Birds on the Baldfaces

The trek up the Baldfaces is one of my favorite hikes in the White Mountains of New Hampshire. The steep, exposed trail leads up overlapping granite ledges to a gently sloping summit with great views of the surrounding peaks.

From South Baldface, NH

The fast-changing weather in the Whites often leads to neat meteorological effects! As we hiked up to the south summit of the Baldfaces in the morning, the low-lying clouds warmed up and flowed up into the valleys. But they never quite reached us - the clouds evaporated about halfway up, leaving clear skies above.

Cedar waxwings!

In addition to views of surrounding peaks, the clear skies provided great conditions to watch a small flock cedar waxwings fly about the low lying trees on the summit. Cedar waxwings aren't particularly rare, but their distinct eye-masks make them a fun bird to watch!

Close-up!

Pillow Talk

Ahh, quintessential New England.

Vinalhaven sits an hour offshore Maine by ferry and seemingly a century back in time. The small island houses a population of just over a thousand residents who live off the sea and the summertime migration of vacationers. It also holds an exceptional exposure of a solidfied magma chamber that has been uplifted, turned over and eroded to reveal an entire cross-section. I featured a photo from Vinalhaven last week, but couldn't leave it at just one...

Cross-section of pillow basalts intruded into magma

Usually pillow basalts form underwater. As lava erupts, the lava in direct contact with the water quenches, forming a hard pillow-shaped shell (here's a nice photo). The magma chamber on Vinalhaven, however, preserves pillows of a different sort. The pillows pictured above formed as fresh, hot magma intruded into an already cooled, but not yet solidified magma chamber. The cooler magma was still hot enough to deform, so these pillows ended up more like smooshed Hershey kisses. 

The dock at Hurricane Island

If you take a geologist to Vinalhaven, expect to be there a while. And if possible, try to stay overnight with the good folks of the Hurricane Island Center for Science and Leadership on the nearby Hurricane Island. The Hurricane Island Foundation renovated abandonded Outward Bound buildings and repurposed them to facilitate educational programs in a natural setting. In addition to their on-island educational program, they help organize geology field trips, providing boat transport, sleeping arrangements and awesome home cooked meals. Just bring your own pillows.

A tale of two squishies and modern art

Rocks usually seem to be permanent, solid fixtures on the Earth, but occasionally I come across a rock that blurs the line between solid and liquid. These rocks preserve fluid-like behavior in crystalline form and can envoke a sense of abstract expressionism, perhaps reminiscient of a Jackson Pollrock painting (I'm so sorry). Today's rocks come from islands on opposite ends of the U.S. - Antelope Island in Utah and Vinalhaven in Maine.

Antelope Island juts out into the south end of the Great Salt Lake in Utah. In addition to holding evidence of isostatic rebound (due to the draining of Lake Bonneville), Antelope Island is home to a type of rock called a migmatite. Part metamorphic and part igneous, migmatites form when a metamorphic rock like a gneiss is submitted to high temperatures and high pressure. The high temperatures weaken the rock and causes a little bit of melting, and the high pressure squishes the minerals into a tapestry of swirls. If you're interested in numbers, this paper reports that the migmatites of Antelope Island reached a temperature of 1300-1450 F (700-785 C) and a pressure as high as 400 MPa. To put the pressure into perspective, if the pressure is just due to being buried, these rocks would have been about 7.5 mi (12 km) below the Earth's surface!

Migmatite (1m wide), Antelope Island UT

Vinalhaven, an island off the coast of Maine, is home to a solidified magma chamber (here's a description of the geologic history). After cooling and solidify, subsequent erosion and tectonic rotation now allows us to walk across a magma chamber from top to bottom and observe many examples of magma frozen in the act of flowing. The rock in the photo below captures two magmas of different viscosities coming in contact. When two immiscible fluids (fluids that can't mix) contact each other, an instability called viscous fingering can arise, resulting in fingers of the less viscous fluid reaching into the more viscous material.

Magma mixing preserved in a solidified magma chamber, Vinalhaven ME

Rocks like these are nature's canvases. Even after the paint dries, some essence of motion is captured. From that motion, we can understand aspects of a rock's origin or simply appreciate the brush strokes in an abstract sort of way.

Catching air on Mauna Loa

The climb up Mauna Loa is an ethereal journey on a single lane road through overlapping lava flows to just shy of 12,000 ft (3600 m). At the end of the road is the NOAA observatory, an otherworldy collection of white buildings sitting on black basalt. Most visitors choose to drive up Mauna Kea to the space observatory, but if you prefer to ponder our Earth rather than distant twinkles, the NOAA observatory is a fascinating stop. The observatory is perhaps most famous for the longest continuous record of atmospheric CO2 (the Keeling Curve) - but the most fascinating tidbit I learned while there is that the extreme local topography of Mauna Kea and Mauna Loa creates a massive atmospheric downwelling that can bring air from the  stratosphere down to the summit! 

The NOAA observatory on Mauna Loa

The road up Mauna Loa cuts through lava flow after lava flow, offering ample opportunity to practice your GEO-101 relative dating skills. The photo below shows a series of overlapping flows (of both the a'a and pahoehoe and variety) with an added spatter cone bonus! If you're worried about acclimating to the elevation, just bring along a geologist and the drive will take a long time...

Overlapping flows with a spatter cone along the road up Mauna Loa