1     2     3  

Alison Malcolm


amalcolm [at] mun [dot] ca

Earth Sciences Department
Memorial University of Newfoundland
300 Prince Philip Ave, ER-4027
St John's, NL






Prospective students, click here.

The intro to seismic imaging lectures I gave at MSRI are here and here .

       Research        Students        Publications        Teaching        Personal


Research Overview

My general research interests are described briefly below. If you're interested in my past work, have a look at my CV (pdf), for my guess at what I might be up to in the future, you can check out my research statement.

Uncertainty Quantification

As well as being interested in how to best image the Earth's subsurface, I am also interested in how to quantify the limits of our understanding. Students, Greg Ely and Maria Kotsi are currently working on this topic.
Maria is looking at 4D uncertainty, attempting to compare various methods and highlight those that give the smallest uncertainties.
Greg is using monte carlo techniques to recover a range of models that fit the data using the Field Expansions method developed by Dave Nicholls and I. For example, here are some representative velocity models from a forthcoming paper


from which we get the following set of images


and can recover various properties of those models as probability distributions



Nonlinear Imaging Techniques

Rocks are nonlinear materials. This means that when you send two waves into a rock sample, the two waves will interact resulting in changes in one wave caused by another. We are working on developing techniques that exploit these interactions to image subsurface structures. Right now, we are working on the laboratory scale, to better understand the way the rock's microstructure is involved in the nonlinear coupling of the waves. Future work includes both numerical and laboratory work to better understand these phenomena and how they might best be used in Earth imaging. The beginnings of this work is published jointly with Thomas Gallot, Tom Szabo, Dan Burns, Steve Brown and Mike Fehler. We are continuing work on this topic, now with James TenCate, Mike Fehler and Xuan Feng.

The figure above shows an image made this way of a contrast between room-dry and oil saturated conditions.


Improving Imaging and Full-waveform inversion

I work on a variety of projects that aim to enhance the images we are able to produce of the subsurface. I am particularly interested in ways to target our imaging strategies to substructures of particular interest. This allows us to focus on a particular region for both time-lapse and uncertainty quantification.


The figure above illustrates the computation of a solution to the wave equation in a local region. This is Bram Willemsen's work on target-oriented full-waveform inversion.


Recovering scattering information from coda

Jointly with Dr. Mike Fehler of MIT, I am working to adapt and apply techniques that exploit the radiative transfer theory to image subsurface scattering properties. We are using a data set collected by Mike and other in Krýsuvík, Iceland. This work is being done primarily by undergraduates Samantha Sellars and Manuel Alejandro Jaimes Caballero.



Students and Postdocs
Current:

Postdocs:

Polina Zheglova is working on methods for enhancing full-waveform inversion.

Heru Rusmanugroho is working on modeling cracks and nonlinear elasticity.

Qingjie Yang is working on full-waveform inversion and modelling.

PhD:

Gregory Ely is working on global optimization methods for full-waveform inversion.

Maria Kotsi is working on uncertainty in time-lapse imaging.

Elena Jaimes is working on using a local solver for full-waveform inversion.

Kamal Moravej is working on laboratory experiments for understanding the physical origins of AVO.

Michael Dunham is working with me and Kim Welford and I on using machine learning in seismic data interpretation.

MSc:

Mostafa Akrami is working on full-waveform inversion of vector data.

Jayne Simmons is working on microseismic event location; she is currently on leave.

Meghdad Darijani is working on modeling cracks and nonlinear elasticity.

Xingtong Yue is working on migration and FWI.

Chris Williams is working with me and Kim Welford and I on landslide risk evaluation from seismic data.

BSc:

Lauren Hayes will work on experiments related to nonlinear elasticity.

Manuel Alejandro Jaimes Caballero. will work on scattering estimation in Krýsuvík, Iceland.

Mandy Lim will with Penny Morrill and I on monitoring CO2 in ultramafic rocks.

Alumni:

Bram Willemsen, Ph.D., 2017. Thesis: Problems with a localized nature in seismology. Now at Exxonmobil.

Frédérick Massin was a postdoc 2015-2016 and is now at ETH in Zürich.

Andrey Shabelansky, Ph.D., 2015, thesis: Theory and Application of Source Independent Full Wavefield Elastic Converted Phase Seismic Imaging and Velocity Analysis. Now at Chevron.

Alan Richardson, Ph.D., 2015, thesis: Seismic imaging using internal multiples and overturned waves. Now at Ausar Geophysical

Dylan Mikesell was a postdoc 2013-2015 and is now at Boise State University.

Ben Coughlin, B.Sc., 2017.

Samantha Sellars, B.Sc., 2017.

Colin Ash, B.Sc., 2015, is in medical school at MUN.

David Cray, B.Sc., 2015, works for Shell.

Jamal Alsafwani, B.Sc., 2015, is in graduate school at MUN.

Gabi Melo PhD, 2014, thesis:Using relative traveltimes: SVD-enhanced seismic interferometry and microseismic location uncertainty.

Di Yang PhD, 2014, thesis: Full Wavefield Inversion Methods for Monitoring Time-lapse Subsurface Velocity Changes. Now at Exxonmobil.

Thomas Gallot was a postdoc from 2011-2013, working on nonlinear imaging and is now at Unstituto de Fisica, Uruguay.

Clarion Hess MSc 2013, thesis:Geologic interpretations of seismic scattering and attenuation for the Cianten Caldera and the surrounding area. Now at Chevron.

Harun Omer MSc 2013, thesis: Enhancing reservoir characterization through improved imaging and production management


Prospective Students
Students interested in joining my research group should check out the MUN Earth Sciences Graduate Student information page. If you are interested, please feel free to email me. Your email should include: (1) a brief statement about what you're interested in studying and why, (2) an unofficial transcript, (3) a brief statement about your relevant work and/or research experience, and (4) a brief statement about why you think my research group might be a good fit for you. An excellent post on writing an email to a potential supervisor can be found here . I will not reply to messages that are not pertinent to my research, and/or are not phrased professionally.



Publications
Journal Articles:
This list is often out of date, try my google scholar.

* Where the first author is not the primary or corresponding author of the paper, that author is marked with an asterix.

  • H. A. H. Shehadeh, A. E. Malcolm and J. C. Schotland, (2017), Inversion of the Bremmer Series,Journal of Computational Mathematics, 35 5, 586-599.

  • A. Shabelansky, A. Malcolm and M. Fehler, (2017), Converted-wave seismic imaging: Amplitude-balancing source-independent imaging conditions,Geophysics, 82, S99-S109.

  • B. Willemsen, A. Malcolm, (2017), An efficient coupled acoustic-elastic local solver applied to phase inversion,Geophysics, 82, R219-R234.

  • O. Poliannikov, A. Malcolm and M. Fehler, (2017), What moved where?: The impact of velocity uncertainty on microseismic location and moment tensor inversion,The Leading Edge, 36, 166-170.

  • A. Malcolm and B. Willemsen, (2017), Rapid 4D FWI using a local solver,The Leading Edge, 35, 1053-1059.

  • J. TenCate, A. Malcolm*, X. Feng, and M. Fehler, (2016), The effect of crack orientation on the nonlinear interaction of a P wave with an S wave, Geophysical Research Letters, 43, 6146-6153.

  • B. Willemsen, A. Malcolm, and W. Lewis, (2016), A numerically exact local solver applied to salt boundary inversion in seismic full waveform inversion, Geophysical Journal International, 204, 1703-1720.

  • A. Richardson and A. Malcolm, (2016), Separating a wavefield by propagation direction, Geophysics, 81, T117-T129.

  • D. Yang, F. Liu, S. Morton, A. Malcolm and M. Fehler, (2016), Time-lapse Full Waveform Inversion with Ocean Bottom Cable Data: Application on Valhall Field, Geophysics 81, R225-R235.

  • O. V. Poliannikov and A. Malcolm (2016) The effect of velocity uncertainty on migrated reflectors: Improvements from relative depth imaging, Geophysics, 81 S21-S29.

  • D. Yang, M. Meadows, P. Inderwiesen, J. Landa, A. Malcolm and M. Fehler, (2015), Double Difference Waveform Inversion: Feasibility and Robustness Study with Pressure Data, Geophysics, 80, M129-M141.

  • O.V. Poliannikov, M. Prange, H. Djikpesse, A. E. Malcolm and M. Fehler, (2015), Bayesian inversion of pressure diffusivity from microseismicity, Geophysics, 80 M45-M52.

  • Shabelansky, A., Malcolm, A., Fehler, M., Shang, X. and Rodi, W., (2015), Source-Independent Full Wavefield Converted-Phase Elastic Migration Velocity Analysis, Geophysical Journal International, 200(2) 952-966.

  • Mikesell, T. D., Malcolm, A., Yang, D., and Haney, M., (2015) A comparison of methods to estimate seismic phase delays: Numerical examples for coda wave interferometry, Geophysical Journal International 202 (1) 347-360.

  • Gallot, T., Malcolm, A., Szabo, T., Brown, S., Burns, D. and Fehler, M, (2015), Characterizing the nonlinear interaction of S- and P-waves in a rock sample, Journal of Applied Physics, 117, 034902.

  • Shabelansky, A., Malcolm, A., and Fehler, M., (2015), Measuring Seismic Attenuation Changes Using a 4D Relative Spectrum Method: Case Study from a Heavy Oil Reservoir with Implications for Monitoring Viscosity Changes, Geophysical Prospecting, 10.111/1365-2478.12229.

  • Yang, D., Malcolm, A., Fehler, M., Shang, X., and Baek, H., (2015), Image Registration Guided Wavefield Tomography for Shear Wave Velocity Model Building, Geophysics, 80 U35-U46.

  • Poliannikov, O. V. , Prange, M., Malcolm, A. E. and Djikpesse, H., (2014) Joint location of microseismic events in the presence of velocity uncertainty, Geophysics, 76 KS51-KS60.

  • Yang, D., Malcolm, A. and Fehler, M., (2014) Using image warping for time-lapse image domain wavefield tomography, Geophysics 79 (3), WA141-WA151.

  • Yang, D., Malcolm, A., Fehler, M., and Huang, L. (2014) Time-lapse walkaway vertical seismic profile monitoring for CO2 injection at the SACROC enhanced oil recovery field: A case study, Geophysics, 79(2), B51-B61.

  • Malcolm, A. and Nicholls, D. P.* (2014) Operator Expansions and Constrained Quadratic Optimization for Interface Reconstruction: Impenetrable Acoustic Media, Wave Motion, 51, 23-40.

  • Poliannikov, O., Prange, M., Malcolm, A. and Djikpesse, H. (2013), A unified Bayesian framework for relative microseismic location, Geophysical Journal International, 194 (2), 557-571.

  • Melo, G., Malcolm, A., van Wijk, K. and Mikesell, D., (2013) Using SVD for improved interferometric Green's function Retrieval, Geophysical Journal International 194 (3), 1596-1612.

  • Shabelansky, A., Malcolm, A. and Fehler, M. (2013), Data-Driven Estimation of the Sensitivity of Target-Oriented Time-Lapse Seismic Imaging to Source Geometry, Geophysics 78(2), R47-R58.

  • Poliannikov, O., Malcolm, A. E., Prange, M., and Djikpesse, H. (2012) Checking up on the neighbors: Quantifying uncertainty in relative event location, The Leading Edge, 31(12) 1490-1494.

  • Poliannikov, O., Malcolm, A., Djikpesse, H. and Prange, M., (2011) Interferometric hydrofracture microseism localization using neighboring fracture, Geophysics 76 WC27 DOI:10.1190/geo2010-0325.1

  • Malcolm, A. E. and Nicholls, D. P.* (2011) A Boundary Perturbation Method for Recovering Interface Shapes in Layered Media, Inverse Problems 27 095009.

  • Poliannikov, O., Malcolm, A., Djikpesse, H. and Prange, M. (2011), How can we use one fracture to locate another? , The Leading Edge 30 (5) p 551.

  • Melo, G. and Malcolm, A. (2011), Microquake seismic interferometry with SVD enhanced Green's function recovery The Leading Edge 30 (5) p 556.

  • Malcolm, A. E., and Trampert, J. (2011), Tomographic Errors from Wavefront Healing: more than just a fast bias, Geophysical Journal International 185 (1), p 385-402.

  • Malcolm, A. E., and Nicholls, D. P. (2011), A Method of Field Expansions for Scattering by n Periodic Layers, The Journal of the Acoustical Society of America, 129 (4) p 1783.

  • Malcolm, A. E., de Hoop, M. V., and Ursin, B. (2011) Recursive Imaging with Multiply Scattered Waves using Partial Image Regularization: A North Sea Case Study, Geophysics, 76 B33-B42.

  • Malcolm, A. E., Ursin, B. and de Hoop, M. V. (2009) Seismic imaging and illumination with internal multiples, Geophysical Journal International, 176 847-64.

  • Malcolm, A. E., Reitich, F., Yang, J., Greenleaf, J. F. and Fatemi, M. (2008) A combined parabolic-integral equation approach to the acoustic simulation of vibro-acoustic imaging, Ultrasonics, 48 p553-558.

  • Malcolm, A. E. & Guzina, B. (2008) On the Topological Sensitivity of Transient Acoustic Fields, Wave Motion, 45 821-34.

  • Malcolm, A. E., de Hoop, M. V., & Calandra, H. (2007), Identifying imaging artifacts from internal multiples, Geophysics, 72 S123.

  • Malcolm, A. E., & de Hoop, M. V., (2005), A method for inverse scattering based on the generalized Bremmer coupling series, Inverse Problems 21 No. 3 pp 1137-1167.

  • Malcolm, A. E., de Hoop, M. V., & Le Rousseau, J. H. (2005), The applicability of DMO/AMO in the presence of caustics, Geophysics 70 S1.

  • Malcolm, A. E., Scales, J. A. & van Tiggelen, B. A. (2004), Retrieving the Green function from diffuse, equipartitioned waves , Phys. Rev. E. 70.

  • de Hoop, M. V., Malcolm, A. E., & Le Rousseau, J. H. (2003), Seismic wavefield `continuation' in the single scattering approximation: A framework for dip and azimuth moveout,Can. Apply. Math. Q. 10 199-238.

  • Scales, J. A. & Malcolm, A. E. (2003), Laser characterization of ultrasonic wave propagation in random media , Phys. Rev. E. 67.

    Book Chapter:

  • A. Malcolm, F. Reitich, J. Yang, J. F. Greenleaf, M. Fatemi (2007) "Numerical Modeling for Assessment and Design of Ultrasound Vibroacoustography Systems" in "Biomedical Applications of Vibration and Acoustics in Imaging and Characterisations" editors: M. Fatemi, A. Al-Jumaily and A. Alizad.

    Conference Papers:

  • F. Massin and A. Malcolm, (2016), A better automatic body-wave picker with broad applicability, SEG Expanded Abstracts, 35.

  • B. Willemsen and A. Malcolm, (2016), Coupling a local elastic solver to a background acoustic model to estimate phase variation, SEG Expanded Abstracts, 35.

  • A. Malcolm, J. TenCate, M. Fehler (2016), The role of cracks in the nonlinear interaction of a P-wave with an S-wave, SEG Expanded Abstracts, 35.

  • O. Poliannikov M. Fehler and A. Malcolm, (2015), Error bounds on diffusive flow models from noisy microseismic data, SEG Expanded Abstracts, 34.

  • B. Willemsen, W. Lewis and A. Malcolm, (2015), Toward target-oriented FWI: An exact local wave solver applied to salt boundary inversion, SEG Expanded Abstracts, 34.

  • G. Ely, A. Malcolm, and D. Nicholls (2015) Combining Global Optimization and Boundary Integral Methods to Robustly Estimate Subsurface Velocity Models, SEG Expanded Abstracts, 34.

  • A. Richardson and A. Malcolm, (2015), Separating a Wavefield by Propagation Direction, SEG Expanded Abstracts, 34. Ranked as one of the top 31 of over 1000 papers presented at the meeting.

  • A. Shabelansky, A. Malcolm and M. Fehler, (2015) The Sensitivity of Converted-Phase Extended Images to P- and S-Wavespeed Variations, SEG Expanded Abstracts, 34.

  • B. Willemsen and A. Malcolm, (2015), Regularizing Velocity Differences in Time-Lapse FWI Using Gradient Mismatch Information, SEG Expanded Abstracts, 34.

  • O. Poliannikov, M. Fehler and A. Malcolm, (2015), The Effect of Velocity Uncertainty and Attenuation on Flow Estimates from Microseismicity, Unconventional Resources Technology Conference.

  • A. Shabelansky, A. Malcolm, M. Fehler, X. Shang and W. Rodi, (2015), Converted-phase Seismic Imaging-Amplitude-balancing Source-independent Imaging Conditions EAGE Expanded Abstracts.

  • Gallot, T., Malcolm, A., Burns, D., Brown, S., Fehler, M. and Szabo, T. (2014), Nonlinear interaction of seismic waves in the lab: A potential tool for characterizing pore structure and fluids, SEG Expanded Abstracts 33.

  • Poliannikov, O., Malcolm, A., Fehler, M., Prange, M., and Djikpesse, H. (2014) Propagation of uncertainty from effective-diffusion flow to microseismicity SEG Expanded Abstracts 33.

  • Poliannikov, O. and Malcolm, A., (2014) Effect of velocity uncertainty on migrated reflectors, SEG Expanded Abstracts 33.

  • Richardson, A. and Malcolm, A., (2014) Illumination compensation using Poynting vectors, with special treatment for multiples, SEG Expanded Abstracts 33.

  • Shabelansky, A., Malcolm, A., Fehler, M. and Rodi, W., (2014) Migration-based seismic trace interpolation of sparse converted phase micro-seismic data, SEG Expanded Abstracts 33.

  • Yang, D., Shang, X., Malcolm, A. and Fehler, M., (2014) Image registration guided wavefield tomography for shear wave velocity model building, SEG Expanded Abstracts 33.

  • Yang, D., Malcolm, A., and Fehler, M. Time-lapse Full Waveform Inversion and Uncertainty Analysis with Different Survey Geometries, 76th EAGE Conference and Exhibition (2014).

  • Melo, G., Malcolm, A. and Gallot, T., (2013) Seismic interferometry for sparse data: SVD-enhanced Green's function estimation, IEEE 5th International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP), p 276-279.

  • Poliannikov, O., Malcolm, A., Prange, M. and Djikpesse, H., (2013) Joint microseismic event location with uncertain velocity, SEG Expanded Abstracts 32.

  • Melo, G., Malcolm, A., Poliannikov, O. and Fehler, M., (2013) Analysis of location uncertainty for a microearthquake cluster: A case study, SEG Expanded Abstracts 32.

  • Richarson, A. and Malcolm, A., (2013) Reverse time migration in the presence of known sharp interfaces, SEG Expanded Abstracts 32.

  • Yang, D., Fehler, M., Malcolm, A., Liu, F. and Morton, S., (2013) Double-difference waveform inversion of 4D ocean bottom cable data: Application to Valhall, North Sea, SEG Expanded Abstracts 32.

  • Shabelansky, A., Malcolm, A., Fehler, M., Shang, X., and Rodi, W., (2013) Converted phase elastic migration velocity analysis, SEG Expanded Abstracts 32.

  • Yang, D., Malcolm, A., and Fehler, M., (2013) Using image warping for time-lapse image domain wavefield tomography, SEG Expanded Abstracts 32.

  • Poliannikov, O. V., Prange, M., Malcolm, A., and Djikpesse, H., (2012) Relative event localization in uncertain velocity model, SEG Expanded Abstracts 31.

  • Shabelansky, A., Malcolm, A., Fehler, M. and Bakku, S., (2012) Seismic imaging of hydraulically-stimulated fractures: A numerical study of the effect of the source Mechanism, SEG Expanded Abstracts 31.

  • Yang, D., Zheng, Y., Fehler, M. and Malcolm, A. (2012) Target-oriented time-lapse waveform inversion using virtual survey, SEG Expanded Abstracts 31.

  • Shabelansky, A., Malcolm, A. and Fehler, M. (2012) Monitoring Seismic Attenuation Changes Using a 4D Relative Spectrum Method in Athabsca Heavy Oil Reservoir, Canada, EAGE Expanded Abstracts.

  • Yang, D., Fehler, M., Malcolm, A. and Huang, L. (2011), Carbon sequestration monitoring with acoustic double-difference waveform inversion: A case study on SACROC walkaway VSP data, SEG Expanded Abstracts 30, 4273, DOI:10.1190/1.3628099

  • Poliannikov, O., Malcolm, A., Djikpesse, H., and Prange, M., (2011), Interferometric microseism localization using neighboring fracture, SEG Expanded Abstracts 30, 4263, DOI:10.1190/1.3628449

  • Shabelansky, A. H., Malcolm, A., and Fehler, M. (2011) Visibility analysis using reverse time wave sensitivity for time-lapse target-oriented imaging, SEG Expanded Abstracts 30, 4155, DOI:10.1190/1.3628074

  • Melo, G. and Malcolm, A. (2011) SVD enhanced seismic interferometry for traveltime estimates between microquakes, SEG Expanded Abstracts 30, 1608, DOI:10.1190/1.3627510.

  • Poliannikov, O. V. and Malcolm, A. (2010) Detecting medium changes from coda by interferometry, SEG Expanded Abstracts 29, 4227, DOI:10.1190/1.3513751

  • Melo, G., Malcolm, A., Mikesell, D. and van Wijk, K. (2010) Using SVD for improved interferometric Green's function recovery, SEG Expanded Abstracts 29, 3986, DOI:10.1190/1.3513688

  • Malcolm, A. and de Hoop M. (2010) Interferometric imaging of multiples in an RTM approach, SEG Expanded Abstracts 29, 3327, DOI:10.1190/1.3513539

  • Malcolm, A. E., Ursin, B. and de Hoop, M. V. (2008), Subsalt imaging with internal multiples, SEG Expanded Abstracts 27, 2461, DOI:10.1190/1.3063855

  • Malcolm, A. E., de Hoop, M. V. and Calandra, H. (2005), Estimating imaging artifacts caused by internal multiples, SEG Expanded Abstracts 24, 2111, DOI:10.1190/1.2148129

  • Malcolm, A. E. and de Hoop, M. V. (2004), Data continuation in the presence of caustics: A synthetic data example, SEG Expanded Abstracts 23, 2060, DOI:10.1190/1.1845197

  • Malcolm, A. E. and de Hoop, M. V. (2004), Inverse multiple scattering in the downward-continuation approach, SEG Expanded Abstracts 23, 1293, DOI:10.1190/1.1851104

  • Malcolm, A. E. and Scales, J. A. (2003), Non-contacting ultrasonics for visualizing and exploiting multiple scattering, SEG Expanded Abstracts 22, 1672, DOI:10.1190/1.1817627

  • Malcolm, A. E., de Hoop, M. V. and Le Rousseau, J. H. (2002) DMO/AMO in the presence of caustics, SEG Expanded Abstracts 21, 2265, DOI:10.1190/1.1817164

    Theses:

  • A. Malcolm, (2005) "Data Regularization for Data Continuation and Internal Multiples," Ph.D. Thesis, Colorado School of Mines, supervisor M. V. de Hoop.

  • A. Malcolm, " Algorithm Development for the Fast Computation of the Fourier Transform of Unequally Sampled Data with Applications to Seismic and Sediment Core Data" BSc Thesis, University of British Columbia, supervisor T. J. Ulrych.


  • Teaching Overview
    Current Courses (Winter 2018):

    3170 Seismic and Potential Fields Methods in Geophysics

    6921 Wave Equation Modeling, Processing and Inversion Algorithms

    Past Courses (MUN):

    3170 Seismic and Potential Fields Methods in Geophysics

    1000 Earth Systems

    Past Courses (MIT):

    Advanced Seismic Imaging 12.552

    Continuum Mechanics 12.005      

    Oral communication 12.445

    I teach the oil exploration part of 12.021

    I advised a benchtop CO2 sequestration experiment in 1.016 in 2010.



    Personal

    My husband, Scott, and I both hail from the Vancouver area in western Canada, where we still enjoy visiting our families and gawking at the lovely scenery. We are now excited to be exploring the other coast of the continent! Both of us like to travel and spend most of our non-working hours playing with our two wee daughters and just being outdoors.

    The design of this page was stolen (with permission) from Chad Westphal.