• October 3
  
• October 2
  
• October 1
  
• September 30
  
• September 29
  
• September 28
  
• September 27
  

October 3, 2004

        As per my usual Sunday schedule, I could not work on Mission today.
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October 2, 2004

       Today I read some parts of The Fishes of the Galápagos Islands and Galápagos Diary: A Complete Guide to the Archipelago's Birdlife, focusing on the species of the northern islands.  I expect to compile a list of all the bird species and some endemic marine species within the next few weeks.
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October 1, 2004

• Team meeting minutes are available here.  I will be shifting my research focus from geology to fauna and flora species starting next week.
  
• I called the Ecuadorian Consulate in the Boston area and left a message.  I also e-mailed the Consulate.  I called again a few weeks later and left another message.  As of 12/12/04, I have not heard a reply.
  

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September 30, 2004

• I made a photographic collage presentation of the northern islands in PowerPoint, available to view here.  (Note: PowerPoint is needed to open this link.)
  
• Bob replied to my e-mail.  He has had a few years of experience advising students in this course, and his thoughts on this year's assignment are below:

        Thank you for your very welcoming Email.  You have chosen a great course, 12.000.  This is real life!!  You have been charged with a very complex problem.  As you are finding out, information gathering will be a big task.  Another challenge will be that of working together as a team and an even greater challenge will be that of ultimately getting the teams to work together.  Things were organized a bit differently in past Missions. Each team worked on only one aspect of the overall problem.  Then, the teams were challenged to assemble the pieces.  This year, each of the teams will work on the complete problem and then a master plan will be developed for the whole geographical area.  For the Galapagos, I believe that makes excellent sense.  
        You sound like you are off to a good start.  Some general information gathering is very important. You may also want to consider adding some economic and political investigation to your efforts. I would also suggest that you start to get organized on your three objectives. Then, as you do your general information gathering, you can begin to prioritize your efforts.  
        In past efforts, the teams generally spent a little too much time on their individual aspects of the problem before they started to get into the difficult issues of an overall plan (which required leadership and coordination between the teams).  This lead to some varying degrees of frustration.  In the end, however, all came together very nicely.  What made the difference were a few of the students standing up and taking charge (not as dictators but as good consensus builders).  Also in past efforts, the students initially, at least, were a little reluctant to contact out side sources.  There are many people on the outside who would very much like to support a group of enthusiastic and intelligent people such as yourselves.  The name MIT will be a great "door opener".  You mentioned that you are having some problems getting information particular to your remote islands.  I see that that there is an Honorary Ecuadorian Consulate in the Boston area:

Boston, MA
Mrs. Beatriz G. Almeida Stein, Consul  Ad-Honorem
Consulado Ad-Honorem del Ecuador
52 Cranberry Lane
Needham MA 02492    
(781) 400-1212  
(781) 455-9019
ecuadorconsulateboston@attbi.com
Mass, (MA) Maine (ME)

I look forward to meeting with you all next week and to working with you as you successfully complete your project.
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September 29, 2004

• Minutes from our coordination meeting can be seen here.  We have to put up the rough draft of our team site by Friday.  Bryan from our team is web master, so he will put up my geology research.
• I e-mailed our two alumni mentors today.  I understand that one of them, Bob, is interested in coming to meet us sometime next week.  I am looking forward to meeting with him and hearing what he has to say.

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September 28, 2004

       I finished the first draft of my geology write-up for the team web site today.  A copy of it is below:

Geology/Geography - Background

        The Galápagos Islands lie on the northern edge of the Nazca plate, which is crawling southeast and subducting underneath the South American plate, forming the Andes Mountains.  When the subducted Nazca pate reaches the asthenosphere (about sixty miles below), it melts and forms magma [1].  The comparably lighter magma rises between crustal cracks and accumulates near the surface.  In the area below the Galápagos, a hot spot formed where the magma was pushed above the crust and the Galápagos volcanoes subsequently formed.  The volcanoes on the Marchena, Pinta, and Tower islands are currently active and contain an abundance of intriguing information.  The Wolf and Darwin islands to the northwest of the three larger islands are eroded volcanoes that are now extinct.
        Many of the volcanoes of the Galápagos, with the northern islands being no exception, are classified as shield volcanoes [2,3].  Shield volcanoes are identifiable by their gentle slopes and flat coastline [1].  They regenerate through lava flows, which pour out of a central vent creating its warrior shield profile, hence the name.  The lava flows thin out by spreading over a large area and years of accumulation of thin layers yields a shield volcano.
        Some of the northern islands also exhibit calderas, which should not be confused with a crater.  Calderas can be large, and form when magma is withdrawn from an underground reservoir beneath the volcano.  This leads to a partial collapse of the overlying ground and consequently a large depression [1].                 

Geology/Geography – Northern Islands  

        Marchena is a low-lying shield volcano about 200 square kilometers in area.  It has a central 6 kilometer wide caldera, which has been partially filled with recent basalt flows [2].  The flows are similar in composition to those of mid-ocean ridge basalts, making it an interesting geological formation [4].  The island has apparently been active for the past half million years, with the most recent eruption occurring in 1992.  Because of the volcanic activity on this desolate island, and also because it has no fresh water, Marchena has never been settled [5].
        Tower island, like Marchena, is also a ‘hot spot’ for geologists.  The island has a smaller active shield volcano than Marchena.  Curiously, the chemical composition of its lavas are like those on Marchena, mid-ocean ridge basalt, strikingly different from most island lavas [6].  Years ago, the crater of the volcano collapsed below sea level, creating Darwin Bay, which is one of the two tourist spots on the island, the other being Prince Philip’s Steps [7].
        Pinta, or Abington, Island is an elongated steep active shield volcano.  Research has shown that there was a two stage development of the island: a shield stage from about 800,000 years ago, and a newer fissure stage [3].  The newer stage has created many cinder cones at the northern and southern ends of the island.  The older shield stage is responsible for the abundance of plagioclase crystals on the island, which have been dubbed “abingtonite” after the island.  Abingtonites are also found on smaller neighboring northern islands [3].
        The literature indicates that Galápagos magmas are derived from a mixture of material from the Galápagos mantle plume and upper mantle.  Pinta magmas represent the northern extreme of the range of compositions observed in the Galápagos, indicating that they are derived mostly from the Galápagos mantle plume. This contrasts with magmas from neighboring Marchena and Tower, which are derived mostly from the ambient upper mantle [3].

References

[1] http://www.galapagosonline.com/Galapagos_Natural_History/Geology/Geology.html

[2] http://users.bendnet.com/bjensen/volcano/eastpacific/galapagos-marchena.html

[3] http://www.geo.cornell.edu/geology/GalapagosWWW/Pinta.html

[4] http://www.galapaguide.com/islands_pinta_marchena_genovesa.htm

[5] http://www.geo.cornell.edu/geology/GalapagosWWW/Marchena.html

[6] http://www.galapaguide.com/islands_pinta_marchena_genovesa.htm

[7] http://www.galapagosonline.com/Galapagos_Natural_History/Geology/Geology.html

Future work to review:

Chadwick, W.W., and J.H. Dietrerich, Mechanical modeling of circumferential and radial  dike intrusion on Galapagos volcanoes, J. Volcanol. Geothermal Res., 66, 37-52,
    1995.

Cullen, A., E. Vicenzi, and A.R. McBirney, Plagioclase-ultraphyric basalts of the Galapagos archipelago, J. Volcanol. Geotherm. Res., 37, 325-337, 1989.

Cullen, A.B., A.R. McBirney, and R.D. Rogers, Structural controls on the morphology of Galapagos shields, J. Volcanol. Geotherm. Res., 34, 143-151, 1987.

Cullen, A.B., Geology and Petrology of Isla Pinta, Galapagos, MS thesis, Univ. of Oregon, 1985.

Feighner, M.A., L.H. Kellogg, and B.J. Travis, Numerical modeling of chemically buoyant mantle plumes at spreading ridges, Geophys. Res. Lett., 22 , 715-718, 1995.

Feighner, M.A., and M.A. Richards, Lithospheric structure and compensation mechanisms of the Galapagos archipelago, J. Geophys. Res., 99, 6711-6729, 1995.

Geist, D.J., An appraisal of melting processes and the Galapagos hotspot: major and trace element evidence, J. Volcanol. Geotherm. Res., 52, 65-82, 1992.

Geist, D.J., W.M. White, and A.R. McBirney, Plume-asthenosphere mixing beneath the Galapagos archipelago., Nature, 333, 657-660, 1988.

Graham, D.W., D.M. Christie, K.S. Harpp, and J.E. Lupton, Mantle plume helium in submarine basalts from the Galapagos Platform, Science, 262, 2023-2026, 1993.

Harpp, K.S., Magmatic Evolution at Hotspots and Mid-Ocean Ridges: Isotopic and Trace Element Studies from the Galapagos Islands and the East Pacific Rise, PhD thesis,
    Cornell Univ., 1994.

Herron, E.M., and J.R. Heirtzler, Sea-floor spreading near the Galapagos, Science, 158, 775-780, 1967.

McBirney, A.R., Differentiated rocks of the Galapagos hotspot, in Magmatic Processes and Plate Tectonics Geol. Soc. Lond. Spec. Pub. 76, pp. 61-69, Geol. soc. Lond.,
    London, 1993.

Munro, D.C., and Rowland S. K, Caldera morphology in the western Galapagos and implications for volcano eruptive behavior and mechanisms of caldera formation.,
    J. Volcanol. Geotherm. Res., 72, 85-100, 1996.

Rowland, S.K., D.C. Munro, and V. Perez-Oviedo, Volcan Ecuador, Galapagos Islands: erosion as a possible mechanism for the generation of steep-sided basaltic volcanos,
    Bull. Volcanol., 56, 271-283, 1994.

Schilling, J.-G., R.N. Anderson, and P. Vogt, Rare earth, Fe and Ti variations along the Galapagos spreading centre, and their relationship to the Galapagos mantle plume.,
    Nature, 261, 108-113, 1976.

Shimizu, H., A. Masuda, and N. Masui, Rare-earth element geochemistry of volcanic rocks from the Galapagos Islands, Geochemical J., 15, 81-93, 1981.

Sinton, C.W., D.M. Christie, and R.A. Duncan, Geochronology of Galapagos seamounts, J Geophys. Res., 101, 13689-13700, 1996.

Vicenzi, E.P., A.R. McBirney, W.M. White, and M. Hamilton, The geology and geochemistry of Isla Marchena, Galapágos Archipelago: an ocean island adjacent to a mid-ocean
    ridge, J. Volcanol. Geotherm. Res., 40, 291-315, 1990.

White, W.M., A.R. McBirney, and R.A. Duncan, Petrology and Geochemistry of the Galapagos: Portrait of a Pathological Mantle Plume, J. Geophys.
    Res., 93, 19533-19563, 1993.

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September 27, 2004

       The information session today was entitled "Galápagos Now."  Minutes can be obtained here.