Instructions To Authors
By the Editor of Geophysics
Revised January 2007

Manuscript Preparation

Spacing and paragraphs
Manuscripts must be double-spaced in 12-point type. Doublespace all parts of the manuscript, including the abstract, footnotes, quoted material, references, and figure captions. Each paragraph must be indented.

Page numbers
Page numbers must appear on all pages of text, including references, figure captions, and tables.

Page length, line width, and margins
Each page should have no more than 30 lines of type, with no line exceeding six (6) inches in length. Ample margins should be left at the top, bottom, and sides.

Meeting citations
If your technical paper was presented at an SEG meeting, please note that on the title page. The presentation will be cited on the title page in the journal with the number of the meeting, organization, and date.

Headings
It is necessary for you to distinguish the categories of headings in your manuscript so your intentions will be clear to the editors and typesetters. Please follow the guidelines below.

Place principal headings (Category 1 heads) at the center of the page in capital letters.

Place Category 2 heads at the left margin (without indentation) in boldface type, with only the first word of the heading and proper nouns capitalized. Start the text that follows on the next line and indent it.

Place Category 3 heads at the left margin (without indentation) in italics, with only the first word of the heading and proper nouns capitalized. Start the text that follows on the next line and indent it.

If headings of still lower rank are necessary, indent, underline (or italicize), place a period and dash after the heading, and follow with text on the same line.

Do not number sections of the text. Refer to sections by name or content, e.g., "Discussion on deconvolution."

Figures and tables
In the manuscript, figures should not be embedded in the text but should be collected at the end of the manuscript, with each figure on a separate page (see the section "Preparation of Illustrations"). Figure captions should be listed on a separate sheet at the end of the manuscript.

Related Link: Preparation of Illustrations

Tables should not be included within the text but should follow the manuscript, with each table in a separate digital file. Other types of lists may be run within the text.

Examples of style for terms

acknowledgments
air gun*
airwave
antialias
audio frequency*
back projection*
band limited*
band-pass
bandwidth
borehole
CDP (common depth point)
CMP (common midpoint)
CRP (common reflection point)
Chebychev
crosscorrelation
crosshole
crossline
cross section*
crosswell
database
data set
far-field
finite difference*
f-k filter
free space*
groundwater
half-space
high resolution*
inline
least squares*
mis-tie
near-field
noncolinear
passband
plane wave*
poststack
prestack
pseudosection
P-wave
Q filter
raypath
rms (root mean square)
seismic (adj.)
seismics (n.)
semi-infinite
subbottom
S-wave
3D
time slice*
traveltime
2D
wavefield
waveform
wavefront
waveguide
wavelength
wavenumber
wave stack
wave test
wavetrain
wide band*
z-plane

*Hyphenate as an adjective; e.g., finite-difference method.

Examples of style in text

• Use American English spelling, e.g., modeling, color, analyze, behavior, etc.
• Each sentence must begin with a capital letter. Lowercase Greek letters, mathematical symbols, or numerals may not be used to begin a sentence.
• Use a semicolon before the adverbial conjunctions however, thus, hence, therefore, etc., in compound sentences.
• Use a semicolon between independent clauses not joined by a conjunction.
• Do not use a colon when an equation or list comes immediately after a verb or preposition.
• Mathematical symbols serve as verbs.
• Equations are punctuated as sentences and should be numbered.
• The abbreviations et al., i.e., and e.g. are set off with commas, except when et al. is used in a text reference. In that case only, the preceding comma is omitted.
• Extensive use of italics in text is discouraged; use them only for the most necessary emphasis.
• Do not use italics for foreign and Latin words that have become common in English usage, e.g., a priori, et al. Check Webster's Third New International Dictionary or Merriam-Webster's Collegiate Dictionary, 11th edition, to determine if the term is in common English usage.
• Use quotation marks to refer to a special term only the first time the term appears.
• Hyphens are not generally used in words formed with prefixes; e.g., antisymmetric, multidip, nonlinear, semimajor, subbottom, prestack, poststack, pseudosection, etc. Check Webster's Third New International Dictionary or Merriam-Webster's Collegiate Dictionary, 11th edition.
• Hyphens are not used between adverbs ending in ly and the words they modify, e.g., horizontally layered.
• Do not use newly invented acronyms or trade names to describe your technique. Widely used trade names that appear in the Encyclopedic Dictionary of Applied Geophysics, fourth edition (e.g., microlog), are acceptable.
• Use symbols for percent (%) and degree (°) in the text as well as in mathematical expressions, tables, or figures.
• Spell out points of the compass, e.g., east-west, north-northwest.
• In a series of three or more items, a comma (or a semicolon, where appropriate) follows each item, including the one that precedes and.

Examples of style for units
Physical quantities should be expressed in SI units. When field measurements were obtained or equipment was specified with different units, the value of non-SI units can be specified in parentheses following the SI units, e.g., 2200 m/s (7200 ft/s). Do not carry more significant figures in the unit conversion than in the original measurement. For example, note that 7200 ft/s converts to 2200 m/s, not 2195 m/s.

All of the following conform to SI metric standards:

s for second
Ωm or ohm-m for ohm-meter
S/m for siemens/meter
Hz as unit, hertz as word
A as unit, ampere as word
F as unit, farad as word
H as unit, henry as word
V as unit, volt as word
J as unit, joule as word
N as unit, newton as word
W as unit, watt as word
Pa as unit, pascal as word
m/s for meter per second (not ms^-1)
1000 or 10 000 for 1,000 or 10,000
times sign (×) instead of dot for multiplication
space between number and unit (10 m, not 10m)
mGal (not mgal) for abbreviation, milligal for word
ms for millisecond
GHz for gigahertz
MHz for megahertz
kHz for kilohertz
cm for centimeter
mm for millimeter
µm for micrometer
µs for microsecond
nm for nanometer
pm for picometer

The exceptions to SI units listed below are acceptable if SI units follow them in parentheses:

bar as pressure unit
darcy as permeability unit
ft
ft/s
gamma as magnetic field intensity unit
mi
µs/ft

Mathematical material
One of the most complicated and expensive operations in publishing Geophysics is typesetting mathematical formulas. Because Geophysics is now tagged in XML to facilitate online delivery, some rerendering of equations may occur. However, every effort is made to ensure that all mathematical symbols and terms appear in the galley proof just as the author created them (see the section “Acceptable forms of the manuscript” for instructions on submitting manuscripts in LATEX). You can help reduce these costs by writing equations in their simplest forms. Often, a complicated expression can be simplified if various terms are assigned symbols that are defined individually. For some good examples, see the paper by Nelson in Geophysics, 53, 1088–1095.

Fractional exponents should be used instead of radicals wherever feasible. Radicals are preferred, however, for simple square roots, e.g., rather than 2^1/2.

When there is any doubt that subscripts and superscripts will be clear to the typesetter, they should be indicated by carets and inverted carets, for example,

To standardize space and time coordinates, use lowercase letters x, y, z for Cartesian space coordinates. Designate corresponding axes by x-axis, y-axis, and z-axis, and designate the time coordinate by t. To represent traveltime and finite changes in traveltime, use t and ∆t rather than T and ∆T. All axis coordinates on figures must be indicated and should be consistent with the text.

Equations are punctuated as sentences, e.g., an equation should be followed by a comma when good English usage requires a comma at that position in the sentence. Equations that cannot be placed on one line must be broken only at the "addition" symbols. The sign should be placed at the start of the second line.

Terms in equations are grouped with the following symbols: parentheses ( ), brackets [ ], and braces {}. For example, X = {2R + [(k + 1)(k + 2)]²}^1/2.

The typesetter is instructed to set all mathematical symbols and all isolated letters in the text in italic type, if there are no markings to the contrary. Use italics for all symbols for scalar quantities, including those represented by Greek letters. Please note that vectors are set in boldface lowercase roman (regular) letters, whereas matrices and tensors are set in boldface capital roman letters. Uppercase boldface letters also may be used for vectors, and lowercase boldface letters may be used for tensors, if such use is customary. Different fonts may be used to further distinguish scalars, vectors, tensors, and matrices.

Here are some ways you can facilitate the processing of your article: (1) Set all letters (including Greek) representing scalar quantities in italics. Do not use italics for such items as sin, cos, max, min, etc. Do not use italics for letters representing units of measurement: ms, ft, etc. (2) Set all vector quantities in bold lowercase except as otherwise noted, as in the case of electromagnetic fields.

All displayed equations should be numbered sequentially throughout the manuscript. When referring to an equation in text, please identify it with a phrase that could serve to identify the type of equations throughout the text, as shown in the following example:

Without phrase: "inserting equations 5 and 6 into equation 9 ..."
With phrase: "inserting the form, equation 5, of the electric field E and the Lindhard form, equation 6, of the dielectric function e into the constitutive equation 9 ..."

Equation numbers in the text should not be shown in parentheses, e.g., "As shown in equation 10." Please note that this is a change in SEG style. (However, the equation number at the right margin of the column should be enclosed in parentheses.) A mention of the equation number in the text must be accompanied by equation, expression, or another synonym to identify the number itself. Equations in Appendix A should be numbered with the prefix A-, e.g., "equation A-1."

For complicated and detailed mathematical papers, authors are encouraged to include a table near the beginning of the paper to define their mathematical symbols. Authors are also strongly encouraged to place complicated and detailed mathematics in appendices.

References
Authors are requested to be meticulous in following instructions for references, which typically require more editing than any other section of the manuscript. In addition, accuracy and proper form are essential so that references in online Geophysics papers will link to the sources cited. Authors who do not follow guidelines for references can expect a delay in publication because the article may be returned by reviewers or editors for revision to proper style.

Citation of previous work acknowledges the importance of those investigations and makes available to the reader much more background information than is practical to include in a single paper. However, to be of real value, all references must be readily accessible to the reader. If internal reports with wide circulation constitute an important reference, cite them in the text but not in the reference list, e.g., (G. M. Levy, 1984, Geonics Ltd. Tech., note TN-16). Similarly, citations of personal communications, including papers submitted to a journal but not yet accepted, may be placed in the text but not in the reference list. Cite personal communications with initial(s), surname, and year, e.g. (J. Smith, personal communication, 2003).

In the text, literature citations should show the author's name followed by the year of publication in parentheses, e.g., Nettleton (1940). If the author's name is not referred to in the text, it and the year should be inserted in parentheses at the point where the reference applies: (Nettleton, 1940).

If there is more than one reference to the same author at a given point in the text, list the years in chronological order with a comma between. When more than one author is referenced at a given point in the text, separate the references by semicolons. If a specific page is referenced, include the page number within the parentheses, after the year (Nettleton, 1940, p. 142).

References should be grouped alphabetically under the heading "References" at the end of the article, after the acknowledgments and appendices (if any). References should be alphabetized according to sections 16.81–16.83 in The Chicago Manual of Style, 15th edition, i.e., a single-author work precedes a multiauthor work beginning with the same author's name. For a given author referenced more than once for the same year, use the suffixes a, b, etc., after the year of publication to distinguish references. References with identical authorship should be listed in chronological order.

Material in preparation, submitted, or not yet accepted and scheduled for publication should not be included in the references. Material accepted for publication may be cited as a reference if its publication date has been established, but it will be necessary to double-check the status of the material before your article is published. If the material has not yet been published, it should be cited only as a personal communication.

References not cited in the text should not be included in the reference list unless the paper is of a survey or tutorial nature. Under such circumstances, those references should be grouped separately under the heading "References for General Reading."

In the reference list, the form and punctuation shown in the examples below will be observed. Please note that this includes some changes in SEG style. Also please note especially that (1) SEG no longer abbreviates titles of journals and names of institutions and publishers and (2) initials of secondary authors' names precede the surnames.

For types of references not included below, follow the guidelines for author-date citations in The Chicago Manual of Style, 15th edition.

Papers from journals
Kosloff, D. D., and E. Baysal, 1982, Forward modeling by a Fourier method: Geophysics, 47, 1402-1412.

Rouse, W. C., A. J. Reading, and R. P. D. Walsh, 1986, Volcanic soil properties in Dominica, West Indies: Engineering Geology, 23, 1-28.

Capitalize only the first word of the title and proper nouns. Do not use quotation marks unless they are actually part of the title. Do not underline or use italics. Show the volume numbers in bold, omit the issue number, and show beginning and ending page numbers.

Papers from magazines
Castagna, J. P., 1993, Petrophysical imaging using AVO: The Leading Edge, 12, 172-179.

Follow the instructions for papers from journals. If each issue of the magazine begins with page 1, include the issue number after the volume number, e.g., no. 3.

Books
Davis, P. J., and P. Rabinowitz, 1975, Methods of numerical integration: Academic Press Inc.

Follow the instructions for papers from journals. Reference the full name of the publisher. Do not reference the city of publication or the number of pages in the book.

Articles in books
Baker, D. W., and N. L. Carter, 1972, Seismic velocity aniso-tropy calculated for ultramafic minerals and aggregates, in H. C. Heard, I. V. Borg, N. L. Carter, and C. B. Raleigh, eds., Flow and fracture of rocks: American Geophysical Union Geophysical Monographs 16, 157-166.

Theses and dissertations
Lodha, G. S., 1974, Quantitative interpretation of airborne electromagnetic response for a spherical model: M.S. thesis, University of Toronto.

Reference to a thesis or dissertation requires neither the name of the department nor the number of pages.

Discussions
Zhou, B., 1992, Discussion on: "The use of Hartley transform in geophysical applications," R. Saatcilar, S. Ergintav, and N. Canitez, authors: Geophysics, 57, 196-197.

Electronic material
Electronic publications:
Hellman, H., 1998, Great feuds in science: Ten of the liveliest disputes ever: John Wiley & Sons, e-book.

Electronic journal citation with access date:
Mongall, J. E., and J. J. Hanley, 2004, Origins of outliers of the Huronian Super group withing the Sudbury Structure: Journal of Geology, 112, 59-70, accessed March 20, 2006; http://www.journals.uchicago.edu/JG/journal/contents/v112n1.html?erFrom=5036588460214438945guest

Linking:
Shindell, D., G. Faluvegi, N. Bell, and G. Schmidt, 2005, An emissions-based view of climate forcing by methane and tropospheric ozone: Geophysical Research Letters, 32, L04804, accessed March 31, 2006; http://www.agu.org/pubs/crossref/2005/2004GL0219%2000.shtml; http://dx.doi.org/10.1029/2004GL021900.

Web site (or part of Web site):
Roemmich, D., 1990, Sea-level change, http://www.nap.edu/books/0309040396.html, accessed July 14, 2003.

References to electronic material should include (1) the standard information, (2) the format (e-book, CD-ROM, DVD-ROM, etc.), and (3) the date of access if it is an online source.

Oral presentations that are not published in a proceedings or abstract volume
Hubbard, T. P., 1979, Deconvolution of surface recorded data using vertical seismic profiles: Presented at the 49th Annual International Meeting, SEG.

Do not include city.

Expanded abstracts
Constable, S. C., 1986, Offshore electromagnetic surveying techniques: 56th Annual International Meeting, SEG, Expanded Abstracts, 81-82.

References to proceedings of many conferences are appropriate only if these proceedings are generally available to the reader. Authors are requested to avoid such references to material of limited availability. The SEG Expanded Abstracts do qualify as references because of their general accessibility.

Patents
Anstey, N., 1976, Seismic delineation of oil and gas reservoirs using borehole geophones: Canadian Patents 1 106 957 and 1 114 937.

After name, indicate year patent was granted.