Hapuna Beach, Big Island of Hawaii’i

The pounding waves, the relentless tides, the winds, the shape and geology of the shoreline give us the unrivaled beauty and diversity of the Hawaiian beaches . Their ever-changing nature is breathtaking: black, white, green, rocky or sandy, quiet or roaring, they are magical. Their dynamic personality is rivaled perhaps only by Pele and her home, Kilauea, the place where fluid magma becomes solid earth.

A visit to the Hapuna Beach on the Big Island of Hawai’i during low tide on a beautiful day in May turned into an invitation to explore the space at the intersection between the native Hawaiian knowledge of the place and the approaches of Western science.

Hapuna Beach at low tide, looking towards South.

Hapuna, a crescent shape, white sand beach located on the NW shore of the Big Island, is one of the best known beaches of the Hawaiian chain.  It was named ‘#1 Beach in the US’ in 1993 by Dr. Beach, the coastal research scientist from Florida International University. Hapuna makes a good location for research because it is close to Kawaihae, a place steeped in Hawaiian history and tradition wonderfully captured by the Pacific Worlds at their comprehensive website.  Kawaihae is also one of the two NOAA data collection stations on the Big Island.

NOAA observation stations at Kawaihae, north of Hapuna Beach. Image captured with MotionX GPS iPhone App.

NOAA collects tide and current data at an offshore station (HAI1128), and meteorologic measurements at an onshore station (161 7433). The only other NOAA station on the Big Island is located in Hilo area, on the east side.

The Winds

Usually in the morning, wind comes from the East. Then at a certain time, around noon, it turns around and comes from the West. So these two winds, they just circle in like this. (William ‘Papa’ Akau, 1959 – courtesy of Pacific Worlds/Kawaihae)

The kama’aina (local Hawaiians) careful observations document two dominant wind directions: Apa’apa’a is a very strong wind that sweeps over the top of the mountain and down the slope. The Naulu is a convection wind, caused by heated air moving up the slope.

Rose diagram showing wind direction during the month of April, 2017. Data from NOAA Tides&Currents, plotted with Stereonet9 developed by Rick Allmendinger)

The NOAA wind data from April 2017, displayed using a rose diagram, shows the Apa’apa’a WNW wind and the Naulu easterly, convection wind. The speeds are typically up to 13 m/s, with gusts up to 20 m/s.

The currents, tides and waves

Water current direction varies with depth.  Measurements by NOAA from March 2011 show near surface currents (6m water depth) with directions similar to the tides, winds and waves, while the deeper currents (38m water depth) are parallel to the the coastline.

Curent directions measured during March 2011 by NOAA, in Kawaihae area. Data from NOAA tides and currents

Hapuna Beach is a micromareal environment, with tide ranges typically below 2m.

Tides at Kawaihae NOAA station during the month of April 2017. Data source NOAA Tides and currents.

But see, all the three waves out here and the shore line, you hear people talk. Because when they hear what kind of surf’s happening, they quick know which place. Ka‘ewa is a heavy, rough, pounding. Pua ka ‘Ilima is a nice soft. And Kukui is a nice long, starts from way out. That’s where Kamehameha surfed. Kukui. They surfed at night time. So this is the story. (William ‘Papa’ Akau via Pacific Worlds/Kawaihae).

Wave direction is predominantly from the north-west, with wave heights up to 15 m.

Map showing the mean (white arrows) and variability (red ellipses) of wave directions and heights, in meters, during the 2010–2011 NOAA winter experiment for the Kawaihae area, Big Island of Hawaii. All of the sites showed a predominant wave direction from the northwest, with the largest wave heights measured in the more-exposed central portion of the bay. Image from USGS Report

The rocks

The host rocks at Hapuna Beach are Pleistocene basalts of the Hamakua Volcanics series.  They are 250-65 thousand years old and were sourced by lava flows from the Mauna Kea volcano. These basalts are obviously not the source of the sand on the beach, given that the Hapuna sand is white and most likely transported by currents from the coral reefs to the north (and south?).

Geologic map (left) and close-up picture of the basalt rocks cropping out around the Hapuna beach area. Olivine crystals are easily visible in the basalt, and they form small pockets of green sand.

Some of the questions to address in future posts are: what is the sand composition and what controls the sediment transport? Are there seasonal variations in beach configuration? What is the effect of storms on the beach geometry in comparison to the fair weather processes?

The Climb

The climb to the Mauna Kea summit at night, with a full moon was, physically, the most challenging thing I ever did. Michael and I left our home in Hilo around 8:30pm on July 31st, 2015 – a full moon/blue moon night. As we were pulling off the driveway it started to rain – a steady, persistent rain. About a mile into our drive the low-pressure tire sensor lit on the dashboard, not a big deal I told myself, as it almost always happens during rapid changes in temperature or air pressure, but still….

I was driving in the rain, on the Saddle Road, then turned into the Mauna Kea Access Road and immediately went into the clouds. The road is windy and with the cloud cover the visibility was low, especially at night. In my mind I was going through all the reasons why we should not do this – two people hiking for over seven hours at night, to reach a 4000m+ summit – crazy! We drove on. We reached the Mauna Kea Visitor Information Station at around 9:30pm, cars were going in and out. The visitor center, normally open until 10pm, was closed indefinitely because of ongoing protests related to the construction of a new telescope on Mauna Kea. Our plan was to acclimatize for the high altitude at the visitor center for about an hour before staring out hike. As we were taking our time and getting ready, a truck drives by, stops near our car, and the driver says: ‘be careful, the police may come around after 10pm’. Great! I was thinking it would be something to get arrested even before we start out climb. I read a few days ago about police arrests at the visitor center of protesters who were camping in undesignated areas. I was hoping we are safe since we were not camping; in the end we did not get arrested :).

Mauna Kea is, allegedly, the highest mountain in the Pacific Rim area, and with an elevation of 4205m (13,796ft) is the highest peak in the state of Hawai’i. When measured from the sea floor, Mauna Kea is over 10,000 m (33,000 ft) tall—significantly taller than Everest. It is a shield volcano, with gentle slopes made of countless basaltic lava flows, its shape resembling the shield of a warrior resting on the ground. Geologically, the volcano that produced the mountain is over 500,000 years old.

We prepared for our climb for several days in advance – rain and wind gear, layers of clothing, sturdy hiking boots, lots of water, serious gloves and hats appropriate for sub-freezing temperature, rain and heavy winds. I did this climb during the day about three years ago, so I know what to expect.

Starting the ascent to the summit.

We started our ascent around 10:30pm, the blue moon was fantastic, the clouds below us, the gentle slopes of Mauna Loa in the distance. There was no need for the headlamps or flashlights we brought, as the path laid clear ahead, lit by the moonlight. It was peaceful and beautiful, the worries of the rain, the low tire pressure, the clouds, the police arrests, the protesters, and everything else, all left behind. From that point on it was just us and the mountain, in a gentle, uneven embrace.

We hiked up for five hours straight and reached the 4000m altitude mark at around 3:40am. It was getting cold and we could definitely
feel the effects of the altitude: I felt very nauseous and Michael was light-headed and with a headache.

Besides climbing the mountain at night the other goal was to watch the sunrise from the summit. Since we got near the summit at 3:40, we had more that two hours to wait around until the sunrise. With all the high altitude symptoms both of us were experiencing, it was becoming unsafe to wait until the sunrise. We turned around and hiked down to our car for about two hours. It would have been spectacular to see the sun rising over the Pacific from Mauna Kea, but sometimes safety takes priority. This way it can be a ‘next time’. As we got to the car at the visitor center, ready to get back home, the sun was rising from the east as the moon was setting to the west – different from what would have been at the summit, but still beautiful.
It was difficult and beautiful, challenging and fulfilling, and perhaps the first crazy thing Michael and I did together. A great experience to have, two weeks before he is off to college.

Read the narrative of my first Mauna Kea climb here.

Healing the forest

Maili stream, Big Island – Hawai’i

I moved to the Big Island of Hawai’i in June 2015 on a seventeen-acre property west of downtown Hilo, on the slopes of Mauna Kea. A hundred or so years ago this property was a lush rain forest, dominated by Ōhi’a, Koa and Hapu’u ferns. Then the sugar industry came and went, the forest was decimated, and the native vegetation was gradually replaced by strawbery guava, ginger, Koster’s curse and other invasive plants.

The native Hawaiian forest is beautiful and harmonious, the forest covering my property today is anything but.  My longterm goal is to re-establish the habitat that once existed on this land.  I initially thought of this project as being about  ‘tropical forest restoration’.  For the past month or so, however, while exploring the property, I find that many of the native species are still present but struggling to survive, and so my effort must be directed more towards learning how to help the forest heal itself.

Geology and wine – Cotnari, Romania

Considering its location, the Cotnari region in Romania should be a difficult place to grow grapes.  The  vineyards are located between 47o17′ and 47o35′ northern latitude, in the middle of the continent, away from the beneficial influence of the Atlantic or the Mediteranean Sea.  In spite of that, from Cotnari come some of the finest wines in Romania, thought to be “some of the best in the world” by A. Julien, the Frenchmen who mentioned this area in Topographie des vignobles connus of 1832.

There are two factors that cause this area to be great for wine-grape growers: the Foehn-type winds, and the string of depressions that offer protection from the cold air from the North.  By the way, “depression” in geography is a landform at a lower elevation compared to the surrounding areas — nothing to get depressed about.  Both the Foehn-type winds and the depressions are influenced by geology, hence the point of the post: geology and wine are very much linked.

The Foehn winds, or Chinook winds as they are known in North America, are dry and warm winds that blow downslope of a mountain range.

The Cotnari area is in the rain shadow of the Eastern Carpathians, hence the warmer climate, somewhat unusual for this northern latitude.  The Eastern Carpathians started forming over 100 million years ago, in Cretaceous time, by collision between tectonic plates.  The Eastern Carpathians thrust-and-fold belt slowly uplifted since the Cretaceous to become the beautiful mountains of today.  Prior to the Cretaceous time there were no mountains, therefore no Foehn winds, no warm climate, no wine.  The dinosaurs could not have grown grapes around the Cotnari area, maybe this is one of the reasons they went extinct 🙂  The small depressions that offer protection and good micro-climate for grape-vine growing are also a result of geology: they are controlled by subsidence along the myriad of faults associated with the mountain belt.  The result for the Cotnari area and its wine?  Nice annual average temperatures of 9deg C, early springs and nice late autums lasting through October.

The Cotnari wines come from native varieties of grape: Grasa de Cotnari, Feteasca Alba, Francusa, Busuioaca de Moldova.  My favorites are Francusa, for its subtle, flowery taste, and of course Grasa de Cotnari, the perfect companion for a dessert.  So this weekend, enjoy your favorite glass of wine and think about the geology that made it possible.  As we say in Romania – Noroc!

Sources and further info:

Cotnari website

Romania, the land of wine by V. Cotea and F. Andreescu

Nice photography from the Carpathians in Romania are found here

Cotnari vineyard blogpost on TrueRomania

Geoscience metaphors (geo-puns) – “Won by a landslide”

Geologic terms are often used in everyday life as metaphors.  Some examples are: volcanic temper, a stress drop (after a major event), glacial pace, rock solid, etc.  In this post I will search for the origin and first uses of landslide as a geoscience metaphor.  First some definitions.

The term landslide, as far as I can tell, was first defined by Charles Lyell in “Principles of Geology” in 1830.  Lyell used the term “landslip” and not “landslide” and defined it as

A portion of land that has slid down in consequence of disturbance by an earthquake or from being undermined by water washing away the lower beds that supported it.

Principal components of a landslide are shown in this figure from the North Carolina Geological Survey .

The Wikipedia definition can be found here.  Here and here are examples of landslides from Romania, taken from the post on “Hazards and mud volcanoes in Romania”

The most common use of landslide as a metaphor is in politics; “won by a landslide” refers to capturing an overwhelming majority of votes by one party or candidate in an election.  First record I could find with this meaning is from a New York Times article from August 8, 1884 describing the Chicago’s Mayor Carter Harrison outlook on his chances for an upcoming election:

If it shall become reasonably clear in October that the Democratic Party will carry New York, New Jersey and Connecticut – and by October we shall know about where we stand – I shall look for the election of the Democratic Electoral ticket in Illinois by 10,000 majority – a perfect landslide in fact

Jacques Chirac’s victory in the French presidential election of 2002 by 82% is perhaps the best modern example of a landslide election.  In Romania’s historic election of 1990, Ion Iliescu, a former communist party official, won by a landslide and became the first post-communits president.

Politics also inspired two boardgames named “Landslide“, about the US presidential elections.  And of course there is also the music: Fleetwood Mac’s 1975 “Landslide” song remade in 1994 by the Smashing Pumpkins and later in 2002 by Dixie Chicks.


Dracula and geology

Poienari Fortress (in Romanian -Cetatea Poienari) is located on the upper reaches of the Arges Valley, in the Southern Carpathians of Romania.  It was built between 1456-1462 by Vlad Tepes, or Vlad the Impaler (photo below), the Prince who ruled what was at that time the southern part of Romania, the Pricipality of Valachia.  Yeah, the one that inspired the story of Dracula, but I am talking about the real person here, so let’s stick to the facts and history.


Legend has it that part of the construction was done by some of Vlad’s landlords who conspired against him.  The Impaler brought them at the construction site and pointing his sword he told them to build it or else….

I discovered the fortress during geology field work one summer, while working on my graduate degree in geology.  Geologically speaking the site is located very close to the boundary between the Paleogene strata of the Carpathian Foredeep and the crystalline basement of the Southern Carpathians.  This geologic boundary results in a very rough topography, which of course was the main reason why Vlad chose this location – another example of how geology and culture intertwine.


During the mid 1400s, Valachia was on the border between the Christian Europe and the Ottoman Empire, and Vlad had a big problem with the Turks, as in …. he did not want them in his country.  His court was in Targoviste, a locality in the hills of south-central Romania, but this place was too exposed, easy to get to and hard to defend.  Vlad needed remote places to take refuge when the Ottomans attacked.  The roughed peaks of the Southern Carpathians thrust and fold belt offered good protection, and a place to regroup and then attack back to defend the land.


Today, the Poienari fortress can be reached by climbing ~1480 steps, which were built between 1969-1972 by the local Government, in an effort to make the place accessible to the public.

Poienari fortress. ©EarthRelated

Natural beauty, ancient deserts, tectonics and erosion


The Arches National Park in Utah is a must see. I was not too long ago in the Moab area for geology-related field work and stopped for a few hours in the park.  This was not my first visit, but I enjoyed it as much as the first time. Below is a short account of how, from a geologic point of view, the arches formed.

It started with a “see-of-sand” in Jurassic, about 200 million years ago; at that time the Moab area looked not unlike the Sahara.  The desert-like environment persisted for fifty million years or so, and resulted in the accumulation of the two sandstone formations that make the natural beauty of the Arches today: the Navajo and the Entrada.  These formations overly a layer of salt, three hundred million years old. The salt has the interesting property of moving when loaded with sediment, just like tooth-paste moves when loaded and squeezed from the tube. Imagine a brittle layer of sandstone pushed up by a mobile layer of salt from beneath; the sandstone will break along faults just like this:


The faults are enhanced with time by erosion (water, wind etc.), which results in the sandstone fins – intriguing features when viewed from above.  Some of the sandstone fins are more resistant than others, and get preserved (at least for a while) as arches, spires, balanced rocks we see today in the park.



Delicate Arch

Tufa towers on Mono Lake, California

We visited Mono Lake a few years back during a family vacation on the US West Coast.  The best time for a visit, especially in the summer,  is late in the afternoon because the lighting is better for photography and the temperature is more pleasant. Low angle light makes the beautiful blue-green color of the lake and the tufa towers sticking out of the water even more spectacular.


Unlike most lakes, which are fresh water, the Mono Lake is an enclosed saline lake formed in a low area of the Mono Basin, which is located in the Basin and Range province of the United States. The greatest attraction are the tufa towers, spectacular features in the form spires and rounded knobs rising several feet above lake level.


Tufa is a form of calcium carbonate, and is similar to the stalactites and stalagmites that we enjoy so much in caves. At this location the towers start forming on the bottom of the lake, where fresh water springs rich in calcium mix with the water from the lake, which contains sodium and potassium carbonate in solution. The fresh water is lighter than the saline water of the lake and, as a result, it rises up. As the fresh water rises, the calcium in solution combines with the sodium and potassium dissolved in the lake water and precipitates tufa.


The tufa in the towers is porous, and as more fresh water enters the lake through the springs, it flows through the intricate structure of the pores and when escapes and reaches the lake water, it precipitates more tufa, creating the impressive knobs and spires we see today.

Before 1941 this place looked completely different.  About 15,000 years ago the ancient lake had a surface area of almost five times as today and was nearly 800 feet deeper.  When initially formed, after the last ice-age, it was fed by glacial meltwater, and later on by five fresh-water streams derived from the snow melt in the Sierra Nevada range. Growing water demands in the city of Los Angeles resulted in the diversion of the fresh water streams 350 miles south.  This change had a dramatic effect on the lake’s water level, the salinity and the entire ecosystem.  If interested, you can read more on the Mono Lake story here.

Scandinavian mansions, glaciers, tea-houses and roche moutoneé

This eclectic title expresses my fascination with how Earth history and human culture intertwine.  In 1929, Lora J. Knight commissioned a Swedish architect to build a Scandinavian-style summer home on her property on Emerald Bay, Lake Tahoe area.  Why Scandinavian architecture on the shores of a lake at the border between California and Nevada?  Natural beauty opens up the heart and allows the mind to wonder free and make connections would seldom make otherwise. Mrs. Knight may have been intrigued by the fjord-like shape of the bay, so Scandinavia and Lake Tahoe became a natural link.

Emerald Bay, Lake Tahoe

Emerald Bay (foreground) entering Lake Tahoe (background) through a gap in a recessional moraine. ©EarthRelated

Emerald Bay and Scandinavia have at least one thing in common: glaciers were present in both places in recent geologic past, and they had a dramatic influence on the modern-day landscape.


Fanette Island – a roche moutonnée (or sheepback): a rock formation created by the passing of a glacier. ©EarthRelated

The Emerald Bay is located in a depression scooped up by glaciers about two million years ago, in Pleistocene, and the Scandinavian fjords are sculpted by glaciers too. Ms. Knight was captivated by the beauty of both places and she started extensive research, which resulted in visits to Scandinavia, and eventually in the building of  Vikingsholm, her summer retreat on the shores of Lake Tahoe.  Besides being carved by glaciers, the Emerald Bay has another interesting feature of glacial origin, the Fannette Island, a roche moutonnée – a piece of remnant basement rock sculpted by the slow movement of a glacier.

Close up of the Fannette Island showing the typical characteristics of a roche moutonnée- a gently inclined upstream slope to the right, and its steep and rough downstream side ( to the left). ©EarthRelated

Close up of the Fannette Island showing the typical characteristics of a roche moutonnée – a gently inclined upstream slope to the right, and its steep and rough downstream side ( to the left). ©EarthRelated

Lora Knight built a tea-house on top of the island, visible in the picture if you look carefully.  Unfortunately the structure is presently in a state of disrepair, but ah! how I would like to steep and enjoy a perfect cup of tea while pondering the glaciated geologic past and enjoying the view of a magical place like Lake Tahoe.


The mind and heart of an Earth-Scientist

I fell in love with the Earth when I was sixteen.  I was in the Southern Carpathians of Romania, in a cave, learning about and doing spelunking.  We were crawling through this narrow passage, which at times required exhaling completely in order to be able to fit through and advance.  I stayed behind my travel companions for a short while and for a minute I turned off the little head-lamp attached to my hard hat.  It was the first time experiencing complete darkness – I was frightened, humbled and thrilled beyond expression.  It felt as if the Earth opened up a small space, large enough for me to fit in, and invited me to immerse in her mystery, to experience her secrets, to feel her essence.  For a moment there was no ‘me’ anymore, I was one with ‘her’, and in that moment I knew I wanted to be an earth-scientist.


Rock-embrace. ©EarthRelated

Earth-scientists are experientialists at heart: we have to touch the rocks, to smell them, to (yes!) taste them, to experiment with them, because only then we became intimate with, and understand the stories they tell.  We  are multi-scale thinkers and have to bend our minds to understand, for example, how fluids pass through micrometer scale pores, but also how mountains form, or how continents travel in space and time, in an endless dance  that gives us the amazing landscape we are marveling at today.

Geoscience is about bridging the past, the present and the future, it is about understanding time beyond human scale, it is about seeing the cause in the effect and then being able to visualize the impact of an action at multiple levels and multiple scales, it is about knowing. Knowing of the wind and the wave, the river, the sea and the desert, the deep forces that consume land and ocean floor, only to spew it out later in the form of hot lava that creates the Earth anew, with gentleness or with tremendous, creative force.