NOTE: This is an earthcache, there is no physical container to find at the coordinates. To get your smiley for the cache, e-mail your answers for the questions below to the cache owner.
1- Looking North towards the port, find the tallest dune. How many sides does it have?
2- What type of dune is it and what does that tell you about the direction of the wind here?
3- What similarities do you find between the dunes at Jetty Park and the dunes on Mars?
This earthcache is located with permission in Jetty Park at Port Canaveral. The parks director would like geocachers to know that, there is a parking fee to enter Jetty Park with a vehicle (walkers and bikers are free to enter) and participants are not to disturb the sand dunes. Coordinates to the entrance gate are N 28 24.366, W 80 35.804. Jetty Park offers beach access, pier fishing, camping, a playground, and a fun place to surf!
Sand on Planet Earth
On planet Earth, where granite rocks are common, most of the sand we see on the beach is a light color because it is made from granite-derived quartz rock. Our ocean floor, on the other hand, is mostly made of volcanic basalt which has a dark color. This dark color black sand can be seen on some beaches on earth, but it is rare.
Sand on Planet Mars
On planet Mars, where volcanic basalt rocks are common, most of the sand seen should be dark but it isn’t. Scientists believe that the light color seen is actually dust that has fallen from the atmosphere that is covering up the dark sand. This dust coating suggests that the dunes on Mars do not move a lot, probably due to lack of wind on the planet. Mars’ atmosphere is also too thin and cold to support liquid water on its surface which is why it mostly has sand dunes and not beaches.
Jetty Park
Here at Jetty Park visitors have a unique opportunity to view a sea of sand dunes close to the ocean waves. Jetty Park provides a wider surface space for dune formation for 2 reasons. The first reason dunes are abundant in this area is due to the protection the jetty rocks to the north provide. The second reason for greater dune formation here is because extra sand is pumped into the area as part of beach restoration every 4 to 6 years. These conditions combined with the vegetation on this beach help create a special dune environment.
Common Earth and Mars Sand Dune Types
Sand has the ability to form many different dune shapes depending on the kind of sand, directions the wind blows in that area, and the environment. Earth and Mars share some of the same types of dune formations such as Barchan (BAR-kahn), Transverse, and Star.
Barchan Dunes
Barchan dunes are crescent shaped dunes made on a flatter landscape when the wind blows from mostly one direction. They are common all over Earth especially in sandy deserts. On Mars barchan dunes migrate very slowly compared to the Earth because of the lack of wind on Mars. Barchan dunes found on Mars today were shaped by winds from many years ago.
Transverse Dunes
As sand supply increases, barchan dunes connect with other barchan dunes and create ridges. Over time, these ridges, which are called transverse dunes, become more longitudinal and form lines perpendicular to the wind direction. Transverse dunes can mostly be seen along beaches on Earth. On Mars transverse dunes are quite common which helps scientists understand how wind interacts with the surface of Mars.
Star Dunes
Star Dunes are found in places where the wind blows sand from different directions throughout the year. The multi- directional wind causes the sand to accumulate in a central peak with three or more arms extending out and creating a star like shape. On Earth, star dunes are quite rare as only about 8.5% of dunes found are stars. Comparatively on Mars star dunes are quite common due to impact craters. Inside the crater, wind swirls around and bounces off the edges coming from many different directions and then settles inside the crater, creating star dunes.
Questions:
Now it is time for the questions. To get credit for the cache, please answer the questions below. When answering the questions, do your best. It is more important that you learn a new concept about our earth and can apply your knowledge, rather than have a precise answer.
1- Looking North towards the port, find the tallest dune. How many sides does it have?
2- What type of dune is it and what does that tell you about the direction of the wind here?
3- What similarities do you find between the dunes at Jetty Park and the dunes on Mars?
Thank you for visiting this earthcache. Please send your answers to the above questions to the cache owner. In your "found it" log, feel free to write about your experience, but don't include the earthcache answers. Thanks and we hope you enjoy beautiful Jetty Park!
Sources:
https://marsed.asu.edu/mep/dunes
https://www.nps.gov/grsa/learn/nature/dune-types.htm
https://www.doi.gov/sites/doi.gov/files/usgs-dune-models.508.pdf
https://www.esa.int/Science_Exploration/Space_Science/Mars_Express/Colourful_dunes_on_wind-swept_Mars
https://en.wikipedia.org/wiki/Punalu%CA%BBu_Beach
https://www.astronomy.com/science/the-shapes-of-martian-sand-dunes-reveal-the-planets-winds/
https://phys.org/news/2021-09-dunes-mars.html#google_vignette
https://airandspace.si.edu/multimedia-gallery/6233hjpeg
https://www.jpl.nasa.gov/images/pia18109-sand-dunes-in-spring
https://www.jpl.nasa.gov/images/pia07203-martian-sand-dunes
https://www.jpl.nasa.gov/images/pia04620-north-polar-sand-dunes
https://www.americaspace.com/2015/12/15/welcome-to-bagnold-curiosity-rover-reaches-massive-dark-sand-dunes-near-mount-sharp/
https://www.universetoday.com/155162/these-are-star-dunes-on-mars-formed-when-the-wind-comes-from-many-different-directions/#google_vignette