Venus's Ishtar Terra

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DESIGN GUIDE

How to change the template color theme This PowerPoint 2007 template produces a 36”x56” You can easily change the color theme of your poster by going to the presentation poster. You can use it to create your research DESIGN menu, click on COLORS, and choose the color theme of your poster and save valuable time placing titles, subtitles, text, choice. You can also create your own color theme. and graphics.

We provide a series of online tutorials that will guide you through the poster design process and answer your poster production questions. To view our template tutorials, go online to PosterPresentations.com and click on HELP DESK. You can also manually change the color of your background by going to The principal components assess the degree of similarity and variability of the shapes of the VIEW > SLIDE MASTER. After you finish working on the master be sure to When you are ready to print your poster, go online to Principal component analysis offers an independent and objective mode of comparison of the average profiles [Fig. 3 & 4], offering an independent and objective mode of comparison [14,15]. go to VIEW > NORMAL to continue working on your poster. PosterPresentations.com We use topographic data from the Magellan mission (1990-1994) to Venus. Using this dataset venusian mountains with terrestrial counterparts with known tectonic origins. Comparison can be How to add Text made with other topographic features on Venus, such as chasmata. We use topographic profiles to we extract profiles for the four Montes (Maxwell, Freyja, Akna and Danu) of Ishtar Terra. Need assistance? Call us at 1.510.649.3001 The template comes with a number of compare the venusian montes of Ishtar Terra using principal component analysis (PCA). Comparing pre-formatted placeholders for headers and text the profiles may help us in understanding the processes involved in the formation of the montes. blocks. You can add more blocks by copying and

pasting the existing ones or by adding a text box QUICK START from the HOME menu.

Text size Zoom in and out Western Ishtar Terra consists of a central plateau of smooth plains (Lakshmi Planum) surrounded Adjust the size of your text based on how much content you have to As you work on your poster zoom in and out to the level that is more by four mountain ranges (Akna, Freyja, Maxwell, and Danu Montes [Fig. 1]) and regions of tessera present. The default template text offers a good starting point. Follow comfortable to you. the conference requirements. Go to VIEW > ZOOM. outboard of these mountains. Elevations in Lakshmi Planum range from ~2.5 to 4.0 km above mean

planetary radius (6051.9 km)[1]. Critical to the understanding of the tectonic style of Venus is the How to add Tables Title, Authors, and Affiliations origin of the major mountain ranges on western Ishtar Terra. To add a table from scratch go to the INSERT menu and Start designing your poster by adding the title, the names of the authors, click on TABLE. A drop-down box will help you select rows and the affiliated institutions. You can type or paste text into the and columns. provided boxes. The template will automatically adjust the size of your You can also copy and a paste a table from Word or another PowerPoint text to fit the title box. You can manually override this feature and document. A pasted table may need to be re-formatted by RIGHT-CLICK > change the size of your text. Figure 4: Average profiles vs. synthetic profiles constructed from the first three principal components. FORMAT SHAPE, TEXT BOX, Margins.

TIP: The font size of your title should be bigger than your name(s) and Graphs / Charts institution name(s). Figure 2: Topographic profiles for Venus' Ishtar Terra Montes, colored lines individual profiles with bold lines averages. You can simply copy and paste charts and graphs from Excel or Word. Some reformatting may be required depending on how the original The decomposition of the principal components of the Ishtar Terra montes shows that the first Procedure in PCA: document has been created. PC is marked by a steep decline and the second PC by a central uplift. These characteristics and the ● Averaging all profiles for each feature PCA technique provide a quantitative avenue of comparison of the montes. The first component How to change the column configuration ● Cross-correlating the individual profiles with the average profile. Adding Logos / Seals represents a generic or archetypal feature never exactly found. The second and third components RIGHT-CLICK on the poster background and select LAYOUT to see the Most often, logos are added on each side of the title. You can insert a ● Shifting the individual profiles to find maximum correlation with average [Fig.2]. describe principal modes of variation. column options available for this template. The poster columns can also be customized on the Master. VIEW > MASTER. logo by dragging and dropping it from your desktop, copy and paste or by ● Cross-correlating average profiles and computing correlation percentages [Table 1]. going to INSERT > PICTURES. Logos taken from web sites are likely to be The ternary diagram to the right gives a visual representation low quality when printed. Zoom it at 100% to see what the logo will look How to remove the info bars like on the final poster and make any necessary adjustments. of how similar the montes are to each other. The points Figure 1: USGS topographic map of the western Ishtar Terra region of Venus, with highlighted study regions. If you are working in PowerPoint for Windows and have finished your corresponding to each feature tend to scatter and do not show poster, save as PDF and the bars will not be included. You can also delete TIP: See if your school’s logo is available on our free poster templates any similarity among the montes. them by going to VIEW > MASTER. On the Mac adjust the Page-Setup to page. The highland regions of western Ishtar Terra surround the high plains region of Lakshmi Planum. match the Page-Setup in PowerPoint before you create a PDF. You can

This roughly axisymmetric configuration has been variously attributed to compression and crustal also delete them from the Slide Master. Photographs / Graphics You can add images by dragging and dropping from your desktop, copy thickening [2], accompanied by a subsequent cylindrical downwelling [3,4,5] or upwelling [6,7] of Table 1: Correlations of average profiles. Save your work and paste, or by going to INSERT > PICTURES. Resize images the mantle [8]. In these models the montes form approximately synchronously. Other models Save your template as a PowerPoint document. For printing, save as proportionally by holding down the SHIFT key and dragging one of the ● Constructing the covariance matrix from the correlation coefficients. PowerPoint or “Print-quality” PDF. corner handles. For a professional-looking poster, do not distort your suggest motion of discreet blocks driven by regional stresses and eventual collisions [9,10], The mountains of Venus will be compared with Earth's mountains of known tectonic origin. ● Diagonalizing the covariance matrix to find eigenvalues (principal components) [Table 2]. images by enlarging them disproportionally. different topographic compensations [11], distinct tectonic fabrics [12] and pulsating continents [13] Some possible analogues: Print your poster ● Himalayas – Active Continental Collision as alternative scenarios for the formation. The formation of Venus’ mountain chains remains When you are ready to have your poster printed go online to ● Aleutians – Active Subduction (Oceanic) unresolved. PosterPresentations.com and click on the “Order Your Poster” button. ● Andes – Active Subduction (Continental) Choose the poster type the best suits your needs and submit your order.

● Urals – Extinct Continental Collision. If you submit a PowerPoint document you will be receiving a PDF proof for your approval prior to printing. If your order is placed and paid for before noon, Pacific, Monday through Friday, your order will ship out that Table 2: Principal component synthesis. The first three principal components construct, greater than 98% of each average profiles. same day. Next day, Second day, Third day, and Free Ground services are offered. Go to PosterPresentations.com for more information. Image Quality Check [1] Ansan, V., Vergely, P. and Masson, P. (1994) ‘Tectonic interpretations of central Ishtar Terra (Venus) from Venera 15 16 and Magellan full-resolution radar images’, Planetary and Space Science, Zoom in and look at your images at 100% magnification. If they look good 42(3), pp. 239–261. they will print well. [2] Head, J. W. (1990) ‘Formation of mountain belts on Venus: Evidence for large-scale convergence, underthrusting, and crustal imbrication in Freyja Montes, Ishtar Terra’, Geology. GeoScienceWorld, 18(2), pp. 99–102. [3] Bindschadler, D. L., Schubert, G. and Kaula, W. M. (1990) ‘Mantle flow tectonics and the origin of Ishtar Terra, Venus’, Geophysical Research Letters. Wiley-Blackwell, 17(9), pp. 1345-1348 [4] Arkani-Hamed, J. (1996) ‘Analysis and interpretation of high-resolution topography and gravity of Ishtar Terra, Venus’, Journal of Geophysical Research E: Planets, 101(E2), pp. 4691–4710. [5] Marinangeli, L. and Gilmore, M. S. (2000) ‘Geologic evolution of the Akna Montes-Atropos Tessera region, Venus’, Journal of Geophysical Research E: Planets, 105(E5), pp. 12053–12075. [6] Pronin, A. A. and A., A. (1986) ‘The Lakshmi Plateau structure as an indicator of asthenosphere horizontal flows on Venus’, Geotektonika, No. 4, p. 26 - 41, 4, pp. 26–41. [7] Grimm, R. E. and Phillips, R. J. (1991) ‘Gravity anomalies, compensation mechanisms, and the geodynamics of western Ishtar Terra, Venus’, Journal of Geophysical Research, 96(B5), pp. 8305–8324. Figure 2: Cartoon of Ishtar Terra formation from surface and gravity constraints; an example of venusian orogeny models [Ref. 12]. [8] Kaula, W. M. et al. (1992) ‘Styles of Deformation in Ishtar Terra and Their Implications’, Journal of Geophysical Research-Planets, 97(E10), pp. 16085–16120. [9] Crumpler, L. S., Head, J. W. and Campbell, D. B. (1986) ‘Orogenic belts on Venus’, Geology. GeoScienceWorld, 14(12), p. 1031. [10] Ansan, V., Vergely, P. and Masson, P. (1994) ‘Tectonic interpretations of central Ishtar Terra (Venus) from Venera 15 16 and Magellan full-resolution radar images’, Planetary and Space Science, In this study, we address this question with the analysis of Magellan topographic data for 42(3), pp. 239–261. Student discounts are available on our Facebook page. [11] Kucinskas, A. B., Turcotte, D. L. and Arkani-Hamed, J. (1996) ‘Isostatic compensation of Ishtar Terra, Venus’, Journal of Geophysical Research: Planets. Wiley-Blackwell, 101(E2), pp. Go to PosterPresentations.com and click on the FB icon. quantitative comparison of Venus' four mountain chains: Maxwell, Freyja, Akna and Danu. Patterns 4725–4736. [12] Hansen, V. L. and Phillips, R. J. (1995) ‘Formation of Ishtar Terra, Venus: Surface and gravity constraints’, Geology. GeoScienceWorld, 23(4), p. 292. in topography may provide clues to the dynamics forming these Venusian orogenic belts. [13] Romeo, I. and Turcotte, D. L. (2008) ‘Pulsating continents on Venus: An explanation for crustal plateaus and tessera terrains’, Earth and Planetary Science Letters. Elsevier, 276(1–2), pp. 85–97. Figure 3: Projection of average profiles on PC-subspace in order of importance (eigenvalues weights decreasing upwards). [14] Lay, D.C. (2006) ‘Linear Algebra and its Applications’, Pearson, Addison-Wesley, New York, pp. 492. [15] Stoddard, P. R. and Jurdy, D. M. (2012) ‘Topographic comparisons of uplift features on Venus and Earth: Implications for Venus tectonics’, Icarus, 217, pp. 524–533.