab to analyze and see what we find. It’s a mystery!  In my view, it’s equally interesting to have clear objectives as it is to not have them. It is a way to observe without preconceived beliefs about the potential information that nature has to show us.  If we are open to listen to it of course.

Photo author Adam Hartland

This gets more and more interesting, but for the moment our time in the cave has ended. We take a few minutes to contemplate and little by little say our goodbyes to the magical cave.


Photo author Inken Heidke

By the end of the day, we are physically tired but filled with good underground vibes that comforts, cheers and recharges our energy to continue life’s journey.

Many thanks to Dr. Adam Hartland and Dr. Sebastian Breitenbach for making this possible. To QUEST project and DAAD for the funding.

And if you have two minutes, why don’t we go…

To close this chapter a nice short concert performed by “The Flowstone Orchestra”

Adventure in the cave from Cinthya Nava on Vimeo.