Testing geophysical methods to confirm plate tectonics on Mars

¶ … theories regarding plate tectonics, with the researcher contending that as Mars tectonics cannot currently be confirmed, more research, including two geophysical methods the researcher would utilize to test the *** theory of Mars tectonics need to be conducted.

Along with exploring issues relating to Mars tectonics, the paper addresses: (a) Whether Mars has mobile plates, and a plate tectonic system similar to earth; (b) Whether Mars has Igenous, Metamorphic and/or Sedimentary rock types, as well as which rock would one most/least likely find on Mars; - What two geophysical methods one would use to test his/her theory of Mars tectonics; (d) What long-term records would prove best for one to begin to collect.

MARS TECTONICS

Introduction

Questions Regarding Mars Mobile Plates

Approximately 50 years ago, Richard a Kerr (1999) purports in "Signs of plate tectonics on an infant Mars," geophysicists determined that plate tectonics shape Earth's surface, as they move around the globe, and create new crust in mid-ocean ridges and plates (p. 719).

Data the Mars Global Surveyor (MOS) spacecraft retrieved indicates that in its history, Mars, referred to as "Earth's diminutive cousin," "resurfaced itself the way Earth does today, spreading freshly made crust away from long, narrow volcanic rifts" (Kerr, p. 719). Frederick Vine, a professor emeritus at the University of East Anglia in Norwich, United Kingdom, who contributed significant work on magnetic stripes, instrumental to the plate tectonics revolution during the 1960s, contends the claim that plate tectonics also created the Martian magnetic stripes constitutes "an eloquent hypothesis" (Vine, as cited in Kerr, p. 719). As this paper relates several theories regarding plate tectonics, the researcher purports that as Mars tectonics cannot currently be confirmed, more research, including two geophysical methods the researcher would utilize to test the *** theory of mars tectonics need to be conducted.

As this paper explores issues relating to Mars tectonics, it also addresses the following questions:

Does Mars have mobile plates and a plate tectonic system similar to earth, or is the crust of Mars less active?

Which of the three basic rock types (Igenous, Metamorphic and/or Sedimentary) would one most likely find, and least likely find on Mars (based on answer to question, number 1)?

What two geophysical methods would one use to test his/her theory of Mars tectonics (assuming one could land any currently available equipment on Mars and collect data for 2-4 weeks, and assume that geophysical principles on Mars are similar to those on earth)?

What long-term records would one like to begin to collect?

Guesses Embrace Questions Regarding Mars Mobile Plates

Researchers currently question if Mars stripes formed through some other means, such as slow chemical alteration, rather than through creation of new crust, as evidenced on Earth by plate tectonics. Ronald Merrill, paleomagnetist of the University of Washington, Seattle, contends that Martian stripes proffer convincing evidence a magnetic dynamo existed early on Mars, but reversed. Merrill's explanation for the overall pattern of Mars' stripes spreading, albeit, as he contends that no persuasive alternative exists, equals "the best guess at this time" (Merrill, as cited in Kerr, p. 719). The pattern, however, does not exactly match Earth's, and along with numerous differences:

the Martian stripes are a 10 time field reversals, or both;

they are also far less regular in either side of a spreading center;

the ph of a "spreading center" [dramatically differs];

To achieve] the "staggering" intensity of the recorded magnetism [of Earth's],...each Martian plate would have to be 30 Kilometers thick, assuming that they were uniformly magnetized as intensely as the uppermost few hundred meters of Earth's ocean crust. (Merril, as cited in Kerr, p. 719)

Sean Solomon of the Carnegie Institution of Washington does not concur with the concept of plate tectonics on Mars, and contends that the theory proves challenging to comprehend. Solomon purports that Earth's upper ocean crust "is intensely magnetized because seawater cooled it rapidly forming tiny, easily magnetized crystals. But cooling a 30-kilometer slab would take tens of millions of years, leading to larger crystals that would be less easily magnetized" (Solomon, as cited in Kerr, p. 719). Solomon admits: "There's so much we don't know" (Ibid.). The myriad of guesses and questions enveloping Mars mobile plates prompts researchers to wonder if perhaps the stripes were not formed through creation of new crust, but through some other means, such as slow chemical alteration.

In regard to the three basic rock types, Igenous, Metamorphic and Sedimentary, the researcher contends that Sedimentary and Metaphoric are most likely to be found on Mars, while Igneous rocks are least likely to be found there, as the lengthy time element, the researcher asserts, would have likely transformed the Igneous rocks into Metamorphic rocks.

Sedimentary rocks formed from sediment, consist of solid, loose pieces of rocks "in the form of sand, silt, clay, and/or gravel "or the remains of living things found at the surface of the Earth." Sediment evolves from eroded substances that wind, running water, waves, and/or ice deposit, however, may also form from material that seawater evaporation, or the settling of the remains of animals and plants in oceans, lakes, and swamps leave behind. In some instances, over a long period, sediment, which is frequently discovered in layers, "may become compacted and cemented into sedimentary rock" ("How can you tell," n.d.). A researcher may determine if a rock sample is sedimentary by examining whether it consists of grains. An igneous (from the Latin word for fire) rock, known as granite, consists of minerals like quartz, mica, and feldspar. "Igneous rocks come from melted rock material, or magma, that lies under Earth's surface" ("How can you tell," n.d.), forming when magma from inside the Earth travels toward the Earth's surface, or a volcano forced it in the form of lava and ash above the Earth's surface, where it cools and crystallizes into rock. Metamorphic rocks, rocks, which may be sedimentary and igneous rocks, changed by intense heat or pressure while they form, come from hot, pressured conditions inside the Earth's crust. At times, these rocks cool and crystallize, into bands of crystals. A researcher may determine if a rock sample is metamorphic by examining the crystals to see if they are arranged in bands ("How can you tell," n.d.).

Images Worth a World of Words

On Mars's surface, magnetic stripes replicate fields in the Earth's sea floors, which some scientes assert could indicate that ancient crustal movements occurred on the Red Planet. ("Plate Tectonics on Mars?" 1999).

The following figure depicts "a map of Martian magnetic fields in the southern highlands near the Terra Cimmeria and Terra Sirenum regions centered around 180 degrees longitude from the equator to the pole" ("Plate Tectonics on Mars?" 1999).

It is where magnetic stripes possibly resulting from crustal movement are most prominent. The bands are oriented approximately east - west and are about 100 miles wide and 600 miles long, although the longest band stretches more than 1200 miles. The false blue and red colors represent invisible magnetic fields in the Martian crust that point in opposite directions. The magnetic fields appear to be organized in bands, with adjacent bands pointing in opposite directions, giving these stripes a striking similarity to patterns seen in the Earth's crust at the mid-oceanic ridges.

Imagine a thin coat of dried paint on a balloon, where the paint is the crust of Mars," explained Dr. Mario Acuna of Goddard, principal investigator on the Global Surveyor magnetometer. "If we inflate the balloon further, cracks can develop in the paint, and the edges of the cracks will automatically have opposite polarities, because nature does not allow there to be a positive pole without a negative countepart." ("Plate Tectonics on Mars?" 1999)

Plate Tectonics on Mars?" 1999). PHOTO CREDIT: NASA, Jack Connerney, Mario Acuna, Carol Ladd

Plate Tectonics on Mars?" 1999)

Info in Red not yet rewritten Apr. 29, 1999: NASA's Mars Global Surveyor has discovered surprising new evidence of past movement of the Martian crust, suggesting that ancient Mars was a more dynamic, Earth-like planet than it is today.

Scientists using the spacecraft's magnetometer have found banded patterns of magnetic fields on the Martian surface. The adjacent magnetic bands point in opposite directions, giving these invisible stripes a striking similarity to patterns seen in the crust of Earth's sea floors.

An artist's concept comparing the present day magnetic fields on Earth and Mars. Earth's magnetic field is generated by an active dynamo - a hot core of molten metal. The magnetic field surrounds Earth and is considered global (image B, below). The various Martian magnetic fields (image a, above) do not encompass the entire planet and are local. The Martian dynamo is extinct, and its magnetic fields are "fossil" remnants of its ancient, global magnetic field. IMAGE CREDIT: NASA Mario Acuna, Jack Connerney, Chris Meaney

The bands of magnetized crust apparently formed in the distant past when Mars had an active dynamo, or hot core of molten metal, which generated a global magnetic field. Mars was geologically active, with molten rock rising from below cooling at the surface and forming new crust. As the new crust solidified, the magnetic field that permeated the rock was "frozen" in the crust. Periodically, conditions in the dynamo changed and the global magnetic field reversed direction. The oppositely directed magnetic field was then frozen into newer crust.

Plate Tectonics on Mars?" 1999)IMAGE CREDIT: NASA Jack Connerney/Mario Acuna/Chris Meaney

These images are an artist's concept of the process that may have generated magnetic stripes in the crust of ancient Mars. In the left image, the blue arrows and compass needle indicate the direction of the magnetic field. The yellow-orange shape represents a pool of molten rock (magma) upwelling beneath the Martian crust. The red and blue bands are magnetized crust on either side of a spreading center, or rift. ("Plate Tectonics on Mars?" 1999)

Conclusion

The sedimentary record of early planetary history which Mars possesses, according to www.highbeam.com/doc/1P3-1445150761.html"10 questions that are driving 21st-century earth science" (2008), reportedly predates the oldest rocks on Earth rocks, as well as those on other star systems with planets. In the spirit of scientists, currently turning toward Mars, in the search for a number of answers contributing to life, the researcher proposes to utilize *** two geophysical methods to test the *** theory of Mars tectonics. To complete this project the researcher would initially land *** and collect data for 2-4 weeks [assuming geophysical principles on Mars replicate those on earth].

Long-term records, the researcher would prefer to begin to collect would include, but not be limited to: